/**
 * Sayva - Modern CSS Design System
 * Color Palette from Logo:
 * - Primary Yellow: #FDDC28
 * - Coral Pink: #F9837A
 * - White: #FFFFFF
 * - Deep Blue: #1556D3
 */

/* ==================== CSS Variables ==================== */
:root {
    /* Brand Colors */
    --color-primary: #FDDC28;
    --color-primary-dark: #E5C520;
    --color-secondary: #F9837A;
    --color-secondary-dark: #E5726A;
    --color-accent: #1556D3;
    --color-accent-dark: #0D3D9E;
    --color-white: #FFFFFF;
    --color-black: #1A1A2E;

    /* Light Mode Colors */
    --bg-primary: #FFFFFF;
    --bg-secondary: #F8FAFC;
    --bg-tertiary: #F1F5F9;
    --bg-card: #FFFFFF;
    --text-primary: #1A1A2E;
    --text-secondary: #64748B;
    --text-muted: #94A3B8;
    --border-color: #E2E8F0;
    --shadow-color: rgba(0, 0, 0, 0.1);

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-heading: 'Plus Jakarta Sans', var(--font-family);

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    --space-4xl: 6rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 300ms ease;
    --transition-slow: 500ms ease;

    /* Z-index */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal-backdrop: 400;
    --z-modal: 500;
    --z-tooltip: 600;
}

/* Dark Mode Variables */
[data-theme="dark"] {
    --bg-primary: #0F172A;
    --bg-secondary: #1E293B;
    --bg-tertiary: #334155;
    --bg-card: #1E293B;
    --text-primary: #F8FAFC;
    --text-secondary: #CBD5E1;
    --text-muted: #64748B;
    --border-color: #334155;
    --shadow-color: rgba(0, 0, 0, 0.3);
}

/* ==================== Reset & Base ==================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color var(--transition-base), color var(--transition-base);
    overflow-x: hidden;
}

/* ==================== Typography ==================== */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: clamp(2rem, 4vw, 3rem); }
h3 { font-size: clamp(1.5rem, 3vw, 2rem); }
h4 { font-size: clamp(1.25rem, 2.5vw, 1.5rem); }

p {
    margin-bottom: var(--space-md);
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-accent-dark);
}

/* ==================== Layout ==================== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.section {
    padding: var(--space-4xl) 0;
}

.section-alt {
    background-color: var(--bg-secondary);
}

/* ==================== Navigation ==================== */
/* ==================== Navbar 重写 ==================== */

/* navbar 本身全透明，无背景无边框 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-fixed);
    background: transparent;
    border-bottom: none;
    padding: 12px 16px;     /* 给胶囊留出左右间距 */
    transition: padding var(--transition-base);
}

/* 胶囊容器：白色椭圆，右下阴影 */
.navbar-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    height: 52px;
    background: var(--bg-primary);
    border-radius: 9999px;
    box-shadow: 4px 6px 24px rgba(0,0,0,0.10), 0 1px 3px rgba(0,0,0,0.06);
    transition: box-shadow var(--transition-base);
}

[data-theme="dark"] .navbar-container {
    background: var(--bg-secondary);
    box-shadow: 4px 6px 24px rgba(0,0,0,0.4), 0 1px 3px rgba(0,0,0,0.2);
}

/* Logo 文字 */
.nav-brand-text {
    font-family: 'Plus Jakarta Sans', sans-serif;
    font-weight: 800;
    font-size: 1.2rem;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

/* 桌面端语言选择器 */
.desktop-only {
    display: flex;
}

/* ==================== 移动端 ==================== */
@media (max-width: 768px) {
    .navbar {
        padding: 8px 10px;
    }

    .navbar-container {
        border-radius: 16px;     /* 移动端稍小圆角，不用完整胶囊 */
        padding: 0 14px;
        height: 48px;
        position: relative;      /* 下拉菜单绝对定位的参照 */
    }

    /* 桌面语言选择器在移动端隐藏 */
    .desktop-only {
        display: none !important;
    }

    /* 移动端折叠菜单：紧贴胶囊下方 */
    .nav-menu {
        position: absolute;
        top: calc(100% + 6px);   /* 紧贴胶囊，间距6px */
        left: 0;
        right: 0;
        background: var(--bg-primary);
        border-radius: 16px;
        padding: 12px 16px 16px;
        box-shadow: 4px 6px 24px rgba(0,0,0,0.12), 0 1px 3px rgba(0,0,0,0.06);
        border: 1px solid var(--border-color);
        flex-direction: column;
        gap: 4px;
        /* 初始隐藏 */
        transform: translateY(-8px);
        opacity: 0;
        visibility: hidden;
        transition: transform 0.25s ease, opacity 0.25s ease, visibility 0.25s ease;
        /* 覆盖原来的 fixed 定位 */
        top: calc(100% + 6px);
    }

    [data-theme="dark"] .nav-menu {
        background: var(--bg-secondary);
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    /* 移动端链接样式 */
    .nav-menu .nav-link {
        display: block;
        padding: 10px 12px;
        border-radius: 10px;
        font-size: 0.95rem;
    }

    .nav-menu .nav-link:hover {
        background: var(--bg-secondary);
    }

    /* 语言网格 */
    .nav-lang-item {
        border-top: 1px solid var(--border-color);
        margin-top: 8px;
        padding-top: 12px;
        list-style: none;
    }

    .nav-lang-grid {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 6px;
    }

    .nav-lang-option {
        display: block;
        text-align: center;
        padding: 7px 4px;
        border-radius: 8px;
        font-size: 0.78rem;
        color: var(--text-secondary);
        background: var(--bg-tertiary);
        transition: all var(--transition-fast);
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .nav-lang-option:hover {
        background: var(--color-accent);
        color: white;
    }
}

/* 桌面端隐藏移动端语言栏 */
@media (min-width: 769px) {
    .nav-lang-item {
        display: none;
    }

    /* 桌面端菜单恢复水平布局 */
    .nav-menu {
        position: static;
        flex-direction: row;
        transform: none;
        opacity: 1;
        visibility: visible;
        background: transparent;
        box-shadow: none;
        border: none;
        padding: 0;
    }
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.nav-brand:hover {
    color: var(--text-primary);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--space-xl);
    list-style: none;
}

.nav-link {
    font-weight: 500;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: width var(--transition-base);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

/* Mobile Menu Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-sm);
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-fast);
}

/* ==================== Buttons ==================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    border: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: var(--color-black);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(253, 220, 40, 0.3);
    color: var(--color-black);
}

.btn-secondary {
    background: var(--color-accent);
    color: var(--color-white);
}

.btn-secondary:hover {
    background: var(--color-accent-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(21, 86, 211, 0.3);
    color: var(--color-white);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--border-color);
    color: var(--text-primary);
}

.btn-outline:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
}

.btn-ghost:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

/* ==================== Hero Section ==================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 70px;
    position: relative;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: -1;
    background: radial-gradient(circle at 30% 20%, rgba(253, 220, 40, 0.15) 0%, transparent 50%),
                radial-gradient(circle at 70% 80%, rgba(249, 131, 122, 0.15) 0%, transparent 50%),
                radial-gradient(circle at 50% 50%, rgba(21, 86, 211, 0.1) 0%, transparent 70%);
}

[data-theme="dark"] .hero-bg {
    background: radial-gradient(circle at 30% 20%, rgba(253, 220, 40, 0.1) 0%, transparent 50%),
                radial-gradient(circle at 70% 80%, rgba(249, 131, 122, 0.1) 0%, transparent 50%),
                radial-gradient(circle at 50% 50%, rgba(21, 86, 211, 0.15) 0%, transparent 70%);
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
    padding: var(--space-3xl) var(--space-lg);
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: 0.5rem 1rem;
    background: rgba(253, 220, 40, 0.1);
    border: 1px solid rgba(253, 220, 40, 0.2);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-secondary);
    margin-bottom: var(--space-lg);
    animation: fadeInUp 0.6s ease forwards;
}

.hero-title {
    margin-bottom: var(--space-lg);
    animation: fadeInUp 0.6s ease 0.1s forwards;
    opacity: 0;
}

.hero-title .highlight {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-2xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    animation: fadeInUp 0.6s ease 0.2s forwards;
    opacity: 0;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md);
    justify-content: center;
    animation: fadeInUp 0.6s ease 0.3s forwards;
    opacity: 0;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--space-3xl);
    margin-top: var(--space-3xl);
    animation: fadeInUp 0.6s ease 0.4s forwards;
    opacity: 0;
}

.hero-stat {
    text-align: center;
}

.hero-stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.hero-stat-label {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Hero App Preview */
.hero-app-preview {
    margin-top: var(--space-xl);
    position: relative;
    animation: fadeInUp 0.8s ease 0.5s forwards;
    opacity: 0;
}

.app-preview-container {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
    perspective: 1000px;
}

.app-preview-phone {
    width: 277px;
    height: 555px;
    background: var(--bg-card);
    border-radius: 30px;
    border: 8px solid var(--text-primary);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    margin: 0 auto;
    transform: rotateY(-5deg) rotateX(5deg);
    transition: transform var(--transition-base);
}

.app-preview-phone:hover {
    transform: rotateY(0) rotateX(0);
}

.app-preview-screen {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--color-accent), #2563EB);
    border-radius: 22px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1rem;
}

/* Floating Elements */
.floating-element {
    position: absolute;
    animation: float 6s ease-in-out infinite;
}

.floating-element-1 {
    top: 20%;
    left: 10%;
    animation-delay: 0s;
}

.floating-element-2 {
    top: 30%;
    right: 15%;
    animation-delay: 2s;
}

.floating-element-3 {
    bottom: 20%;
    left: 20%;
    animation-delay: 4s;
}


/* ==================== Features Section ==================== */
.features {
    padding: var(--space-4xl) 0;
}

.features-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto var(--space-3xl);
}

.features-header h2 {
    margin-bottom: var(--space-md);
}

.features-header p {
    color: var(--text-secondary);
    font-size: 1.125rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-xl);
}

.feature-card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-base);
}

.feature-card:hover::before {
    transform: scaleX(1);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, rgba(253, 220, 40, 0.1), rgba(249, 131, 122, 0.1));
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-lg);
    color: var(--color-accent);
}

.feature-icon svg {
    width: 32px;
    height: 32px;
}

.feature-title {
    font-size: 1.25rem;
    margin-bottom: var(--space-sm);
}

.feature-description {
    color: var(--text-secondary);
    margin-bottom: 0;
}

/* ==================== How It Works ==================== */
.how-it-works {
    background: var(--bg-secondary);
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-2xl);
    position: relative;
}

.steps::before {
    content: '';
    position: absolute;
    top: 40px;
    left: 15%;
    right: 15%;
    height: 2px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
    opacity: 0.3;
}

@media (max-width: 768px) {
    .steps::before {
        display: none;
    }
}

.step {
    text-align: center;
    position: relative;
}

.step-number {
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    border-radius: 50%;
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-black);
    margin: 0 auto var(--space-lg);
    position: relative;
    z-index: 1;
}

.step-title {
    font-size: 1.25rem;
    margin-bottom: var(--space-sm);
}

.step-description {
    color: var(--text-secondary);
    margin-bottom: 0;
}

/* ==================== Testimonials ==================== */
.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--space-xl);
}

.testimonial-card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

.testimonial-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

.testimonial-content {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-xl);
    line-height: 1.8;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.testimonial-avatar {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-black);
}

.testimonial-info h4 {
    font-size: 1rem;
    margin-bottom: 0.25rem;
}

.testimonial-info span {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.testimonial-rating {
    display: flex;
    gap: 2px;
    margin-top: var(--space-sm);
}

.testimonial-rating svg {
    width: 16px;
    height: 16px;
    color: var(--color-primary);
}

/* ==================== CTA Section ==================== */
.cta-section {
    background: linear-gradient(135deg, var(--color-accent) 0%, #1E40AF 100%);
    color: white;
    text-align: center;
    padding: var(--space-4xl) var(--space-lg) calc(var(--space-4xl) + 60px); /* 增加底部padding */
    border-radius: var(--radius-xl);
    position: relative;
    overflow: hidden;
    /* 新增：底部圆弧裁切 */
    clip-path: ellipse(100% 100% at 50% 100%);
}

@media (max-width: 768px) {
    .cta-section {
        clip-path: ellipse(120% 100% at 50% 100%);
        padding-bottom: calc(var(--space-3xl) + 20px);  /* 底部padding也相应减小 */
    }
}

/* 圆弧伪元素 */
.cta-section::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 60px;
    background: var(--bg-secondary); /* 与 footer 背景色一致 */
}

.cta-section h2 {
    color: white;
    margin-bottom: var(--space-md);
    text-align: center;
    position: relative;
    z-index: 1;
}

.cta-section p {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: var(--space-2xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    text-align: center;
    position: relative;
    z-index: 1;
}

.cta-section .cta-actions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-lg);
    justify-content: center;
    align-items: center;
    margin-bottom: var(--space-xl);
    position: relative;
    z-index: 1;
}

.cta-section .cta-actions .store-btn {
    display: inline-block;
    transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.cta-section .cta-actions .store-btn:hover {
    transform: scale(1.05);
    opacity: 0.9;
}

.cta-section .cta-actions .store-btn img {
    height: 50px;
    width: auto;
}

.cta-section .cta-links {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
    font-size: 0.875rem;
    position: relative;
    z-index: 1;
}

.cta-section .cta-links a {
    color: rgba(255, 255, 255, 0.7);
}

.cta-section .cta-links a:hover {
    color: var(--color-primary);
}

.cta-section .cta-links span {
    color: rgba(255, 255, 255, 0.5);
}

/* ==================== Footer ==================== */
.footer {
    background: var(--bg-secondary);
    padding: var(--space-4xl) 0 var(--space-xl);
    border-top: 1px solid var(--border-color);
    margin-top: -60px; /* 消除圆弧带来的间距 */
}

/* 大屏幕：4列布局 */
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--space-3xl);
    margin-bottom: var(--space-3xl);
}
/* 中等屏幕：2列布局 */
@media (max-width: 992px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }

    .footer-brand {
        grid-column: 1 / -1;  /* Logo占满整行 */
        margin-bottom: var(--space-xl);
    }
}

/* 小屏幕：2列布局，Product和Company并排 */
@media (max-width: 768px) {
    .footer-grid {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
        text-align: center;
    }

    .footer-brand {
        grid-column: 1 / -1;
        max-width: 100%;
        text-align: center; /* 整体文字居中 */
        margin-bottom: var(--space-xl);
        display: flex;
        flex-direction: column;
        align-items: center; /* flex 居中 */
    }

    /* Logo居中 */
    .footer-brand .nav-brand {
        justify-content: center;
        margin-bottom: var(--space-md);
    }

    /* 描述文字 */
    .footer-brand p {
        text-align: center;
        max-width: 100%;
    }

    /* 社交图标居中 */
    .footer-social {
        justify-content: center;
    }

    /* 隐藏Legal列 */
    .footer-column:nth-child(4) {
        display: none;
    }

    /* 新增：让所有列居中 */
    .footer-column {
        text-align: center;
    }

    .footer-column h4 {
        text-align: center;
    }

    .footer-links {
        display: flex;
        flex-direction: column;
        align-items: center;
    }
}

/* 极小屏幕：保持2列 */
@media (max-width: 480px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }

    /* 隐藏Legal列 */
    .footer-column:nth-child(4) {
        display: none;
    }
}

/* Logo文字样式 */
.footer-brand .nav-brand span {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-left: 8px;
}

.footer-brand .nav-brand {
    margin-bottom: var(--space-md);
    display: flex;
    align-items: center;
}

.footer-brand p {
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

.footer-social {
    display: flex;
    gap: var(--space-md);
}

.footer-social a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-card);
    border-radius: 50%;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.footer-social a:hover {
    background: var(--color-accent);
    color: white;
}

.footer-column h4 {
    font-size: 1rem;
    margin-bottom: var(--space-lg);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--space-sm);
}

.footer-links a {
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: var(--color-accent);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-xl);
    border-top: 1px solid var(--border-color);
    flex-wrap: wrap;
    gap: var(--space-md);
}

.footer-bottom p {
    color: var(--text-muted);
    margin: 0;
}

.footer-legal {
    display: flex;
    gap: var(--space-lg);
}

.footer-legal a {
    color: var(--text-muted);
    font-size: 0.875rem;
}

.footer-legal a:hover {
    color: var(--color-accent);
}

/* ==================== Mobile App Banner ==================== */
.mobile-app-banner {
    display: none;
    position: fixed;
    bottom: 16px;
    left: 12px;
    right: 12px;
    z-index: var(--z-fixed);
    background: var(--bg-card);
    border-radius: 20px;
    padding: 16px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.18), 0 2px 8px rgba(0,0,0,0.10);
    border: 1px solid var(--border-color);
    transform: translateY(120%);
    opacity: 0;
    transition: transform 0.5s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.4s ease;
}

.mobile-app-banner.visible {
    transform: translateY(0);
    opacity: 1;
}

.banner-close {
    position: absolute;
    top: 10px;
    right: 10px;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    color: var(--text-muted);
    padding: 0;
}

.banner-content {
    display: flex;
    flex-direction: column;   /* 上下排列 */
    gap: 14px;
}

.banner-info {
    display: flex;
    align-items: center;
    gap: 12px;
    padding-right: 20px;      /* 避免和关闭按钮重叠 */
}

.banner-app-icon {
    width: 56px;
    height: 56px;
    border-radius: 14px;
    flex-shrink: 0;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

.banner-title {
    font-size: 1rem;
    font-weight: 800;
    color: var(--text-primary);
    margin: 0 0 3px 0;
    line-height: 1.2;
}

.banner-sub {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin: 0;
}

/* 下载按钮区域 */
.banner-buttons {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

/* 单个下载按钮 */
.banner-dl-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: 100%;
    padding: 13px 16px;
    border-radius: 12px;
    font-size: 0.95rem;
    font-weight: 700;
    text-decoration: none;
    transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.banner-dl-btn:active {
    transform: scale(0.97);
}

/* Google Play — 渐变蓝紫 */
.banner-dl-btn.android {
    background: linear-gradient(135deg, #1556D3, #7C3AED);
    color: #fff;
    box-shadow: 0 4px 16px rgba(21, 86, 211, 0.35);
}

/* App Store — 深色 */
.banner-dl-btn.ios {
    background: linear-gradient(135deg, #1A1A2E, #2D2D4E);
    color: #fff;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
}

.banner-dl-btn svg {
    flex-shrink: 0;
}

@media (min-width: 769px) {
    .mobile-app-banner { display: none !important; }
}

@media (max-width: 768px) {
    .mobile-app-banner { display: block; }
}

/* ==================== Blog ==================== */
.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: var(--space-xl);
}

.blog-card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    overflow: hidden;
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

.blog-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

.blog-card-image {
    aspect-ratio: 16/9;
    background: linear-gradient(135deg, var(--color-accent), #2563EB);
    overflow: hidden;
}

.blog-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-base);
}

.blog-card:hover .blog-card-image img {
    transform: scale(1.05);
}

.blog-card-content {
    padding: var(--space-xl);
}

.blog-card-meta {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-bottom: var(--space-md);
    font-size: 0.875rem;
    color: var(--text-muted);
}

.blog-card-category {
    background: rgba(253, 220, 40, 0.1);
    color: var(--color-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
}

.blog-card-title {
    font-size: 1.25rem;
    margin-bottom: var(--space-sm);
    line-height: 1.4;
}

.blog-card-title a {
    color: var(--text-primary);
}

.blog-card-title a:hover {
    color: var(--color-accent);
}

.blog-card-excerpt {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    margin-bottom: var(--space-md);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.blog-card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-md);
    border-top: 1px solid var(--border-color);
}

.blog-card-author {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.blog-card-author-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--color-black);
}

.blog-card-author-name {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
}

.blog-card-read-time {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Blog Sidebar */
.blog-sidebar {
    position: sticky;
    top: 90px;
}

.sidebar-widget {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    border: 1px solid var(--border-color);
    margin-bottom: var(--space-xl);
}

.sidebar-widget h3 {
    font-size: 1.125rem;
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-md);
    border-bottom: 2px solid var(--color-primary);
}

.sidebar-categories {
    list-style: none;
}

.sidebar-categories li {
    margin-bottom: var(--space-sm);
}

.sidebar-categories a {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.sidebar-categories a:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.sidebar-categories .count {
    background: var(--bg-tertiary);
    padding: 2px 8px;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
}

.popular-post {
    display: flex;
    gap: var(--space-md);
    margin-bottom: var(--space-md);
    padding-bottom: var(--space-md);
    border-bottom: 1px solid var(--border-color);
}

.popular-post:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.popular-post-image {
    width: 80px;
    height: 80px;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, var(--color-accent), #2563EB);
    overflow: hidden;
    flex-shrink: 0;
}

.popular-post-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.popular-post-content h4 {
    font-size: 0.875rem;
    margin-bottom: var(--space-xs);
    line-height: 1.4;
}

.popular-post-content h4 a {
    color: var(--text-primary);
}

.popular-post-content h4 a:hover {
    color: var(--color-accent);
}

.popular-post-date {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* ==================== Blog Post Detail ==================== */
.post-single {
    max-width: 800px;
    margin: 0 auto;
}

.post-header {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.post-category {
    display: inline-block;
    background: rgba(253, 220, 40, 0.1);
    color: var(--color-secondary);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--space-lg);
}

.post-title {
    font-size: clamp(2rem, 4vw, 3rem);
    margin-bottom: var(--space-lg);
}

.post-meta {
    display: flex;
    justify-content: center;
    gap: var(--space-xl);
    color: var(--text-muted);
    flex-wrap: wrap;
}

.post-meta-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.post-featured-image {
    border-radius: var(--radius-xl);
    overflow: hidden;
    margin-bottom: var(--space-2xl);
    aspect-ratio: 16/9;
    background: linear-gradient(135deg, var(--color-accent), #2563EB);
}

.post-featured-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.post-content {
    font-size: 1.125rem;
    line-height: 1.8;
}

.post-content h2 {
    margin-top: var(--space-2xl);
    margin-bottom: var(--space-lg);
}

.post-content h3 {
    margin-top: var(--space-xl);
    margin-bottom: var(--space-md);
}

.post-content p {
    margin-bottom: var(--space-lg);
}

.post-content ul, .post-content ol {
    margin-bottom: var(--space-lg);
    padding-left: var(--space-xl);
}

.post-content li {
    margin-bottom: var(--space-sm);
}

.post-content img {
    max-width: 100%;
    border-radius: var(--radius-lg);
    margin: var(--space-xl) 0;
}

.post-content blockquote {
    border-left: 4px solid var(--color-primary);
    padding-left: var(--space-xl);
    margin: var(--space-xl) 0;
    font-style: italic;
    color: var(--text-secondary);
}

.post-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    margin-top: var(--space-2xl);
    padding-top: var(--space-xl);
    border-top: 1px solid var(--border-color);
}

.post-tag {
    background: var(--bg-secondary);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.post-tag:hover {
    background: var(--color-accent);
    color: white;
}

.post-author {
    display: flex;
    gap: var(--space-xl);
    background: var(--bg-secondary);
    padding: var(--space-xl);
    border-radius: var(--radius-xl);
    margin-top: var(--space-2xl);
}

@media (max-width: 768px) {
    .post-author {
        flex-direction: column;
        text-align: center;
    }
}

.post-author-avatar {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-black);
    flex-shrink: 0;
}

.post-author-info h4 {
    margin-bottom: var(--space-sm);
}

.post-author-bio {
    color: var(--text-secondary);
    margin-bottom: 0;
}

/* ==================== Language Selector ==================== */
.language-selector {
    position: relative;
}

.language-toggle {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: 0.875rem;
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.language-toggle:hover {
    border-color: var(--color-accent);
}

.language-dropdown {
    position: absolute;
    top: 100%;
    right: 0;
    margin-top: var(--space-sm);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--space-sm);
    min-width: 180px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-fast);
    z-index: var(--z-dropdown);
}

.language-selector:hover .language-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.language-option {
    display: block;
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.875rem;
    transition: all var(--transition-fast);
}

.language-option:hover {
    background: var(--bg-secondary);
}

.language-option.active {
    background: var(--color-accent);
    color: white;
}

/* ==================== Theme Toggle ==================== */
.theme-toggle {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    cursor: pointer;
    transition: all var(--transition-fast);
    color: var(--text-primary);
}

.theme-toggle:hover {
    background: var(--color-accent);
    border-color: var(--color-accent);
    color: white;
}

.theme-toggle svg {
    width: 20px;
    height: 20px;
}

/* ==================== Pagination ==================== */
.pagination {
    display: flex;
    justify-content: center;
    gap: var(--space-sm);
    margin-top: var(--space-3xl);
}

.pagination-item {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    font-weight: 500;
    transition: all var(--transition-fast);
}

.pagination-item:hover {
    background: var(--color-accent);
    border-color: var(--color-accent);
    color: white;
}

.pagination-item.active {
    background: var(--color-accent);
    border-color: var(--color-accent);
    color: white;
}

.pagination-item.disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* ==================== Animations ==================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) rotate(0deg);
    }
    50% {
        transform: translateY(-20px) rotate(5deg);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 0.5;
        transform: scale(1);
    }
    50% {
        opacity: 1;
        transform: scale(1.05);
    }
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.animate-fadeInUp {
    animation: fadeInUp 0.6s ease forwards;
}

.animate-fadeIn {
    animation: fadeIn 0.6s ease forwards;
}

.animate-float {
    animation: float 6s ease-in-out infinite;
}

/* Scroll animations */
.scroll-reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

.scroll-reveal.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* ==================== Responsive ==================== */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--bg-card);
        flex-direction: column;
        padding: var(--space-xl);
        gap: var(--space-lg);
        border-bottom: 1px solid var(--border-color);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-base);
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-toggle {
        display: flex;
    }

    .hero-stats {
        flex-direction: column;
        gap: var(--space-lg);
    }

    .mobile-app-banner {
        display: block;
    }

    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero-actions {
        flex-direction: column;
    }

    .hero-actions .btn {
        width: 100%;
    }

    .banner-content {
        flex-direction: column;
        text-align: center;
    }

    .banner-buttons {
        flex-direction: column;
        width: 100%;
    }

    .banner-btn {
        flex: 1;
    }
}

/* ==================== Utilities ==================== */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: var(--space-xs); }
.mt-2 { margin-top: var(--space-sm); }
.mt-3 { margin-top: var(--space-md); }
.mt-4 { margin-top: var(--space-lg); }
.mt-5 { margin-top: var(--space-xl); }

.mb-1 { margin-bottom: var(--space-xs); }
.mb-2 { margin-bottom: var(--space-sm); }
.mb-3 { margin-bottom: var(--space-md); }
.mb-4 { margin-bottom: var(--space-lg); }
.mb-5 { margin-bottom: var(--space-xl); }

.hidden { display: none !important; }
.visible { display: block !important; }

/* Accessibility */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Focus styles */
:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

/* Selection */
::selection {
    background: var(--color-primary);
    color: var(--color-black);
}

/* ==================== New Home Page Styles ==================== */

/* Hero Video */
.hero-video {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* Section Titles */
.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    margin-bottom: var(--space-lg);
}

.section-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-2xl);
}

.section-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-xl);
}

/* ==================== Speak Section ==================== */
.speak-section {
    padding: var(--space-4xl) 0;
}

.speak-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-4xl);
    align-items: center;
}

@media (max-width: 992px) {
    .speak-grid {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }
}

.speak-content h2 {
    margin-bottom: var(--space-lg);
}

.speak-features h3 {
    font-size: 1.25rem;
    margin-bottom: var(--space-md);
}

.speak-features ul {
    list-style: none;
    margin-bottom: var(--space-xl);
}

.speak-features li {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) 0;
    color: var(--text-secondary);
}

.speak-features li svg {
    color: var(--color-accent);
    flex-shrink: 0;
}

.speak-highlight {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-accent);
    margin-bottom: 0;
}

.speak-visual {
    display: flex;
    justify-content: center;
}

.speak-card {
    background: linear-gradient(135deg, var(--color-accent), #1E40AF);
    color: white;
    padding: var(--space-2xl);
    border-radius: var(--radius-xl);
    text-align: center;
    max-width: 560px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-md);
}

.speak-card .speak-icon {
    width: 80px;
    height: 80px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
}

.speak-card .text-image {
    width: 100%;
    height: auto;
    object-fit: contain;
}

/* ==================== Conversations Section ==================== */
.conversations-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-4xl);
    align-items: center;
}

@media (max-width: 992px) {
    .conversations-grid {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }
}

.conversations-content h2 {
    margin-bottom: var(--space-xl);
}

.scenario-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
    margin-bottom: var(--space-xl);
}

.scenario-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md);
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
}

.scenario-item svg {
    color: var(--color-accent);
    flex-shrink: 0;
}

.conversations-highlight {
    font-weight: 600;
    color: var(--color-secondary);
    margin-bottom: 0;
}

.conversations-visual {
    display: flex;
    justify-content: center;
}

.conversation-card {
    background: linear-gradient(135deg, var(--color-secondary), var(--color-primary));
    color: var(--color-black);
    padding: var(--space-2xl);
    border-radius: var(--radius-xl);
    text-align: center;
    max-width: 450px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-md);
}

.conversation-card .conversation-icon {
    width: 80px;
    height: 80px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
}

.conversation-card .text-image {
    width: 100%;
    height: auto;
    object-fit: contain;
}

.conversation-card h3 {
    margin-bottom: 0;
}

/* ==================== AI Feedback Section ==================== */
.ai-feedback-section {
    padding: var(--space-4xl) 0;
}

.ai-feedback-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-4xl);
    align-items: center;
}

@media (max-width: 992px) {
    .ai-feedback-grid {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }
}

.ai-feedback-list {
    list-style: none;
    margin-bottom: var(--space-xl);
}

.ai-feedback-list li {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md) 0;
    font-size: 1.125rem;
}

.feedback-icon {
    font-size: 1.5rem;
}

.ai-feedback-tagline {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-accent);
    margin-bottom: 0;
}

.ai-feedback-visual {
    display: flex;
    justify-content: center;
}

.ai-feedback-card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    border: 1px solid var(--border-color);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    max-width: 350px;
}

.ai-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: var(--color-black);
    padding: var(--space-xs) var(--space-md);
    border-radius: var(--radius-full);
    font-weight: 700;
    font-size: 0.875rem;
    margin-bottom: var(--space-lg);
}

.ai-message {
    background: var(--bg-secondary);
    padding: var(--space-lg);
    border-radius: var(--radius-lg);
}

.ai-message p {
    margin-bottom: 0;
    color: var(--text-secondary);
}

/* ==================== Progress Section ==================== */
.progress-section {
    padding: var(--space-4xl) 0;
}

.progress-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-4xl);
    align-items: center;
}

@media (max-width: 992px) {
    .progress-grid {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }
}

.stats-chart {
    margin: var(--space-2xl) 0;
}

.chart-bars {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    height: 200px;
    padding: 16px 16px 0 16px;
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border-color);
}

.chart-bar {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-end;
    height: 100%;
}

.bar-fill {
    width: 28px;
    height: 0;                          /* 初始高度为0 */
    background: linear-gradient(180deg, var(--color-primary), var(--color-secondary));
    border-radius: 4px 4px 0 0;
    transition: height 0.7s ease-out;  /* 唯一的动画控制 */
}

.bar-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 6px;
    margin-bottom: 4px;
    white-space: nowrap;
}

.chart-title {
    text-align: center;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: var(--space-md);
}

.total-sessions {
    text-align: center;
    padding: var(--space-xl);
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border-color);
}

.sessions-number {
    display: block;
    font-size: 3rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.sessions-label {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.progress-video {
    display: flex;
    justify-content: center;
}

@media (max-width: 768px) {
    .progress-video {
        display: none;
    }
}

.video-container {
    width: 100%;
    max-width: 400px;
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.15);
}

.video-container video {
    width: 100%;
    display: block;
}

/* ==================== Personalized Section ==================== */
.personalized-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-4xl);
    align-items: center;
}

@media (max-width: 992px) {
    .personalized-grid {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }
}

.personalized-visual {
    display: flex;
    justify-content: center;
}

.path-card {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: var(--color-black);
    padding: var(--space-2xl);
    border-radius: var(--radius-xl);
    text-align: center;
    max-width: 300px;
}

.path-card .path-icon {
    width: 80px;
    height: 80px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-lg);
}

.path-card h3 {
    margin-bottom: 0;
}

.path-list {
    list-style: none;
}

.path-list li {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md) 0;
    font-size: 1.125rem;
    border-bottom: 1px solid var(--border-color);
}

.path-list li:last-child {
    border-bottom: none;
}

.path-level {
    font-weight: 700;
    color: var(--color-accent);
    min-width: 60px;
}

/* ==================== How It Works Section ==================== */
.how-it-works-section {
    padding: var(--space-4xl) 0;
}

.how-header {
    text-align: center;
    margin-bottom: var(--space-3xl);
}

.how-steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-xl);
}

@media (max-width: 992px) {
    .how-steps {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .how-steps {
        grid-template-columns: 1fr;
    }
}
/* ==================== Why Section ==================== */
.why-section {
    padding: var(--space-4xl) 0;
}

.why-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-4xl);
    align-items: center;
}

@media (max-width: 992px) {
    .why-grid {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }
}

.why-list {
    list-style: none;
}

.why-list li {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md) 0;
    font-size: 1.25rem;
}

.why-check {
    color: var(--color-accent);
    font-weight: 700;
}

.why-visual {
    display: flex;
    justify-content: center;
}

.sayva-pro-card {
    background: linear-gradient(135deg, var(--color-accent), #1E40AF);
    color: white;
    padding: var(--space-2xl);
    border-radius: var(--radius-xl);
    max-width: 350px;
    text-align: center;
}

.sayva-pro-card h3 {
    font-size: 1.5rem;
    color: var(--color-primary);
    margin-bottom: var(--space-lg);
}

.sayva-pro-card h4 {
    color: white;
    margin-bottom: var(--space-md);
}

.sayva-pro-card ul {
    list-style: none;
    margin-bottom: var(--space-lg);
}

.sayva-pro-card li {
    padding: var(--space-sm) 0;
    opacity: 0.9;
}

.pro-note {
    font-size: 0.75rem;
    opacity: 0.7;
    margin-bottom: 0;
}

/* ==================== Testimonials Section ==================== */
.testimonials-section {
    background: var(--bg-secondary);
    padding: var(--space-4xl) 0;
    overflow: hidden;
}

.testimonials-header {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.testimonials-header h2 {
    font-size: clamp(2rem, 4vw, 2.5rem);
    color: var(--text-primary);
    margin-bottom: var(--space-md);
}

/* Auto Scroll Container */
.testimonials-scroll {
    display: flex;
    gap: var(--space-xl);
    margin-bottom: var(--space-xl);
    width: max-content;
}

.testimonials-scroll:hover {
    animation-play-state: paused;
}

/* Row 1: Left to Right */
.testimonials-scroll-left {
    animation: scroll-left 40s linear infinite;
}

@keyframes scroll-left {
    0% {
        transform: translateX(0);
    }
    100% {
        transform: translateX(-50%);
    }
}

/* Row 2: Right to Left */
.testimonials-scroll-right {
    animation: scroll-right 40s linear infinite;
}

@keyframes scroll-right {
    0% {
        transform: translateX(-50%);
    }
    100% {
        transform: translateX(0);
    }
}

/* Testimonial Card */
.testimonial-card {
    flex: 0 0 350px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    transition: all 0.3s ease;
}

.testimonial-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
    border-color: var(--color-primary);
}

/* Star Rating */
.testimonial-rating {
    display: flex;
    gap: 4px;
    margin-bottom: var(--space-md);
}

.testimonial-rating svg {
    flex-shrink: 0;
}

/* Content */
.testimonial-content {
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

/* Author */
.testimonial-author {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.author-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--color-primary);
}

.author-info h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.author-info p {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin: 0;
}

/* Hide scrollbar */
.testimonials-scroll {
    scrollbar-width: none;
    -ms-overflow-style: none;
}

.testimonials-scroll::-webkit-scrollbar {
    display: none;
}

/* ==================== Responsive Adjustments ==================== */
@media (max-width: 768px) {
    .hero {
        padding-top: 26px;
    }

    .hero-content {
        padding: var(--space-2xl) var(--space-md);
    }

    .hero-stats {
        flex-direction: column;
        gap: var(--space-lg);
    }

    .app-preview-phone {
        width: 220px;
        height: 450px;
        border-radius: 30px;
    }

    .floating-element {
        display: none;
    }

    .section {
        padding: var(--space-3xl) 0;
    }

    .scenario-list {
        grid-template-columns: 1fr;
    }
}

/* ==================== How It Works with Image Cards ==================== */
.how-steps-grid {
    display: grid;                              /* 改这里 */
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-xl);
    margin-bottom: var(--space-3xl);
}

@media (max-width: 992px) {
    .how-steps-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .how-steps-grid {
        grid-template-columns: 1fr;
    }
}

.step-card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    overflow: hidden;
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.step-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.step-card-image {
    width: 100%;
    height: 160px;
    overflow: hidden;
}

.step-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.step-card:hover .step-card-image img {
    transform: scale(1.05);
}

.step-card-content {
    padding: var(--space-lg);
    text-align: center;
}

.step-number-circle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: #000;
    font-weight: 700;
    font-size: 1.25rem;
    border-radius: 50%;
    margin-bottom: var(--space-md);
}

.step-card-content h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

/* ==================== Why Features with Background ==================== */
.why-features-scroll {
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
    padding-bottom: var(--space-lg);
    /* 隐藏滚动条但保持功能 */
    scrollbar-width: none;  /* Firefox */
    -ms-overflow-style: none;  /* IE/Edge */
}

.why-features-scroll::-webkit-scrollbar {
    display: none;  /* Chrome/Safari */
}

.why-features-grid {
    display: flex;
    gap: var(--space-xl);
    width: max-content;
    margin-bottom: var(--space-3xl);
}

.why-feature-card {
    position: relative;
    flex: 0 0 280px;
    height: 350px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: var(--space-xl);
    border-radius: var(--radius-xl);
    overflow: hidden;
    scroll-snap-align: start;
    transition: transform 0.3s ease;
}

.why-feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(180deg, rgba(0,0,0,0.2) 0%, rgba(0,0,0,0.7) 100%);
    z-index: 1;
}

.why-feature-card:hover {
    transform: scale(1.05);
}

.feature-icon-circle {
    position: relative;
    z-index: 2;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 60px;
    height: 60px;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 50%;
    margin-bottom: var(--space-md);
    color: var(--color-accent);
}

.why-feature-card h4 {
    position: relative;
    z-index: 2;
    font-size: 1.1rem;
    font-weight: 600;
    color: white;
    margin: 0;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

/* 大屏幕：横排展示 */
@media (min-width: 992px) {
    .why-features-scroll {
        overflow-x: visible;
    }

    .why-features-grid {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        width: 100%;
        gap: var(--space-xl);
    }

    .why-feature-card {
        flex: none;
        height: 300px;
    }
}

/* ==================== Testimonials Horizontal Scroll ==================== */
.testimonials-section {
    background: var(--bg-primary);
    padding: var(--space-3xl) 0;
    overflow: hidden;
}

.testimonials-scroll-container {
    display: flex;
    gap: var(--space-lg);
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    padding-bottom: var(--space-lg);
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    justify-content: flex-start;
}

.testimonials-scroll-container::-webkit-scrollbar {
    display: none;
}

.testimonial-card {
    flex: 0 0 320px;
    scroll-snap-align: start;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    transition: all 0.3s ease;
}

.testimonial-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
    border-color: var(--color-primary);
}

.testimonial-content {
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.author-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    display: flex;
    align-items: center;
    justify-content: center;
    color: #000;
    font-weight: 700;
    font-size: 1.25rem;
}

.author-info h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.author-info p {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin: 0;
}

/* ==================== Responsive ==================== */
@media (min-width: 992px) {
    .testimonials-scroll-container {
        justify-content: center;
    }

    .why-feature-card {
        flex: 0 0 200px;
        scroll-snap-align: start;
    }
}

@media (max-width: 768px) {
    -webkit-overflow-scrolling: touch;
}

/* ==================== About Page Styles ==================== */

/* Hero Section */
.about-hero {
    position: relative;
    padding: 140px 0 80px;
    background: linear-gradient(135deg, var(--color-accent) 0%, #0d47a1 100%);
    color: #fff;
    overflow: hidden;
}

.about-hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.5;
}

.about-hero-content {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-hero-title {
    font-size: 3rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 24px;
    animation: fadeInUp 0.8s ease-out;
}

.about-hero-subtitle {
    font-size: 1.25rem;
    line-height: 1.6;
    opacity: 0.95;
    animation: fadeInUp 0.8s ease-out 0.2s backwards;
}

/* Stats Section */
.about-stats {
    padding: 60px 0;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    text-align: center;
}

.stat-item {
    padding: 20px;
}

.stat-number {
    font-size: 3rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
}

.stat-label {
    font-size: 1rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Mission Section */
.about-mission {
    background: var(--bg-primary);
}

.mission-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.mission-content {
    padding-right: 40px;
}

.mission-text {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.mission-image-wrapper {
    position: relative;
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.15);
}

.mission-image-wrapper img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.5s ease;
}

.mission-image-wrapper:hover img {
    transform: scale(1.05);
}

/* Values Section */
.about-values {
    background: var(--bg-secondary);
}

.values-header {
    text-align: center;
    margin-bottom: 60px;
}

.values-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.value-card {
    background: var(--bg-card);
    padding: 40px 30px;
    border-radius: var(--radius-xl);
    text-align: center;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.value-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    border-color: var(--color-primary);
}

.value-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    border-radius: 50%;
    margin-bottom: 24px;
    color: #000;
}

.value-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.value-card p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Technology Section */
.about-tech {
    background: var(--bg-primary);
}

.tech-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.tech-content {
    padding-left: 40px;
}

.tech-text {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-secondary);
    margin-bottom: 30px;
}

.tech-features {
    list-style: none;
    padding: 0;
    margin: 0;
}

.tech-features li {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 0;
    font-size: 1rem;
    color: var(--text-primary);
}

.tech-features svg {
    color: var(--color-primary);
    flex-shrink: 0;
}

.tech-image-wrapper {
    position: relative;
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.15);
}

.tech-image-wrapper img {
    width: 100%;
    height: auto;
    display: block;
}

/* CTA Section */
.about-cta {
    background: linear-gradient(135deg, var(--color-accent) 0%, #0d47a1 100%);
    color: #fff;
    text-align: center;
}

.about-cta .cta-content {
    max-width: 600px;
    margin: 0 auto;
}

.about-cta .cta-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.about-cta .cta-text {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 32px;
}

.about-cta .btn-primary {
    background: var(--color-primary);
    color: #000;
}

.about-cta .btn-primary:hover {
    background: #fff;
}

.about-cta .btn-outline {
    border-color: #fff;
    color: #fff;
}

.about-cta .btn-outline:hover {
    background: #fff;
    color: var(--color-accent);
}

/* Responsive */
@media (max-width: 992px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .values-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .mission-grid,
    .tech-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .mission-content,
    .tech-content {
        padding: 0;
        text-align: center;
    }
}

@media (max-width: 768px) {
    .about-hero-title {
        font-size: 2rem;
    }

    .about-hero-subtitle {
        font-size: 1rem;
    }

    .stat-number {
        font-size: 2.5rem;
    }

    .values-grid {
        grid-template-columns: 1fr;
    }

    .about-cta .cta-title {
        font-size: 1.75rem;
    }
}

/* ==================== Floating Images ==================== */
.floating-images-container {
    position: relative;
    width: 100%;
    height: 400px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.floating-image-wrapper {
    position: absolute;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.floating-image-wrapper:hover {
    transform: scale(1.05) !important;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
    z-index: 10;
}

.floating-image-wrapper img {
    width: 120px;
    height: 120px;
    object-fit: cover;
    display: block;
}

/* 图片位置 */
.img-1 { top: 10%; left: 15%; animation: float1 6s ease-in-out infinite; }
.img-2 { top: 5%; left: 50%; animation: float2 7s ease-in-out infinite; }
.img-3 { top: 15%; right: 15%; animation: float3 5s ease-in-out infinite; }
.img-4 { bottom: 20%; left: 10%; animation: float4 8s ease-in-out infinite; }
.img-5 { bottom: 15%; right: 20%; animation: float5 6.5s ease-in-out infinite; }
.img-6 { bottom: 25%; left: 45%; animation: float6 7.5s ease-in-out infinite; }

/* 浮动动画 - 不同速度和方向 */
@keyframes float1 {
    0%, 100% { transform: translateY(0) rotate(-3deg); }
    50% { transform: translateY(-15px) rotate(3deg); }
}

@keyframes float2 {
    0%, 100% { transform: translateY(0) rotate(2deg); }
    50% { transform: translateY(-20px) rotate(-2deg); }
}

@keyframes float3 {
    0%, 100% { transform: translateY(0) rotate(-2deg); }
    50% { transform: translateY(-12px) rotate(4deg); }
}

@keyframes float4 {
    0%, 100% { transform: translateY(0) rotate(3deg); }
    50% { transform: translateY(-18px) rotate(-3deg); }
}

@keyframes float5 {
    0%, 100% { transform: translateY(0) rotate(-1deg); }
    50% { transform: translateY(-14px) rotate(2deg); }
}

@keyframes float6 {
    0%, 100% { transform: translateY(0) rotate(2deg); }
    50% { transform: translateY(-16px) rotate(-2deg); }
}

/* 响应式 */
@media (max-width: 768px) {
    .floating-images-container {
        height: 350px;
    }

    .floating-image-wrapper img {
        width: 80px;
        height: 80px;
    }

    .img-1 { top: 8%; left: 10%; }
    .img-2 { top: 5%; left: 40%; }
    .img-3 { top: 10%; right: 10%; }
    .img-4 { bottom: 25%; left: 5%; }
    .img-5 { bottom: 15%; right: 15%; }
    .img-6 { bottom: 20%; left: 35%; }
}

/* ==================== AI Feedback Visual ==================== */
.ai-feedback-visual {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.ai-feedback-image {
    width: 60%;
    max-width: 300px;
    max-height: 600px;
    border-radius: var(--radius-xl);
    overflow: hidden;
}

.ai-feedback-image img {
    width: 100%;
    height: auto;
    display: block;
}

/* 弹出卡片容器 - 定位左上角 */
.ai-popup-card {
    position: absolute;
    top: 20px;
    left: 0;
    max-width: 280px;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
    border: 1px solid var(--border-color);
    padding: var(--space-md);

    /* 初始隐藏 */
    opacity: 0;
    transform: translateY(20px) scale(0.9);

    /* 循环动画 */
    animation: popupCycle 6s ease-in-out infinite;
    animation-play-state: paused;
}

/* 滚动触发后开始动画 */
.ai-feedback-visual.revealed .ai-popup-card {
    animation-play-state: running;
}

/* 打字指示器 */
.ai-typing-indicator {
    display: flex;
    gap: 4px;
    padding: var(--space-xs) 0;
}

.ai-typing-indicator span {
    width: 8px;
    height: 8px;
    background: var(--text-muted);
    border-radius: 50%;
}

/* 消息气泡 - 上下排列 */
.ai-popup-message {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
    margin-top: var(--space-sm);
}

.ai-popup-badge {
    display: flex;
    align-items: center;
    gap: 4px;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: var(--text-inverse);
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    flex-shrink: 0;
    width: fit-content;
}

.ai-popup-message p {
    margin: 0;
    font-size: 0.875rem;
    line-height: 1.5;
    color: var(--text-primary);
}

/* ==================== 循环动画关键帧（6秒循环） ==================== */
@keyframes popupCycle {
    /* 初始状态 - 隐藏 */
    0% {
        opacity: 0;
        transform: translateY(20px) scale(0.9);
    }

    /* 显示并弹出 */
    8% {
        opacity: 1;
        transform: translateY(0) scale(1);
    }

    /* 打字指示器出现 (8% - 25%) */
    8% {
        /* 点开始动画 */
    }

    /* 消息显示 (25% - 83%) */
    25% {
        /* 切换到消息 */
    }

    /* 消息完全显示 */
    30% {
        opacity: 1;
        transform: translateY(0) scale(1);
    }

    /* 保持显示直到 83% */
    83% {
        opacity: 1;
        transform: translateY(0) scale(1);
    }

    /* 淡出 */
    90% {
        opacity: 0;
        transform: translateY(-10px) scale(0.95);
    }

    100% {
        opacity: 0;
        transform: translateY(20px) scale(0.9);
    }
}

/* 三个点的循环动画 */
@keyframes dotPulse {
    0%, 8% {
        opacity: 0;
        transform: scale(0);
    }
    10% {
        opacity: 1;
        transform: scale(1);
    }
    13% {
        transform: translateY(-6px);
    }
    16% {
        transform: translateY(0);
    }
    19% {
        transform: translateY(-6px);
    }
    22% {
        transform: translateY(0);
    }
    25% {
        opacity: 1;
        transform: scale(1);
    }
    28%, 100% {
        opacity: 0;
        transform: scale(0);
    }
}

.ai-typing-indicator span {
    animation: dotPulse 6s ease-in-out infinite;
}

.ai-typing-indicator span:nth-child(1) {
    animation-delay: 0s;
}
.ai-typing-indicator span:nth-child(2) {
    animation-delay: 0.1s;
}
.ai-typing-indicator span:nth-child(3) {
    animation-delay: 0.2s;
}

/* 消息淡入淡出 */
.ai-popup-message {
    opacity: 0;
    animation: messageFade 6s ease-in-out infinite;
}

@keyframes messageFade {
    0%, 24% {
        opacity: 0;
    }
    30%, 80% {
        opacity: 1;
    }
    88%, 100% {
        opacity: 0;
    }
}

/* 响应式 */
@media (max-width: 768px) {
    .ai-feedback-image {
        width: 80%;
        max-width: 250px;
    }

    .ai-popup-card {
        top: 10px;
        left: 0;
        max-width: 200px;
    }
}

/* 替换原来的 video-container 样式 */
.progress-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.progress-image img {
    border-radius: var(--radius-xl);
}

@media (max-width: 768px) {
    .progress-image img {
        width: 100%;
    }
}

/* 桌面端隐藏语言列 */
.footer-lang-column {
    display: none;
}

@media (max-width: 768px) {
    /* 移动端显示，并让它独占一整行 */
    .footer-lang-column {
        display: block;
        grid-column: 1 / -1;   /* 横跨所有列 */
        border-top: 1px solid var(--border-color);
        padding-top: var(--space-xl);
        margin-top: var(--space-sm);
    }

    .footer-lang-column h4 {
        margin-bottom: var(--space-md);
        font-size: 1rem;
    }

    /* 语言选项 grid 排列 */
    .footer-lang-grid {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 8px;
    }

    .footer-lang-opt {
        display: block;
        padding: 8px 6px;
        border-radius: 8px;
        font-size: 0.78rem;
        color: var(--text-secondary);
        background: var(--bg-secondary);
        text-align: center;
        transition: background var(--transition-fast), color var(--transition-fast);
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .footer-lang-opt:hover {
        background: var(--color-accent);
        color: white;
    }
}