:root {
    /* 轻奢金配色 */
    --bg-primary: #060b14;
    --bg-deep: #060b14;
    --text-primary: #e8ecf1;
    --text-secondary: #a0aab4;
    --text-tertiary: #6b7a8f;
    --accent: #c9a96e;
    --accent-rgb: 201, 169, 110;
    --accent-gold: #c9a96e;
    --accent-gold-light: #d4b87a;
    --accent-gold-dark: #b89555;
    --accent-gold-glow: rgba(201, 169, 110, 0.4);
    --card-bg: rgba(255, 255, 255, 0.03);
    --bg-card: rgba(255, 255, 255, 0.03);
    --bg-card-hover: rgba(255, 255, 255, 0.06);
    --card-border: rgba(255, 255, 255, 0.08);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-border-hover: rgba(255, 255, 255, 0.18);
    --glass: blur(20px);
    
    /* 辅助色 - 金色系协调 */
    --accent-blue: #4a7eb8;
    --accent-purple: #8b7cc0;
    --accent-teal: #00b894;
    --accent-rose: #d65568;
    --accent-orange: #d99555;
    --accent-green: #55c75a;
    
    /* 区块配色方案 - 轻奢金渐变 */
    --section-hero: linear-gradient(135deg, #060b14 0%, #0a1020 50%, #060b14 100%);
    --section-features: linear-gradient(135deg, #060b14 0%, #0d1525 50%, #060b14 100%);
    --section-chapters: linear-gradient(135deg, #060b14 0%, #0a1020 50%, #060b14 100%);
    --section-cta: linear-gradient(135deg, #0a1020 0%, #060b14 50%, #0d1525 100%);
    
    /* 圆角 */
    --radius-sm: 12px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-xl: 32px;
    
    /* 阴影 - 轻奢金风格 */
    --shadow-card: 0 4px 32px rgba(0, 0, 0, 0.4), 0 1px 0 rgba(255, 255, 255, 0.06) inset;
    --shadow-card-hover: 0 12px 40px rgba(0, 0, 0, 0.5), 0 0 40px rgba(201, 169, 110, 0.12);
    --shadow-glow-gold: 0 0 50px rgba(201, 169, 110, 0.25);
    
    /* 过渡 */
    --transition-smooth: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    
    /* 字体 */
    --font-heading: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
    --font-body: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
    
    /* 导航高度 */
    --nav-height: 72px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--nav-height);
}

body {
    font-family: var(--font-body);
    background: var(--bg-deep);
    color: var(--text-primary);
    line-height: 1.7;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* 背景网格 */
.bg-grid {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 0;
    opacity: 0.15;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
    background-size: 60px 60px;
}

/* 粒子效果 */
.particles {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 0;
    opacity: 0.4;
}
.particle {
    position: absolute;
    width: 3px;
    height: 3px;
    border-radius: 50%;
    background: rgba(201, 169, 110, 0.6);
    animation: floatUp 15s infinite ease-in;
}
.particle:nth-child(1) { left: 10%; animation-delay: 0s; animation-duration: 18s; }
.particle:nth-child(2) { left: 25%; animation-delay: 4s; animation-duration: 14s; }
.particle:nth-child(3) { left: 40%; animation-delay: 2s; animation-duration: 16s; }
.particle:nth-child(4) { left: 55%; animation-delay: 6s; animation-duration: 12s; }
.particle:nth-child(5) { left: 70%; animation-delay: 1s; animation-duration: 17s; }
.particle:nth-child(6) { left: 85%; animation-delay: 5s; animation-duration: 13s; }

@keyframes floatUp {
    0% { bottom: -20px; opacity: 0; transform: translateY(0) scale(0.5); }
    15% { opacity: 0.8; }
    50% { opacity: 0.4; transform: translateY(-50vh) scale(1.2); }
    85% { opacity: 0.1; }
    100% { bottom: 105vh; opacity: 0; transform: translateY(-105vh) scale(0.3); }
}

/* ============ 导航栏 ============ */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    height: var(--nav-height);
    background: rgba(10, 14, 26, 0.8);
    backdrop-filter: blur(30px) saturate(150%);
    -webkit-backdrop-filter: blur(30px) saturate(150%);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    transition: all var(--transition-smooth);
    display: flex;
    align-items: center;
    padding: 0 40px;
}
.nav.scrolled {
    background: rgba(8, 10, 20, 0.9);
    border-bottom: 1px solid rgba(201, 169, 110, 0.15);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.5);
}
.nav-inner {
    max-width: 1400px;
    width: 100%;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 30px;
}
.nav-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-primary);
    text-decoration: none;
    white-space: nowrap;
    letter-spacing: -0.02em;
}
.nav-logo .logo-icon {
    width: 40px;
    height: 40px;
    border-radius: 12px;
    background: linear-gradient(135deg, rgba(201, 169, 110, 0.4), rgba(201, 169, 110, 0.2));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    border: 1px solid rgba(201, 169, 110, 0.3);
    box-shadow: 0 4px 15px rgba(201, 169, 110, 0.3);
}
.nav-links {
    display: flex;
    align-items: center;
    gap: 8px;
    list-style: none;
    flex-wrap: wrap;
    justify-content: flex-end;
}
.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.92rem;
    padding: 10px 18px;
    border-radius: 24px;
    transition: all var(--transition-smooth);
    white-space: nowrap;
    letter-spacing: 0.01em;
    position: relative;
    font-weight: 500;
}
.nav-links a:hover {
    color: #fff;
    background: rgba(255, 255, 255, 0.08);
    transform: translateY(-1px);
}
.nav-links a.active {
    color: var(--accent-gold-light);
    background: rgba(201, 169, 110, 0.18);
    box-shadow: 0 0 20px rgba(201, 169, 110, 0.2);
}
.nav-links a.nav-cta {
    background: linear-gradient(135deg, rgba(201, 169, 110, 0.3), rgba(201, 169, 110, 0.15));
    border: 1px solid rgba(201, 169, 110, 0.4);
    color: var(--accent-gold-light);
    font-weight: 600;
    padding: 10px 22px;
}
.nav-links a.nav-cta:hover {
    background: linear-gradient(135deg, rgba(201, 169, 110, 0.45), rgba(201, 169, 110, 0.25));
    box-shadow: var(--shadow-glow-gold);
    color: #fff;
    transform: translateY(-2px);
}

/* 下拉菜单 */
.nav-links li.has-submenu {
    position: relative;
}
.nav-links li.has-submenu > a::after {
    content: '▼';
    font-size: 0.55rem;
    margin-left: 4px;
    opacity: 0.5;
    transition: transform var(--transition-smooth);
}
.nav-links li.has-submenu:hover > a::after {
    transform: rotate(180deg);
}
.nav-links .submenu {
    position: absolute;
    top: calc(100% + 10px);
    left: 0;
    background: rgba(10, 14, 26, 0.98);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-md);
    list-style: none;
    padding: 10px 0;
    min-width: 220px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-smooth);
    box-shadow: 0 12px 48px rgba(0, 0, 0, 0.6);
    z-index: 1000;
}
.nav-links li.has-submenu:hover .submenu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.nav-links .submenu li {
    padding: 0;
}
.nav-links .submenu a {
    display: block;
    padding: 12px 20px;
    border-radius: 10px;
    white-space: nowrap;
    font-size: 0.85rem;
}
.nav-links .submenu a:hover {
    background: rgba(201, 169, 110, 0.12);
    color: var(--accent-gold-light);
}
.nav-links .submenu-divider {
    height: 1px;
    background: rgba(255, 255, 255, 0.06);
    margin: 8px 0;
}

/* 移动端菜单按钮 */
.nav-hamburger {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
    flex-direction: column;
    gap: 6px;
    z-index: 1001;
}
.nav-hamburger span {
    display: block;
    width: 26px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-smooth);
}

@media (max-width: 1024px) {
    .nav-links {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        right: 0;
        bottom: 0;
        background: rgba(8, 12, 22, 0.98);
        backdrop-filter: blur(30px);
        -webkit-backdrop-filter: blur(30px);
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 20px;
        transform: translateY(-110%);
        transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        z-index: 999;
        padding: 40px 20px;
    }
    .nav-links.active {
        transform: translateY(0);
    }
    .nav-links a {
        font-size: 1.2rem;
        padding: 14px 30px;
    }
    .nav-hamburger {
        display: flex;
    }
}

/* ============ 布局 ============ */
.main-content {
    position: relative;
    z-index: 1;
    padding-top: var(--nav-height);
}

/* PPT风格区块 - 黑金配色 */
.ppt-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 60px 40px;
    position: relative;
    overflow: hidden;
}
.ppt-section::before {
    content: '';
    position: absolute;
    inset: 0;
    opacity: 0.5;
}
.section-gradient-1 {
    background: linear-gradient(135deg, #060b14 0%, #0a1020 40%, #060b14 60%, #0a1020 100%);
}
.section-gradient-2 {
    background: linear-gradient(135deg, #060b14 0%, #0d1525 40%, #060b14 60%, #0d1525 100%);
}
.section-gradient-3 {
    background: linear-gradient(135deg, #060b14 0%, #0a1020 40%, #060b14 60%, #0a1020 100%);
}
.section-gradient-4 {
    background: linear-gradient(135deg, #0a1020 0%, #060b14 40%, #0d1525 60%, #0a1020 100%);
}

.section-container {
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
    position: relative;
    z-index: 2;
}

/* 章节编号装饰 */
.section-number {
    font-family: var(--font-heading);
    font-size: 12rem;
    font-weight: 900;
    color: rgba(201, 169, 110, 0.04);
    position: absolute;
    top: 20px;
    right: 40px;
    line-height: 1;
    pointer-events: none;
}

/* ============ Hero区域 - 轻奢金 ============ */
.hero-section {
    min-height: calc(100vh - var(--nav-height));
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 60px 40px;
    background: linear-gradient(135deg, #060b14 0%, #0a1020 40%, #060b14 60%, #0a1020 100%);
    position: relative;
}
.hero-section::before {
    content: '';
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(ellipse at 30% 20%, rgba(201, 169, 110, 0.06) 0%, transparent 50%),
        radial-gradient(ellipse at 70% 80%, rgba(201, 169, 110, 0.04) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(201, 169, 110, 0.03) 0%, transparent 60%);
}
.hero-content {
    position: relative;
    z-index: 2;
    max-width: 900px;
}
.hero-badge {
    display: inline-block;
    padding: 8px 24px;
    border-radius: 28px;
    font-size: 0.85rem;
    letter-spacing: 0.08em;
    color: var(--accent-gold-light);
    background: rgba(201, 169, 110, 0.1);
    border: 1px solid rgba(201, 169, 110, 0.3);
    margin-bottom: 24px;
    backdrop-filter: blur(10px);
    animation: fadeInUp 0.8s ease-out;
}
.hero-icon {
    font-size: 5rem;
    margin-bottom: 24px;
    animation: bounce 2s infinite;
}
@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}
.hero-title {
    font-family: var(--font-heading);
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 800;
    letter-spacing: -0.04em;
    line-height: 1.15;
    margin-bottom: 16px;
    background: linear-gradient(135deg, #ffffff 0%, #c9a96e 40%, #c9a96e 70%, #ffffff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    filter: drop-shadow(0 4px 12px rgba(201, 169, 110, 0.3));
    animation: fadeInUp 0.8s ease-out 0.2s both;
}
.hero-subtitle {
    font-size: clamp(1.1rem, 3vw, 1.4rem);
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto 36px;
    line-height: 1.65;
    letter-spacing: 0.02em;
    animation: fadeInUp 0.8s ease-out 0.4s both;
}
.hero-description {
    font-size: 1.15rem;
    color: var(--text-secondary);
    margin: 20px auto 32px;
    max-width: 650px;
    line-height: 1.75;
    animation: fadeInUp 0.8s ease-out 0.5s both;
}
.hero-buttons {
    display: flex;
    gap: 18px;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease-out 0.6s both;
}

/* ============ 按钮样式 ============ */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 16px 32px;
    border-radius: 32px;
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: 0.03em;
    cursor: pointer;
    text-decoration: none;
    transition: all var(--transition-smooth);
    border: 1px solid transparent;
    white-space: nowrap;
    font-family: var(--font-body);
    position: relative;
    overflow: hidden;
}
.btn::before {
    content: '';
    position: absolute;
    inset: 0;
    opacity: 0;
    transition: opacity var(--transition-smooth);
}
.btn-primary {
    background: linear-gradient(135deg, #c9a96e 0%, #b89555 50%, #c9a96e 100%);
    color: #1a1a1a;
    border: none;
    box-shadow: 0 6px 24px rgba(201, 169, 110, 0.4);
    background-size: 200% 200%;
}
.btn-primary:hover {
    box-shadow: 0 10px 40px rgba(201, 169, 110, 0.6);
    transform: translateY(-3px);
    animation: gradientShift 3s ease infinite;
}
@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}
.btn-secondary {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: var(--text-primary);
    backdrop-filter: blur(12px);
}
.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.12);
    border-color: rgba(255, 255, 255, 0.35);
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
}
.btn-large {
    padding: 20px 44px;
    font-size: 1.1rem;
}
.btn-glass {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.18);
    color: var(--text-primary);
    backdrop-filter: blur(16px);
}
.btn-glass:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.35);
    box-shadow: 0 6px 28px rgba(255, 255, 255, 0.08);
}
.btn-outline-gold {
    border: 1.5px solid rgba(201, 169, 110, 0.5);
    color: var(--accent-gold-light);
    background: transparent;
}
.btn-outline-gold:hover {
    background: rgba(201, 169, 110, 0.12);
    border-color: rgba(201, 169, 110, 0.8);
    box-shadow: var(--shadow-glow-gold);
}

/* ============ 章节标题 ============ */
.section-header {
    text-align: center;
    margin-bottom: 56px;
}
.section-label {
    display: inline-block;
    font-size: 0.82rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--accent-gold-light);
    margin-bottom: 12px;
    font-weight: 700;
}
.section-title {
    font-family: var(--font-heading);
    font-size: clamp(1.8rem, 4vw, 2.8rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 14px;
    color: #fff;
}
.section-desc {
    font-size: 1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.65;
}
.section-divider {
    width: 60px;
    height: 4px;
    border-radius: 2px;
    background: linear-gradient(90deg, var(--accent-gold), var(--accent-purple));
    margin: 20px auto 0;
    opacity: 0.8;
}

/* ============ PPT风格卡片 ============ */
.ppt-card {
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: all var(--transition-smooth);
    position: relative;
    overflow: hidden;
    height: 100%;
    display: flex;
    flex-direction: column;
}
.ppt-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, transparent, var(--accent-gold), transparent);
    opacity: 0;
    transition: opacity var(--transition-smooth);
}
.ppt-card:hover {
    background: rgba(255, 255, 255, 0.06);
    border-color: rgba(255, 255, 255, 0.18);
    transform: translateY(-6px);
    box-shadow: var(--shadow-card-hover);
}
.ppt-card:hover::before {
    opacity: 1;
}
.ppt-card .card-icon {
    width: 56px;
    height: 56px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    margin-bottom: 20px;
    flex-shrink: 0;
    background: rgba(201, 169, 110, 0.12);
    color: var(--accent-gold-light);
}
.ppt-card h3 {
    font-family: var(--font-heading);
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: #fff;
    letter-spacing: -0.01em;
}
.ppt-card p {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.6;
    flex-grow: 1;
}
.ppt-card .card-tag {
    display: inline-block;
    padding: 6px 14px;
    border-radius: 16px;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    font-weight: 600;
    margin-top: 12px;
    background: rgba(201, 169, 110, 0.12);
    color: var(--accent-gold-light);
}

/* 彩色图标卡片 - 黑金配色 */
.card-icon.blue {
    background: rgba(201, 169, 110, 0.15);
    color: var(--accent-gold);
}
.card-icon.purple {
    background: rgba(201, 169, 110, 0.15);
    color: var(--accent-gold-dark);
}
.card-icon.teal {
    background: rgba(201, 169, 110, 0.12);
    color: var(--accent-gold-light);
}
.card-icon.rose {
    background: rgba(201, 169, 110, 0.1);
    color: var(--accent-gold);
}
.card-icon.orange {
    background: rgba(201, 169, 110, 0.15);
    color: var(--accent-gold-light);
}
.card-icon.green {
    background: rgba(201, 169, 110, 0.12);
    color: var(--accent-gold-dark);
}

/* ============ 特色区域 - 轻奢金 ============ */
.features-section {
    padding: 80px 40px;
    background: linear-gradient(135deg, #060b14 0%, #0a1020 50%, #060b14 100%);
}
.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
@media (max-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}
@media (max-width: 640px) {
    .features-grid {
        grid-template-columns: 1fr;
    }
}
.feature-card {
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-lg);
    padding: 32px;
    text-align: center;
    transition: all var(--transition-smooth);
}
.feature-card:hover {
    background: rgba(255, 255, 255, 0.06);
    border-color: rgba(255, 255, 255, 0.18);
    transform: translateY(-8px);
    box-shadow: var(--shadow-card-hover);
}
.feature-card .feature-icon {
    font-size: 3rem;
    margin-bottom: 20px;
    display: block;
}
.feature-card h3 {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: #fff;
}
.feature-card p {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ============ 章节预览 - 轻奢金 ============ */
.chapters-preview {
    padding: 80px 40px;
    background: linear-gradient(135deg, #060b14 0%, #0a1020 50%, #060b14 100%);
    position: relative;
}
.chapters-preview::before {
    content: '00';
    font-family: var(--font-heading);
    font-size: 18rem;
    font-weight: 900;
    color: rgba(201, 169, 110, 0.02);
    position: absolute;
    top: 0;
    right: 0;
    line-height: 1;
    pointer-events: none;
}
.chapters-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
@media (max-width: 1024px) {
    .chapters-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}
@media (max-width: 640px) {
    .chapters-grid {
        grid-template-columns: 1fr;
    }
}
.chapter-card {
    display: flex;
    align-items: center;
    gap: 24px;
    padding: 28px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-lg);
    text-decoration: none;
    transition: all var(--transition-smooth);
    backdrop-filter: blur(16px);
}
.chapter-card:hover {
    background: rgba(255, 255, 255, 0.06);
    border-color: rgba(201, 169, 110, 0.3);
    transform: translateY(-4px);
    box-shadow: var(--shadow-card-hover);
}
.chapter-number {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--accent-gold);
    opacity: 0.9;
    min-width: 60px;
    text-shadow: 0 0 30px rgba(201, 169, 110, 0.3);
}
.chapter-info h3 {
    font-family: var(--font-heading);
    font-size: 1.15rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 4px;
}
.chapter-info p {
    font-size: 0.88rem;
    color: var(--text-secondary);
}

/* ============ CTA区域 - 深蓝配色 ============ */
.cta-section {
    padding: 100px 40px;
    background: linear-gradient(135deg, #060b14 0%, #0a1020 50%, #060b14 100%);
    text-align: center;
    position: relative;
    overflow: hidden;
}
.cta-section::before {
    content: '';
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(ellipse at 30% 30%, rgba(201, 169, 110, 0.15) 0%, transparent 40%),
        radial-gradient(ellipse at 70% 70%, rgba(201, 169, 110, 0.1) 0%, transparent 40%);
}
.cta-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    margin: 0 auto;
}
.cta-section h2 {
    font-family: var(--font-heading);
    font-size: clamp(1.8rem, 4vw, 2.6rem);
    font-weight: 700;
    margin-bottom: 18px;
    letter-spacing: -0.03em;
}
.cta-section p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 40px;
    line-height: 1.65;
}

/* ============ 时间轴 ============ */
.timeline {
    position: relative;
    padding-left: 50px;
    margin: 30px 0;
}
.timeline::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(180deg, var(--accent-gold) 0%, var(--accent-purple) 50%, transparent);
    border-radius: 2px;
}
.timeline-item {
    position: relative;
    margin-bottom: 32px;
    padding-left: 24px;
}
.timeline-item::before {
    content: '';
    position: absolute;
    left: -34px;
    top: 6px;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--accent-gold);
    border: 3px solid rgba(201, 169, 110, 0.4);
    box-shadow: 0 0 20px rgba(201, 169, 110, 0.4);
}
.timeline-item .time-label {
    font-size: 0.82rem;
    color: var(--accent-gold-light);
    letter-spacing: 0.08em;
    font-weight: 700;
    margin-bottom: 4px;
}
.timeline-item .time-content {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ============ 横向时间轴 ============ */
.timeline-horizontal {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    gap: 8px;
    padding: 20px 0;
    overflow-x: auto;
    scrollbar-width: thin;
    scrollbar-color: rgba(255,255,255,0.2) transparent;
}
.timeline-horizontal::-webkit-scrollbar {
    height: 4px;
}
.timeline-horizontal::-webkit-scrollbar-track {
    background: transparent;
}
.timeline-horizontal::-webkit-scrollbar-thumb {
    background: rgba(255,255,255,0.2);
    border-radius: 2px;
}
.timeline-step {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    min-width: 120px;
    max-width: 160px;
    flex: 1;
}
.step-icon {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 12px;
    position: relative;
}
.step-icon.blue { background: linear-gradient(135deg, var(--accent-blue) 0%, #1e88e5 100%); box-shadow: 0 4px 20px rgba(74, 158, 255, 0.4); }
.step-icon.purple { background: linear-gradient(135deg, var(--accent-purple) 0%, #7b1fa2 100%); box-shadow: 0 4px 20px rgba(157, 78, 221, 0.4); }
.step-icon.teal { background: linear-gradient(135deg, var(--accent-teal) 0%, #00897b 100%); box-shadow: 0 4px 20px rgba(0, 212, 170, 0.4); }
.step-icon.orange { background: linear-gradient(135deg, var(--accent-orange) 0%, #e65100 100%); box-shadow: 0 4px 20px rgba(251, 146, 60, 0.4); }
.step-icon.rose { background: linear-gradient(135deg, var(--accent-rose) 0%, #c2185b 100%); box-shadow: 0 4px 20px rgba(251, 113, 133, 0.4); }
.step-icon.green { background: linear-gradient(135deg, var(--accent-green) 0%, #2e7d32 100%); box-shadow: 0 4px 20px rgba(52, 211, 153, 0.4); }
.step-title {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 6px;
}
.step-desc {
    font-size: 0.82rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
}
.step-result {
    font-size: 0.78rem;
    color: var(--text-tertiary);
    padding: 4px 12px;
    background: rgba(255,255,255,0.05);
    border-radius: 20px;
    border: 1px solid rgba(255,255,255,0.1);
}
.timeline-arrow {
    font-size: 1.5rem;
    color: var(--text-tertiary);
    margin-top: 18px;
    flex-shrink: 0;
}

/* ============ 手风琴 ============ */
.accordion {
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.08);
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(16px);
}
.accordion-header {
    padding: 22px 28px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-weight: 600;
    font-size: 1rem;
    color: #fff;
    transition: all var(--transition-smooth);
    user-select: none;
    letter-spacing: 0.01em;
    border-bottom: 1px solid transparent;
}
.accordion-header:hover {
    background: rgba(255, 255, 255, 0.04);
}
.accordion-item.open .accordion-header {
    border-bottom-color: rgba(255, 255, 255, 0.08);
    background: rgba(201, 169, 110, 0.05);
}
.accordion-arrow {
    transition: transform var(--transition-smooth);
    font-size: 0.8rem;
    color: var(--text-tertiary);
    flex-shrink: 0;
}
.accordion-item.open .accordion-arrow {
    transform: rotate(180deg);
    color: var(--accent-gold-light);
}
.accordion-body {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s cubic-bezier(0.4, 0, 0.2, 1), padding 0.4s ease;
    padding: 0 28px;
}
.accordion-item.open .accordion-body {
    max-height: 1000px;
    padding: 24px 28px;
}

/* ============ 表格样式 ============ */
.glass-table-wrap {
    overflow-x: auto;
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.08);
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(16px);
    margin: 24px 0;
}
.glass-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.88rem;
    min-width: 600px;
}
.glass-table th, .glass-table td {
    padding: 16px 20px;
    text-align: left;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}
.glass-table th {
    font-weight: 700;
    color: var(--accent-gold-light);
    letter-spacing: 0.05em;
    font-size: 0.82rem;
    text-transform: uppercase;
    background: rgba(201, 169, 110, 0.05);
}
.glass-table tr:hover td {
    background: rgba(255, 255, 255, 0.04);
}
.glass-table td {
    color: var(--text-secondary);
}

/* ============ 高亮框 ============ */
.highlight-box {
    border-radius: var(--radius-lg);
    padding: 28px;
    border: 1px solid rgba(201, 169, 110, 0.3);
    background: rgba(201, 169, 110, 0.05);
    backdrop-filter: blur(12px);
    margin: 24px 0;
    position: relative;
    overflow: hidden;
}
.highlight-box::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-gold), var(--accent-purple));
}
.highlight-box h4 {
    color: var(--accent-gold-light);
    margin-bottom: 12px;
    font-size: 1rem;
    letter-spacing: 0.02em;
}
.highlight-box p {
    color: var(--text-secondary);
    font-size: 0.92rem;
    line-height: 1.65;
}

/* ============ 平台按钮 ============ */
.platform-btn-row {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 20px;
}
.platform-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: 28px;
    font-size: 0.88rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    text-decoration: none;
    transition: all var(--transition-smooth);
    border: 1px solid rgba(255, 255, 255, 0.15);
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
    backdrop-filter: blur(10px);
    white-space: nowrap;
}
.platform-btn:hover {
    background: rgba(255, 255, 255, 0.12);
    border-color: rgba(255, 255, 255, 0.35);
    box-shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
    transform: translateY(-2px);
    color: #fff;
}
.platform-btn.bilibili {
    border-color: rgba(251, 114, 153, 0.4);
    background: rgba(251, 114, 153, 0.1);
}
.platform-btn.bilibili:hover {
    border-color: rgba(251, 114, 153, 0.7);
    box-shadow: 0 0 32px rgba(251, 114, 153, 0.25);
}

/* ============ 页脚 ============ */
.site-footer {
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    text-align: center;
    padding: 50px 40px;
    color: var(--text-tertiary);
    font-size: 0.85rem;
    letter-spacing: 0.03em;
    background: rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(20px);
}
.site-footer .footer-brand {
    font-weight: 700;
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 16px;
}
.site-footer .footer-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    margin-bottom: 20px;
}
.site-footer .footer-links a {
    color: var(--text-tertiary);
    text-decoration: none;
    font-size: 0.85rem;
    padding: 6px 14px;
    border-radius: 14px;
    transition: all var(--transition-smooth);
}
.site-footer .footer-links a:hover {
    color: var(--accent-gold-light);
    background: rgba(201, 169, 110, 0.1);
}

/* ============ 实用类 ============ */
.text-gold { color: var(--accent-gold-light); }
.text-blue { color: var(--accent-blue); }
.text-purple { color: var(--accent-purple); }
.text-teal { color: var(--accent-teal); }
.text-sm { font-size: 0.85rem; }
.text-xs { font-size: 0.75rem; }
.mt-2 { margin-top: 10px; }
.mt-4 { margin-top: 20px; }
.mt-6 { margin-top: 30px; }
.mb-2 { margin-bottom: 10px; }
.mb-4 { margin-bottom: 20px; }
.mb-6 { margin-bottom: 30px; }
.gap-2 { gap: 10px; }
.gap-3 { gap: 15px; }
.flex-wrap { display: flex; flex-wrap: wrap; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }

/* ============ 滚动条 ============ */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.15);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.25);
}

/* ============ 动画 ============ */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}
.animate-in {
    animation: fadeInUp 0.8s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}
.delay-1 { animation-delay: 0.15s; opacity: 0; }
.delay-2 { animation-delay: 0.3s; opacity: 0; }
.delay-3 { animation-delay: 0.45s; opacity: 0; }
.delay-4 { animation-delay: 0.6s; opacity: 0; }

/* 卡片网格布局 */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
}
.card-grid-2 { grid-template-columns: repeat(2, 1fr); }
.card-grid-3 { grid-template-columns: repeat(3, 1fr); }
.card-grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 1024px) {
    .card-grid-4 { grid-template-columns: repeat(2, 1fr); }
    .card-grid-3 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
    .card-grid, .card-grid-4, .card-grid-3, .card-grid-2 {
        grid-template-columns: 1fr;
    }
}

/* ============ 章节页面样式 ============ */
.chapter-container {
    max-width: 950px;
    margin: 0 auto;
    padding: 40px;
}
.chapter-content {
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-xl);
    padding: 50px;
    margin-bottom: 30px;
}
.chapter-content h1 {
    font-family: var(--font-heading);
    font-size: 2rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 12px;
    letter-spacing: -0.02em;
    padding-bottom: 20px;
    border-bottom: 1px solid rgba(201, 169, 110, 0.2);
}
.chapter-content h2 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 600;
    color: #fff;
    margin-top: 40px;
    margin-bottom: 16px;
    padding-bottom: 10px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    display: flex;
    align-items: center;
    gap: 12px;
}
.chapter-content h2::before {
    content: '';
    width: 4px;
    height: 24px;
    background: linear-gradient(180deg, var(--accent-gold), var(--accent-purple));
    border-radius: 2px;
}
.chapter-content h3 {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--accent-gold-light);
    margin-top: 30px;
    margin-bottom: 12px;
}
.chapter-content p {
    font-size: 0.98rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 16px;
}
.chapter-content ul, .chapter-content ol {
    padding-left: 28px;
    margin-bottom: 20px;
}
.chapter-content li {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 10px;
}
.chapter-content li::marker {
    color: var(--accent-gold);
}
.chapter-content code {
    background: rgba(201, 169, 110, 0.1);
    color: var(--accent-gold-light);
    padding: 4px 10px;
    border-radius: 6px;
    font-size: 0.88rem;
    font-family: 'Fira Code', monospace;
}
.chapter-content pre {
    background: rgba(0, 0, 0, 0.4);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-md);
    padding: 20px;
    margin: 20px 0;
    overflow-x: auto;
}
.chapter-content pre code {
    background: transparent;
    padding: 0;
    font-size: 0.85rem;
    line-height: 1.6;
}

@media (max-width: 768px) {
    .chapter-container {
        padding: 20px;
    }
    .chapter-content {
        padding: 30px 24px;
    }
    .chapter-content h1 {
        font-size: 1.6rem;
    }
    .chapter-content h2 {
        font-size: 1.3rem;
    }
}

/* 视频卡片 */
.video-card {
    position: relative;
    border-radius: var(--radius-lg);
    overflow: hidden;
    cursor: pointer;
    aspect-ratio: 16/9;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    transition: all var(--transition-smooth);
}
.video-card:hover {
    border-color: var(--accent-gold);
    transform: translateY(-6px);
    box-shadow: var(--shadow-glow-gold);
}
.video-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-smooth);
}
.video-card:hover img {
    transform: scale(1.05);
}
.video-card .play-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition-smooth);
}
.video-card:hover .play-overlay {
    opacity: 1;
}
.video-card .play-btn {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    background: rgba(201, 169, 110, 0.95);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    transition: all var(--transition-smooth);
}
.video-card:hover .play-btn {
    transform: scale(1.15);
    box-shadow: 0 0 40px rgba(201, 169, 110, 0.6);
}

/* 响应式调整 */
@media (max-width: 768px) {
    .nav {
        padding: 0 20px;
    }
    .hero-section, .features-section, .chapters-preview, .cta-section {
        padding: 40px 20px;
    }
    .section-number {
        font-size: 6rem;
        right: 20px;
    }
}