/* 《盛世危机》- 移动优先设计 */

:root {
    /* 主色调 - 更亮的深蓝星空 */
    --space-dark: #162032;
    --space-mid: #253550;
    --space-light: #3d5070;

    /* 金星强调色 */
    --venus-gold: #f59e0b;
    --venus-orange: #f97316;
    --venus-glow: #fbbf24;

    /* 科技蓝 */
    --tech-cyan: #06b6d4;
    --tech-blue: #3b82f6;
    --tech-glow: #22d3ee;

    /* 文字颜色 */
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;

    /* 渐变 */
    --gradient-venus: linear-gradient(135deg, #f59e0b 0%, #f97316 100%);
    --gradient-tech: linear-gradient(135deg, #06b6d4 0%, #3b82f6 100%);
    --gradient-hero: linear-gradient(180deg, #162032 0%, #253550 50%, #3d5070 100%);

    /* 光晕 */
    --glow-tech: 0 0 40px rgba(6, 182, 212, 0.3);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background: var(--gradient-hero);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

/* 星空背景 - 移动端简化版 */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(ellipse at 20% 30%, rgba(6, 182, 212, 0.12) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 70%, rgba(245, 158, 11, 0.08) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

/* ===== 导航栏 - 移动端汉堡菜单 ===== */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(10, 22, 40, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(6, 182, 212, 0.2);
    z-index: 1000;
    padding: 12px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
}

.nav-logo {
    font-size: 22px;
    font-weight: 800;
    background: linear-gradient(135deg, var(--tech-cyan) 0%, var(--venus-gold) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: 1px;
}

/* 汉堡菜单按钮 */
.hamburger {
    display: flex;
    flex-direction: column;
    justify-content: space-around;
    width: 32px;
    height: 32px;
    cursor: pointer;
    z-index: 1002;
    padding: 5px;
}

.hamburger span {
    display: block;
    width: 100%;
    height: 3px;
    background: var(--tech-cyan);
    border-radius: 2px;
    transition: all 0.3s;
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

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

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* 移动端菜单侧边栏 */
.nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 70%;
    max-width: 280px;
    height: 100vh;
    background: rgba(10, 22, 40, 0.98);
    backdrop-filter: blur(20px);
    display: flex;
    flex-direction: column;
    padding: 80px 30px 30px;
    transition: right 0.3s ease;
    box-shadow: -5px 0 30px rgba(0, 0, 0, 0.5);
    z-index: 1001;
}

.nav-links.active {
    right: 0;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 18px;
    font-weight: 500;
    padding: 15px 20px;
    margin-bottom: 8px;
    border-radius: 12px;
    transition: all 0.3s;
    display: block;
}

.nav-links a:hover {
    color: var(--tech-glow);
    background: rgba(6, 182, 212, 0.15);
}

/* 遮罩层 */
.overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
}

.overlay.active {
    opacity: 1;
    visibility: visible;
}

/* ===== Hero区域 - 移动端优化 ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: var(--gradient-hero);
    position: relative;
    overflow: hidden;
    padding: 100px 20px 60px;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 100%;
}

.hero-title {
    font-size: 42px;
    font-weight: 900;
    margin-bottom: 20px;
    background: linear-gradient(135deg, var(--tech-glow) 0%, var(--venus-gold) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: 2px;
    line-height: 1.3;
    filter: drop-shadow(0 0 20px rgba(6, 182, 212, 0.5));
}

.hero-subtitle {
    font-size: 20px;
    margin-bottom: 25px;
    color: var(--text-primary);
    font-weight: 600;
    letter-spacing: 1px;
}

.hero-desc {
    font-size: 16px;
    max-width: 100%;
    margin: 0 auto 30px;
    color: var(--text-secondary);
    line-height: 1.8;
    padding: 0 10px;
}

/* 移动端统计数据 */
.hero-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
    margin: 30px 0;
    max-width: 320px;
    margin-left: auto;
    margin-right: auto;
}

.stat {
    text-align: center;
    padding: 15px 20px;
    background: rgba(6, 182, 212, 0.1);
    border: 1px solid rgba(6, 182, 212, 0.25);
    border-radius: 16px;
    backdrop-filter: blur(10px);
}

.stat-number {
    font-size: 28px;
    font-weight: 900;
    background: var(--gradient-venus);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: block;
}

.stat-label {
    font-size: 12px;
    color: var(--text-muted);
    margin-top: 5px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* CTA按钮 */
.hero-cta {
    display: inline-block;
    padding: 16px 40px;
    background: var(--gradient-tech);
    color: white;
    text-decoration: none;
    border-radius: 50px;
    font-size: 18px;
    font-weight: 700;
    transition: all 0.4s;
    box-shadow: var(--glow-tech);
    border: 2px solid rgba(6, 182, 212, 0.4);
    margin-top: 20px;
}

.hero-cta:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 40px rgba(6, 182, 212, 0.5);
}

/* ===== 章节区域 ===== */
.section {
    padding: 60px 20px;
    max-width: 100%;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.section-title {
    text-align: center;
    font-size: 32px;
    margin-bottom: 40px;
    background: linear-gradient(135deg, var(--tech-glow) 0%, var(--venus-gold) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 900;
    letter-spacing: 1px;
}

/* 移动端章节卡片 - 单列 */
.chapter-grid {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.chapter-card {
    background: rgba(26, 40, 69, 0.6);
    border: 1px solid rgba(6, 182, 212, 0.25);
    border-radius: 20px;
    padding: 25px;
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(10px);
}

.chapter-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-tech);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

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

.chapter-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(6, 182, 212, 0.25);
    border-color: rgba(6, 182, 212, 0.5);
}

.chapter-number {
    font-size: 12px;
    color: var(--tech-cyan);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 12px;
}

.chapter-title {
    font-size: 22px;
    color: var(--text-primary);
    margin-bottom: 15px;
    font-weight: 700;
}

.chapter-desc {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 20px;
}

.chapter-meta {
    display: flex;
    gap: 15px;
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 5px;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 25px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary {
    background: var(--gradient-tech);
    color: white;
    box-shadow: var(--glow-tech);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(6, 182, 212, 0.4);
}

.btn-secondary {
    background: rgba(6, 182, 212, 0.12);
    color: var(--tech-glow);
    border: 1px solid rgba(6, 182, 212, 0.25);
}

.btn-secondary:hover {
    background: rgba(6, 182, 212, 0.2);
}

/* ===== 页脚 ===== */
.footer {
    background: rgba(5, 10, 20, 0.95);
    padding: 50px 20px;
    text-align: center;
    border-top: 1px solid rgba(6, 182, 212, 0.15);
    margin-top: 80px;
    position: relative;
    z-index: 1;
}

.footer-quote {
    font-size: 20px;
    font-style: italic;
    background: var(--gradient-venus);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 20px;
    font-weight: 600;
    line-height: 1.5;
}

.footer-text {
    font-size: 13px;
    color: var(--text-muted);
    line-height: 1.8;
}

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

/* ===== 桌面端适配 ===== */
@media (min-width: 768px) {
    .nav {
        padding: 15px 50px;
    }

    .nav-logo {
        font-size: 28px;
    }

    /* 桌面端显示传统菜单 */
    .hamburger {
        display: none;
    }

    .nav-links {
        position: static;
        width: auto;
        height: auto;
        background: transparent;
        flex-direction: row;
        padding: 0;
        box-shadow: none;
        display: flex;
        gap: 30px;
    }

    .nav-links a {
        padding: 8px 16px;
        margin-bottom: 0;
        font-size: 16px;
    }

    .hero {
        padding: 120px 50px 80px;
    }

    .hero-title {
        font-size: 72px;
    }

    .hero-subtitle {
        font-size: 32px;
    }

    .hero-desc {
        font-size: 19px;
        max-width: 800px;
        padding: 0;
    }

    .hero-stats {
        display: flex;
        gap: 40px;
        max-width: none;
        margin: 50px 0;
    }

    .stat {
        padding: 20px 40px;
    }

    .stat-number {
        font-size: 38px;
    }

    .stat-label {
        font-size: 14px;
    }

    .hero-cta {
        padding: 18px 50px;
        font-size: 20px;
    }

    .section {
        padding: 100px 50px;
        max-width: 1400px;
    }

    .section-title {
        font-size: 48px;
        margin-bottom: 60px;
    }

    .chapter-grid {
        display: grid;
        grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
        gap: 30px;
    }

    .chapter-card {
        padding: 35px;
    }

    .chapter-title {
        font-size: 26px;
    }

    .footer {
        padding: 80px 50px;
        margin-top: 120px;
    }

    .footer-quote {
        font-size: 28px;
    }
}

/* 大屏幕优化 */
@media (min-width: 1200px) {
    .hero-title {
        font-size: 80px;
    }

    .chapter-grid {
        grid-template-columns: repeat(auto-fill, minmax(400px, 1fr));
    }
}