:root {
  --white: #ffffff;
  --ink: #111827;
  --muted: #4b5563;
  --line: #d7dee7;
  --soft: #f6f8fa;
  --green: #25864f;
  --green-dark: #17673b;
  --green-soft: #eef7f1;
  --navy: #0b2b50;
  --blue-soft: #eef4fa;
  --amber: #b66a00;
  --amber-soft: #fff7e8;
  --danger: #b42318;
  --danger-soft: #fff1f0;
  --font: "Noto Sans TC", "Microsoft JhengHei", system-ui, sans-serif;
  --font-en: Inter, "Noto Sans TC", system-ui, sans-serif;
  --content: 1320px;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  background: var(--white);
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--white);
  font-family: var(--font);
  font-size: 18px;
  line-height: 1.72;
  letter-spacing: 0;
}

a { color: var(--green-dark); text-underline-offset: 3px; }
a:hover { color: var(--navy); }
button, input, select, textarea { font: inherit; }
img { max-width: 100%; height: auto; }

.skip-link {
  position: fixed;
  left: 16px;
  top: -80px;
  z-index: 1000;
  padding: 10px 14px;
  color: var(--white);
  background: var(--navy);
}

.skip-link:focus { top: 12px; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.98);
  border-bottom: 1px solid var(--line);
}

.topbar-inner {
  max-width: var(--content);
  min-height: 68px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 260px;
  color: var(--navy);
  text-decoration: none;
  font-family: var(--font-en);
  font-weight: 800;
}

.brand-mark {
  width: 10px;
  height: 34px;
  background: var(--green);
}

.brand small {
  display: block;
  color: var(--muted);
  font-size: 12px;
  font-weight: 600;
}

.nav-wrap { flex: 1; min-width: 0; }
.site-nav {
  display: flex;
  gap: 4px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.site-nav a {
  flex: 0 0 auto;
  padding: 10px 12px;
  border-bottom: 3px solid transparent;
  color: var(--muted);
  text-decoration: none;
  font-size: 15px;
  font-weight: 700;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--navy);
  border-bottom-color: var(--green);
}

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--navy);
  background: var(--white);
  cursor: pointer;
}

.progress-track { height: 4px; background: #edf0f3; }
.progress-value {
  width: 0;
  height: 100%;
  background: var(--green);
  transition: width 240ms ease;
}

.page-shell {
  animation: page-enter 220ms ease both;
}

.hero {
  max-width: var(--content);
  min-height: 58vh;
  margin: 0 auto;
  padding: 40px 24px 16px;
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.92fr);
  align-items: center;
  gap: 52px;
}

.hero.no-image {
  min-height: 44vh;
  grid-template-columns: 1fr;
  max-width: 980px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--green-dark);
  font-family: var(--font-en);
  font-size: 15px;
  font-weight: 800;
}

.hero h1 {
  max-width: 850px;
  margin: 0;
  color: var(--navy);
  font-size: 48px;
  line-height: 1.18;
  letter-spacing: 0;
}

.hero-copy {
  max-width: 780px;
  margin: 20px 0 0;
  color: var(--muted);
  font-size: 21px;
}

.outcome-strip {
  margin-top: 28px;
  padding: 16px 18px;
  border-left: 5px solid var(--green);
  background: var(--green-soft);
}

.outcome-strip strong { color: var(--green-dark); }

.hero-visual {
  margin: 0;
}

.hero-visual img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: contain;
  border: 1px solid var(--line);
  background: var(--white);
}

.hero-visual figcaption {
  margin-top: 8px;
  color: var(--muted);
  font-size: 14px;
}

.home-tools {
  margin-top: 28px;
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.mobile-start-band { display: none; }
.mobile-start-visual { margin: 0; }
.mobile-start-visual img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: contain;
  border: 1px solid var(--line);
  background: var(--white);
}
.mobile-start-visual figcaption {
  margin-top: 8px;
  color: var(--muted);
  font-size: 14px;
}

.primary-link,
.secondary-link,
.copy-button,
.page-link {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 9px 15px;
  border: 1px solid var(--green-dark);
  border-radius: 6px;
  text-decoration: none;
  font-weight: 800;
  cursor: pointer;
}

.primary-link { color: var(--white); background: var(--green-dark); }
.primary-link:hover { color: var(--white); background: var(--navy); border-color: var(--navy); }
.secondary-link, .page-link { color: var(--green-dark); background: var(--white); }
.secondary-link:hover, .page-link:hover { color: var(--navy); border-color: var(--navy); }

.qr-button {
  width: 96px;
  height: 96px;
  padding: 7px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--white);
  cursor: zoom-in;
}

.qr-button img { display: block; width: 100%; height: 100%; }

.content-band {
  border-top: 1px solid var(--line);
  padding: 54px 24px;
}

.content-band:nth-of-type(even) { background: var(--soft); }
.content-inner { max-width: var(--content); margin: 0 auto; }

.section-heading {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  align-items: start;
  gap: 18px;
  margin-bottom: 24px;
}

.section-number {
  padding-top: 4px;
  color: var(--green);
  font-family: var(--font-en);
  font-size: 16px;
  font-weight: 800;
}

.section-heading h2 {
  margin: 0;
  color: var(--navy);
  font-size: 30px;
  line-height: 1.3;
}

.section-intro { margin: 8px 0 0; color: var(--muted); }

.table-shell {
  overflow-x: auto;
  border: 1px solid var(--line);
  background: var(--white);
}

.data-table {
  width: 100%;
  min-width: 720px;
  border-collapse: collapse;
  font-size: 16px;
}

.data-table th,
.data-table td {
  padding: 14px 16px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.data-table th:last-child,
.data-table td:last-child { border-right: 0; }
.data-table tr:last-child td { border-bottom: 0; }
.data-table thead th {
  color: var(--white);
  background: var(--navy);
  font-weight: 800;
}
.data-table tbody th { color: var(--navy); background: var(--blue-soft); }
.data-table tbody tr:hover td { background: var(--green-soft); }

.worksheet-table textarea {
  display: block;
  width: 100%;
  min-width: 190px;
  min-height: 112px;
  padding: 10px 12px;
  resize: vertical;
  border: 1px solid #aeb9c6;
  border-radius: 4px;
  color: var(--ink);
  background: var(--white);
  line-height: 1.55;
}

.worksheet-table textarea:focus {
  outline: 3px solid rgba(37, 134, 79, .22);
  border-color: var(--green-dark);
}

.worksheet-tools {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 14px;
}

.worksheet-clear {
  min-height: 44px;
  padding: 9px 15px;
  border: 1px solid var(--danger);
  border-radius: 6px;
  color: var(--danger);
  background: var(--white);
  font-weight: 800;
  cursor: pointer;
}

.worksheet-status {
  margin-left: auto;
  color: var(--muted);
  font-size: 14px;
}

.check-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0;
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.check-item {
  min-width: 0;
  min-height: 76px;
  padding: 16px 18px 16px 50px;
  position: relative;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--white);
  overflow-wrap: anywhere;
}

.check-item code {
  white-space: normal;
  overflow-wrap: anywhere;
  word-break: break-word;
}

.check-item::before {
  content: "✓";
  position: absolute;
  left: 18px;
  top: 15px;
  color: var(--green);
  font-size: 22px;
  font-weight: 900;
}

.callout {
  padding: 18px 20px;
  border-left: 5px solid var(--green);
  background: var(--green-soft);
}
.callout.warning { border-left-color: var(--amber); background: var(--amber-soft); }
.callout.danger { border-left-color: var(--danger); background: var(--danger-soft); }
.callout h3 { margin: 0 0 6px; color: var(--navy); font-size: 20px; }
.callout p { margin: 0; }

.prompt-wrap { position: relative; }
.prompt-wrap pre {
  margin: 0;
  padding: 54px 20px 22px;
  overflow-x: auto;
  color: #ecf4ff;
  background: var(--navy);
  border-radius: 6px;
  white-space: pre-wrap;
  word-break: break-word;
  font-family: Consolas, "Noto Sans TC", monospace;
  font-size: 15px;
  line-height: 1.65;
}
.copy-button {
  position: absolute;
  right: 10px;
  top: 10px;
  min-height: 34px;
  padding: 4px 10px;
  border-color: rgba(255,255,255,.7);
  color: var(--white);
  background: transparent;
  font-size: 14px;
}

.prompt-download { margin-top: 14px; }
.prompt-file.load-error pre { background: var(--danger); }

.resource-list { margin: 0; padding: 0; list-style: none; border-top: 1px solid var(--line); }
.resource-list li { padding: 15px 0; border-bottom: 1px solid var(--line); }
.resource-list strong { display: block; color: var(--navy); }

.video-frame {
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--line);
  background: #000;
}

.page-footer-nav {
  max-width: var(--content);
  margin: 0 auto;
  padding: 36px 24px 54px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.page-footer-nav .next { justify-self: end; }

.site-footer {
  padding: 26px 24px;
  color: var(--muted);
  background: var(--soft);
  border-top: 1px solid var(--line);
  font-size: 14px;
}
.site-footer-inner { max-width: var(--content); margin: 0 auto; }

.qr-dialog {
  width: min(92vw, 560px);
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
}
.qr-dialog::backdrop { background: rgba(11, 43, 80, .72); }
.qr-dialog img { display: block; width: min(100%, 440px); margin: 12px auto; }
.dialog-head { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.dialog-head h2 { margin: 0; color: var(--navy); font-size: 24px; }
.dialog-close {
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--navy);
  background: var(--white);
  cursor: pointer;
}
.qr-url { overflow-wrap: anywhere; color: var(--muted); font-size: 14px; }

.screen-reader-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

@keyframes page-enter {
  from { opacity: 0; transform: translateX(12px); }
  to { opacity: 1; transform: translateX(0); }
}

@media (max-width: 980px) {
  .topbar-inner { min-height: 62px; }
  .brand { min-width: 0; flex: 1; }
  .brand span:last-child { font-size: 15px; }
  .nav-wrap {
    display: none;
    position: absolute;
    left: 0;
    right: 0;
    top: 62px;
    padding: 10px 16px 16px;
    border-bottom: 1px solid var(--line);
    background: var(--white);
  }
  .nav-wrap.open { display: block; }
  .site-nav { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .site-nav a { white-space: normal; }
  .menu-toggle { display: block; }
  .hero { grid-template-columns: 1fr; gap: 30px; padding-top: 46px; }
  .hero > .hero-visual { display: none; }
  .hero h1 { font-size: 40px; }
}

@media (max-width: 640px) {
  body { font-size: 17px; }
  .topbar-inner { padding: 0 16px; }
  .brand small { display: none; }
  .site-nav { grid-template-columns: 1fr; }
  .hero { min-height: auto; padding: 36px 16px 38px; }
  .hero.no-image { min-height: auto; }
  .hero h1 { font-size: 30px; line-height: 1.24; }
  .hero-copy { font-size: 18px; }
  .hero > .hero-visual,
  .hero .outcome-strip,
  .hero .home-tools { display: none; }
  .mobile-start-band { display: block; }
  .content-band { padding: 42px 16px; }
  .section-heading { grid-template-columns: 48px minmax(0,1fr); gap: 10px; }
  .section-heading h2 { font-size: 26px; }
  .check-list { grid-template-columns: 1fr; }
  .home-tools { align-items: flex-start; }
  .primary-link, .secondary-link { width: 100%; }
  .page-footer-nav { padding: 28px 16px 42px; grid-template-columns: 1fr; }
  .page-footer-nav .next { justify-self: stretch; }
  .page-link { width: 100%; }
  .worksheet-tools .secondary-link,
  .worksheet-clear { width: 100%; }
  .worksheet-status { width: 100%; margin-left: 0; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

@media print {
  .topbar, .page-footer-nav, .site-footer, .copy-button, .home-tools, .worksheet-tools { display: none !important; }
  .hero { min-height: auto; padding: 24px 0; }
  .content-band { break-inside: avoid; padding: 24px 0; }
}