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

    :root {
      --bg: #f1f4ff;
      --bg2: #e8ecfa;
      --bg3: #dde3f5;
      --ink: #1a1e35;
      --ink2: #3a3f5c;
      --ink3: #6b718f;
      --accent: #3a4baa;
      --accent2: #5566cc;
      --card: #ffffff;
      --border: #c8ceec;
      --radius: 14px;
      --radius-sm: 8px;
      --font: 'Inter', 'Segoe UI', Arial, sans-serif;
      --max: 1200px;
    }

    body {
      font-family: var(--font);
      background: var(--bg);
      color: var(--ink);
      font-size: 15px;
      line-height: 1.65;
    }

    h1 { font-size: clamp(1.8rem, 5vw, 3rem); font-weight: 700; letter-spacing: -0.03em; }
    h2 { font-size: clamp(1.3rem, 3.5vw, 2rem); font-weight: 600; letter-spacing: -0.02em; }
    h3 { font-size: clamp(1rem, 2.5vw, 1.25rem); font-weight: 600; }
    p  { color: var(--ink2); }

    .wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }
    .section { padding: 72px 0; }
    .section--alt { background: var(--bg2); }

    /* NAV */
    .nav {
      position: sticky; top: 0; z-index: 100;
      background: rgba(241,244,255,0.93);
      backdrop-filter: blur(14px);
      -webkit-backdrop-filter: blur(14px);
      border-bottom: 1px solid var(--border);
      padding: 0 24px;
      height: 60px;
      display: flex; align-items: center; justify-content: space-between;
    }
    .nav__brand {
      font-size: 1.1rem; font-weight: 700;
      color: var(--accent); letter-spacing: 0.06em;
      text-transform: uppercase;
    }
    .nav__tagline {
      font-size: 0.75rem; color: var(--ink3); letter-spacing: 0.08em;
      text-transform: uppercase;
    }

    /* HERO */
    .hero {
      background: linear-gradient(135deg, #f1f4ff 0%, #e2e8ff 60%, #dde3f5 100%);
      padding: 100px 24px 90px;
      text-align: center;
    }
    .hero__eyebrow {
      display: inline-block;
      font-size: 0.72rem; letter-spacing: 0.18em; text-transform: uppercase;
      color: var(--accent2); font-weight: 500;
      margin-bottom: 18px;
    }
    .hero h1 { margin-bottom: 18px; }
    .hero > p { font-size: 1.05rem; max-width: 520px; margin: 0 auto; color: var(--ink2); }
    .hero__divider {
      width: 48px; height: 3px;
      background: var(--accent); border-radius: 2px;
      margin: 28px auto 0;
    }

    /* SECTION HEADER */
    .sec-head { text-align: center; margin-bottom: 44px; }
    .sec-head__label {
      font-size: 0.7rem; letter-spacing: 0.18em; text-transform: uppercase;
      color: var(--accent2); font-weight: 500; margin-bottom: 10px;
    }
    .sec-head h2 { margin-bottom: 10px; }
    .sec-head p { max-width: 540px; margin: 0 auto; font-size: 0.95rem; }

    /* FEATURES */
    .features {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
      gap: 20px;
    }
    .feat {
      background: var(--card);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 28px 22px;
      text-align: center;
    }
    .feat__icon { font-size: 2rem; margin-bottom: 10px; }
    .feat h3 { font-size: 0.95rem; margin-bottom: 6px; color: var(--ink); }
    .feat p { font-size: 0.85rem; color: var(--ink3); }

    /* SEQUENCE GRID (B组) */
    .seq-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
      gap: 18px;
    }
    .seq-card {
      background: var(--card);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: 0 2px 12px rgba(58,75,170,0.07);
      transition: transform 0.22s ease, box-shadow 0.22s ease;
    }
    .seq-card:hover {
      transform: translateY(-4px);
      box-shadow: 0 8px 28px rgba(58,75,170,0.14);
    }
    .seq-card img {
      width: 100%; display: block;
      aspect-ratio: 1 / 1;
      object-fit: cover;
      background: var(--bg);
    }
    .seq-card__meta { padding: 14px 16px 16px; }
    .seq-card__badge {
      display: inline-block;
      font-size: 0.65rem; letter-spacing: 0.1em; text-transform: uppercase;
      font-weight: 500; color: var(--accent2);
      background: var(--bg2); border: 1px solid var(--border);
      border-radius: 4px; padding: 2px 7px; margin-bottom: 6px;
    }
    .seq-card__title { font-size: 0.92rem; font-weight: 600; color: var(--ink); }

    /* MASONRY (C组) */
    .msnry { columns: 3; column-gap: 16px; }
    @media (max-width: 700px) { .msnry { columns: 2; } }
    @media (max-width: 420px) { .msnry { columns: 1; } }
    .msnry-item {
      break-inside: avoid;
      margin-bottom: 16px;
      border-radius: var(--radius);
      overflow: hidden;
      background: var(--card);
      box-shadow: 0 2px 10px rgba(58,75,170,0.07);
      transition: transform 0.22s, box-shadow 0.22s;
    }
    .msnry-item:hover { transform: translateY(-3px); box-shadow: 0 8px 24px rgba(58,75,170,0.13); }
    .msnry-item img { width: 100%; display: block; object-fit: cover; background: var(--bg); }
    .msnry-item__cap { padding: 11px 13px 13px; font-size: 0.82rem; color: var(--ink3); }

    /* SHOWCASE SPLIT */
    .showcase {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }
    .showcase--flip { direction: rtl; }
    .showcase--flip > * { direction: ltr; }
    @media (max-width: 640px) {
      .showcase, .showcase--flip { grid-template-columns: 1fr; }
      .showcase--flip { direction: ltr; }
    }
    .showcase img {
      width: 100%; border-radius: var(--radius);
      aspect-ratio: 1/1; object-fit: cover;
      background: var(--bg);
      box-shadow: 0 4px 20px rgba(58,75,170,0.1);
    }
    .showcase__text h2 { margin-bottom: 14px; }
    .showcase__text p { font-size: 0.95rem; }

    /* FAQ */
    .faq-list { max-width: 760px; margin: 0 auto; }
    .faq-item {
      background: var(--card);
      border: 1px solid var(--border);
      border-radius: var(--radius-sm);
      margin-bottom: 10px;
      overflow: hidden;
    }
    .faq-q {
      width: 100%; text-align: left;
      padding: 18px 22px;
      background: none; border: none; cursor: pointer;
      font-family: var(--font); font-size: 0.97rem; font-weight: 600;
      color: var(--ink);
      display: flex; justify-content: space-between; align-items: center;
      gap: 12px;
    }
    .faq-q:hover { background: var(--bg2); }
    .faq-icon {
      flex-shrink: 0; width: 22px; height: 22px;
      background: var(--bg2); border: 1px solid var(--border);
      border-radius: 50%;
      display: flex; align-items: center; justify-content: center;
      font-size: 0.8rem; color: var(--accent);
      transition: transform 0.22s;
    }
    .faq-item.open .faq-icon { transform: rotate(45deg); }
    .faq-a {
      max-height: 0; overflow: hidden;
      transition: max-height 0.32s ease, padding 0.22s;
      padding: 0 22px; font-size: 0.92rem; color: var(--ink2);
    }
    .faq-item.open .faq-a {
      max-height: 400px;
      padding: 0 22px 18px;
    }

    /* FOOTER */
    .footer {
      background: var(--bg3);
      border-top: 1px solid var(--border);
      padding: 44px 24px;
      text-align: center;
    }
    .footer__brand {
      font-size: 0.85rem; font-weight: 700; color: var(--accent);
      letter-spacing: 0.12em; text-transform: uppercase; margin-bottom: 8px;
    }
    .footer p { font-size: 0.78rem; color: var(--ink3); }

    @media (max-width: 480px) {
      .nav__tagline { display: none; }
      .section { padding: 52px 0; }
    }