:root {
  --paper: #f4f1e9;
  --ink: #171512;
  --muted: #625d53;
  --line: #cfc6b5;
  --panel: #fffdf7;
  --panel-strong: #ebe4d6;
  --assist: #0f6f63;
  --blue: #255d82;
  --rust: #a24e2f;
  --gold: #b1842f;
  --danger: #9a2f2f;
  --shadow: 0 18px 48px rgba(23, 21, 18, 0.14);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    linear-gradient(90deg, rgba(23, 21, 18, 0.055) 1px, transparent 1px),
    linear-gradient(180deg, rgba(23, 21, 18, 0.045) 1px, transparent 1px),
    var(--paper);
  background-size: 42px 42px;
  color: var(--ink);
  font-family: "Noto Sans TC", system-ui, sans-serif;
  letter-spacing: 0;
}

a {
  color: inherit;
  text-decoration: none;
}

button,
input,
select,
textarea {
  font: inherit;
}

button {
  cursor: pointer;
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 3px solid rgba(15, 111, 99, 0.48);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 100;
  transform: translateY(-150%);
  border: 1px solid var(--ink);
  border-radius: 4px;
  padding: 10px 14px;
  background: var(--panel);
  font-weight: 900;
  transition: transform 160ms ease-out;
}

.skip-link:focus-visible {
  transform: translateY(0);
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 22px;
  align-items: center;
  padding: 14px clamp(18px, 4vw, 54px);
  border-bottom: 1px solid rgba(23, 21, 18, 0.18);
  background: rgba(244, 241, 233, 0.92);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  gap: 10px;
  align-items: center;
}

.brand img {
  width: 34px;
  height: 34px;
}

.brand span {
  display: grid;
  line-height: 1.12;
}

.brand small {
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

.topbar nav,
.footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  color: var(--muted);
  font-size: 14px;
  font-weight: 900;
}

.topbar nav a:hover,
.footer nav a:hover {
  color: var(--ink);
}

.header-action,
.btn,
.filters button,
.text-button {
  border: 1px solid var(--ink);
  border-radius: 4px;
  min-height: 42px;
  padding: 0 16px;
  background: var(--panel);
  color: var(--ink);
  font-weight: 900;
  transition: transform 140ms ease-out, background-color 140ms ease-out, color 140ms ease-out;
}

.header-action:hover,
.btn:hover,
.filters button:hover {
  transform: translateY(-1px);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.btn.primary {
  background: var(--ink);
  color: var(--paper);
}

.btn.secondary {
  border-color: rgba(23, 21, 18, 0.28);
  background: var(--panel);
}

.btn.ghost {
  border-color: var(--line);
  min-height: 38px;
  background: transparent;
}

.btn.danger,
.text-button.danger {
  color: var(--danger);
}

.hero,
.product-proof,
.assistants-section,
.workbench,
.pricing,
.footer {
  width: min(1180px, calc(100% - 36px));
  margin: 0 auto;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.82fr) minmax(380px, 1fr);
  gap: clamp(30px, 6vw, 78px);
  align-items: center;
  min-height: calc(100dvh - 72px);
  padding: clamp(56px, 8vw, 108px) 0 60px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--assist);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 10ch;
  margin-bottom: 24px;
  font-family: "Noto Serif TC", serif;
  font-size: clamp(40px, 5vw, 56px);
  font-weight: 900;
  line-height: 1.02;
  letter-spacing: 0;
  text-wrap: balance;
}

.lead {
  max-width: 680px;
  margin-bottom: 30px;
  color: var(--muted);
  font-size: 19px;
  line-height: 1.86;
  text-wrap: pretty;
}

.hero-actions,
.generation-actions,
.panel-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.hero-board,
.assistant-rail,
.work-panel,
.pricing article,
.checkout-panel {
  border: 1px solid var(--ink);
  border-radius: 6px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.hero-board {
  padding: 16px;
}

.board-strip {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 14px;
  padding: 14px;
  background: var(--ink);
  color: var(--paper);
}

.board-strip span,
.product-proof span,
.assistant-card span,
.rail-meta span,
.pricing span {
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.board-grid,
.product-proof,
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.board-grid article,
.product-proof article {
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 18px;
  background: var(--panel-strong);
}

.board-grid strong {
  display: block;
  margin: 8px 0;
  font-family: "Noto Serif TC", serif;
  font-size: 40px;
}

.board-grid p,
.product-proof p,
.assistant-card p,
.rail-head p,
.pricing p,
.footer p,
.checkout-panel p {
  color: var(--muted);
  line-height: 1.72;
}

.board-output {
  min-height: 126px;
  margin-top: 12px;
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 18px;
  background: #f9f7f1;
  color: var(--muted);
  line-height: 1.78;
  white-space: pre-wrap;
}

.product-proof {
  padding: 26px 0 78px;
}

.product-proof strong {
  display: block;
  margin: 8px 0;
  font-size: 20px;
}

.assistants-section,
.pricing {
  padding: 80px 0;
  border-top: 2px solid var(--ink);
}

.section-head,
.panel-head,
.mini-head {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: end;
  margin-bottom: 22px;
}

.section-head h2,
.panel-head h2 {
  margin-bottom: 0;
  font-family: "Noto Serif TC", serif;
  font-size: clamp(32px, 4vw, 42px);
  line-height: 1.14;
  letter-spacing: 0;
}

.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.filters button.is-active {
  background: var(--assist);
  color: #fff;
}

.search-box {
  display: grid;
  gap: 8px;
  margin-bottom: 18px;
  color: var(--muted);
  font-weight: 900;
}

.search-box input,
.work-form input,
.work-form textarea,
.work-form select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 12px 13px;
  background: var(--panel);
  color: var(--ink);
}

.assistant-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.assistant-card {
  display: grid;
  gap: 12px;
  min-height: 245px;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 20px;
  background: var(--panel);
  box-shadow: 0 12px 28px rgba(23, 21, 18, 0.08);
}

.assistant-card h3 {
  margin: 0;
  font-family: "Noto Serif TC", serif;
  font-size: 25px;
  line-height: 1.14;
}

button.assistant-card {
  width: 100%;
  color: var(--ink);
  text-align: left;
}

button.assistant-card strong {
  display: block;
  margin: 0;
  font-family: "Noto Serif TC", serif;
  font-size: 25px;
  line-height: 1.14;
}

button.assistant-card small {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
}

button.assistant-card.is-active {
  border-color: var(--assist);
  box-shadow: inset 0 0 0 2px rgba(15, 111, 99, 0.18), 0 12px 28px rgba(23, 21, 18, 0.08);
}

.assistant-card span {
  color: var(--blue);
}

.assistant-card button {
  align-self: end;
  justify-self: start;
}

.workbench {
  display: grid;
  grid-template-columns: minmax(250px, 0.35fr) minmax(0, 1fr);
  gap: 18px;
  align-items: start;
  padding: 80px 0;
  border-top: 2px solid var(--ink);
}

.assistant-rail {
  position: sticky;
  top: 88px;
  padding: 22px;
}

.rail-head h2 {
  margin-bottom: 12px;
  font-family: "Noto Serif TC", serif;
  font-size: 34px;
}

.rail-meta,
.rail-list,
.task-list,
.artifact-list {
  display: grid;
  gap: 10px;
}

.rail-meta {
  grid-template-columns: 1fr;
  margin: 18px 0;
}

.rail-meta span,
.rail-list div,
.task-item,
.artifact-item {
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 12px;
  background: #fbf8ef;
}

.work-panel {
  padding: clamp(20px, 3vw, 30px);
}

.work-form {
  display: grid;
  gap: 14px;
}

.work-form label {
  display: grid;
  gap: 8px;
  color: var(--muted);
  font-weight: 900;
}

.form-grid,
.workarea-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.output-panel,
.task-panel,
.artifact-panel {
  margin-top: 18px;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 18px;
  background: #fbf8ef;
}

.mini-head {
  align-items: center;
  margin-bottom: 12px;
}

.mini-head h3 {
  margin: 0;
  font-size: 18px;
}

.text-button {
  min-height: auto;
  border: 0;
  padding: 0;
  background: transparent;
  color: var(--assist);
}

pre[data-output] {
  min-height: 330px;
  max-height: 540px;
  overflow: auto;
  margin: 0;
  border: 1px solid rgba(23, 21, 18, 0.12);
  border-radius: 4px;
  padding: 16px;
  background: var(--panel);
  color: var(--ink);
  font-family: "Noto Sans TC", system-ui, sans-serif;
  line-height: 1.75;
  white-space: pre-wrap;
}

.task-item {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 10px;
  align-items: start;
}

.task-item input {
  width: 18px;
  height: 18px;
  margin-top: 2px;
}

.task-item strong,
.artifact-item strong {
  display: block;
  margin-bottom: 5px;
}

.task-item p,
.artifact-item p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.58;
}

.artifact-item button {
  margin-top: 10px;
}

.pricing-grid article {
  display: grid;
  gap: 14px;
  min-height: 300px;
  padding: 24px;
}

.pricing-grid article.featured {
  border-top: 8px solid var(--assist);
}

.pricing strong {
  display: block;
  font-family: "Noto Serif TC", serif;
  font-size: 30px;
}

.pricing .btn {
  align-self: end;
}

.checkout-panel {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: 18px;
  align-items: center;
  margin-top: 16px;
  padding: 18px;
}

.checkout-email {
  display: grid;
  gap: 7px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 900;
}

.checkout-email input,
.checkout-email select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 11px 12px;
  background: var(--panel);
  color: var(--ink);
}

.checkout-mode {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 34px;
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0 12px;
  color: var(--muted);
  background: #fbf8ef;
  font-weight: 900;
}

.footer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 28px;
  align-items: start;
  padding: 28px 0 36px;
  border-top: 1px solid var(--line);
}

.footer p {
  max-width: 740px;
  margin: 8px 0 0;
  font-size: 13px;
}

@media (max-width: 980px) {
  .topbar,
  .hero,
  .workbench,
  .checkout-panel,
  .footer {
    grid-template-columns: 1fr;
  }

  .topbar nav {
    justify-content: flex-start;
  }

  .hero {
    min-height: auto;
  }

  .assistant-rail {
    position: static;
  }

  .assistant-grid,
  .board-grid,
  .product-proof,
  .pricing-grid,
  .form-grid,
  .workarea-columns {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .hero,
  .product-proof,
  .assistants-section,
  .workbench,
  .pricing,
  .footer {
    width: min(100% - 26px, 1180px);
  }

  .topbar {
    position: static;
  }

  .section-head,
  .panel-head {
    align-items: stretch;
    flex-direction: column;
  }

  h1 {
    font-size: 42px;
  }
}