:root {
    --navy: #173158;
    --navy-deep: #0F2340;
    --navy-card: #1E3E6E;
    --orange: #F49545;
    --green: #239557;
    --red: #D6524A;
    --ink: #FFFFFF;
    --ink-soft: #B9C4D6;
  }
  * { box-sizing: border-box; }
  html, body {
    margin: 0;
    height: 100%;
    background: var(--navy-deep);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    color: var(--ink);
    overflow-x: hidden;
  }
  .bg-decor {
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    background:
      radial-gradient(circle at 88% 8%, rgba(244,149,69,0.16), transparent 42%),
      radial-gradient(circle at 6% 92%, rgba(35,149,87,0.14), transparent 42%);
  }
  .crane {
    position: fixed;
    right: -30px;
    top: -20px;
    width: 260px;
    opacity: 0.10;
    z-index: 0;
  }
  .wrap {
    position: relative;
    z-index: 1;
    max-width: 760px;
    margin: 0 auto;
    padding: 22px 18px 40px;
    min-height: 100%;
    display: flex;
    flex-direction: column;
  }

  .topbar {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 10px;
    margin-bottom: 18px;
  }
  .brand-mark { display: flex; align-items: center; gap: 10px; }
  .bull {
    width: 36px; height: 36px;
    flex-shrink: 0;
  }
  .brand-text .b1 {
    font-size: 15px;
    font-weight: 800;
    letter-spacing: 0.5px;
    color: var(--ink);
  }
  .brand-text .b2 {
    font-size: 11.5px;
    font-weight: 700;
    letter-spacing: 2.2px;
    color: var(--orange);
    margin-top: 1px;
  }
  .score-box {
    text-align: right;
    background: rgba(255,255,255,0.06);
    border: 1px solid rgba(255,255,255,0.12);
    border-radius: 10px;
    padding: 7px 12px;
    cursor: pointer;
  }
  .score-box .n { font-size: 17px; font-weight: 800; }
  .score-box .l { font-size: 10px; color: var(--ink-soft); letter-spacing: 0.4px; }

  .controls-row {
    display: flex;
    gap: 8px;
    margin-bottom: 18px;
  }
  select {
    flex: 1;
    background: rgba(255,255,255,0.07);
    border: 1px solid rgba(255,255,255,0.16);
    color: var(--ink);
    font-size: 13px;
    font-weight: 600;
    padding: 10px 12px;
    border-radius: 10px;
    appearance: none;
    -webkit-appearance: none;
    color-scheme: dark;
  }
  select option {
    background: var(--navy-card);
    color: var(--ink);
  }

  .stage {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
  }

  .card {
    background: linear-gradient(180deg, var(--navy-card), var(--navy));
    border: 1px solid rgba(255,255,255,0.10);
    border-radius: 22px;
    padding: 30px 26px 26px;
    box-shadow: 0 20px 50px rgba(0,0,0,0.35);
  }

  .cat-pill {
    display: inline-block;
    background: var(--orange);
    color: var(--navy-deep);
    font-size: 12px;
    font-weight: 800;
    letter-spacing: 0.6px;
    padding: 6px 14px;
    border-radius: 20px;
    margin-bottom: 18px;
  }

  .question {
    font-size: 25px;
    font-weight: 800;
    line-height: 1.35;
    margin: 0 0 26px;
    min-height: 90px;
  }

  .options {
    display: grid;
    grid-template-columns: 1fr;
    gap: 11px;
  }
  .opt {
    text-align: left;
    background: rgba(255,255,255,0.06);
    border: 1.5px solid rgba(255,255,255,0.16);
    color: var(--ink);
    font-size: 16px;
    font-weight: 600;
    padding: 15px 16px;
    border-radius: 13px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 12px;
    transition: background 0.15s, border-color 0.15s, transform 0.1s;
  }
  .opt:active { transform: scale(0.985); }
  .opt .tag {
    flex-shrink: 0;
    width: 26px; height: 26px;
    border-radius: 7px;
    background: rgba(255,255,255,0.10);
    display: flex; align-items: center; justify-content: center;
    font-size: 12.5px;
    font-weight: 800;
  }
  .opt.correct {
    background: rgba(35,149,87,0.28);
    border-color: var(--green);
  }
  .opt.correct .tag { background: var(--green); }
  .opt.wrong {
    background: rgba(214,82,74,0.28);
    border-color: var(--red);
    animation: shake 0.35s;
  }
  .opt.wrong .tag { background: var(--red); }
  .opt.disabled { pointer-events: none; opacity: 0.55; }
  .opt.disabled.correct, .opt.disabled.wrong { opacity: 1; }

  @keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
  }

  .feedback {
    margin-top: 18px;
    text-align: center;
    font-size: 15px;
    font-weight: 700;
    min-height: 22px;
  }
  .feedback.correct-text { color: #7CD9A0; }
  .feedback.wrong-text { color: #F0958D; }

  .actions {
    display: flex;
    justify-content: center;
    margin-top: 22px;
  }
  .next-btn {
    background: var(--orange);
    color: var(--navy-deep);
    border: none;
    font-size: 15px;
    font-weight: 800;
    letter-spacing: 0.3px;
    padding: 14px 34px;
    border-radius: 30px;
    cursor: pointer;
  }
  .next-btn:active { transform: scale(0.97); }

  .footer-note {
    text-align: center;
    color: var(--ink-soft);
    font-size: 12px;
    margin-top: 22px;
  }

  .idle {
    text-align: center;
    padding: 20px 0;
  }
  .idle h1 {
    font-size: 26px;
    font-weight: 800;
    margin: 0 0 8px;
  }
  .idle p {
    color: var(--ink-soft);
    font-size: 14.5px;
    margin: 0 0 26px;
    line-height: 1.5;
  }
  .start-btn {
    background: var(--orange);
    color: var(--navy-deep);
    border: none;
    font-size: 17px;
    font-weight: 800;
    padding: 16px 40px;
    border-radius: 32px;
    cursor: pointer;
  }