:root {
    --navy: #1E2B5C; --blue: #2563EB; --ink: #1C1C1E; --sub: #6E6E73; --line: #E5E5EA;
    --canvas: #F2F2F7; --card: #FFFFFF; --amber: #E8770C; --amber-bg: #FFF4E5;
  }
  * { box-sizing: border-box; }
  html, body { margin: 0; background: var(--canvas); color: var(--ink);
    font-family: -apple-system, BlinkMacSystemFont, "Inter", "Helvetica Neue", Arial, sans-serif; }
  header { display: flex; align-items: center; justify-content: space-between; gap: 12px;
    max-width: 1200px; margin: 0 auto; padding: 16px; }
  header img { height: 36px; }
  header a { color: var(--blue); font-weight: 600; text-decoration: none; font-size: 15px; }
  main { max-width: 1200px; margin: 0 auto; padding: 0 16px 32px; }
  .progress { display: flex; gap: 6px; margin: 4px 0 14px; }
  .progress button { flex: 1; height: 6px; border: 0; border-radius: 3px; background: #D1D1D6; cursor: pointer; padding: 0; }
  .progress button.done { background: #93B4F6; }
  .progress button.on { background: var(--blue); }
  .stage { position: relative; background: var(--card); border-radius: 16px; overflow: hidden;
    box-shadow: 0 1px 3px rgba(0,0,0,.08); }
  .stage img { display: block; width: 100%; height: auto; }
  .hot { position: absolute; border: 3px solid var(--amber); border-radius: 12px;
    box-shadow: 0 0 0 9999px rgba(15, 23, 42, .38); transition: all .35s ease; pointer-events: none; }
  .hot::after { content: ""; position: absolute; inset: -9px; border-radius: 16px;
    border: 2px solid rgba(232,119,12,.55); animation: pulse 1.8s ease-out infinite; }
  @keyframes pulse { from { opacity: 1; transform: scale(1); } to { opacity: 0; transform: scale(1.04); } }
  @media (prefers-reduced-motion: reduce) { .hot, .hot::after { transition: none; animation: none; } }
  .intro { display: grid; place-items: center; min-height: 420px; padding: 40px 24px; text-align: center;
    background: linear-gradient(160deg, #EEF3FE, #FFFFFF); }
  .intro h1 { color: var(--navy); font-size: clamp(28px, 4vw, 44px); margin: 12px 0 8px; letter-spacing: -.5px; }
  .intro p { color: var(--sub); font-size: 18px; max-width: 640px; margin: 0 auto 8px; line-height: 1.5; }
  .panel { margin-top: 14px; background: var(--card); border-radius: 16px; padding: 18px 20px;
    box-shadow: 0 1px 3px rgba(0,0,0,.08); display: grid; grid-template-columns: 1fr auto; gap: 16px; align-items: center; }
  .panel .k { color: var(--blue); font-size: 12px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; }
  .panel h2 { margin: 4px 0 6px; font-size: 22px; color: var(--navy); }
  .panel p { margin: 0; color: #3A3A3C; font-size: 16px; line-height: 1.55; }
  .nav { display: flex; gap: 10px; }
  .btn { min-height: 44px; padding: 0 18px; border-radius: 10px; font-size: 15px; font-weight: 600; cursor: pointer;
    border: 1px solid var(--line); background: #fff; color: var(--ink); text-decoration: none; display: inline-flex; align-items: center; }
  .btn.primary { background: var(--blue); border-color: var(--blue); color: #fff; }
  .btn:disabled { opacity: .4; cursor: default; }
  .cta { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-top: 18px; }
  .note { text-align: center; color: var(--sub); font-size: 13px; margin-top: 16px; }
  @media (max-width: 760px) {
    .panel { grid-template-columns: 1fr; }
    .nav { justify-content: space-between; }
    .nav .btn { flex: 1; justify-content: center; }
  }
  .intro .k { color: var(--blue); font-size: 12px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; }
  .other { margin-top: 18px; font-size: 15px; }
  .other a, .choose a { color: var(--blue); font-weight: 600; text-decoration: none; }
  .choose { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); margin-top: 8px; }
  .choose a { display: block; background: var(--card); border-radius: 16px; padding: 22px; box-shadow: 0 1px 3px rgba(0,0,0,.08); color: var(--ink); }
  .choose a:hover { box-shadow: 0 4px 14px rgba(0,0,0,.10); }
  .choose h2 { margin: 6px 0; color: var(--navy); font-size: 22px; }
  .choose p { margin: 0; color: var(--sub); line-height: 1.5; }