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

:root {
    --bg-primary: #000000;
    --bg-secondary: #1d1d1f;
    --bg-tertiary: #2d2d2f;
    --text-primary: #f5f5f7;
    --text-secondary: #a1a1a6;
    --text-tertiary: #6e6e73;
    --accent-blue: #2997ff;
    --accent-purple: #bf5af2;
    --accent-green: #30d158;
    --accent-orange: #ff9f0a;
    --accent-pink: #ff375f;
    --nav-height: 48px;
    --container-max: 1200px;
    --radius-sm: 12px;
    --radius-md: 18px;
    --radius-lg: 24px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text', 'Helvetica Neue', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background: var(--bg-primary); color: var(--text-primary); line-height: 1.5; overflow-x: hidden;
    -webkit-user-select: none; -moz-user-select: none; -ms-user-select: none; user-select: none;
}

a { text-decoration: none; color: inherit; }
.container { max-width: var(--container-max); margin: 0 auto; padding: 0 24px; }

/* ===== 导航栏 ===== */
.navbar {
    position: fixed; top: 0; left: 0; right: 0; height: var(--nav-height); z-index: 1000;
    background: rgba(0,0,0,0.72); backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 0.5px solid rgba(255,255,255,0.08); transition: background 0.3s;
}
.nav-inner { max-width: 1024px; margin: 0 auto; padding: 0 24px; height: 100%; display: flex; align-items: center; justify-content: space-between; }
.nav-logo { display: flex; align-items: center; gap: 10px; font-size: 14px; font-weight: 600; letter-spacing: -0.01em; }
.logo-icon { width: 28px; height: 28px; background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple)); border-radius: 7px; display: flex; align-items: center; justify-content: center; font-size: 13px; font-weight: 700; color: #fff; flex-shrink: 0; }
.logo-text { color: var(--text-primary); }
.nav-links { display: flex; align-items: center; gap: 0; list-style: none; }
.nav-links li a { display: flex; align-items: center; gap: 4px; padding: 0 12px; height: var(--nav-height); font-size: 12px; font-weight: 400; color: var(--text-secondary); transition: color 0.2s; white-space: nowrap; }
.nav-links li a:hover { color: var(--text-primary); }
.nav-links li a i { font-size: 10px; transition: transform 0.2s; }
.nav-links li.has-dropdown:hover a i { transform: rotate(180deg); }

/* 下拉菜单 */
.dropdown-menu {
    position: absolute; top: var(--nav-height); left: 50%; transform: translateX(-50%) translateY(8px);
    background: rgba(30,30,30,0.95); backdrop-filter: blur(40px); -webkit-backdrop-filter: blur(40px);
    border-radius: var(--radius-sm); border: 0.5px solid rgba(255,255,255,0.1); padding: 6px;
    min-width: 200px; opacity: 0; visibility: hidden; transition: all 0.25s; box-shadow: 0 8px 32px rgba(0,0,0,0.5);
}
.nav-links li.has-dropdown:hover .dropdown-menu { opacity: 1; visibility: visible; transform: translateX(-50%) translateY(0); }
.dropdown-menu a { display: flex; align-items: center; gap: 10px; padding: 10px 14px !important; height: auto !important; border-radius: 8px; font-size: 13px !important; color: var(--text-secondary) !important; transition: all 0.15s; }
.dropdown-menu a:hover { background: rgba(255,255,255,0.08); color: var(--text-primary) !important; }
.dropdown-menu a i { width: 18px; text-align: center; color: var(--accent-blue); }

/* 移动端 */
.nav-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 4px; }
.nav-toggle span { display: block; width: 18px; height: 1.5px; background: var(--text-primary); border-radius: 1px; }
.mobile-menu { position: fixed; top: 0; right: -300px; width: 300px; height: 100vh; background: rgba(20,20,20,0.98); backdrop-filter: blur(40px); z-index: 2000; padding: 20px 0; transition: right 0.35s cubic-bezier(0.4,0,0.2,1); overflow-y: auto; }
.mobile-menu.open { right: 0; }
.mobile-menu-header { display: flex; justify-content: space-between; align-items: center; padding: 0 24px 20px; border-bottom: 0.5px solid rgba(255,255,255,0.08); margin-bottom: 10px; }
.mobile-close { background: none; border: none; color: var(--text-secondary); font-size: 28px; cursor: pointer; }
.mobile-menu a { display: flex; align-items: center; justify-content: space-between; padding: 14px 24px; font-size: 15px; color: var(--text-secondary); transition: all 0.15s; }
.mobile-menu a:hover { color: var(--text-primary); background: rgba(255,255,255,0.04); }
.mobile-submenu { max-height: 0; overflow: hidden; transition: max-height 0.3s; background: rgba(0,0,0,0.3); }
.mobile-submenu.open { max-height: 400px; }
.mobile-submenu a { padding: 12px 24px 12px 40px; font-size: 13px; }
.mobile-submenu a i { width: 18px; margin-right: 8px; color: var(--accent-blue); }
.overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.5); z-index: 1500; opacity: 0; visibility: hidden; transition: all 0.3s; }
.overlay.active { opacity: 1; visibility: visible; }

/* ===== 右上角圆形时钟 ===== */
.floating-clock { position: fixed; top: calc(var(--nav-height) + 16px); right: 24px; z-index: 999; display: flex; flex-direction: column; align-items: center; gap: 8px; opacity: 0; animation: fadeInUp 0.8s 0.8s forwards; }
.analog-clock { width: 140px; height: 140px; filter: drop-shadow(0 4px 20px rgba(0,0,0,0.4)); }
.clock-outer-ring { fill: none; stroke: rgba(255,255,255,0.12); stroke-width: 1.5; }
.clock-inner-bg { fill: rgba(0,0,0,0.6); }
.clock-tick { stroke: rgba(255,255,255,0.25); stroke-linecap: round; }
.clock-tick-major { stroke: rgba(255,255,255,0.7); stroke-width: 2; }
.clock-number { fill: rgba(255,255,255,0.5); font-size: 11px; font-weight: 500; text-anchor: middle; dominant-baseline: central; font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', sans-serif; }
.clock-hand-hour { stroke: #f5f5f7; stroke-width: 3.5; stroke-linecap: round; transform-origin: 100px 100px; transition: transform 0.5s cubic-bezier(0.4,0,0.2,1); }
.clock-hand-minute { stroke: #f5f5f7; stroke-width: 2.5; stroke-linecap: round; transform-origin: 100px 100px; transition: transform 0.5s cubic-bezier(0.4,0,0.2,1); }
.clock-hand-second { stroke: var(--accent-blue); stroke-width: 1; stroke-linecap: round; transform-origin: 100px 100px; }
.clock-center-dot { fill: var(--accent-blue); }
.clock-center-inner { fill: #000; }
.floating-clock-date { font-size: 11px; color: var(--text-tertiary); letter-spacing: 0.04em; text-align: center; white-space: nowrap; }

/* ===== Hero ===== */
.hero { position: relative; min-height: 100vh; display: flex; flex-direction: column; align-items: center; justify-content: center; padding: calc(var(--nav-height) + 60px) 24px 80px; overflow: hidden; }
.hero-bg-animation { position: absolute; inset: 0; overflow: hidden; z-index: 0; }
.orb { position: absolute; border-radius: 50%; filter: blur(80px); opacity: 0.3; animation: orbFloat 12s ease-in-out infinite; }
.orb-1 { width: 500px; height: 500px; background: var(--accent-blue); top: -10%; left: -5%; }
.orb-2 { width: 400px; height: 400px; background: var(--accent-purple); bottom: -5%; right: -5%; animation-delay: -4s; }
.orb-3 { width: 350px; height: 350px; background: var(--accent-green); top: 40%; left: 50%; animation-delay: -8s; opacity: 0.15; }
@keyframes orbFloat { 0%,100% { transform: translate(0,0) scale(1); } 33% { transform: translate(30px,-40px) scale(1.05); } 66% { transform: translate(-20px,20px) scale(0.95); } }

.hero-content { position: relative; z-index: 1; text-align: center; max-width: 800px; }
.hero-eyebrow { font-size: 18px; font-weight: 500; color: var(--accent-blue); letter-spacing: 0.02em; margin-bottom: 12px; opacity: 0; animation: fadeInUp 0.8s 0.2s forwards; }
.hero-title { font-size: clamp(42px,8vw,76px); font-weight: 700; letter-spacing: -0.03em; line-height: 1.05; margin-bottom: 16px; background: linear-gradient(135deg,#fff 0%,#a1a1a6 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; opacity: 0; animation: fadeInUp 0.8s 0.4s forwards; }
.hero-subtitle { font-size: 18px; color: var(--text-secondary); font-weight: 400; margin-bottom: 32px; opacity: 0; animation: fadeInUp 0.8s 0.6s forwards; }

@keyframes fadeInUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }

/* Hero统计 */
.hero-stats { display: flex; align-items: center; justify-content: center; gap: 24px; margin-bottom: 40px; opacity: 0; animation: fadeInUp 0.8s 0.7s forwards; }
.hero-stat { text-align: center; }
.hero-stat-num { display: block; font-size: 36px; font-weight: 700; letter-spacing: -0.02em; color: var(--accent-blue); }
.hero-stat-label { font-size: 13px; color: var(--text-tertiary); letter-spacing: 0.02em; }
.hero-stat-divider { width: 1px; height: 36px; background: rgba(255,255,255,0.1); }

.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; opacity: 0; animation: fadeInUp 0.8s 0.9s forwards; }
.btn { display: inline-flex; align-items: center; justify-content: center; padding: 14px 32px; border-radius: 980px; font-size: 15px; font-weight: 500; transition: all 0.3s cubic-bezier(0.4,0,0.2,1); cursor: pointer; border: none; }
.btn-primary { background: var(--accent-blue); color: #fff; }
.btn-primary:hover { background: #0077ed; transform: scale(1.02); }
.btn-secondary { background: transparent; color: var(--accent-blue); border: 1px solid rgba(41,151,255,0.3); }
.btn-secondary:hover { background: rgba(41,151,255,0.08); border-color: var(--accent-blue); }

.scroll-indicator { position: absolute; bottom: 32px; left: 50%; transform: translateX(-50%); display: flex; flex-direction: column; align-items: center; gap: 8px; opacity: 0; animation: fadeInUp 0.8s 1.1s forwards; }
.scroll-indicator span { font-size: 11px; color: var(--text-tertiary); }
.mouse { width: 22px; height: 34px; border: 2px solid rgba(255,255,255,0.2); border-radius: 11px; position: relative; }
.wheel { width: 3px; height: 8px; background: rgba(255,255,255,0.4); border-radius: 2px; position: absolute; top: 6px; left: 50%; transform: translateX(-50%); animation: scrollWheel 2s ease-in-out infinite; }
@keyframes scrollWheel { 0%,100% { opacity: 1; transform: translateX(-50%) translateY(0); } 50% { opacity: 0.3; transform: translateX(-50%) translateY(8px); } }

/* ===== 通用Section ===== */
.section { padding: 120px 24px; }
.section-eyebrow { font-size: 14px; font-weight: 600; color: var(--accent-blue); text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 12px; text-align: center; }
.section-title { font-size: clamp(32px,5vw,56px); font-weight: 700; letter-spacing: -0.03em; line-height: 1.08; text-align: center; margin-bottom: 16px; }
.section-desc { font-size: 17px; color: var(--text-secondary); text-align: center; max-width: 580px; margin: 0 auto 60px; line-height: 1.6; }

/* ===== 书籍分类 ===== */
.book-category { margin-bottom: 56px; }
.category-header { display: flex; align-items: center; gap: 12px; margin-bottom: 20px; padding-bottom: 12px; border-bottom: 0.5px solid rgba(255,255,255,0.06); }
.category-icon { width: 36px; height: 36px; background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple)); border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 15px; color: #fff; }
.category-header h3 { font-size: 20px; font-weight: 600; letter-spacing: -0.02em; }
.category-badge { font-size: 12px; color: var(--text-tertiary); background: rgba(255,255,255,0.05); padding: 3px 10px; border-radius: 980px; }

.books-row { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 16px; }

/* 书籍卡片 */
.book-card {
    background: rgba(255,255,255,0.03); border: 1px solid rgba(255,255,255,0.06);
    border-radius: var(--radius-md); padding: 20px; display: flex; flex-direction: column;
    transition: all 0.35s cubic-bezier(0.4,0,0.2,1); position: relative;
}
.book-card:hover { background: rgba(255,255,255,0.05); border-color: rgba(255,255,255,0.12); transform: translateY(-3px); box-shadow: 0 12px 36px rgba(0,0,0,0.3); }

.book-cover {
    width: 100%; aspect-ratio: 16/9; border-radius: 10px; margin-bottom: 16px;
    background: linear-gradient(135deg, var(--cover-color, var(--accent-blue)), rgba(0,0,0,0.3));
    display: flex; align-items: center; justify-content: center; position: relative; overflow: hidden;
}
.book-cover i { font-size: 36px; color: rgba(255,255,255,0.3); }
.book-grade { position: absolute; top: 10px; right: 10px; background: rgba(0,0,0,0.5); color: #fff; font-size: 11px; font-weight: 600; padding: 3px 8px; border-radius: 6px; backdrop-filter: blur(8px); }

.book-info { flex: 1; }
.book-info h4 { font-size: 16px; font-weight: 600; letter-spacing: -0.01em; margin-bottom: 4px; line-height: 1.3; }
.book-title-cn { font-size: 14px; color: var(--accent-blue); margin-bottom: 6px; font-weight: 500; }
.book-meta { font-size: 12px; color: var(--text-tertiary); margin-bottom: 10px; }

.book-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.book-tag { font-size: 10px; padding: 2px 8px; border-radius: 4px; background: rgba(255,255,255,0.06); color: var(--text-tertiary); font-weight: 500; }
.book-tag.pd { background: rgba(48,209,88,0.12); color: var(--accent-green); }
.book-tag.gov { background: rgba(41,151,255,0.12); color: var(--accent-blue); }

.book-link { display: flex; align-items: center; gap: 6px; margin-top: 12px; font-size: 12px; color: var(--accent-blue); font-weight: 500; transition: color 0.15s; }
.book-link:hover { color: #0077ed; }
.book-link i { font-size: 10px; }

.book-links-row { display: flex; align-items: center; gap: 12px; margin-top: 12px; flex-wrap: wrap; }
.book-read-link { display: inline-flex; align-items: center; gap: 6px; padding: 6px 14px; background: var(--accent-blue); color: #fff; border-radius: 980px; font-size: 12px; font-weight: 500; transition: all 0.2s; text-decoration: none; }
.book-read-link:hover { background: #0077ed; transform: scale(1.02); color: #fff; }
.book-read-link i { font-size: 10px; }

/* ===== 关于/特色 ===== */
.about { background: var(--bg-secondary); }
.features-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; max-width: 1000px; margin: 0 auto; }
.feature-card { text-align: center; padding: 32px 20px; background: rgba(255,255,255,0.02); border: 1px solid rgba(255,255,255,0.05); border-radius: var(--radius-md); transition: all 0.3s; }
.feature-card:hover { background: rgba(255,255,255,0.04); border-color: rgba(255,255,255,0.1); transform: translateY(-2px); }
.feature-icon { width: 48px; height: 48px; background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple)); border-radius: 14px; display: flex; align-items: center; justify-content: center; font-size: 20px; color: #fff; margin: 0 auto 16px; }
.feature-card h3 { font-size: 18px; font-weight: 600; margin-bottom: 8px; }
.feature-card p { font-size: 13px; color: var(--text-tertiary); line-height: 1.5; }

/* ===== 联系 ===== */
.contact { background: var(--bg-primary); }
.contact-links { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.contact-card { display: flex; align-items: center; gap: 10px; padding: 16px 28px; background: rgba(255,255,255,0.03); border: 1px solid rgba(255,255,255,0.06); border-radius: 980px; font-size: 15px; color: var(--text-secondary); transition: all 0.3s; }
.contact-card i { font-size: 18px; color: var(--accent-blue); }
.contact-card:hover { background: rgba(255,255,255,0.06); border-color: rgba(255,255,255,0.12); color: var(--text-primary); transform: translateY(-2px); }

.wechat-card { position: relative; }
.wechat-tooltip { position: absolute; bottom: calc(100% + 14px); left: 50%; transform: translateX(-50%) translateY(8px); background: rgba(30,30,30,0.98); backdrop-filter: blur(40px); border: 1px solid rgba(255,255,255,0.1); border-radius: 14px; padding: 16px 20px; min-width: 200px; opacity: 0; visibility: hidden; transition: all 0.25s cubic-bezier(0.4,0,0.2,1); pointer-events: none; box-shadow: 0 12px 40px rgba(0,0,0,0.5); z-index: 100; display: flex; flex-direction: column; align-items: center; }
.wechat-card:hover .wechat-tooltip { opacity: 1; visibility: visible; transform: translateX(-50%) translateY(0); }
.wechat-tooltip-arrow { position: absolute; bottom: -6px; left: 50%; transform: translateX(-50%) rotate(45deg); width: 12px; height: 12px; background: rgba(30,30,30,0.98); border-right: 1px solid rgba(255,255,255,0.1); border-bottom: 1px solid rgba(255,255,255,0.1); }
.wechat-qr { width: 160px; height: 160px; border-radius: 10px; overflow: hidden; margin-bottom: 10px; border: 1px solid rgba(255,255,255,0.08); background: #fff; }
.wechat-qr-img { width: 100%; height: 100%; object-fit: cover; }
.wechat-id { display: flex; align-items: center; gap: 10px; padding: 8px 12px; background: rgba(7,193,96,0.12); border: 1px solid rgba(7,193,96,0.2); border-radius: 8px; margin-bottom: 6px; }
.wechat-id i { font-size: 22px; color: #07C160; }
.wechat-id span { font-size: 16px; font-weight: 600; color: var(--text-primary); }
.wechat-hint { font-size: 11px; color: var(--text-tertiary); text-align: center; }

/* ===== 页脚 ===== */
.footer { padding: 32px 24px; border-top: 0.5px solid rgba(255,255,255,0.06); }
.footer-inner { text-align: center; }
.footer-brand { display: flex; align-items: center; justify-content: center; gap: 8px; font-size: 13px; font-weight: 500; margin-bottom: 8px; }
.footer-brand .logo-icon { width: 22px; height: 22px; font-size: 11px; border-radius: 5px; }
.footer-copy { font-size: 12px; color: var(--text-tertiary); margin-bottom: 4px; }
.footer-note { font-size: 12px; color: var(--text-tertiary); opacity: 0.6; }

/* ===== 滚动动画 ===== */
.fade-in { opacity: 0; transform: translateY(30px); transition: all 0.7s cubic-bezier(0.4,0,0.2,1); }
.fade-in.visible { opacity: 1; transform: translateY(0); }

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .features-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
    :root { --nav-height: 44px; }
    .nav-links { display: none; }
    .nav-toggle { display: flex; }
    .floating-clock { top: calc(var(--nav-height) + 10px); right: 12px; }
    .analog-clock { width: 100px; height: 100px; }
    .clock-number { font-size: 8px; }
    .hero-title { font-size: clamp(36px,9vw,52px); }
    .hero-stats { gap: 16px; }
    .hero-stat-num { font-size: 28px; }
    .features-grid { grid-template-columns: 1fr; }
    .books-row { grid-template-columns: 1fr; }
    .section { padding: 80px 20px; }
    .hero { padding: calc(var(--nav-height) + 40px) 20px 60px; }
    .wechat-tooltip { left: auto; right: 0; transform: translateY(8px); }
    .wechat-card:hover .wechat-tooltip { transform: translateY(0); }
    .wechat-tooltip-arrow { left: auto; right: 24px; }
}
@media (max-width: 480px) {
    .hero-actions { flex-direction: column; align-items: center; }
    .btn { width: 100%; max-width: 280px; }
    .hero-stats { flex-direction: column; gap: 12px; }
    .hero-stat-divider { width: 36px; height: 1px; }
}