*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    body { font-family: system-ui, -apple-system, sans-serif; background: #f0f2f5; color: #1f2937; min-height: 100vh; }

    

    /* ── LAYOUT ── */
    .page-wrap { display: flex; max-width: 1100px; margin: 0 auto; padding: 20px 16px; gap: 20px; align-items: flex-start; }

    /* Left sidebar */
    .sidebar-left { width: 230px; flex-shrink: 0; position: sticky; top: 108px; }
    .sidebar-card { background: #ffffff; border-radius: 12px; padding: 14px; margin-bottom: 14px; box-shadow: 0 1px 4px rgba(0,0,0,0.06); }
    .sidebar-card h3 { font-size: 11px; font-weight: 600; color: #9ca3af; text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 10px; }
    .sidebar-link { display: flex; align-items: center; gap: 10px; padding: 8px 10px; border-radius: 8px; font-size: 13px; color: #6b7280; text-decoration: none; transition: background 0.15s, color 0.15s; margin-bottom: 2px; }
    .sidebar-link:hover { background: #f0f2f5; color: #4f46e5; }
    .sidebar-link.active { background: #eef2ff; color: #4f46e5; font-weight: 600; }
    .sidebar-link svg { flex-shrink: 0; color: #9ca3af; }
    .sidebar-link:hover svg, .sidebar-link.active svg { color: #4f46e5; }
    .stat-row { display: flex; justify-content: space-between; align-items: center; padding: 6px 0; border-bottom: 1px solid #f3f4f6; }
    .stat-row:last-child { border-bottom: none; }
    .stat-label { font-size: 12px; color: #6b7280; }
    .stat-val { font-size: 13px; font-weight: 700; color: #1f2937; }

    /* Right sidebar */
    .sidebar-right { width: 260px; flex-shrink: 0; position: sticky; top: 108px; }
    .widget-title { font-size: 15px; font-weight: 700; color: #1f2937; margin-bottom: 12px; }
    .recent-item { display: flex; align-items: center; gap: 10px; padding: 8px 0; border-bottom: 1px solid #f3f4f6; text-decoration: none; }
    .recent-item:last-child { border-bottom: none; }
    .recent-icon { width: 36px; height: 36px; border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 18px; flex-shrink: 0; }
    .recent-info { flex: 1; min-width: 0; }
    .recent-name { font-size: 13px; font-weight: 600; color: #1f2937; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
    .recent-sub { font-size: 11px; color: #9ca3af; }
    .recent-item:hover .recent-name { color: #4f46e5; }

    /* User dropdown */
    .user-wrap { position: relative; }
    .user-dropdown { display: none; position: absolute; top: calc(100% + 8px); right: 0; background: #ffffff; border: 1px solid #e4e6ea; border-radius: 10px; min-width: 160px; box-shadow: 0 8px 24px rgba(0,0,0,0.12); z-index: 300; overflow: hidden; }
    .user-dropdown.open { display: block; }
    .user-dropdown a { display: flex; align-items: center; gap: 8px; padding: 10px 16px; font-size: 13px; color: #6b7280; text-decoration: none; transition: background 0.15s, color 0.15s; }
    .user-dropdown a:hover { background: #f0f2f5; color: #4f46e5; }
    .user-dropdown hr { border: none; border-top: 1px solid #e4e6ea; }

    /* ── MAIN CONTENT ── */
    .main-content { flex: 1; min-width: 0; }

    /* ── QUIZ START PAGE STYLES ── */

    /* Hero Banner */
    .quiz-hero {
      background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 45%, #db2777 100%);
      border-radius: 16px;
      padding: 40px 32px;
      margin-bottom: 20px;
      color: #fff;
      position: relative;
      overflow: hidden;
      text-align: center;
    }
    .quiz-hero::before {
      content: '';
      position: absolute;
      top: -50px; right: -50px;
      width: 220px; height: 220px;
      background: rgba(255,255,255,0.07);
      border-radius: 50%;
    }
    .quiz-hero::after {
      content: '';
      position: absolute;
      bottom: -70px; left: -30px;
      width: 180px; height: 180px;
      background: rgba(255,255,255,0.05);
      border-radius: 50%;
    }
    .quiz-hero-emoji { font-size: 52px; margin-bottom: 12px; position: relative; z-index: 1; display: block; }
    .quiz-hero-title { font-size: 30px; font-weight: 900; margin-bottom: 8px; position: relative; z-index: 1; letter-spacing: -0.5px; }
    .quiz-hero-sub { font-size: 15px; opacity: 0.88; margin-bottom: 28px; position: relative; z-index: 1; line-height: 1.6; max-width: 480px; margin-left: auto; margin-right: auto; }
    .quiz-hero-stats { display: flex; gap: 28px; justify-content: center; margin-bottom: 28px; position: relative; z-index: 1; }
    .quiz-hero-stat { text-align: center; }
    .quiz-hero-stat-val { font-size: 24px; font-weight: 800; }
    .quiz-hero-stat-label { font-size: 11px; opacity: 0.75; text-transform: uppercase; letter-spacing: 0.06em; }
    .quiz-start-btn {
      display: inline-flex;
      align-items: center;
      gap: 10px;
      background: #fff;
      color: #4f46e5;
      border: none;
      border-radius: 12px;
      padding: 16px 36px;
      font-size: 17px;
      font-weight: 800;
      cursor: pointer;
      text-decoration: none;
      box-shadow: 0 6px 24px rgba(0,0,0,0.18);
      transition: transform 0.18s, box-shadow 0.18s;
      position: relative;
      z-index: 1;
    }
    .quiz-start-btn:hover { transform: translateY(-3px) scale(1.03); box-shadow: 0 10px 32px rgba(0,0,0,0.22); color: #4338ca; }
    .quiz-start-btn .btn-arrow { font-size: 20px; transition: transform 0.18s; }
    .quiz-start-btn:hover .btn-arrow { transform: translateX(4px); }

    /* Section card */
    .qs-card {
      background: #ffffff;
      border-radius: 14px;
      box-shadow: 0 1px 4px rgba(0,0,0,0.07);
      margin-bottom: 20px;
      overflow: hidden;
    }
    .qs-card-header {
      display: flex;
      align-items: center;
      gap: 12px;
      padding: 16px 20px;
      border-bottom: 1px solid #f3f4f6;
    }
    .qs-card-icon {
      width: 38px; height: 38px;
      border-radius: 10px;
      display: flex; align-items: center; justify-content: center;
      font-size: 20px;
      flex-shrink: 0;
    }
    .qs-card-header-text h2 { font-size: 16px; font-weight: 700; color: #1f2937; }
    .qs-card-header-text p { font-size: 12px; color: #9ca3af; margin-top: 2px; }
    .qs-card-body { padding: 20px; }

    /* Rules list */
    .rules-list { list-style: none; padding: 0; }
    .rules-list li {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      padding: 10px 0;
      border-bottom: 1px solid #f3f4f6;
      font-size: 14px;
      color: #374151;
      line-height: 1.5;
    }
    .rules-list li:last-child { border-bottom: none; }
    .rule-icon {
      width: 28px; height: 28px;
      border-radius: 8px;
      display: flex; align-items: center; justify-content: center;
      font-size: 15px;
      flex-shrink: 0;
      margin-top: 1px;
    }
    .rules-list li strong { color: #1f2937; }

    /* Rewards grid */
    .rewards-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
      gap: 14px;
    }
    .reward-card {
      background: linear-gradient(135deg, #f8f9ff 0%, #f0f9ff 100%);
      border: 1px solid #e0e7ff;
      border-radius: 12px;
      padding: 16px 14px;
      text-align: center;
      transition: transform 0.18s, box-shadow 0.18s;
      cursor: default;
    }
    .reward-card:hover { transform: translateY(-3px); box-shadow: 0 6px 18px rgba(79,70,229,0.12); }
    .reward-emoji { font-size: 36px; margin-bottom: 8px; display: block; }
    .reward-name { font-size: 13px; font-weight: 700; color: #1f2937; margin-bottom: 4px; }
    .reward-pts {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      background: #4f46e5;
      color: #fff;
      border-radius: 20px;
      padding: 3px 10px;
      font-size: 11px;
      font-weight: 700;
      margin-bottom: 6px;
    }
    .reward-desc { font-size: 11px; color: #6b7280; line-height: 1.4; }

    /* Leaderboard */
    .lb-item {
      display: flex;
      align-items: center;
      gap: 12px;
      padding: 10px 0;
      border-bottom: 1px solid #f3f4f6;
    }
    .lb-item:last-child { border-bottom: none; }
    .lb-rank {
      width: 28px; height: 28px;
      border-radius: 50%;
      display: flex; align-items: center; justify-content: center;
      font-size: 12px;
      font-weight: 800;
      flex-shrink: 0;
    }
    .lb-rank.gold   { background: #fef3c7; color: #d97706; }
    .lb-rank.silver { background: #f3f4f6; color: #6b7280; }
    .lb-rank.bronze { background: #fff7ed; color: #ea580c; }
    .lb-rank.other  { background: #f0f2f5; color: #9ca3af; }
    .lb-avatar {
      width: 38px; height: 38px;
      border-radius: 50%;
      object-fit: cover;
      flex-shrink: 0;
      border: 2px solid #e0e7ff;
    }
    .lb-info { flex: 1; min-width: 0; }
    .lb-name { font-size: 13px; font-weight: 700; color: #1f2937; }
    .lb-meta { font-size: 11px; color: #9ca3af; margin-top: 1px; }
    .lb-pts {
      font-size: 14px;
      font-weight: 800;
      color: #4f46e5;
      white-space: nowrap;
    }
    .lb-badge {
      display: inline-flex;
      align-items: center;
      gap: 3px;
      background: #ecfdf5;
      color: #059669;
      border-radius: 20px;
      padding: 2px 8px;
      font-size: 10px;
      font-weight: 700;
      margin-left: 6px;
    }

    /* Sponsors */
    .sponsors-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
      gap: 14px;
    }
    .sponsor-card {
      background: #f8f9ff;
      border: 1px solid #e4e6ea;
      border-radius: 12px;
      padding: 18px 14px;
      text-align: center;
      transition: transform 0.18s, box-shadow 0.18s, border-color 0.18s;
    }
    .sponsor-card:hover { transform: translateY(-2px); box-shadow: 0 4px 14px rgba(0,0,0,0.09); border-color: #a5b4fc; }
    .sponsor-logo { font-size: 32px; margin-bottom: 8px; display: block; }
    .sponsor-name { font-size: 14px; font-weight: 700; color: #1f2937; margin-bottom: 4px; }
    .sponsor-tag { font-size: 11px; color: #6b7280; line-height: 1.4; }
    .sponsor-badge {
      display: inline-block;
      margin-top: 8px;
      background: #eef2ff;
      color: #4f46e5;
      border-radius: 20px;
      padding: 2px 10px;
      font-size: 10px;
      font-weight: 700;
    }

    /* News feed */
    .news-item {
      display: flex;
      gap: 12px;
      padding: 12px 0;
      border-bottom: 1px solid #f3f4f6;
    }
    .news-item:last-child { border-bottom: none; }
    .news-dot-wrap { display: flex; flex-direction: column; align-items: center; padding-top: 4px; }
    .news-dot { width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; }
    .news-dot-line { width: 2px; flex: 1; background: #f3f4f6; margin-top: 4px; }
    .news-item:last-child .news-dot-line { display: none; }
    .news-content { flex: 1; min-width: 0; }
    .news-title { font-size: 13px; font-weight: 700; color: #1f2937; margin-bottom: 3px; }
    .news-desc { font-size: 12px; color: #6b7280; line-height: 1.5; margin-bottom: 4px; }
    .news-meta { display: flex; align-items: center; gap: 8px; }
    .news-date { font-size: 11px; color: #9ca3af; }
    .news-tag {
      display: inline-flex;
      align-items: center;
      padding: 2px 8px;
      border-radius: 20px;
      font-size: 10px;
      font-weight: 700;
    }

    /* Ad banner */
    .ad-banner {
      background: linear-gradient(135deg, #f9fafb 0%, #f3f4f6 100%);
      border: 2px dashed #d1d5db;
      border-radius: 14px;
      padding: 28px 20px;
      text-align: center;
      margin-bottom: 20px;
    }
    .ad-banner-label {
      display: inline-block;
      background: #e4e6ea;
      color: #6b7280;
      font-size: 10px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.08em;
      padding: 3px 10px;
      border-radius: 20px;
      margin-bottom: 10px;
    }
    .ad-banner-placeholder {
      font-size: 13px;
      color: #9ca3af;
      line-height: 1.6;
    }
    .ad-banner-placeholder strong { color: #6b7280; display: block; font-size: 15px; margin-bottom: 4px; }
    .ad-banner-size {
      display: inline-block;
      margin-top: 10px;
      background: #fff;
      border: 1px solid #e4e6ea;
      border-radius: 8px;
      padding: 6px 16px;
      font-size: 12px;
      color: #9ca3af;
      font-family: monospace;
    }

    /* Responsive */
    @media (max-width: 1000px) { .sidebar-right { display: none; } }
    @media (max-width: 720px) {
      .sidebar-left { display: none; }
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .rewards-grid { grid-template-columns: 1fr 1fr; }
      .sponsors-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 480px) {
      .quiz-hero-title { font-size: 22px; }
      .quiz-hero-stats { gap: 16px; }
      .rewards-grid { grid-template-columns: 1fr 1fr; }
      .sponsors-grid { grid-template-columns: 1fr; }
    }