:root {
      --navy: #071a3d;
      --navy-2: #173357;
      --blue: #1262e8;
      --blue-dark: #0b4fbd;
      --sky: #eaf4ff;
      --cyan: #78d7ff;
      --gold: #ffcb57;
      --gold-soft: #fff2c8;
      --paper: #f6f8fc;
      --white: #fff;
      --muted: #607086;
      --line: #dce5f1;
      --green: #16725c;
      --green-soft: #e3f5ee;
      --shadow: 0 24px 70px rgba(7, 26, 61, .12);
      --container: min(1120px, calc(100% - 40px));
    }

    * { box-sizing: border-box; }
    html { scroll-behavior: smooth; scroll-padding-top: 82px; }
    body {
      margin: 0;
      color: var(--navy);
      background: var(--white);
      font-family: -apple-system, BlinkMacSystemFont, "Noto Sans HK", "PingFang HK", "Microsoft JhengHei", sans-serif;
      font-size: 17px;
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }
    body.modal-open { overflow: hidden; }
    img { display: block; max-width: 100%; }
    a { color: inherit; }
    button { font: inherit; }
    .container { width: var(--container); margin-inline: auto; }
    .skip-link {
      position: fixed; left: 12px; top: 10px; z-index: 100;
      padding: 10px 14px; border-radius: 10px; color: white; background: var(--navy);
      transform: translateY(-160%);
    }
    .skip-link:focus { transform: translateY(0); }
    .progress { position: fixed; inset: 0 auto auto 0; z-index: 90; width: 0; height: 3px; background: var(--gold); }

    .site-header {
      position: sticky; top: 0; z-index: 60; height: 68px;
      border-bottom: 1px solid rgba(220, 229, 241, .82);
      background: rgba(255, 255, 255, .9); backdrop-filter: blur(18px);
    }
    .header-inner { height: 100%; display: flex; align-items: center; justify-content: space-between; gap: 20px; }
    .brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; }
    .brand-mark { display: grid; place-items: center; width: 40px; height: 40px; border-radius: 13px; color: white; background: var(--navy); font-weight: 900; letter-spacing: -.06em; }
    .brand-text { display: flex; flex-direction: column; line-height: 1.12; }
    .brand-text strong { font-size: .96rem; letter-spacing: -.02em; }
    .brand-text small { margin-top: 4px; color: var(--muted); font-size: .67rem; font-weight: 700; letter-spacing: .04em; }
    .header-cta { display: inline-flex; align-items: center; justify-content: center; min-height: 42px; padding: 0 16px; border-radius: 12px; color: white; background: var(--blue); text-decoration: none; font-size: .86rem; font-weight: 800; }
    .header-cta:hover { background: var(--blue-dark); }

    .hero {
      position: relative; overflow: hidden; padding: 74px 0 58px;
      background:
        radial-gradient(circle at 8% 12%, rgba(120, 215, 255, .25), transparent 29%),
        radial-gradient(circle at 88% 12%, rgba(255, 203, 87, .26), transparent 25%),
        linear-gradient(180deg, #fff 0%, #f3f8ff 100%);
    }
    .hero::before {
      content: ""; position: absolute; right: -80px; bottom: -120px; width: 360px; height: 360px;
      border: 54px solid rgba(18, 98, 232, .045); border-radius: 50%;
    }
    .hero-grid { position: relative; display: grid; grid-template-columns: 1.08fr .92fr; align-items: center; gap: 72px; }
    .eyebrow { display: inline-flex; align-items: center; gap: 10px; color: var(--blue); font-size: .8rem; font-weight: 900; letter-spacing: .08em; text-transform: uppercase; }
    .eyebrow::before { content: ""; width: 24px; height: 3px; border-radius: 9px; background: var(--gold); }
    h1 { margin: 18px 0 20px; max-width: 760px; font-size: clamp(2.55rem, 6vw, 5.4rem); line-height: 1.04; letter-spacing: -.065em; }
    h1 span { color: var(--blue); }
    .hero-lead { max-width: 680px; margin: 0; color: var(--navy-2); font-size: clamp(1.05rem, 1.8vw, 1.28rem); line-height: 1.78; }
    .hero-meta { display: flex; flex-wrap: wrap; gap: 10px; margin: 28px 0 30px; }
    .tag { display: inline-flex; align-items: center; gap: 8px; padding: 8px 12px; border: 1px solid var(--line); border-radius: 999px; background: rgba(255, 255, 255, .8); color: var(--navy-2); font-size: .82rem; font-weight: 700; }
    .tag::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: var(--blue); }
    .hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
    .btn { display: inline-flex; align-items: center; justify-content: center; min-height: 49px; padding: 0 19px; border: 0; border-radius: 14px; text-decoration: none; font-weight: 800; cursor: pointer; transition: transform .2s, background .2s, border-color .2s; }
    .btn:hover { transform: translateY(-2px); }
    .btn-primary { color: white; background: var(--blue); box-shadow: 0 12px 28px rgba(18, 98, 232, .2); }
    .btn-primary:hover { background: var(--blue-dark); }
    .btn-secondary { border: 1px solid var(--line); color: var(--navy); background: white; }
    .btn-secondary:hover { border-color: #afc4df; }

    .hero-visual { position: relative; min-height: 455px; }
    .loop-card { position: absolute; inset: 4px 0 20px 18px; padding: 28px; border: 1px solid rgba(220, 229, 241, .82); border-radius: 32px; background: rgba(255, 255, 255, .92); box-shadow: var(--shadow); transform: rotate(1deg); }
    .loop-card h2 { margin: 0; font-size: 1rem; letter-spacing: -.02em; }
    .loop-card p { margin: 4px 0 24px; color: var(--muted); font-size: .84rem; }
    .loop { position: relative; display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
    .loop-step { min-height: 142px; padding: 20px; border-radius: 20px; }
    .loop-step:nth-child(1) { background: var(--navy); color: white; }
    .loop-step:nth-child(2) { background: var(--sky); }
    .loop-step:nth-child(3) { background: var(--gold-soft); }
    .loop-step:nth-child(4) { background: var(--green-soft); }
    .loop-no { display: inline-grid; place-items: center; width: 28px; height: 28px; border-radius: 9px; background: rgba(255, 255, 255, .72); color: var(--blue); font-size: .72rem; font-weight: 900; }
    .loop-step:nth-child(1) .loop-no { background: rgba(255, 255, 255, .14); color: var(--gold); }
    .loop-step b { display: block; margin-top: 15px; font-size: 1.12rem; }
    .loop-step small { display: block; margin-top: 4px; opacity: .72; font-size: .74rem; line-height: 1.45; }
    .float-note { position: absolute; right: -18px; bottom: -12px; max-width: 235px; padding: 15px 17px; border-radius: 16px; color: var(--navy); background: var(--gold); box-shadow: 0 16px 36px rgba(122, 88, 0, .18); transform: rotate(-2deg); font-size: .82rem; font-weight: 800; line-height: 1.5; }

    .quick-nav { border-block: 1px solid var(--line); background: white; }
    .quick-nav-inner { display: flex; align-items: center; gap: 12px; overflow-x: auto; padding-block: 14px; scrollbar-width: none; }
    .quick-nav-inner::-webkit-scrollbar { display: none; }
    .quick-nav strong { flex: 0 0 auto; font-size: .78rem; }
    .quick-nav a { flex: 0 0 auto; padding: 7px 11px; border-radius: 9px; color: var(--muted); background: var(--paper); text-decoration: none; font-size: .78rem; font-weight: 700; }
    .quick-nav a:hover { color: var(--blue); background: var(--sky); }

    main section { padding: 92px 0; }
    .section-label { margin: 0 0 10px; color: var(--blue); font-size: .78rem; font-weight: 900; letter-spacing: .09em; text-transform: uppercase; }
    .section-title { margin: 0; max-width: 820px; font-size: clamp(2rem, 4.5vw, 3.7rem); line-height: 1.15; letter-spacing: -.05em; }
    .section-title span { color: var(--blue); }
    .section-lead { max-width: 760px; margin: 18px 0 0; color: var(--muted); font-size: 1.04rem; }
    .section-head { margin-bottom: 46px; }

    .definition { background: var(--paper); }
    .definition-grid { display: grid; grid-template-columns: .9fr 1.1fr; align-items: start; gap: 58px; }
    .quote-card { position: sticky; top: 100px; padding: 38px; border-radius: 28px; color: white; background: var(--navy); overflow: hidden; }
    .quote-card::after { content: "PBL"; position: absolute; right: -18px; bottom: -55px; color: rgba(255, 255, 255, .06); font-size: 8rem; font-weight: 900; letter-spacing: -.08em; }
    .quote-card small { color: var(--cyan); font-weight: 900; letter-spacing: .08em; }
    .quote-card blockquote { position: relative; z-index: 1; margin: 20px 0 0; font-size: clamp(1.5rem, 3vw, 2.45rem); font-weight: 800; line-height: 1.45; letter-spacing: -.035em; }
    .quote-card blockquote span { color: var(--gold); }
    .definition-copy > p { margin: 0 0 21px; color: var(--navy-2); }
    .comparison { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 30px; }
    .compare-card { padding: 24px; border: 1px solid var(--line); border-radius: 20px; background: white; }
    .compare-card.good { border-color: #b8ddf8; background: #eef8ff; }
    .compare-tag { display: inline-flex; padding: 5px 9px; border-radius: 8px; color: var(--muted); background: var(--paper); font-size: .7rem; font-weight: 900; letter-spacing: .05em; }
    .compare-card.good .compare-tag { color: #0c579b; background: #dbefff; }
    .compare-card h3 { margin: 15px 0 7px; font-size: 1.03rem; }
    .compare-card p { margin: 0; color: var(--muted); font-size: .86rem; }

    .process { overflow: hidden; }
    .process-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; counter-reset: process; }
    .process-card { position: relative; min-height: 300px; padding: 26px; border: 1px solid var(--line); border-radius: 24px; background: white; overflow: hidden; }
    .process-card::after { counter-increment: process; content: "0" counter(process); position: absolute; right: 14px; bottom: -24px; color: rgba(18, 98, 232, .06); font-size: 5rem; font-weight: 900; letter-spacing: -.08em; }
    .process-card:nth-child(1) { border-top: 5px solid var(--blue); }
    .process-card:nth-child(2) { border-top: 5px solid #52a9ef; }
    .process-card:nth-child(3) { border-top: 5px solid var(--gold); }
    .process-card:nth-child(4) { border-top: 5px solid #4cb799; }
    .process-icon { display: grid; place-items: center; width: 48px; height: 48px; border-radius: 15px; color: var(--blue); background: var(--sky); font-weight: 900; }
    .process-card h3 { margin: 24px 0 9px; font-size: 1.3rem; letter-spacing: -.03em; }
    .process-card p { margin: 0; color: var(--muted); font-size: .88rem; }
    .process-example { display: block; margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--line); color: var(--navy-2); font-size: .77rem; font-weight: 700; }

    .skills { color: white; background: var(--navy); }
    .skills .section-label { color: var(--cyan); }
    .skills .section-lead { color: rgba(255, 255, 255, .66); }
    .skills-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
    .skill-card { min-height: 180px; padding: 24px; border: 1px solid rgba(255, 255, 255, .12); border-radius: 20px; background: rgba(255, 255, 255, .055); }
    .skill-card b { display: block; margin: 15px 0 6px; font-size: 1.04rem; }
    .skill-card p { margin: 0; color: rgba(255, 255, 255, .58); font-size: .84rem; }
    .skill-mark { color: var(--gold); font-size: .74rem; font-weight: 900; letter-spacing: .06em; }

    .checklist { background: var(--paper); }
    .checklist-grid { display: grid; grid-template-columns: .86fr 1.14fr; gap: 60px; align-items: start; }
    .checklist-intro { position: sticky; top: 100px; }
    .check-list { display: grid; gap: 12px; }
    .check-item { display: grid; grid-template-columns: 44px 1fr; gap: 16px; padding: 22px; border: 1px solid var(--line); border-radius: 18px; background: white; }
    .check-icon { display: grid; place-items: center; width: 40px; height: 40px; border-radius: 12px; color: var(--green); background: var(--green-soft); font-weight: 900; }
    .check-item h3 { margin: 0 0 5px; font-size: 1rem; }
    .check-item p { margin: 0; color: var(--muted); font-size: .84rem; }

    .try-card { position: relative; overflow: hidden; padding: 42px; border-radius: 30px; background: var(--gold-soft); }
    .try-card::after { content: "?"; position: absolute; right: 26px; top: -45px; color: rgba(88, 63, 0, .08); font-size: 12rem; font-weight: 900; }
    .try-grid { position: relative; z-index: 1; display: grid; grid-template-columns: .8fr 1.2fr; gap: 50px; }
    .try-card h3 { margin: 8px 0 12px; max-width: 420px; font-size: clamp(1.8rem, 3.5vw, 3rem); line-height: 1.22; letter-spacing: -.045em; }
    .try-card p { margin: 0; color: #5c4710; }
    .mini-steps { display: grid; gap: 10px; }
    .mini-step { display: grid; grid-template-columns: 35px 1fr; gap: 12px; padding: 14px 16px; border-radius: 15px; background: rgba(255, 255, 255, .62); }
    .mini-step b { display: grid; place-items: center; width: 30px; height: 30px; border-radius: 10px; color: white; background: var(--navy); font-size: .73rem; }
    .mini-step span { color: #4e3d0d; font-size: .86rem; font-weight: 700; }

    .course { padding-bottom: 118px; background: linear-gradient(180deg, #f4f8ff 0%, #fff 100%); }
    .course-shell { overflow: hidden; border: 1px solid #d7e5f8; border-radius: 34px; background: white; box-shadow: var(--shadow); }
    .course-top { display: grid; grid-template-columns: 1.06fr .94fr; }
    .course-copy { padding: 54px; }
    .course-copy .section-label { color: var(--blue); }
    .course-copy h2 { margin: 9px 0 16px; font-size: clamp(2.2rem, 4.5vw, 4rem); line-height: 1.1; letter-spacing: -.055em; }
    .course-copy h2 span { color: var(--blue); }
    .course-copy > p { margin: 0; color: var(--muted); }
    .journey { display: flex; align-items: center; gap: 10px; margin: 26px 0; font-size: .85rem; font-weight: 900; }
    .journey span { padding: 8px 10px; border-radius: 10px; color: var(--blue); background: var(--sky); }
    .journey i { color: var(--blue); font-style: normal; }
    .course-points { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 28px; }
    .course-point { padding: 13px 14px; border: 1px solid var(--line); border-radius: 13px; color: var(--navy-2); font-size: .82rem; font-weight: 700; }
    .poster-wrap { min-height: 640px; padding: 0; border: 0; background: #09275c; cursor: zoom-in; }
    .poster-wrap img { width: 100%; height: 100%; object-fit: cover; object-position: center top; }
    .course-bottom { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 1px; border-top: 1px solid var(--line); background: var(--line); }
    .detail-card { min-height: 170px; padding: 28px; background: white; }
    .detail-card small { display: block; color: var(--muted); font-size: .72rem; font-weight: 900; letter-spacing: .07em; }
    .detail-card b { display: block; margin: 9px 0 4px; font-size: 1.08rem; }
    .detail-card p { margin: 0; color: var(--muted); font-size: .8rem; }
    .signup-panel { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 28px; padding: 30px 34px; color: white; background: var(--blue); }
    .signup-panel h3 { margin: 0; font-size: 1.45rem; }
    .signup-panel p { margin: 5px 0 0; color: rgba(255, 255, 255, .72); font-size: .84rem; }
    .signup-qr { width: 154px; padding: 10px; border-radius: 16px; background: white; }
    .signup-qr img { width: 100%; image-rendering: pixelated; }
    .signup-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 19px; }
    .signup-actions .btn { min-height: 44px; padding-inline: 15px; font-size: .82rem; }
    .signup-actions .btn:first-child { color: var(--navy); background: var(--gold); }
    .signup-actions .btn:last-child { border: 1px solid rgba(255, 255, 255, .28); color: white; background: rgba(255, 255, 255, .09); }

    .sources { padding: 40px 0 52px; border-top: 1px solid var(--line); }
    .sources details { max-width: 860px; margin-inline: auto; }
    .sources summary { cursor: pointer; color: var(--muted); font-size: .82rem; font-weight: 800; }
    .sources ul { margin: 14px 0 0; padding-left: 20px; color: var(--muted); font-size: .76rem; }
    .sources a { color: var(--blue); text-underline-offset: 3px; }
    footer { padding: 34px 0 104px; color: var(--muted); background: var(--paper); font-size: .78rem; }
    .footer-inner { display: flex; justify-content: space-between; gap: 20px; }
    .footer-inner strong { color: var(--navy); }
    .mobile-bar { display: none; }

    .reveal { opacity: 0; transform: translateY(18px); transition: opacity .55s ease, transform .55s ease; }
    .reveal.visible { opacity: 1; transform: none; }

    dialog { width: min(760px, calc(100% - 28px)); max-height: calc(100vh - 32px); padding: 0; border: 0; border-radius: 24px; background: white; box-shadow: 0 30px 90px rgba(7, 26, 61, .35); }
    dialog::backdrop { background: rgba(7, 26, 61, .74); backdrop-filter: blur(6px); }
    .dialog-head { position: sticky; top: 0; z-index: 2; display: flex; align-items: center; justify-content: space-between; gap: 18px; padding: 14px 16px; border-bottom: 1px solid var(--line); background: rgba(255, 255, 255, .94); backdrop-filter: blur(10px); }
    .dialog-head strong { font-size: .9rem; }
    .dialog-close { display: grid; place-items: center; width: 40px; height: 40px; border: 0; border-radius: 12px; color: var(--navy); background: var(--paper); cursor: pointer; }
    .dialog-body { padding: 14px; }
    .dialog-body img { width: 100%; border-radius: 15px; }

    @media (max-width: 980px) {
      .hero-grid, .definition-grid, .checklist-grid, .try-grid, .course-top { grid-template-columns: 1fr; }
      .hero-visual { min-height: 450px; max-width: 650px; }
      .definition-grid, .checklist-grid { gap: 34px; }
      .quote-card, .checklist-intro { position: static; }
      .process-grid { grid-template-columns: 1fr 1fr; }
      .skills-grid { grid-template-columns: 1fr 1fr; }
      .poster-wrap { min-height: auto; }
      .poster-wrap img { height: auto; }
    }

    @media (max-width: 660px) {
      :root { --container: min(100% - 28px, 1120px); }
      body { font-size: 16px; }
      .site-header { height: 62px; }
      .brand-text small { display: none; }
      .brand-mark { width: 36px; height: 36px; border-radius: 11px; }
      .header-cta { min-height: 38px; padding-inline: 12px; font-size: .78rem; }
      .hero { padding: 54px 0 42px; }
      h1 { font-size: clamp(2.55rem, 13vw, 4.2rem); }
      .hero-meta { margin-block: 22px; }
      .hero-actions .btn { width: 100%; }
      .hero-visual { min-height: 422px; margin-top: 20px; }
      .loop-card { inset: 0 0 30px 0; padding: 19px; border-radius: 24px; transform: none; }
      .loop { gap: 8px; }
      .loop-step { min-height: 132px; padding: 15px; border-radius: 16px; }
      .float-note { right: 10px; bottom: 0; max-width: 225px; }
      main section { padding: 68px 0; }
      .section-head { margin-bottom: 32px; }
      .quote-card { padding: 28px 24px; }
      .comparison, .process-grid, .skills-grid, .course-points, .course-bottom { grid-template-columns: 1fr; }
      .process-card { min-height: 235px; }
      .skill-card { min-height: auto; }
      .try-card { padding: 28px 22px; }
      .try-grid { gap: 28px; }
      .course-copy { padding: 34px 24px; }
      .journey { flex-wrap: wrap; }
      .journey i { display: none; }
      .course-bottom { background: white; }
      .detail-card { min-height: 0; border-top: 1px solid var(--line); }
      .signup-panel { grid-template-columns: 1fr; padding: 28px 24px; }
      .signup-qr { width: min(210px, 72vw); margin-inline: auto; }
      .signup-actions .btn { width: 100%; }
      .footer-inner { display: block; }
      .footer-inner div:last-child { margin-top: 10px; }
      .mobile-bar { position: fixed; left: 10px; right: 10px; bottom: 10px; z-index: 55; display: grid; grid-template-columns: .8fr 1.2fr; gap: 8px; padding: 8px; border: 1px solid var(--line); border-radius: 16px; background: rgba(255, 255, 255, .94); box-shadow: 0 12px 38px rgba(7, 26, 61, .2); backdrop-filter: blur(16px); }
      .mobile-bar .btn { min-height: 44px; padding: 0 10px; font-size: .78rem; }
    }

    @media (prefers-reduced-motion: reduce) {
      html { scroll-behavior: auto; }
      *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
      .reveal { opacity: 1; transform: none; }
    }