/* roulang page: index */
:root {
      --primary: #2D1B3E;
      --primary-hover: #3E2555;
      --accent: #C8A96E;
      --accent-light: #D98C2E;
      --bg-warm: #F9F7F4;
      --bg-grayish: #F0ECE6;
      --text-main: #1E1E1E;
      --text-secondary: #5A5A5A;
      --text-muted: #8C8C8C;
      --white: #FFFFFF;
      --card-shadow: 0 4px 20px rgba(45, 27, 62, 0.04);
      --card-shadow-hover: 0 12px 32px rgba(45, 27, 62, 0.1);
      --card-border: rgba(200, 169, 110, 0.15);
      --font-serif: 'Noto Serif SC', 'Cormorant Garamond', 'Times New Roman', serif;
      --font-sans: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
      --font-mono: 'DM Mono', 'JetBrains Mono', monospace;
      --transition: 0.3s ease;
      --radius-card: 12px;
      --radius-btn: 8px;
    }
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }
    body {
      font-family: var(--font-sans);
      font-size: 16px;
      line-height: 1.8;
      color: var(--text-main);
      background-color: var(--bg-warm);
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    img { max-width: 100%; height: auto; display: block; }
    a { text-decoration: none; color: inherit; transition: color var(--transition); }
    ul { list-style: none; }
    .container { max-width: 1280px; margin: 0 auto; padding: 0 24px; }
    /* Header & Navigation */
    #header {
      position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
      background: rgba(249, 247, 244, 0.85);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--accent);
      transition: background var(--transition), box-shadow var(--transition);
    }
    #header.scrolled {
      background: var(--bg-warm);
      box-shadow: 0 2px 12px rgba(45, 27, 62, 0.08);
    }
    .nav-container {
      display: flex; align-items: center; justify-content: space-between;
      height: 70px; padding: 0 24px;
    }
    .logo {
      font-family: var(--font-serif);
      font-size: 1.8rem; font-weight: 700;
      color: var(--primary); letter-spacing: 0.02em;
      display: flex; align-items: center; gap: 8px;
      white-space: nowrap;
    }
    .logo-icon {
      width: 32px; height: 32px;
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      border-radius: 50%; position: relative;
      display: flex; align-items: center; justify-content: center;
    }
    .logo-icon::after {
      content: ''; width: 12px; height: 12px;
      background: var(--bg-warm); border-radius: 50%;
      box-shadow: 0 0 0 3px var(--accent);
    }
    .nav-links { display: flex; gap: 32px; align-items: center; }
    .nav-links a {
      font-size: 0.95rem; font-weight: 500; color: var(--text-secondary);
      position: relative; padding: 4px 0;
    }
    .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 { color: var(--primary); }
    .nav-links a:hover::after { width: 100%; }
    .nav-cta-btn {
      background: var(--primary); color: var(--white); padding: 10px 24px;
      border-radius: var(--radius-btn); font-weight: 500;
      transition: background var(--transition), box-shadow var(--transition);
    }
    .nav-cta-btn:hover { background: var(--primary-hover); box-shadow: 0 6px 18px rgba(45, 27, 62, 0.3); color: var(--white); }
    .burger { display: none; flex-direction: column; gap: 6px; cursor: pointer; background: none; border: none; }
    .burger span { width: 28px; height: 2px; background: var(--primary); border-radius: 2px; transition: var(--transition); }
    /* Mobile Nav */
    .mobile-menu {
      position: fixed; top: 0; left: 0; width: 100%; height: 100vh;
      background: var(--primary); display: none; flex-direction: column;
      align-items: center; justify-content: center; gap: 32px;
      z-index: 999; opacity: 0; transition: opacity 0.3s;
    }
    .mobile-menu.active { display: flex; opacity: 1; }
    .mobile-menu a {
      font-size: 1.4rem; color: var(--white); font-weight: 500;
      padding: 12px 32px; border-radius: 50px;
      background: rgba(255,255,255,0.1);
      transition: background var(--transition);
    }
    .mobile-menu a:hover { background: rgba(200,169,110,0.3); }
    .close-menu {
      position: absolute; top: 24px; right: 24px;
      font-size: 2rem; color: var(--white); background: none; border: none; cursor: pointer;
    }
    /* Hero */
    #hero {
      padding: 150px 0 100px; display: flex; align-items: center;
      min-height: 90vh; background-color: var(--bg-warm);
      background-image: radial-gradient(circle at 80% 20%, rgba(200,169,110,0.08) 0%, transparent 60%);
    }
    .hero-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 60px; align-items: center; }
    .hero-content h1 {
      font-family: var(--font-serif); font-size: 3.4rem; font-weight: 700;
      line-height: 1.25; color: var(--primary); letter-spacing: -0.02em;
      margin-bottom: 24px;
    }
    .hero-content .subtitle {
      font-size: 1.2rem; font-weight: 300; color: var(--text-secondary);
      margin-bottom: 40px; max-width: 480px;
    }
    .hero-buttons { display: flex; gap: 18px; flex-wrap: wrap; }
    .btn-primary {
      background: var(--primary); color: var(--white); padding: 14px 36px;
      border-radius: var(--radius-btn); font-weight: 500; display: inline-block;
      transition: background var(--transition), box-shadow var(--transition);
    }
    .btn-primary:hover { background: var(--primary-hover); box-shadow: 0 10px 25px rgba(45, 27, 62, 0.3); }
    .btn-outline {
      border: 1.5px solid var(--primary); color: var(--primary);
      padding: 14px 36px; border-radius: var(--radius-btn); font-weight: 500;
      display: inline-block; transition: var(--transition);
    }
    .btn-outline:hover { background: var(--primary); color: var(--white); }
    .hero-visual {
      background: linear-gradient(135deg, rgba(45,27,62,0.1) 0%, rgba(200,169,110,0.2) 100%);
      border-radius: 40% 60% 30% 70% / 50% 40% 60% 50%;
      height: 420px; position: relative;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover; background-position: center;
      box-shadow: 0 20px 40px rgba(45,27,62,0.15);
      animation: float 6s infinite ease-in-out;
    }
    @keyframes float {
      0%, 100% { transform: translateY(0); }
      50% { transform: translateY(-12px); }
    }
    /* Highlights */
    #highlights { padding: 100px 0; background: var(--white); }
    .section-title {
      font-family: var(--font-sans); font-size: 2rem; font-weight: 500;
      color: var(--primary); margin-bottom: 48px; letter-spacing: 0.05em;
      text-align: center;
    }
    .highlights-grid {
      display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
      gap: 28px;
    }
    .highlight-card {
      background: var(--bg-warm); padding: 36px 28px; border-radius: var(--radius-card);
      box-shadow: var(--card-shadow); border: 1px solid var(--card-border);
      transition: var(--transition); position: relative;
    }
    .highlight-card.large { grid-column: span 2; }
    .highlight-card:hover { transform: translateY(-6px); box-shadow: var(--card-shadow-hover); }
    .highlight-number {
      font-family: var(--font-mono); font-size: 2.8rem; color: var(--primary);
      font-weight: 600; display: block;
    }
    .highlight-divider { width: 40px; height: 3px; background: var(--accent); margin: 16px 0; transition: width 0.4s; }
    .highlight-card:hover .highlight-divider { width: 60px; }
    .highlight-label { font-weight: 600; color: var(--text-main); font-size: 1.2rem; }
    /* Cases */
    #cases { padding: 100px 0; background: var(--bg-grayish); }
    .cases-masonry {
      columns: 3; column-gap: 20px;
    }
    .case-item {
      break-inside: avoid; margin-bottom: 20px; border-radius: 16px;
      overflow: hidden; position: relative; cursor: pointer;
      box-shadow: var(--card-shadow);
    }
    .case-item img {
      width: 100%; height: auto; object-fit: cover; transition: transform 0.5s;
    }
    .case-overlay {
      position: absolute; bottom: 0; left: 0; right: 0;
      background: linear-gradient(to top, rgba(45,27,62,0.8), transparent);
      padding: 40px 24px 24px; color: white;
    }
    .case-item:hover img { transform: scale(1.05); }
    .case-title { font-weight: 600; font-size: 1.2rem; }
    /* Comparison */
    #comparison { padding: 100px 0; background: var(--white); }
    .comparison-table {
      display: grid; grid-template-columns: 1fr 1fr 1fr;
      border-radius: var(--radius-card); overflow: hidden;
      box-shadow: var(--card-shadow);
    }
    .comp-row {
      display: contents;
    }
    .comp-cell {
      padding: 18px 24px; background: var(--bg-warm);
      border-bottom: 1px solid var(--card-border);
      display: flex; align-items: center;
    }
    .comp-header {
      background: var(--primary); color: white; font-weight: 600; font-size: 1.1rem;
    }
    .comp-highlight { background: var(--primary-hover); position: relative; }
    .badge {
      background: var(--accent-light); color: white; padding: 4px 12px;
      border-radius: 20px; font-size: 0.8rem; margin-left: 8px;
    }
    .comp-btn { margin-top: 24px; text-align: center; }
    /* FAQ */
    #faq { padding: 100px 0; background: var(--bg-grayish); }
    .faq-list { max-width: 780px; margin: 0 auto; }
    .faq-item {
      border-bottom: 1px solid rgba(140,140,140,0.25); padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600; font-size: 1.1rem; display: flex; justify-content: space-between;
      color: var(--primary);
    }
    .faq-answer {
      max-height: 0; overflow: hidden; transition: max-height 0.4s ease, padding 0.4s;
      color: var(--text-secondary);
    }
    .faq-item.open .faq-answer { max-height: 200px; padding-top: 12px; }
    /* Contact */
    #contact { padding: 100px 0; background: var(--primary); color: white; }
    .contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
    .contact-form input, .contact-form textarea {
      width: 100%; background: transparent; border: none;
      border-bottom: 1px solid rgba(255,255,255,0.4); padding: 12px 4px;
      margin-bottom: 24px; color: white; font-size: 1rem; outline: none;
      transition: border-color var(--transition);
    }
    .contact-form input:focus, .contact-form textarea:focus { border-bottom-color: var(--accent); }
    .btn-submit {
      background: var(--accent-light); color: white; padding: 14px 32px;
      border-radius: var(--radius-btn); border: none; cursor: pointer; font-weight: 600;
      width: 100%; transition: background var(--transition);
    }
    .btn-submit:hover { background: #b8731a; }
    /* Footer */
    #footer { background: #1E1E1E; color: #aaa; padding: 60px 0 30px; }
    .footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; }
    .footer-logo { font-family: var(--font-serif); font-size: 1.8rem; color: white; }
    .footer a:hover { color: var(--accent); }
    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; text-align: center; }
      .hero-visual { height: 300px; margin-top: 24px; }
      .cases-masonry { columns: 2; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .burger { display: flex; }
      .hero-content h1 { font-size: 2.4rem; }
      .cases-masonry { columns: 1; }
      .comparison-table { grid-template-columns: 1fr; }
      .contact-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .highlight-card.large { grid-column: span 1; }
    }