:root {
  --bg: #f8fafd;
  --surface: #ffffff;
  --surface-alt: #f1f5f9;
  --ink: #1f2937;
  --muted: #5f6368;
  --line: #e2e8f0;
  --blue: #1a73e8;
  --blue-soft: #e8f0fe;
  --red: #ea4335;
  --red-soft: #fce8e6;
  --yellow: #fbbc04;
  --yellow-soft: #fef7e0;
  --green: #1e8e3e;
  --green-soft: #e6f4ea;
  --radius: 20px;
  --shadow: 0 4px 20px -2px rgba(15, 23, 42, 0.07), 0 2px 6px -1px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 14px 36px -6px rgba(26, 115, 232, 0.14), 0 4px 12px -2px rgba(15, 23, 42, 0.06);
}

[data-theme="dark"] {
  --bg: #0b0f19;
  --surface: #131b2e;
  --surface-alt: #1c2640;
  --ink: #f1f5f9;
  --muted: #94a3b8;
  --line: #26334d;
  --blue: #60a5fa;
  --blue-soft: rgba(59, 130, 246, 0.16);
  --red: #f87171;
  --red-soft: rgba(239, 68, 68, 0.16);
  --yellow: #facc15;
  --yellow-soft: rgba(250, 204, 21, 0.14);
  --green: #4ade80;
  --green-soft: rgba(34, 197, 94, 0.16);
  --shadow: 0 4px 20px -2px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 14px 36px -6px rgba(0, 0, 0, 0.65);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang HK", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
}

body {
  background: var(--bg);
  color: var(--ink);
  overflow-x: hidden;
  transition: background 0.3s ease, color 0.3s ease;
}

/* Google 4-color top bar */
.top-rainbow {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, #4285f4 0% 25%, #ea4335 25% 50%, #fbbc04 50% 75%, #34a853 75% 100%);
  z-index: 1000;
}

.navbar {
  position: sticky;
  top: 4px;
  z-index: 900;
  backdrop-filter: blur(16px);
  background: color-mix(in srgb, var(--surface) 85%, transparent);
  border-bottom: 1px solid var(--line);
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.05rem;
  color: var(--ink);
  text-decoration: none;
}

.brand-badge {
  background: var(--blue);
  color: #fff;
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
}

.nav-links a {
  text-decoration: none;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 6px 12px;
  border-radius: 999px;
  transition: all 0.2s;
}

.nav-links a:hover {
  color: var(--blue);
  background: var(--blue-soft);
}

.theme-btn {
  border: 1px solid var(--line);
  background: var(--surface-alt);
  color: var(--ink);
  border-radius: 999px;
  padding: 7px 14px;
  font-size: 0.85rem;
  font-weight: 700;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s;
}

.theme-btn:hover {
  border-color: var(--blue);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  background: var(--surface-alt);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 3px;
  gap: 2px;
}

.lang-opt {
  border: none;
  background: transparent;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 800;
  padding: 5px 12px;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.lang-opt.active {
  background: var(--blue);
  color: #fff;
  box-shadow: 0 2px 8px rgba(26, 115, 232, 0.3);
}

html[data-lang="zh"] .en-only {
  display: none !important;
}

html[data-lang="en"] .zh-only {
  display: none !important;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Hero */
.hero {
  position: relative;
  padding: 72px 0 56px;
  overflow: hidden;
  background: radial-gradient(800px 450px at 85% 35%, var(--blue-soft) 0%, transparent 70%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 40px;
  align-items: center;
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--blue);
  background: var(--blue-soft);
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 16px;
}

.hero h1 {
  font-size: clamp(2.2rem, 4.5vw, 3.6rem);
  line-height: 1.15;
  font-weight: 900;
  letter-spacing: -0.02em;
  margin-bottom: 18px;
}

.hero h1 .hl {
  background: linear-gradient(120deg, #1a73e8, #34a853);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-sub {
  font-size: 1.15rem;
  color: var(--muted);
  margin-bottom: 24px;
  max-width: 620px;
}

.pill-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  margin-bottom: 28px;
}

.pill-list li {
  background: var(--surface);
  border: 1px solid var(--line);
  padding: 7px 15px;
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 700;
  box-shadow: var(--shadow);
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 24px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.98rem;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: var(--blue);
  color: #fff;
  box-shadow: 0 8px 20px rgba(26, 115, 232, 0.3);
}

.btn-secondary {
  background: var(--surface);
  color: var(--ink);
  border-color: var(--line);
  box-shadow: var(--shadow);
}

/* Orbit SVG in Hero */
.orbit-wrap {
  display: flex;
  justify-content: center;
  align-items: center;
}

.orb-svg {
  width: 100%;
  max-width: 390px;
  height: auto;
}

.o-ring {
  fill: none;
  stroke: var(--line);
  stroke-dasharray: 6 8;
  stroke-width: 1.8;
  transform-origin: 300px 300px;
}

.o-ring.r1 { animation: spin 42s linear infinite; }
.o-ring.r2 { animation: spinRev 28s linear infinite; }
.o-ring.r3 { animation: spin 18s linear infinite; }

.o-core {
  transform-origin: 300px 300px;
  animation: floatPulse 4s ease-in-out infinite;
}

.o-orbit-1 { transform-origin: 300px 300px; animation: spin 16s linear infinite; }
.o-orbit-2 { transform-origin: 300px 300px; animation: spinRev 22s linear infinite; }
.o-orbit-3 { transform-origin: 300px 300px; animation: spin 12s linear infinite; }

@keyframes spin { to { transform: rotate(360deg); } }
@keyframes spinRev { to { transform: rotate(-360deg); } }
@keyframes floatPulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.06); }
}

/* Section styling */
section.sec {
  padding: 64px 0;
  border-top: 1px solid var(--line);
}

.sec-head {
  margin-bottom: 36px;
}

.sec-head h2 {
  font-size: clamp(1.65rem, 3vw, 2.35rem);
  font-weight: 800;
  margin-top: 6px;
}

.sec-head p {
  color: var(--muted);
  font-size: 1.05rem;
  margin-top: 8px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.card:hover {
  box-shadow: var(--shadow-lg);
}

/* Route Simulator */
.route-sim {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.lane-card {
  display: grid;
  grid-template-columns: 220px 1fr 220px 1fr 190px;
  align-items: center;
  gap: 12px;
  padding: 22px 24px;
  border-radius: var(--radius);
  background: var(--surface);
  border: 2px solid var(--line);
}

.lane-card.lane-no {
  border-color: color-mix(in srgb, var(--red) 40%, var(--line));
}

.lane-card.lane-ok {
  border-color: color-mix(in srgb, var(--green) 50%, var(--line));
  background: color-mix(in srgb, var(--green-soft) 30%, var(--surface));
}

.lane-node {
  background: var(--surface-alt);
  padding: 14px 16px;
  border-radius: 14px;
  font-weight: 700;
  text-align: center;
  font-size: 0.96rem;
  border: 1px solid var(--line);
}

.lane-pipe {
  height: 8px;
  background: var(--surface-alt);
  border-radius: 999px;
  overflow: hidden;
  position: relative;
}

.lane-fill {
  display: block;
  height: 100%;
  width: 0%;
  border-radius: 999px;
  transition: width 0.7s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.lane-no .lane-fill { background: var(--red); }
.lane-ok .lane-fill { background: var(--green); }

.lane-badge {
  padding: 14px 16px;
  border-radius: 14px;
  font-weight: 800;
  text-align: center;
  font-size: 1rem;
  opacity: 0.35;
  transform: scale(0.94);
  transition: all 0.4s cubic-bezier(0.3, 1.4, 0.5, 1);
}

.lane-badge.active {
  opacity: 1;
  transform: scale(1);
}

.lane-no .lane-badge {
  background: var(--red-soft);
  color: var(--red);
}

.lane-ok .lane-badge {
  background: var(--green-soft);
  color: var(--green);
}

/* Agent Workflow */
.wf-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-top: 20px;
}

.wf-step {
  cursor: pointer;
  position: relative;
  border: 2px solid var(--line);
}

.wf-step.active {
  border-color: var(--blue);
  background: color-mix(in srgb, var(--blue-soft) 45%, var(--surface));
  transform: translateY(-4px);
}

.wf-num {
  display: inline-flex;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--blue-soft);
  color: var(--blue);
  font-weight: 800;
  align-items: center;
  justify-content: center;
  margin-bottom: 12px;
}

.wf-step.active .wf-num {
  background: var(--blue);
  color: #fff;
}

.surface-tabs {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-top: 28px;
}

.surf-card {
  padding: 20px;
  border-radius: 16px;
  background: var(--surface);
  border: 1px solid var(--line);
}

.surf-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 8px;
}

.tag-ok { background: var(--green-soft); color: var(--green); }
.tag-no { background: var(--red-soft); color: var(--red); }

/* Interactive Checklist & Setup */
.progress-bar-wrap {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 18px 24px;
  margin-bottom: 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}

.prog-track {
  flex: 1;
  min-width: 200px;
  height: 12px;
  background: var(--surface-alt);
  border-radius: 999px;
  overflow: hidden;
}

.prog-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--blue), var(--green));
  transition: width 0.35s ease;
}

.step-list {
  display: flex;
  flex-direction: column;
  gap: 22px;
}

.step-item {
  border-left: 5px solid var(--blue);
}

.step-item.done {
  border-left-color: var(--green);
  background: color-mix(in srgb, var(--green-soft) 18%, var(--surface));
}

.step-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 14px;
}

.check-label {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  font-size: 1.2rem;
  font-weight: 800;
}

.check-label input[type="checkbox"] {
  width: 22px;
  height: 22px;
  accent-color: var(--green);
  cursor: pointer;
}

.doors-compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 14px;
}

.door-box {
  padding: 18px;
  border-radius: 14px;
  border: 1px solid var(--line);
}

.door-ok {
  background: var(--green-soft);
  border-color: var(--green);
}

.door-no {
  background: var(--red-soft);
  border-color: var(--red);
}

.code-copy {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: var(--surface-alt);
  border: 1px solid var(--line);
  padding: 8px 14px;
  border-radius: 10px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.92rem;
  margin-top: 10px;
}

.copy-btn {
  background: var(--blue);
  color: #fff;
  border: none;
  border-radius: 6px;
  padding: 4px 10px;
  font-size: 0.8rem;
  font-weight: 700;
  cursor: pointer;
}

.proj-memo {
  display: flex;
  gap: 10px;
  margin-top: 12px;
  flex-wrap: wrap;
}

.proj-memo input {
  flex: 1;
  min-width: 220px;
  padding: 10px 14px;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: var(--surface-alt);
  color: var(--ink);
  font-size: 0.95rem;
}

/* 5-step login simulator */
.login-sim-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 24px;
  margin-top: 16px;
  align-items: center;
}

.login-steps-ol {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.login-li {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 13px 16px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: var(--surface-alt);
  cursor: pointer;
  transition: all 0.25s;
}

.login-li.active {
  background: var(--blue-soft);
  border-color: var(--blue);
  transform: translateX(6px);
}

.login-li em {
  font-style: normal;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--surface);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  flex-shrink: 0;
}

.login-li.active em {
  background: var(--blue);
  color: #fff;
}

.mock-window {
  background: var(--surface-alt);
  border: 2px solid var(--line);
  border-radius: 18px;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.mock-bar {
  background: var(--surface);
  padding: 12px 18px;
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 0.88rem;
  color: var(--muted);
}

.dot { width: 10px; height: 10px; border-radius: 50%; display: inline-block; }
.dot.r { background: #ea4335; }
.dot.y { background: #fbbc04; }
.dot.g { background: #34a853; }

.mock-body {
  padding: 24px;
}

/* Credit Calculator & Proof */
.calc-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 28px;
}

.plan-selector {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin: 14px 0 22px;
}

.plan-btn {
  padding: 16px;
  border-radius: 14px;
  border: 2px solid var(--line);
  background: var(--surface-alt);
  color: var(--ink);
  text-align: left;
  cursor: pointer;
  transition: all 0.2s;
}

.plan-btn.active {
  border-color: var(--blue);
  background: var(--blue-soft);
}

.plan-btn b {
  display: block;
  font-size: 1.05rem;
}

.plan-btn span {
  font-size: 1.35rem;
  font-weight: 900;
  color: var(--blue);
}

.calc-result {
  background: linear-gradient(135deg, var(--blue-soft), var(--green-soft));
  border: 1px solid var(--blue);
  border-radius: 18px;
  padding: 22px;
  margin-top: 16px;
}

.big-usd {
  font-size: clamp(2.4rem, 4vw, 3.4rem);
  font-weight: 900;
  line-height: 1.1;
  color: var(--blue);
}

.bill-proof {
  border: 2px solid var(--green);
}

.bill-row {
  display: flex;
  justify-content: space-between;
  padding: 12px 0;
  border-bottom: 1px dashed var(--line);
  font-size: 1.05rem;
}

.bill-row.total {
  border-bottom: none;
  border-top: 2px solid var(--ink);
  font-size: 1.3rem;
  font-weight: 900;
  padding-top: 16px;
}

/* Spend Cap Simulator */
.cap-layout {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 28px;
  align-items: center;
}

.cap-svg {
  width: 100%;
  height: auto;
  background: var(--surface-alt);
  border-radius: 16px;
  padding: 12px;
}

.slider-box {
  margin-top: 18px;
  background: var(--surface-alt);
  padding: 16px 20px;
  border-radius: 14px;
}

.slider-box input[type="range"] {
  width: 100%;
  margin-top: 8px;
  accent-color: var(--blue);
}

/* QR & Links Grid */
.qr-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-bottom: 32px;
}

.qr-card {
  text-align: center;
  text-decoration: none;
  color: var(--ink);
  display: flex;
  flex-direction: column;
  align-items: center;
}

.qr-card img {
  width: 170px;
  height: 170px;
  background: #fff;
  padding: 10px;
  border-radius: 14px;
  margin-bottom: 14px;
  border: 1px solid var(--line);
}

.links-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 12px;
}

.link-chip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  border-radius: 14px;
  background: var(--surface);
  border: 1px solid var(--line);
  color: var(--ink);
  text-decoration: none;
  font-weight: 700;
  transition: all 0.2s;
}

.link-chip:hover {
  border-color: var(--blue);
  background: var(--blue-soft);
  color: var(--blue);
}

/* FAQ Accordion */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

details.faq-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 18px 22px;
}

details.faq-item summary {
  font-weight: 800;
  font-size: 1.06rem;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

details.faq-item summary::after {
  content: "+";
  font-size: 1.4rem;
  color: var(--blue);
  font-weight: 900;
}

details.faq-item[open] summary::after {
  content: "−";
}

details.faq-item p {
  margin-top: 12px;
  color: var(--muted);
  font-size: 0.98rem;
}

footer {
  padding: 48px 0;
  border-top: 1px solid var(--line);
  text-align: center;
  color: var(--muted);
  font-size: 0.92rem;
}

@media (max-width: 920px) {
  .hero-grid,
  .wf-grid,
  .surface-tabs,
  .doors-compare,
  .login-sim-grid,
  .calc-grid,
  .cap-layout,
  .qr-grid {
    grid-template-columns: 1fr;
  }
  .lane-card {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .lane-pipe {
    height: 6px;
  }
}

/* 影片及作者資料（2026-11-09） */
.video-wrap{position:relative;width:100%;max-width:960px;aspect-ratio:16/9;margin-top:20px;border-radius:16px;overflow:hidden;border:1px solid var(--line);background:#000;box-shadow:0 10px 30px rgba(15,23,42,.12)}
.video-wrap iframe{position:absolute;inset:0;width:100%;height:100%;border:0}
.video-link{margin-top:12px}
.video-link a{color:var(--blue);font-weight:700;text-decoration:none}
footer .author{display:flex;flex-wrap:wrap;gap:10px 22px;align-items:center;margin-top:14px;padding-top:14px;border-top:1px solid var(--line)}
footer .author-name{font-weight:800}
footer .author a{color:var(--blue);font-weight:700;text-decoration:none}
footer .author a:hover{text-decoration:underline}

/* 手機版導覽列（2026-11-09）：兩行精簡版，選單改為左右滑動，不再佔半個畫面 */
@media (max-width: 860px) {
  .nav-inner { flex-wrap: wrap; padding: 8px 14px 6px; gap: 6px 10px; }
  .brand { flex: 1 1 0; min-width: 0; font-size: 0.95rem; gap: 8px; }
  .brand > span:last-child { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
  .brand-badge { flex: none; white-space: nowrap; font-size: 0.72rem; padding: 3px 8px; }
  .nav-actions { flex: none; gap: 6px; }
  .lang-opt { padding: 4px 10px; }
  .theme-btn { width: 36px; height: 36px; padding: 0 0 0 8px; overflow: hidden; white-space: nowrap; justify-content: flex-start; font-size: 0.95rem; }
  .nav-links { order: 3; flex: 1 0 100%; flex-wrap: nowrap; overflow-x: auto; -webkit-overflow-scrolling: touch; scrollbar-width: none; gap: 4px; margin: 0 -14px; padding: 2px 14px 4px; }
  .nav-links::-webkit-scrollbar { display: none; }
  .nav-links a { flex: none; white-space: nowrap; font-size: 0.85rem; padding: 6px 12px; background: var(--surface-alt); border: 1px solid var(--line); }
}