/* roulang page: index */
:root {
      --cyan: #0CF2DB;
      --cyan-deep: #00C8D6;
      --obsidian-black: #0B0C10;
      --smoke-white: #F5F5F7;
      --card-white: #FFFFFF;
      --alert-orange: #FF6B35;
      --silver-border: #E0E0E0;
      --text-dark: #2D2D2D;
      --text-gray: #4A4A4A;
      --text-muted: #666;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 4px;
      --shadow-card: 0px 20px 40px rgba(0, 0, 0, 0.06);
      --transition: 0.25s ease-out;
      --container-max: 1280px;
      --section-gap: 120px;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--smoke-white);
      color: var(--text-dark);
      line-height: 1.8;
      font-size: 16px;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
    }

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

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

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 32px;
    }

    /* 导航 */
    #header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      height: 72px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 32px;
      backdrop-filter: blur(12px);
      background: rgba(255, 255, 255, 0.8);
      transition: var(--transition);
      border-bottom: 1px solid transparent;
    }

    #header.scrolled {
      background: rgba(245, 245, 247, 0.95);
      border-bottom: 1px solid var(--silver-border);
    }

    .logo {
      font-size: 24px;
      font-weight: 700;
      letter-spacing: -0.3px;
      color: var(--obsidian-black);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .logo i {
      color: var(--cyan);
      font-size: 28px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }

    .nav-links a {
      font-size: 14px;
      font-weight: 500;
      color: var(--text-dark);
      position: relative;
      padding: 4px 0;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 50%;
      transform: translateX(-50%) scaleX(0);
      width: 100%;
      height: 2px;
      background-color: var(--cyan);
      transition: transform 0.25s ease-out;
      transform-origin: center;
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      transform: translateX(-50%) scaleX(1);
    }

    .btn-primary {
      background: var(--cyan);
      color: #fff;
      font-weight: 600;
      font-size: 14px;
      padding: 12px 24px;
      border-radius: var(--radius-btn);
      border: none;
      cursor: pointer;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      gap: 6px;
      white-space: nowrap;
      letter-spacing: 0.3px;
    }

    .btn-primary:hover {
      background: var(--cyan-deep);
      transform: translateY(-2px);
      box-shadow: 0 10px 20px rgba(12, 242, 219, 0.25);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--cyan);
      color: var(--cyan);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      transition: var(--transition);
      font-size: 14px;
      backdrop-filter: blur(4px);
    }

    .btn-outline:hover {
      background: rgba(12, 242, 219, 0.1);
    }

    .text-link {
      color: var(--cyan);
      font-weight: 600;
      border-bottom: 1.5px solid var(--cyan);
      transition: var(--transition);
    }
    .text-link:hover {
      border-bottom-width: 3px;
    }

    .mobile-nav {
      display: none;
      position: fixed;
      bottom: 16px;
      left: 50%;
      transform: translateX(-50%);
      background: rgba(255,255,255,0.9);
      backdrop-filter: blur(20px);
      padding: 8px 24px;
      border-radius: 40px;
      box-shadow: 0 10px 30px rgba(0,0,0,0.08);
      z-index: 999;
      gap: 28px;
      border: 1px solid var(--silver-border);
    }
    .mobile-nav a {
      font-size: 18px;
      color: var(--text-dark);
      padding: 6px;
    }
    .mobile-nav a.active {
      color: var(--cyan);
    }
    .menu-toggle {
      background: none;
      border: none;
      font-size: 24px;
      color: var(--obsidian-black);
    }

    /* Hero 杂志双栏 */
    #hero {
      padding: 160px 0 100px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      background: radial-gradient(circle at 20% 30%, rgba(12,242,219,0.06) 0%, transparent 50%);
      position: relative;
      overflow: hidden;
    }
    .hero-left {
      width: 55%;
    }
    .hero-left h1 {
      font-size: 56px;
      font-weight: 800;
      letter-spacing: -0.5px;
      color: var(--obsidian-black);
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-left h1 span {
      color: var(--cyan);
      border-bottom: 4px solid var(--cyan);
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-gray);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-actions {
      display: flex;
      align-items: center;
      gap: 28px;
      flex-wrap: wrap;
    }
    .hero-right {
      width: 40%;
      position: relative;
    }
    .hero-right img {
      border-radius: 20px;
      box-shadow: 20px 20px 60px rgba(0,0,0,0.15);
      transform: perspective(800px) rotateY(-2deg);
    }

    /* 板块标题 */
    .section-title {
      font-size: 40px;
      font-weight: 700;
      color: var(--obsidian-black);
      margin-bottom: 12px;
      line-height: 1.2;
    }
    .section-sub {
      font-size: 14px;
      font-weight: 600;
      letter-spacing: 3px;
      text-transform: uppercase;
      color: var(--cyan);
      margin-bottom: 20px;
    }

    #features, #showcase, #compare, #faq, #contact {
      padding: var(--section-gap) 0;
    }

    /* 非对称特色 */
    .features-grid {
      display: grid;
      grid-template-columns: 1fr 1fr 1fr;
      gap: 24px;
      margin-top: 48px;
    }
    .feature-big {
      grid-row: span 2;
      background: var(--card-white);
      border: 1px solid var(--silver-border);
      border-radius: var(--radius-card);
      padding: 40px 32px;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .stat-number {
      font-size: 56px;
      font-weight: 800;
      color: var(--cyan);
    }
    .feature-card {
      background: var(--card-white);
      border: 1px solid var(--silver-border);
      border-radius: var(--radius-card);
      padding: 28px;
      transition: var(--transition);
    }
    .feature-card:hover {
      border-color: var(--cyan);
      transform: translateY(-4px);
      box-shadow: var(--shadow-card);
    }

    /* 瀑布流 */
    .masonry {
      columns: 3;
      column-gap: 20px;
      margin-top: 40px;
    }
    .masonry-item {
      break-inside: avoid;
      margin-bottom: 20px;
      position: relative;
      overflow: hidden;
      border-radius: 8px;
    }
    .masonry-item img {
      width: 100%;
      transition: transform 0.4s ease;
    }
    .masonry-item:hover img {
      transform: scale(1.04);
    }
    .overlay {
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      padding: 20px;
      background: linear-gradient(transparent, rgba(0,0,0,0.8));
      color: white;
    }

    /* 对比卡片 */
    .compare-row {
      display: flex;
      align-items: center;
      gap: 20px;
      margin-top: 32px;
    }
    .compare-card {
      flex:1;
      background: var(--card-white);
      padding: 32px;
      border: 1px solid var(--silver-border);
      border-radius: var(--radius-card);
    }
    .vs {
      font-weight: 800;
      font-size: 28px;
      color: var(--cyan);
    }

    /* FAQ */
    .faq-wrapper {
      display: flex;
      gap: 60px;
    }
    .faq-left {
      width: 30%;
    }
    .faq-right {
      width: 70%;
    }
    .faq-item {
      border-bottom: 1px solid var(--silver-border);
    }
    .faq-question {
      font-weight: 700;
      font-size: 18px;
      padding: 24px 0;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }

    /* CTA dark */
    #contact {
      background: var(--obsidian-black);
      color: white;
      border-radius: 24px;
      margin-top: 40px;
      padding: 80px 48px;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .input-line {
      background: transparent;
      border: none;
      border-bottom: 2px solid rgba(255,255,255,0.3);
      padding: 12px 8px;
      width: 100%;
      color: white;
      margin-bottom: 20px;
    }
    .input-line:focus {
      border-bottom-color: var(--cyan);
    }

    footer {
      background: #EAEAEC;
      padding: 60px 0 30px;
    }

    @media (max-width: 1024px) {
      .nav-links { display: none; }
      .mobile-nav { display: flex; }
      #hero { flex-direction: column; }
      .hero-left, .hero-right { width: 100%; }
      .features-grid { grid-template-columns: 1fr 1fr; }
      .masonry { columns: 2; }
      .faq-wrapper { flex-direction: column; }
    }
    @media (max-width: 768px) {
      .features-grid { grid-template-columns: 1fr; }
      .masonry { columns: 1; }
      .compare-row { flex-direction: column; }
    }