:root {
      --blue-deep: #0a2463;
      --blue-mid: #1565c0;
      --blue-bright: #1e88e5;
      --blue-light: #42a5f5;
      --blue-pale: #e3f2fd;
      --accent: #00b0ff;
      --accent2: #ff6d00;
      --white: #ffffff;
      --gray-soft: #f0f6ff;
    }

    * { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }
    body { font-family: 'Be Vietnam Pro'; background: #f5f9ff; color: #1a2a4a; overflow-x: hidden; }

    /* ========== SCROLLBAR ========== */
    ::-webkit-scrollbar { width: 6px; }
    ::-webkit-scrollbar-track { background: #e3f2fd; }
    ::-webkit-scrollbar-thumb { background: var(--blue-mid); border-radius: 4px; }

    /* ========== HEADER ========== */
    header {
      background: linear-gradient(135deg, var(--blue-deep) 0%, var(--blue-mid) 60%, var(--blue-bright) 100%);
      position: sticky; top: 0; z-index: 100;
      box-shadow: 0 4px 24px rgba(21,101,192,0.25);
    }
    .nav-link {
      color: rgba(255,255,255,0.85);
      font-weight: 500;
      font-size: 0.88rem;
      padding: 6px 14px;
      border-radius: 20px;
      transition: all 0.25s;
      white-space: nowrap;
    }
    .nav-link:hover { background: rgba(255,255,255,0.18); color: #fff; }

    /* ========== HERO ========== */
    .hero {
      background: linear-gradient(135deg, #0a2463 0%, #1565c0 50%, #0288d1 100%);
      position: relative; overflow: hidden;
    }
    .hero::before {
      content: '';
      position: absolute; inset: 0;
      background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    }
    .hero-blob {
      position: absolute; border-radius: 50%; filter: blur(70px); opacity: 0.2;
    }

    /* ========== FILTER BAR ========== */
    .filter-bar {
      background: white;
      border-bottom: 1px solid #dbeafe;
      overflow-x: auto;
      -webkit-overflow-scrolling: touch;
    }
    .filter-bar::-webkit-scrollbar { height: 3px; }
    .filter-tab {
      white-space: nowrap;
      padding: 10px 16px;
      font-size: 0.82rem;
      font-weight: 600;
      color: #5b7ab7;
      border-bottom: 3px solid transparent;
      cursor: pointer;
      transition: all 0.2s;
    }
    .filter-tab:hover, .filter-tab.active { color: var(--blue-mid); border-color: var(--blue-mid); }

    /* ========== CARDS ========== */
    .school-card {
      background: white;
      border-radius: 18px;
      overflow: hidden;
      box-shadow: 0 4px 20px rgba(21,101,192,0.10);
      transition: transform 0.3s, box-shadow 0.3s;
      cursor: pointer;
      border: 1px solid #dbeafe;
    }
    .school-card:hover {
      transform: translateY(-6px) scale(1.015);
      box-shadow: 0 16px 40px rgba(21,101,192,0.22);
    }
    .card-img {
      width: 100%; height: 140px; object-fit: cover;
      background: linear-gradient(135deg, #1565c0, #42a5f5);
      display: flex; align-items: center; justify-content: center;
    }
    .badge {
      display: inline-flex; align-items: center;
      padding: 2px 10px; border-radius: 20px;
      font-size: 0.72rem; font-weight: 700;
    }

    /* ========== SIDEBAR ========== */
    .sidebar-section { margin-bottom: 1.5rem; }
    .sidebar-title {
      /* font-family: 'Be Vietnam Pro'; */
      font-weight: 700; font-size: 0.8rem;
      color: #5b7ab7;
      text-transform: uppercase; letter-spacing: 0.08em;
      margin-bottom: 0.6rem;
    }
    .sidebar-link {
      display: flex; align-items: center; gap: 8px;
      padding: 7px 12px; border-radius: 10px;
      font-size: 0.84rem; font-weight: 500; color: #2a4a8a;
      transition: all 0.2s; cursor: pointer;
    }
    .sidebar-link:hover { background: var(--blue-pale); color: var(--blue-mid); }
    .count-badge {
      margin-left: auto; min-width: 22px; height: 22px;
      background: var(--blue-mid); color: white;
      border-radius: 6px; font-size: 0.72rem; font-weight: 700;
      display: flex; align-items: center; justify-content: center;
    }

    /* ========== RIGHT PANEL ========== */
    .right-card {
      background: linear-gradient(135deg, var(--blue-mid), var(--blue-bright));
      border-radius: 16px; padding: 18px; color: white;
      margin-bottom: 12px;
      box-shadow: 0 6px 20px rgba(21,101,192,0.25);
      transition: transform 0.25s;
      cursor: pointer;
    }
    .right-card:hover { transform: translateX(-4px); }

    /* ========== SCROLL ANIMATIONS ========== */
    .reveal { opacity: 0; transform: translateY(30px); transition: opacity 0.6s ease, transform 0.6s ease; }
    .reveal.visible { opacity: 1; transform: translateY(0); }
    .reveal-left { opacity: 0; transform: translateX(-30px); transition: opacity 0.5s ease, transform 0.5s ease; }
    .reveal-left.visible { opacity: 1; transform: translateX(0); }
    .reveal-right { opacity: 0; transform: translateX(30px); transition: opacity 0.5s ease, transform 0.5s ease; }
    .reveal-right.visible { opacity: 1; transform: translateX(0); }

    /* ========== MOBILE MENU ========== */
    #mobile-menu { transition: max-height 0.4s ease, opacity 0.3s; max-height: 0; overflow: hidden; opacity: 0; }
    #mobile-menu.open { max-height: 600px; opacity: 1; }

    /* ========== SECTION HEADERS ========== */
    .section-title {
      font-weight: 800;
      font-size: clamp(1.4rem, 3vw, 2rem);
      color: var(--blue-deep);
      position: relative;
      display: inline-block;
    }
    .section-title::after {
      content: '';
      position: absolute; bottom: -6px; left: 0;
      width: 50%; height: 4px;
      background: linear-gradient(90deg, var(--blue-bright), var(--accent));
      border-radius: 2px;
    }

    /* ========== TABS ========== */
    .tier-tab {
      padding: 8px 20px; border-radius: 25px;
      font-weight: 600; font-size: 0.85rem;
      cursor: pointer; transition: all 0.25s;
      border: 2px solid transparent;
    }
    .tier-tab.active { background: var(--blue-mid); color: white; }
    .tier-tab:not(.active) { background: white; color: var(--blue-mid); border-color: #bdd7f5; }
    .tier-tab:not(.active):hover { background: var(--blue-pale); }

    /* ========== SEARCH INPUT ========== */
    .search-input {
      background: rgba(255,255,255,0.15);
      border: 1.5px solid rgba(255,255,255,0.3);
      color: white; border-radius: 30px;
      padding: 10px 20px 10px 44px;
      width: 100%; outline: none;
      font-size: 0.9rem;
      transition: all 0.3s;
    }
    .search-input::placeholder { color: rgba(255,255,255,0.6); }
    .search-input:focus { background: rgba(255,255,255,0.25); border-color: rgba(255,255,255,0.7); }

    /* ========== KOREAN FLAG DECO ========== */
    .taegeuk {
      width: 56px; height: 56px;
      background: conic-gradient(#cd2e3a 0 25%, white 25% 50%, #003478 50% 75%, white 75%);
      border-radius: 50%; position: absolute;
      opacity: 0.15;
    }

    /* ========== LOADING SKELETON ========== */
    @keyframes shimmer {
      0% { background-position: -400px 0; }
      100% { background-position: 400px 0; }
    }
    .skeleton {
      background: linear-gradient(90deg, #dbeafe 25%, #e8f4fd 50%, #dbeafe 75%);
      background-size: 400px 100%;
      animation: shimmer 1.4s infinite;
      border-radius: 8px;
    }

    /* ========== WAVE DIVIDER ========== */
    .wave-divider svg { display: block; }

    @media (max-width: 768px) {
      .filter-tab { font-size: 0.75rem; padding: 8px 10px; }
      .school-card { border-radius: 14px; }
    }