:root {
    /* ========================================
    LIQUID GLASS DESIGN TOKENS
               基于原设计系统结构，转换为液态玻璃美学
               ======================================== */

    /* --- 品牌色系：水蓝碧波 --- */
    --color-primary: #5ba4b0;
    --color-primary-active: #3d8794;
    --color-primary-disabled: #c8e2e7;
    --color-primary-glow: rgba(91, 164, 176, 0.35);

    /* --- 强调色 --- */
    --color-accent-teal: #4db8a0;
    --color-accent-amber: #d4a850;
    --color-accent-coral-soft: #c47d6a;

    /* --- 文字色 --- */
    --color-ink: #18282d;
    --color-body-strong: #1e3239;
    --color-body: #2e444c;
    --color-muted: #5a727a;
    --color-muted-soft: #7d949b;

    /* --- 浅色表面（玻璃白/水色） --- */
    --color-canvas: #eaf4f7;
    --color-canvas-warm: #ecf5f6;
    --color-surface-soft: #e0eef2;
    --color-surface-card: rgba(255, 255, 255, 0.55);
    --color-surface-card-hover: rgba(255, 255, 255, 0.72);
    --color-surface-cream-strong: rgba(255, 255, 255, 0.7);

    /* --- 深色表面（深海玻璃） --- */
    --color-surface-dark: rgba(18, 36, 42, 0.82);
    --color-surface-dark-elevated: rgba(28, 48, 55, 0.88);
    --color-surface-dark-soft: rgba(22, 40, 47, 0.78);

    /* --- 边框/分割线 --- */
    --color-hairline: rgba(255, 255, 255, 0.55);
    --color-hairline-soft: rgba(255, 255, 255, 0.35);
    --color-hairline-dark: rgba(255, 255, 255, 0.12);

    /* --- 语义色 --- */
    --color-on-primary: #ffffff;
    --color-on-dark: #eaf4f7;
    --color-on-dark-soft: #9bb5bd;
    --color-success: #5db892;
    --color-warning: #d4a840;
    --color-error: #c45555;

    /* --- 排版：保留衬线标题+无衬线正文结构 --- */
    --font-display: 'Noto Serif SC', 'Cormorant Garamond', 'STSong', '华文宋体', 'Georgia', 'Times New Roman', serif;
    --font-body: 'Noto Sans SC', 'Inter', 'PingFang SC', 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-code: 'JetBrains Mono', 'SF Mono', 'Cascadia Code', ui-monospace, monospace;

    /* 字号层级（保留原系统结构，微调适配中文） */
    --text-display-xl: 4rem;
    --text-display-lg: 3rem;
    --text-display-md: 2.25rem;
    --text-display-sm: 1.75rem;
    --text-title-lg: 1.375rem;
    --text-title-md: 1.125rem;
    --text-title-sm: 1rem;
    --text-body-md: 1rem;
    --text-body-sm: 0.875rem;
    --text-caption: 0.8125rem;
    --text-caption-upper: 0.75rem;
    --text-button: 0.875rem;
    --text-nav: 0.875rem;

    /* --- 圆角 --- */
    --rounded-xs: 4px;
    --rounded-sm: 6px;
    --rounded-md: 8px;
    --rounded-lg: 14px;
    --rounded-xl: 18px;
    --rounded-pill: 9999px;
    --rounded-full: 9999px;

    /* --- 间距 --- */
    --spacing-xxs: 4px;
    --spacing-xs: 8px;
    --spacing-sm: 12px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;
    --spacing-section: 96px;

    /* --- 玻璃特效 --- */
    --glass-blur: 18px;
    --glass-blur-strong: 28px;
    --glass-blur-light: 10px;
    --glass-border: 1px solid rgba(255, 255, 255, 0.5);
    --glass-border-soft: 1px solid rgba(255, 255, 255, 0.3);
    --glass-border-dark: 1px solid rgba(255, 255, 255, 0.13);
    --glass-shadow: 0 4px 24px rgba(30, 50, 55, 0.08), 0 1px 4px rgba(30, 50, 55, 0.04);
    --glass-shadow-elevated: 0 8px 40px rgba(30, 50, 55, 0.12), 0 2px 8px rgba(30, 50, 55, 0.06);
    --glass-shadow-dark: 0 4px 28px rgba(0, 0, 0, 0.2), 0 1px 4px rgba(0, 0, 0, 0.1);

    /* --- 过渡 --- */
    --transition-fast: 180ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-spring: 400ms cubic-bezier(0.34, 1.56, 0.64, 1);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-body);
    font-size: var(--text-body-md);
    font-weight: 400;
    line-height: 1.6;
    color: var(--color-body);
    background: var(--color-canvas);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
    /* 水光焦散背景 */
    background-image:
        /* 大光斑 - 模拟水底光折射 */
        radial-gradient(ellipse 900px 600px at 15% 10%, rgba(165, 215, 225, 0.45) 0%, transparent 70%),
        radial-gradient(ellipse 700px 500px at 75% 5%, rgba(180, 220, 210, 0.4) 0%, transparent 65%),
        radial-gradient(ellipse 650px 550px at 50% 30%, rgba(200, 230, 225, 0.3) 0%, transparent 60%),
        radial-gradient(ellipse 800px 500px at 20% 55%, rgba(170, 210, 220, 0.35) 0%, transparent 65%),
        radial-gradient(ellipse 600px 450px at 80% 60%, rgba(160, 205, 215, 0.4) 0%, transparent 60%),
        radial-gradient(ellipse 750px 500px at 40% 75%, rgba(175, 215, 210, 0.35) 0%, transparent 65%),
        radial-gradient(ellipse 500px 400px at 65% 85%, rgba(185, 220, 220, 0.3) 0%, transparent 60%),
        /* 微小的焦散光点 */
        radial-gradient(circle 120px at 25% 18%, rgba(255, 255, 255, 0.5) 0%, transparent 100%),
        radial-gradient(circle 80px at 68% 22%, rgba(255, 255, 255, 0.4) 0%, transparent 100%),
        radial-gradient(circle 100px at 42% 48%, rgba(255, 255, 255, 0.35) 0%, transparent 100%),
        radial-gradient(circle 70px at 78% 52%, rgba(255, 255, 255, 0.4) 0%, transparent 100%),
        radial-gradient(circle 90px at 30% 68%, rgba(255, 255, 255, 0.35) 0%, transparent 100%),
        radial-gradient(circle 60px at 55% 80%, rgba(255, 255, 255, 0.4) 0%, transparent 100%);
    background-attachment: fixed;
    background-color: var(--color-canvas);
}

/* --- 气泡容器 --- */
.bubbles-container {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 0;
    overflow: hidden;
}

.bubble {
    position: absolute;
    border-radius: 50%;
    background: radial-gradient(circle at 35% 30%,
            rgba(255, 255, 255, 0.7) 0%,
            rgba(200, 225, 230, 0.35) 40%,
            rgba(180, 210, 220, 0.1) 70%,
            transparent 100%);
    box-shadow:
        inset 0 2px 6px rgba(255, 255, 255, 0.6),
        0 0 12px rgba(160, 210, 220, 0.2);
    animation: float-up var(--dur) ease-in infinite;
    animation-delay: var(--delay);
    opacity: 0;
    will-change: transform, opacity;
}

@keyframes float-up {
    0% {
        transform: translateY(105vh) translateX(0) scale(0.6);
        opacity: 0;
    }

    8% {
        opacity: 0.7;
    }

    25% {
        transform: translateY(72vh) translateX(var(--drift1)) scale(1);
        opacity: 0.65;
    }

    50% {
        transform: translateY(40vh) translateX(var(--drift2)) scale(1.05);
        opacity: 0.5;
    }

    75% {
        transform: translateY(15vh) translateX(var(--drift3)) scale(0.9);
        opacity: 0.25;
    }

    100% {
        transform: translateY(-8vh) translateX(var(--drift4)) scale(0.5);
        opacity: 0;
    }
}

/* --- 水纹装饰线 --- */
.water-ripple-divider {
    width: 100%;
    height: 1px;
    background: none;
    border: none;
    position: relative;
    overflow: visible;
    margin: 0;
    opacity: 0.5;
}

.water-ripple-divider::after {
    content: '';
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    width: 120px;
    height: 2px;
    background: linear-gradient(90deg,
            transparent 0%,
            rgba(140, 195, 205, 0.6) 20%,
            rgba(120, 185, 195, 0.8) 50%,
            rgba(140, 195, 205, 0.6) 80%,
            transparent 100%);
    border-radius: 2px;
}

/* ========================================
           LAYOUT CONTAINER
           ======================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    position: relative;
    z-index: 1;
}

/* ========================================
           TOP NAVIGATION — 磨砂玻璃导航
           ======================================== */
.top-nav {
    position: sticky;
    top: 0;
    z-index: 100;
    height: 64px;
    background: rgba(234, 244, 247, 0.7);
    backdrop-filter: blur(var(--glass-blur-strong));
    -webkit-backdrop-filter: blur(var(--glass-blur-strong));
    border-bottom: var(--glass-border-soft);
    display: flex;
    align-items: center;
    transition: background var(--transition-smooth), box-shadow var(--transition-smooth);
}

.top-nav.scrolled {
    background: rgba(234, 244, 247, 0.85);
    box-shadow: 0 2px 20px rgba(30, 50, 55, 0.08);
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    text-decoration: none;
    color: var(--color-ink);
    font-family: var(--font-display);
    font-size: var(--text-title-md);
    font-weight: 500;
    letter-spacing: -0.01em;
    white-space: nowrap;
}

.nav-brand-mark {
    width: 28px;
    height: 28px;
    flex-shrink: 0;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 水滴品牌标记 */
.water-drop-mark {
    width: 22px;
    height: 26px;
    background: var(--color-primary);
    border-radius: 50% 50% 50% 50% / 30% 30% 70% 70%;
    position: relative;
    box-shadow:
        inset 0 3px 6px rgba(255, 255, 255, 0.5),
        0 2px 8px rgba(91, 164, 176, 0.3);
    animation: drop-shimmer 3s ease-in-out infinite;
}

.water-drop-mark::after {
    content: '';
    position: absolute;
    top: 4px;
    left: 5px;
    width: 6px;
    height: 8px;
    background: rgba(255, 255, 255, 0.7);
    border-radius: 50%;
}

@keyframes drop-shimmer {

    0%,
    100% {
        box-shadow: inset 0 3px 6px rgba(255, 255, 255, 0.5), 0 2px 8px rgba(91, 164, 176, 0.3);
    }

    50% {
        box-shadow: inset 0 3px 8px rgba(255, 255, 255, 0.7), 0 3px 14px rgba(91, 164, 176, 0.5);
    }
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    list-style: none;
    flex-wrap: wrap;
    justify-content: flex-end;
}

.nav-links a {
    display: inline-block;
    padding: 8px 14px;
    text-decoration: none;
    color: var(--color-body);
    font-family: var(--font-body);
    font-size: var(--text-nav);
    font-weight: 500;
    line-height: 1.4;
    letter-spacing: 0;
    border-radius: var(--rounded-md);
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.nav-links a:hover {
    background: rgba(255, 255, 255, 0.5);
    color: var(--color-ink);
}

/* 按钮 — 主按钮（水蓝玻璃） */
.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary);
    color: var(--color-on-primary);
    font-family: var(--font-body);
    font-size: var(--text-button);
    font-weight: 500;
    line-height: 1;
    padding: 12px 20px;
    height: 40px;
    border: none;
    border-radius: var(--rounded-md);
    cursor: pointer;
    text-decoration: none;
    white-space: nowrap;
    transition: all var(--transition-fast);
    box-shadow: 0 2px 8px var(--color-primary-glow);
    position: relative;
    overflow: hidden;
}

.btn-primary::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg,
            rgba(255, 255, 255, 0.2) 0%,
            transparent 50%);
    border-radius: inherit;
    pointer-events: none;
}

.btn-primary:hover {
    background: var(--color-primary-active);
    box-shadow: 0 4px 16px rgba(61, 135, 148, 0.4);
    transform: translateY(-1px);
}

.btn-primary:active {
    background: var(--color-primary-active);
    transform: translateY(0);
    box-shadow: 0 1px 4px rgba(61, 135, 148, 0.3);
}

/* 次要按钮 */
.btn-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.5);
    backdrop-filter: blur(var(--glass-blur-light));
    -webkit-backdrop-filter: blur(var(--glass-blur-light));
    color: var(--color-ink);
    font-family: var(--font-body);
    font-size: var(--text-button);
    font-weight: 500;
    line-height: 1;
    padding: 12px 20px;
    height: 40px;
    border: var(--glass-border);
    border-radius: var(--rounded-md);
    cursor: pointer;
    text-decoration: none;
    white-space: nowrap;
    transition: all var(--transition-fast);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.7);
    box-shadow: var(--glass-shadow);
    border-color: rgba(255, 255, 255, 0.65);
}

/* 暗色表面上的次要按钮 */
.btn-secondary-on-dark {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--color-surface-dark-elevated);
    color: var(--color-on-dark);
    font-family: var(--font-body);
    font-size: var(--text-button);
    font-weight: 500;
    line-height: 1;
    padding: 12px 20px;
    height: 40px;
    border: var(--glass-border-dark);
    border-radius: var(--rounded-md);
    cursor: pointer;
    text-decoration: none;
    white-space: nowrap;
    transition: all var(--transition-fast);
    backdrop-filter: blur(var(--glass-blur-light));
    -webkit-backdrop-filter: blur(var(--glass-blur-light));
}

.btn-secondary-on-dark:hover {
    background: rgba(40, 58, 64, 0.9);
    border-color: rgba(255, 255, 255, 0.25);
}

/* 文字链接 */
.text-link {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
}

.text-link::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 100%;
    height: 1px;
    background: var(--color-primary);
    transform: scaleX(0);
    transform-origin: right;
    transition: transform var(--transition-smooth);
}

.text-link:hover::after {
    transform: scaleX(1);
    transform-origin: left;
}

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

/* --- 汉堡菜单（移动端） --- */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 8px;
    z-index: 101;
    background: none;
    border: none;
    width: 36px;
    height: 28px;
    justify-content: center;
}

.hamburger span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--color-ink);
    border-radius: 2px;
    transition: var(--transition-fast);
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ========================================
           HERO BAND
           ======================================== */
.hero-band {
    padding: var(--spacing-section) 0;
    position: relative;
    z-index: 1;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xxl);
    align-items: center;
}

.hero-content h1 {
    font-family: var(--font-display);
    font-size: var(--text-display-xl);
    font-weight: 400;
    line-height: 1.1;
    letter-spacing: -0.02em;
    color: var(--color-ink);
    margin-bottom: var(--spacing-lg);
}

.hero-content h1 .highlight {
    color: var(--color-primary);
    position: relative;
}

.hero-content .hero-subtitle {
    font-family: var(--font-body);
    font-size: var(--text-title-lg);
    font-weight: 400;
    line-height: 1.5;
    color: var(--color-body-strong);
    margin-bottom: var(--spacing-xl);
    max-width: 480px;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

/* Hero 玻璃卡片 */
.hero-glass-card {
    background: var(--color-surface-card);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border: var(--glass-border);
    border-radius: var(--rounded-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--glass-shadow-elevated);
    position: relative;
    overflow: hidden;
    aspect-ratio: 4/3;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 320px;
}

.hero-glass-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at 30% 25%,
            rgba(255, 255, 255, 0.4) 0%,
            transparent 60%);
    border-radius: inherit;
    pointer-events: none;
}

.hero-card-inner {
    text-align: center;
    position: relative;
    z-index: 1;
}

.hero-fish-icon {
    font-size: 5rem;
    display: block;
    margin-bottom: var(--spacing-md);
    animation: swim-gently 4s ease-in-out infinite;
    filter: drop-shadow(0 8px 16px rgba(91, 164, 176, 0.3));
}

@keyframes swim-gently {

    0%,
    100% {
        transform: translateX(0) translateY(0);
    }

    25% {
        transform: translateX(8px) translateY(-5px);
    }

    50% {
        transform: translateX(-4px) translateY(3px);
    }

    75% {
        transform: translateX(6px) translateY(-2px);
    }
}

.hero-card-label {
    font-family: var(--font-display);
    font-size: var(--text-title-lg);
    color: var(--color-ink);
    font-weight: 500;
    letter-spacing: -0.01em;
}

.hero-card-sub {
    font-family: var(--font-body);
    font-size: var(--text-body-sm);
    color: var(--color-muted);
    margin-top: var(--spacing-xs);
}

/* ========================================
           SECTION TITLES
           ======================================== */
.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xxl);
}

.section-header h2 {
    font-family: var(--font-display);
    font-size: var(--text-display-lg);
    font-weight: 400;
    line-height: 1.15;
    letter-spacing: -0.015em;
    color: var(--color-ink);
    margin-bottom: var(--spacing-sm);
}

.section-header .section-tag {
    display: inline-block;
    font-family: var(--font-body);
    font-size: var(--text-caption-upper);
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--color-primary);
    background: rgba(91, 164, 176, 0.1);
    padding: 4px 14px;
    border-radius: var(--rounded-pill);
    margin-bottom: var(--spacing-md);
}

.section-header p {
    font-family: var(--font-body);
    font-size: var(--text-body-md);
    color: var(--color-muted);
    max-width: 560px;
    margin: 0 auto;
    line-height: 1.6;
}

/* ========================================
           FEATURE CARDS — 磨砂玻璃卡片
           ======================================== */
.features-section {
    padding: var(--spacing-section) 0;
    position: relative;
    z-index: 1;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.feature-card {
    background: var(--color-surface-card);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border: var(--glass-border);
    border-radius: var(--rounded-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--glass-shadow);
    transition: all var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg,
            transparent 0%,
            rgba(255, 255, 255, 0.7) 30%,
            rgba(180, 210, 220, 0.5) 50%,
            rgba(255, 255, 255, 0.7) 70%,
            transparent 100%);
    border-radius: var(--rounded-lg) var(--rounded-lg) 0 0;
    opacity: 0;
    transition: opacity var(--transition-smooth);
}

.feature-card:hover {
    background: var(--color-surface-card-hover);
    box-shadow: var(--glass-shadow-elevated);
    transform: translateY(-3px);
    border-color: rgba(255, 255, 255, 0.65);
}

.feature-card:hover::before {
    opacity: 1;
}

.feature-card-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--rounded-md);
    background: rgba(91, 164, 176, 0.12);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    transition: all var(--transition-smooth);
}

.feature-card:hover .feature-card-icon {
    background: rgba(91, 164, 176, 0.2);
    box-shadow: 0 0 20px rgba(91, 164, 176, 0.15);
}

.feature-card h3 {
    font-family: var(--font-display);
    font-size: var(--text-title-md);
    font-weight: 500;
    line-height: 1.35;
    letter-spacing: -0.005em;
    color: var(--color-ink);
    margin-bottom: var(--spacing-sm);
}

.feature-card p {
    font-family: var(--font-body);
    font-size: var(--text-body-sm);
    line-height: 1.6;
    color: var(--color-muted);
}

/* ========================================
           DARK GLASS CARDS — 深海玻璃展示
           ======================================== */
.dark-cards-section {
    padding: var(--spacing-section) 0;
    position: relative;
    z-index: 1;
}

.dark-cards-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.dark-glass-card {
    background: var(--color-surface-dark);
    backdrop-filter: blur(var(--glass-blur-strong));
    -webkit-backdrop-filter: blur(var(--glass-blur-strong));
    border: var(--glass-border-dark);
    border-radius: var(--rounded-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--glass-shadow-dark);
    color: var(--color-on-dark);
    transition: all var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.dark-glass-card::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(ellipse at 30% 20%,
            rgba(255, 255, 255, 0.06) 0%,
            transparent 50%);
    pointer-events: none;
    transition: all var(--transition-smooth);
}

.dark-glass-card:hover {
    background: var(--color-surface-dark-elevated);
    border-color: rgba(255, 255, 255, 0.2);
    box-shadow: 0 8px 40px rgba(0, 0, 0, 0.3);
    transform: translateY(-3px);
}

.dark-glass-card:hover::after {
    background: radial-gradient(ellipse at 30% 20%,
            rgba(255, 255, 255, 0.1) 0%,
            transparent 50%);
}

.dark-card-top {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    position: relative;
    z-index: 1;
}

.dark-card-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--color-accent-teal);
    box-shadow: 0 0 10px rgba(77, 184, 160, 0.6);
    animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {

    0%,
    100% {
        box-shadow: 0 0 8px rgba(77, 184, 160, 0.5);
    }

    50% {
        box-shadow: 0 0 18px rgba(77, 184, 160, 0.8);
    }
}

.dark-card-tag {
    font-family: var(--font-body);
    font-size: var(--text-caption-upper);
    font-weight: 500;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--color-on-dark-soft);
}

.dark-glass-card h3 {
    font-family: var(--font-display);
    font-size: var(--text-title-md);
    font-weight: 500;
    line-height: 1.35;
    letter-spacing: -0.005em;
    color: var(--color-on-dark);
    margin-bottom: var(--spacing-sm);
    position: relative;
    z-index: 1;
}

.dark-glass-card p {
    font-family: var(--font-body);
    font-size: var(--text-body-sm);
    line-height: 1.6;
    color: var(--color-on-dark-soft);
    position: relative;
    z-index: 1;
}

.dark-card-highlight {
    display: inline-block;
    margin-top: var(--spacing-md);
    font-family: var(--font-code);
    font-size: 0.8rem;
    color: var(--color-accent-teal);
    background: rgba(77, 184, 160, 0.08);
    padding: 4px 10px;
    border-radius: var(--rounded-xs);
    position: relative;
    z-index: 1;
}

/* ========================================
           CTA BAND — 水蓝玻璃全宽
           ======================================== */
.cta-band {
    margin: var(--spacing-section) auto;
    max-width: 1200px;
    padding: 0 var(--spacing-lg);
    position: relative;
    z-index: 1;
}

.cta-band-inner {
    background: rgba(91, 164, 176, 0.25);
    backdrop-filter: blur(var(--glass-blur-strong));
    -webkit-backdrop-filter: blur(var(--glass-blur-strong));
    border: 1px solid rgba(255, 255, 255, 0.55);
    border-radius: var(--rounded-lg);
    padding: 64px var(--spacing-xxl);
    text-align: center;
    box-shadow: var(--glass-shadow-elevated), 0 0 60px rgba(91, 164, 176, 0.12);
    position: relative;
    overflow: hidden;
}

.cta-band-inner::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at 50% 30%,
            rgba(255, 255, 255, 0.35) 0%,
            transparent 55%);
    border-radius: inherit;
    pointer-events: none;
}

.cta-band-inner h2 {
    font-family: var(--font-display);
    font-size: var(--text-display-sm);
    font-weight: 400;
    line-height: 1.2;
    letter-spacing: -0.01em;
    color: var(--color-ink);
    margin-bottom: var(--spacing-md);
    position: relative;
    z-index: 1;
}

.cta-band-inner p {
    font-family: var(--font-body);
    font-size: var(--text-body-md);
    color: var(--color-body);
    margin-bottom: var(--spacing-xl);
    position: relative;
    z-index: 1;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.cta-band-inner .btn-primary {
    position: relative;
    z-index: 1;
    font-size: 1rem;
    padding: 14px 28px;
    height: 48px;
    border-radius: var(--rounded-md);
}

/* ========================================
           FOOTER — 深海玻璃页脚
           ======================================== */
.site-footer {
    background: var(--color-surface-dark);
    backdrop-filter: blur(var(--glass-blur-strong));
    -webkit-backdrop-filter: blur(var(--glass-blur-strong));
    border-top: var(--glass-border-dark);
    padding: 64px 0;
    color: var(--color-on-dark-soft);
    font-family: var(--font-body);
    font-size: var(--text-body-sm);
    position: relative;
    z-index: 1;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-xl);
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.footer-col h4 {
    font-family: var(--font-display);
    font-size: var(--text-title-sm);
    font-weight: 500;
    color: var(--color-on-dark);
    margin-bottom: var(--spacing-md);
    letter-spacing: -0.005em;
}

.footer-col ul {
    list-style: none;
}

.footer-col ul li {
    margin-bottom: var(--spacing-xs);
}

.footer-col ul li a {
    color: var(--color-on-dark-soft);
    text-decoration: none;
    transition: color var(--transition-fast);
    font-size: var(--text-body-sm);
}

.footer-col ul li a:hover {
    color: var(--color-on-dark);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-xl);
    margin-top: var(--spacing-xl);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    color: var(--color-on-dark-soft);
    font-size: var(--text-caption);
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
    padding-left: var(--spacing-lg);
    padding-right: var(--spacing-lg);
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.footer-brand .water-drop-mark {
    width: 18px;
    height: 20px;
}

.footer-brand span {
    font-family: var(--font-display);
    font-weight: 500;
    color: var(--color-on-dark);
    font-size: var(--text-title-sm);
}

/* ========================================
           BADGE / TAG
           ======================================== */
.badge-pill {
    display: inline-block;
    font-family: var(--font-body);
    font-size: var(--text-caption);
    font-weight: 500;
    color: var(--color-ink);
    background: rgba(255, 255, 255, 0.55);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    padding: 4px 12px;
    border-radius: var(--rounded-pill);
    border: var(--glass-border-soft);
}

.badge-accent {
    display: inline-block;
    font-family: var(--font-body);
    font-size: var(--text-caption-upper);
    font-weight: 500;
    letter-spacing: 0.06em;
    color: var(--color-on-primary);
    background: var(--color-primary);
    padding: 4px 12px;
    border-radius: var(--rounded-pill);
    box-shadow: 0 2px 8px var(--color-primary-glow);
}

/* ========================================
           RESPONSIVE DESIGN
           ======================================== */
@media (max-width: 1024px) {
    :root {
        --text-display-xl: 3rem;
        --text-display-lg: 2.25rem;
        --text-display-md: 1.75rem;
        --text-display-sm: 1.4rem;
        --spacing-section: 64px;
    }

    .hero-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }

    .hero-glass-card {
        aspect-ratio: auto;
        min-height: 240px;
    }

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

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

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

    .cta-band-inner {
        padding: 48px var(--spacing-lg);
    }
}

@media (max-width: 768px) {
    :root {
        --text-display-xl: 2.25rem;
        --text-display-lg: 1.75rem;
        --text-display-md: 1.5rem;
        --text-display-sm: 1.25rem;
        --text-title-lg: 1.15rem;
        --text-title-md: 1rem;
        --spacing-section: 48px;
        --spacing-xxl: 32px;
        --glass-blur: 12px;
        --glass-blur-strong: 18px;
    }

    .nav-links {
        display: none;
        position: fixed;
        top: 64px;
        left: 0;
        right: 0;
        background: rgba(234, 244, 247, 0.9);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        flex-direction: column;
        padding: var(--spacing-lg);
        gap: var(--spacing-xs);
        border-bottom: var(--glass-border);
        box-shadow: 0 8px 30px rgba(30, 50, 55, 0.1);
        z-index: 99;
    }

    .nav-links.open {
        display: flex;
    }

    .nav-links a {
        padding: 12px 16px;
        width: 100%;
        border-radius: var(--rounded-md);
    }

    .hamburger {
        display: flex;
    }

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

    .dark-cards-grid {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }

    .hero-content h1 {
        letter-spacing: -0.01em;
    }

    .cta-band-inner {
        padding: 40px var(--spacing-lg);
    }

    .hero-buttons {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .hero-buttons .btn-primary,
    .hero-buttons .btn-secondary {
        width: 100%;
        justify-content: center;
    }

    .container {
        padding: 0 var(--spacing-md);
    }

    .section-header {
        margin-bottom: var(--spacing-xl);
    }
}

@media (min-width: 1441px) {
    .container {
        max-width: 1200px;
    }
}

/* ========================================
           ACCESSIBILITY & FALLBACKS
           ======================================== */
@supports not (backdrop-filter: blur(1px)) {
    .top-nav {
        background: rgba(234, 244, 247, 0.92);
    }

    .feature-card {
        background: rgba(255, 255, 255, 0.7);
    }

    .dark-glass-card {
        background: rgba(18, 36, 42, 0.9);
    }

    .cta-band-inner {
        background: rgba(91, 164, 176, 0.35);
    }

    .hero-glass-card {
        background: rgba(255, 255, 255, 0.7);
    }
}

/* 焦点可见 */
a:focus-visible,
button:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
    border-radius: var(--rounded-sm);
}

/* 减少动画偏好 */
@media (prefers-reduced-motion: reduce) {
    .bubble {
        animation: none;
        opacity: 0;
    }

    .hero-fish-icon {
        animation: none;
    }

    .water-drop-mark {
        animation: none;
    }

    * {
        transition-duration: 0.01ms !important;
    }
}