/* ===== 全局重置与CSS变量 ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #ff6b6b;
    --primary-dark: #e55a5a;
    --secondary: #ffd93d;
    --accent: #6c5ce7;
    --bg: #0f0f1a;
    --bg-card: rgba(255,255,255,0.05);
    --text: #f0f0f5;
    --text-muted: #a0a0b0;
    --glass: rgba(255,255,255,0.08);
    --glass-border: rgba(255,255,255,0.15);
    --shadow: 0 8px 32px rgba(0,0,0,0.4);
    --radius: 16px;
    --radius-sm: 8px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font: 'Segoe UI', system-ui, -apple-system, sans-serif;
    --max-width: 1200px;
    --nav-height: 70px;
    --banner-gradient: linear-gradient(135deg, #0f0f1a 0%, #1a1a2e 30%, #16213e 60%, #0f3460 100%);
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

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

a:hover {
    color: var(--primary);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

ul, ol {
    list-style: none;
}

button {
    cursor: pointer;
    border: none;
    background: none;
    font-family: inherit;
    font-size: inherit;
    color: inherit;
}

/* ===== 滚动条 ===== */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg);
}

::-webkit-scrollbar-thumb {
    background: var(--primary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-dark);
}

/* ===== 导航栏 ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(15, 15, 26, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--glass-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 2rem;
    z-index: 1000;
    transition: background var(--transition), box-shadow var(--transition);
}

.navbar.scrolled {
    background: rgba(15, 15, 26, 0.95);
    box-shadow: 0 4px 20px rgba(0,0,0,0.5);
}

.nav-brand a {
    font-size: 1.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: 1px;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text);
    position: relative;
    padding: 0.25rem 0;
    transition: color var(--transition);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: width var(--transition);
}

.nav-links a:hover::after {
    width: 100%;
}

.nav-actions {
    display: flex;
    gap: 0.75rem;
    align-items: center;
}

.nav-actions button {
    font-size: 1.3rem;
    padding: 0.5rem;
    border-radius: 50%;
    background: var(--glass);
    border: 1px solid var(--glass-border);
    transition: background var(--transition), transform var(--transition);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.nav-actions button:hover {
    background: rgba(255,255,255,0.15);
    transform: scale(1.1);
}

#menuToggle {
    display: none;
}

/* ===== 面包屑 ===== */
.breadcrumb {
    padding: 0.5rem 2rem;
    font-size: 0.85rem;
    color: var(--text-muted);
    max-width: var(--max-width);
    margin: 0 auto;
    width: 100%;
}

.breadcrumb a {
    color: var(--text-muted);
}

.breadcrumb a:hover {
    color: var(--secondary);
}

/* ===== Hero ===== */
.hero {
    min-height: 70vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 6rem 2rem 4rem;
    background: var(--banner-gradient);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 50%, rgba(255,107,107,0.15) 0%, transparent 50%),
                radial-gradient(circle at 70% 50%, rgba(108,92,231,0.1) 0%, transparent 50%);
    animation: heroGlow 8s ease-in-out infinite alternate;
}

@keyframes heroGlow {
    0% { transform: translate(0, 0); }
    100% { transform: translate(5%, 5%); }
}

.hero h1 {
    font-size: clamp(2.5rem, 8vw, 4.5rem);
    font-weight: 900;
    background: linear-gradient(135deg, var(--primary), var(--secondary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1rem;
    position: relative;
    z-index: 1;
    letter-spacing: 2px;
}

.hero p {
    font-size: clamp(1rem, 3vw, 1.4rem);
    color: var(--text-muted);
    margin-bottom: 2rem;
    position: relative;
    z-index: 1;
    max-width: 600px;
}

.btn-hero {
    display: inline-block;
    padding: 0.9rem 2.8rem;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: #fff;
    border-radius: 50px;
    font-weight: 700;
    font-size: 1.1rem;
    transition: transform var(--transition), box-shadow var(--transition);
    position: relative;
    z-index: 1;
    box-shadow: 0 4px 20px rgba(255,107,107,0.3);
}

.btn-hero:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 30px rgba(255,107,107,0.5);
    color: #fff;
}

/* ===== 通用Section ===== */
section {
    padding: 3rem 1rem;
    max-width: var(--max-width);
    margin: 0 auto;
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    margin-bottom: 2rem;
    gap: 1rem;
}

.section-header h2 {
    font-size: 1.8rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.sub-bread {
    padding: 0;
    font-size: 0.8rem;
}

/* ===== 卡片网格 ===== */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.card {
    background: var(--glass);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius);
    overflow: hidden;
    transition: transform var(--transition), box-shadow var(--transition);
    animation: fadeInUp 0.6s ease both;
    animation-delay: calc(var(--i, 0) * 0.1s);
}

.card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow);
    border-color: var(--primary);
}

.card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: transform 0.5s ease;
}

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

.card-body {
    padding: 1.2rem;
}

.card-body h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text);
}

.card-body p {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
    line-height: 1.5;
}

.card-link {
    display: inline-block;
    padding: 0.5rem 1.5rem;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: #fff;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.85rem;
    transition: transform var(--transition), box-shadow var(--transition);
}

.card-link:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(255,107,107,0.4);
    color: #fff;
}

/* ===== 相关链接 ===== */
.related-links {
    margin-top: 1.5rem;
    font-size: 0.9rem;
    color: var(--text-muted);
    text-align: center;
}

.related-links a {
    color: var(--secondary);
    margin: 0 0.3rem;
}

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

/* ===== 排行榜 ===== */
.ranking-list {
    counter-reset: rank;
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.ranking-list li {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.5rem;
    background: var(--glass);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    transition: transform var(--transition), background var(--transition);
    animation: fadeInUp 0.5s ease both;
    animation-delay: calc(var(--i, 0) * 0.08s);
}

.ranking-list li:hover {
    transform: translateX(8px);
    background: rgba(255,255,255,0.1);
}

.rank-num {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: 50%;
    font-weight: 800;
    font-size: 1rem;
    color: #fff;
    flex-shrink: 0;
}

.hot-badge {
    margin-left: auto;
    font-size: 0.85rem;
    color: var(--secondary);
    font-weight: 600;
}

/* ===== 分类标签 ===== */
.category-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
    justify-content: center;
}

.category-tags a {
    padding: 0.6rem 1.5rem;
    background: var(--glass);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid var(--glass-border);
    border-radius: 50px;
    font-weight: 500;
    font-size: 0.95rem;
    color: var(--text);
    transition: all var(--transition);
}

.category-tags a:hover {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: #fff;
    border-color: transparent;
    transform: translateY(-2px);
}

.tag-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
    justify-content: center;
    margin-top: 1.5rem;
}

.tag {
    padding: 0.4rem 1rem;
    background: rgba(255,255,255,0.05);
    border-radius: 50px;
    font-size: 0.8rem;
    color: var(--text-muted);
    border: 1px solid var(--glass-border);
    transition: all var(--transition);
}

.tag:hover {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

/* ===== FAQ ===== */
.faq-item {
    padding: 1.2rem 1.5rem;
    background: var(--glass);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    margin-bottom: 1rem;
    transition: background var(--transition);
}

.faq-item:hover {
    background: rgba(255,255,255,0.1);
}

.faq-item h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--secondary);
}

.faq-item p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* ===== 长文本正文 ===== */
.long-text {
    max-width: 900px;
    margin: 0 auto;
    padding: 1rem 0;
}

.long-text p {
    margin-bottom: 1.2rem;
    color: var(--text-muted);
    font-size: 1rem;
    line-height: 1.8;
    text-align: justify;
}

/* ===== 底部 ===== */
footer {
    background: rgba(0,0,0,0.3);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-top: 1px solid var(--glass-border);
    padding: 3rem 1rem 1.5rem;
    margin-top: 3rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    max-width: var(--max-width);
    margin: 0 auto;
}

.footer-col h3 {
    font-size: 1.3rem;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
}

.footer-col h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.8rem;
    color: var(--text);
}

.footer-col ul li {
    margin-bottom: 0.4rem;
}

.footer-col ul li a {
    color: var(--text-muted);
    font-size: 0.9rem;
    transition: color var(--transition);
}

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

.footer-col p {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.footer-keywords {
    text-align: center;
    margin-top: 2rem;
    padding-top: 1rem;
    border-top: 1px solid var(--glass-border);
    font-size: 0.75rem;
    color: var(--text-muted);
    letter-spacing: 1px;
}

/* ===== 返回顶部 ===== */
#backToTop {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: #fff;
    font-size: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 20px rgba(255,107,107,0.4);
    transition: transform var(--transition), opacity var(--transition);
    opacity: 0;
    visibility: hidden;
    z-index: 999;
}

#backToTop.visible {
    opacity: 1;
    visibility: visible;
}

#backToTop:hover {
    transform: scale(1.1) translateY(-3px);
}

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

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    .navbar {
        padding: 0 1rem;
    }

    .nav-links {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background: rgba(15, 15, 26, 0.95);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 1.5rem;
        gap: 1rem;
        transform: translateY(-100%);
        opacity: 0;
        pointer-events: none;
        transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        border-bottom: 1px solid var(--glass-border);
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: all;
    }

    #menuToggle {
        display: flex;
    }

    .hero {
        min-height: 60vh;
        padding: 5rem 1rem 3rem;
    }

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

    .section-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .ranking-list li {
        padding: 0.8rem 1rem;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }

    #backToTop {
        bottom: 1.5rem;
        right: 1.5rem;
        width: 44px;
        height: 44px;
        font-size: 1.2rem;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 0.95rem;
    }

    .btn-hero {
        padding: 0.7rem 2rem;
        font-size: 1rem;
    }

    .card img {
        height: 160px;
    }

    .breadcrumb {
        padding: 0.5rem 1rem;
        font-size: 0.75rem;
    }
}

/* ===== 暗色模式（默认已暗，但保留切换能力） ===== */
body.light-mode {
    --bg: #f5f5fa;
    --bg-card: rgba(0,0,0,0.03);
    --text: #1a1a2e;
    --text-muted: #555;
    --glass: rgba(255,255,255,0.6);
    --glass-border: rgba(0,0,0,0.1);
    --shadow: 0 8px 32px rgba(0,0,0,0.1);
    --banner-gradient: linear-gradient(135deg, #f0f0ff 0%, #e8e8ff 30%, #dcdcff 60%, #c8c8ff 100%);
}

body.light-mode .navbar {
    background: rgba(245, 245, 250, 0.85);
    border-bottom-color: rgba(0,0,0,0.1);
}

body.light-mode .navbar.scrolled {
    background: rgba(245, 245, 250, 0.95);
}

body.light-mode .nav-links a {
    color: #1a1a2e;
}

body.light-mode .hero h1 {
    -webkit-text-fill-color: initial;
    color: var(--primary);
    background: none;
}

body.light-mode .section-header h2 {
    -webkit-text-fill-color: initial;
    color: var(--primary);
    background: none;
}

body.light-mode .footer-col h3 {
    -webkit-text-fill-color: initial;
    color: var(--primary);
    background: none;
}

body.light-mode .card-body h3 {
    color: #1a1a2e;
}

body.light-mode .faq-item h3 {
    color: var(--accent);
}

body.light-mode .rank-num {
    background: linear-gradient(135deg, var(--primary), var(--accent));
}

body.light-mode .category-tags a {
    color: #1a1a2e;
}

body.light-mode .tag {
    color: #555;
}

body.light-mode .related-links a {
    color: var(--accent);
}

body.light-mode footer {
    background: rgba(0,0,0,0.02);
    border-top-color: rgba(0,0,0,0.1);
}

/* ===== 滚动动画支持 ===== */
[data-animate] {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-animate].animated {
    opacity: 1;
    transform: translateY(0);
}