:root {
    --bg: #0d0614;
    --bg-alt: #180a24;
    --card: #200d30;
    --neon-pink: #ff2a6d;
    --neon-cyan: #05d9e8;
    --neon-purple: #9d4edd;
    --text: #e0d4ec;
    --text-dim: #a08cb3;
    --border: #3a1d52;
  }
  * { margin: 0; padding: 0; box-sizing: border-box; }
  body {
    background-color: var(--bg);
    color: var(--text);
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
  }
  a { color: inherit; text-decoration: none; }
  img { max-width: 100%; display: block; }

  /* 霓虹发光文字 */
  .glow-cyan { text-shadow: 0 0 5px var(--neon-cyan), 0 0 10px var(--neon-cyan); color: #fff; }
  .glow-pink { text-shadow: 0 0 5px var(--neon-pink), 0 0 10px var(--neon-pink); color: #fff; }

  /* 顶部导航 */
  .cyber-header {
    position: fixed;
    top: 0; left: 0; width: 100%;
    background: rgba(13, 6, 20, 0.85);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 20px;
  }
  .brand-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.2rem;
    font-weight: bold;
    color: #fff;
    text-shadow: 0 0 8px var(--neon-cyan);
  }
  .brand-logo img { height: 32px; }
  
  .nav-links {
    display: none;
    gap: 20px;
    font-size: 0.95rem;
  }
  .nav-links a:hover {
    color: var(--neon-cyan);
    text-shadow: 0 0 8px var(--neon-cyan);
  }
  
  .download-group {
    display: flex;
    gap: 10px;
  }
  .btn-dl {
    padding: 6px 12px;
    border: 1px solid var(--neon-pink);
    border-radius: 4px;
    font-size: 0.85rem;
    color: var(--neon-pink);
    transition: all 0.3s;
  }
  .btn-dl:hover {
    background: var(--neon-pink);
    color: #fff;
    box-shadow: 0 0 12px var(--neon-pink);
  }

  /* 布局 */
  main { padding-top: 70px; }
  .container { padding: 0 20px; margin: 0 auto; max-width: 1100px; }

  /* 首屏大字报 */
  .hero {
    padding: 60px 0;
    text-align: center;
    position: relative;
  }
  .hero::before {
    content: '';
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    width: 100vw; height: 100%;
    background: radial-gradient(circle, rgba(157,78,221,0.15) 0%, transparent 60%);
    z-index: -1;
  }
  .hero h1 {
    font-size: 2.5rem;
    line-height: 1.2;
    margin-bottom: 20px;
    background: linear-gradient(90deg, var(--neon-pink), var(--neon-cyan));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 900;
  }
  .hero p {
    font-size: 1.1rem;
    color: var(--text-dim);
    margin-bottom: 30px;
    max-width: 600px;
    margin-inline: auto;
  }
  .btn-main {
    display: inline-block;
    padding: 12px 32px;
    background: transparent;
    color: var(--neon-cyan);
    border: 2px solid var(--neon-cyan);
    border-radius: 4px;
    font-size: 1.1rem;
    font-weight: bold;
    text-shadow: 0 0 8px var(--neon-cyan);
    box-shadow: 0 0 15px rgba(5,217,232,0.4), inset 0 0 15px rgba(5,217,232,0.4);
    transition: all 0.3s;
  }
  .btn-main:hover {
    background: var(--neon-cyan);
    color: var(--bg);
    box-shadow: 0 0 25px var(--neon-cyan);
  }

  /* 错落瀑布流布局 */
  .waterfall-grid {
    column-count: 1;
    column-gap: 20px;
    margin-top: 40px;
  }
  .wf-item {
    break-inside: avoid;
    margin-bottom: 20px;
    border-radius: 8px;
    overflow: hidden;
    position: relative;
    border: 1px solid var(--border);
    background: var(--card);
    transition: transform 0.3s;
  }
  .wf-item:hover {
    transform: translateY(-5px);
    border-color: var(--neon-pink);
    box-shadow: 0 5px 15px rgba(255,42,109,0.2);
  }
  .wf-item img { width: 100%; height: auto; }
  .wf-text {
    padding: 15px;
  }
  .wf-text h3 {
    font-size: 1.1rem;
    margin-bottom: 8px;
    color: var(--neon-cyan);
  }
  .wf-text p { font-size: 0.9rem; color: var(--text-dim); }

  /* 模块通用标题 */
  .sec-title {
    font-size: 1.8rem;
    margin: 60px 0 30px;
    border-left: 4px solid var(--neon-pink);
    padding-left: 15px;
    color: #fff;
  }

  /* 追剧日历 */
  .calendar-row {
    display: flex;
    gap: 15px;
    overflow-x: auto;
    padding-bottom: 10px;
  }
  .cal-card {
    flex: 0 0 140px;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 15px;
    text-align: center;
  }
  .cal-card .day { font-size: 0.9rem; color: var(--neon-cyan); margin-bottom: 5px; }
  .cal-card .title { font-size: 1rem; font-weight: bold; color: #fff; }

  /* AI流程 - 横向步骤 */
  .steps { display: grid; gap: 20px; grid-template-columns: 1fr; }
  .step-item {
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 20px;
    position: relative;
  }
  .step-item::before {
    content: attr(data-step);
    position: absolute;
    top: -10px; left: 20px;
    background: var(--neon-purple);
    color: #fff;
    font-weight: bold;
    padding: 2px 10px;
    border-radius: 12px;
    font-size: 0.8rem;
  }

  /* 3D 旋转卡 */
  .card-3d-wrap {
    perspective: 1000px;
    margin: 40px auto;
    max-width: 300px;
    height: 400px;
    position: relative;
  }
  .card-3d {
    width: 100%; height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
  }
  .card-face {
    position: absolute;
    width: 100%; height: 100%;
    backface-visibility: hidden;
    border-radius: 12px;
    overflow: hidden;
    border: 2px solid var(--neon-pink);
    box-shadow: 0 0 20px rgba(255,42,109,0.3);
  }
  .card-face img { width: 100%; height: 100%; object-fit: cover; }
  .card-face.back { transform: rotateY(180deg); border-color: var(--neon-cyan); box-shadow: 0 0 20px rgba(5,217,232,0.3); }

  /* FAQ */
  .faq-item {
    border-bottom: 1px solid var(--border);
    margin-bottom: 10px;
  }
  .faq-q {
    padding: 15px 0;
    font-weight: bold;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: #fff;
  }
  .faq-a {
    padding-bottom: 15px;
    color: var(--text-dim);
    display: none; /* JS增强：通过展开类控制 */
  }
  .faq-item.open .faq-a { display: block; }

  /* 跑马灯 / 弹幕区 */
  .marquee-wrap {
    width: 100%;
    overflow: hidden;
    background: var(--bg-alt);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    padding: 10px 0;
    margin: 40px 0;
    display: flex;
    white-space: nowrap;
  }
  .marquee-content {
    display: inline-block;
    animation: scroll-left 20s linear infinite;
  }
  .marquee-content span {
    margin: 0 30px;
    font-size: 0.95rem;
    color: var(--neon-cyan);
  }
  @keyframes scroll-left {
    0% { transform: translateX(0); }
    100% { transform: translateX(-50%); }
  }

  /* 排行榜紧凑列表 */
  .rank-list { margin-top: 20px; }
  .rank-item {
    display: flex;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px dashed var(--border);
  }
  .rank-num {
    width: 30px;
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--text-dim);
  }
  .rank-item:nth-child(1) .rank-num { color: var(--neon-pink); }
  .rank-item:nth-child(2) .rank-num { color: var(--neon-cyan); }
  .rank-item:nth-child(3) .rank-num { color: var(--neon-purple); }
  .rank-title { flex: 1; color: #fff; font-size: 1rem; }
  .rank-tag {
    font-size: 0.8rem;
    padding: 2px 6px;
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-dim);
  }

  /* 页脚 */
  .site-footer {
    background: #05020a;
    padding: 40px 20px 20px;
    border-top: 1px solid var(--border);
    margin-top: 60px;
  }
  .footer-seo {
    font-size: 0.85rem;
    color: #555;
    line-height: 2;
    text-align: center;
    margin-bottom: 20px;
  }
  .footer-seo a { margin: 0 5px; color: #777; }
  .footer-seo a:hover { color: var(--neon-cyan); }
  .copyright {
    text-align: center;
    font-size: 0.8rem;
    color: #444;
    border-top: 1px solid #1a1a1a;
    padding-top: 20px;
  }

  /* 响应式 */
  @media (min-width: 768px) {
    .nav-links { display: flex; }
    .waterfall-grid { column-count: 2; }
    .hero h1 { font-size: 3.5rem; }
    .steps { grid-template-columns: 1fr 1fr; }
  }
  @media (min-width: 1024px) {
    .waterfall-grid { column-count: 3; }
    .hero h1 { font-size: 4.5rem; }
    .steps { grid-template-columns: 1fr 1fr 1fr; }
    .card-3d-wrap { max-width: 350px; height: 460px; }
  }