/* ═══════════════════════════════════════════════════════
   毛豆聊天 官网 — Design System
   Edamame green / warm paper / ink. Light-first, dark-complete.
   ═══════════════════════════════════════════════════════ */

:root {
  color-scheme: dark;

  --bg: #0b100e;
  --bg-soft: #0f1713;
  --surface: #121b17;
  --surface-2: #17231d;
  --line: rgba(211, 232, 219, .12);
  --line-strong: rgba(211, 232, 219, .22);

  --text: #eef6f0;
  --text-2: #b3c4ba;
  --text-3: #74867b;

  --brand: #3fae78;
  --brand-strong: #7bd7a8;
  --brand-soft: rgba(86, 196, 141, .13);
  --on-brand: #07120c;

  --accent: #e8b45a;
  --accent-soft: rgba(232, 180, 90, .12);
  --info: #6cc3e8;
  --danger: #f18a9a;
  --success: #64d18b;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, .18);
  --shadow-md: 0 12px 32px rgba(0, 0, 0, .22);
  --shadow-lg: 0 24px 64px rgba(0, 0, 0, .34);
  --nav-bg: rgba(11, 16, 14, .82);

  --max-w: 1120px;
  --radius: 8px;
  --radius-sm: 6px;

  --t-fast: 150ms ease;
  --t-normal: 260ms cubic-bezier(.2, .8, .2, 1);
}

[data-theme="light"] {
  color-scheme: light;

  --bg: #f4f6f1;
  --bg-soft: #eef3ec;
  --surface: #ffffff;
  --surface-2: #f7f9f6;
  --line: rgba(20, 45, 34, .12);
  --line-strong: rgba(20, 45, 34, .2);

  --text: #16231c;
  --text-2: #52645a;
  --text-3: #819087;

  --brand: #1f8a5f;
  --brand-strong: #137a51;
  --brand-soft: rgba(31, 138, 95, .1);
  --on-brand: #ffffff;

  --accent: #c87522;
  --accent-soft: rgba(200, 117, 34, .1);
  --info: #0877a5;
  --danger: #c43d55;
  --success: #168a4c;

  --shadow-sm: 0 1px 2px rgba(20, 45, 34, .06);
  --shadow-md: 0 12px 28px rgba(20, 45, 34, .1);
  --shadow-lg: 0 24px 56px rgba(20, 45, 34, .12);
  --nav-bg: rgba(244, 246, 241, .84);
}

/* Legacy aliases kept for the developer console and older sub-pages. */
:root {
  --bg-alt: var(--bg-soft);
  --surface-border: var(--line);
  --surface-hover: var(--surface-2);
  --radius-sm: var(--radius);
  --radius-lg: var(--radius);
  --brand-light: var(--brand-strong);
  --brand-dark: var(--brand);
  --brand-glow: var(--brand-soft);
  --accent-glow: var(--accent-soft);
  --shadow-glow: 0 0 0 1px var(--brand-soft), 0 8px 24px var(--brand-soft);
  --grad-brand: linear-gradient(135deg, var(--brand) 0%, var(--brand-strong) 100%);
  --text-secondary: var(--text-2);
  --text-muted: var(--text-3);
  --t-slow: 400ms cubic-bezier(.4, 0, .2, 1);
}

/* ═══ Reset ═══ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
  font-size: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: .34;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: linear-gradient(to bottom, black, transparent 86%);
}

a {
  color: var(--brand-strong);
  text-decoration: none;
  transition: color var(--t-fast);
}

a:hover {
  color: var(--brand);
}

img {
  max-width: 100%;
  display: block;
}

button {
  cursor: pointer;
  font: inherit;
  color: inherit;
}

button:disabled {
  cursor: not-allowed;
}

svg {
  display: block;
  flex-shrink: 0;
}

h1, h2, h3, h4 {
  letter-spacing: 0;
}

.hidden {
  display: none !important;
}

[hidden] {
  display: none !important;
}

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

/* ═══ Theme toggle ═══ */
.theme-toggle {
  position: fixed;
  top: 14px;
  right: 18px;
  z-index: 80;
  width: 42px;
  height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text-2);
  box-shadow: var(--shadow-sm);
  transition: border-color var(--t-fast), transform var(--t-fast), color var(--t-fast);
}

.theme-toggle:hover {
  border-color: var(--brand);
  color: var(--text);
  transform: translateY(-1px);
}

/* ═══ Nav ═══ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 70;
  background: var(--nav-bg);
  -webkit-backdrop-filter: blur(18px) saturate(1.3);
  backdrop-filter: blur(18px) saturate(1.3);
  border-bottom: 1px solid var(--line);
  transition: box-shadow var(--t-normal), background var(--t-normal);
}

.nav.scrolled {
  box-shadow: var(--shadow-md);
}

.nav-inner {
  max-width: calc(var(--max-w) + 72px);
  margin: 0 auto;
  padding: 0 78px 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.nav-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
  font-size: 18px;
  white-space: nowrap;
}

.nav-brand:hover {
  color: var(--text);
}

.nav-brand img {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  object-fit: cover;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav-links a {
  display: inline-flex;
  align-items: center;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  color: var(--text-2);
  font-size: 14px;
  font-weight: 500;
  transition: background var(--t-fast), color var(--t-fast);
}

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

.nav-links .btn-download {
  margin-left: 8px;
  padding: 9px 16px;
  background: var(--brand);
  color: var(--on-brand);
  font-weight: 700;
  border-radius: var(--radius);
}

.nav-links .btn-download:hover {
  background: var(--brand-strong);
  color: var(--on-brand);
}

.nav-mobile {
  display: none;
  width: 42px;
  height: 42px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text-2);
}

/* ═══ Buttons ═══ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 18px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 700;
  white-space: nowrap;
  transition: transform var(--t-fast), background var(--t-fast), border-color var(--t-fast), color var(--t-fast), box-shadow var(--t-fast);
}

.btn svg {
  width: 18px;
  height: 18px;
}

.btn-primary {
  background: var(--brand);
  color: var(--on-brand);
  box-shadow: 0 8px 24px var(--brand-soft);
}

.btn-primary:hover {
  background: var(--brand-strong);
  color: var(--on-brand);
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--line-strong);
}

.btn-ghost:hover {
  border-color: var(--brand);
  color: var(--brand-strong);
  background: var(--brand-soft);
}

/* ═══ Hero ═══ */
.hero {
  position: relative;
  min-height: 760px;
  display: flex;
  align-items: center;
  overflow: hidden;
  padding: 132px 24px 96px;
}

.hero-copy {
  position: relative;
  z-index: 2;
  max-width: 640px;
}

.hero-kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 18px;
  padding: 7px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  color: var(--brand-strong);
  font-size: 13px;
  font-weight: 700;
}

.hero-kicker::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--brand);
  box-shadow: 0 0 0 4px var(--brand-soft);
}

.hero-title {
  margin-bottom: 16px;
  font-size: 60px;
  line-height: 1.08;
  font-weight: 850;
  color: var(--text);
}

.hero-desc {
  max-width: 560px;
  margin-bottom: 28px;
  font-size: 18px;
  line-height: 1.75;
  color: var(--text-2);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 32px;
}

.hero-proof {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  color: var(--text-3);
  font-size: 13px;
  font-weight: 600;
}

.hero-proof-item {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}

.hero-proof-item svg {
  width: 16px;
  height: 16px;
  color: var(--brand);
}

.service-status .status-dot {
  color: var(--text-3);
  animation: statusPulse 1.6s ease-in-out infinite;
}

.service-status[data-state="online"] .status-dot {
  color: var(--success);
  animation: none;
}

.service-status[data-state="offline"] .status-dot {
  color: var(--danger);
  animation: none;
}

@keyframes statusPulse {
  0%, 100% { opacity: .45; }
  50% { opacity: 1; }
}

.hero-scene {
  position: absolute;
  top: 50%;
  right: -84px;
  width: 660px;
  height: 680px;
  transform: translateY(-48%);
  z-index: 1;
  pointer-events: none;
}

.hero-scene::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: linear-gradient(90deg, transparent, black 40%, black 80%, transparent);
  opacity: .5;
}

.hero-chat {
  position: absolute;
  width: 372px;
  height: 560px;
  border: 1px solid var(--line-strong);
  border-radius: 24px;
  background: var(--surface);
  box-shadow: var(--shadow-lg);
  padding: 14px;
  overflow: hidden;
}

.hero-chat.back {
  top: 32px;
  right: 18px;
  width: 348px;
  height: 524px;
  transform: rotate(7deg);
  opacity: .42;
  filter: saturate(.75);
}

.hero-chat.front {
  top: 76px;
  right: 154px;
  transform: rotate(-3deg);
}

.chat-topbar {
  display: flex;
  align-items: center;
  gap: 10px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.chat-avatar {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--brand-soft);
  color: var(--brand-strong);
  font-size: 13px;
  font-weight: 800;
}

.chat-title {
  min-width: 0;
  flex: 1;
}

.chat-title strong {
  display: block;
  font-size: 14px;
  color: var(--text);
}

.chat-title span {
  display: block;
  font-size: 12px;
  color: var(--text-3);
}

.chat-secure {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 5px 8px;
  border: 1px solid var(--brand-soft);
  border-radius: 999px;
  background: var(--brand-soft);
  color: var(--brand-strong);
  font-size: 11px;
  font-weight: 700;
}

.chat-secure svg {
  width: 12px;
  height: 12px;
}

.chat-body {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 18px 4px;
}

.chat-row {
  display: flex;
  align-items: flex-end;
  gap: 8px;
  max-width: 86%;
}

.chat-row.out {
  align-self: flex-end;
  flex-direction: row-reverse;
}

.chat-bubble {
  padding: 10px 12px;
  border-radius: 14px 14px 14px 4px;
  background: var(--surface-2);
  border: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.55;
  color: var(--text-2);
}

.chat-row.out .chat-bubble {
  border-radius: 14px 14px 4px 14px;
  background: var(--brand);
  border-color: transparent;
  color: var(--on-brand);
}

.chat-meta {
  margin-top: 5px;
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 10px;
  color: var(--text-3);
}

.chat-input {
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 14px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--bg-soft);
}

.chat-input span {
  flex: 1;
  color: var(--text-3);
  font-size: 12px;
}

.chat-input svg {
  width: 17px;
  height: 17px;
  color: var(--brand-strong);
}

.chat-pill {
  position: absolute;
  left: -54px;
  top: 244px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow-md);
  font-size: 13px;
  font-weight: 700;
  color: var(--text);
}

.chat-pill svg {
  width: 18px;
  height: 18px;
  color: var(--accent);
}

/* ═══ Section base ═══ */
.section {
  position: relative;
  padding: 104px 0;
}

.section-alt {
  background: var(--bg-soft);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.section-head {
  max-width: 720px;
  margin: 0 auto 56px;
  text-align: center;
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
  color: var(--brand-strong);
  font-size: 13px;
  font-weight: 800;
}

.kicker::before {
  content: "";
  width: 18px;
  height: 2px;
  background: var(--brand);
}

.section-title {
  margin-bottom: 12px;
  font-size: 38px;
  line-height: 1.18;
  font-weight: 800;
  color: var(--text);
}

.section-desc {
  color: var(--text-2);
  font-size: 16px;
  line-height: 1.75;
}

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity .6s ease, transform .6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ═══ Features ═══ */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(248px, 1fr));
  gap: 14px;
}

.feature-card {
  position: relative;
  min-height: 210px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  transition: transform var(--t-normal), border-color var(--t-normal), box-shadow var(--t-normal), background var(--t-normal);
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--brand);
  background: var(--surface-2);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  margin-bottom: 16px;
  border: 1px solid var(--brand-soft);
  border-radius: var(--radius);
  background: var(--brand-soft);
  color: var(--brand-strong);
}

.feature-icon svg {
  width: 20px;
  height: 20px;
}

.feature-card h3 {
  margin-bottom: 8px;
  font-size: 16px;
  font-weight: 750;
  color: var(--text);
}

.feature-card p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-2);
}

/* ═══ Security flow ═══ */
.security-flow {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  align-items: stretch;
  gap: 0;
}

.flow-step {
  position: relative;
  padding: 20px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  text-align: center;
}

.flow-step + .flow-step {
  margin-left: 10px;
}

.flow-step + .flow-step::before {
  content: "";
  position: absolute;
  top: 50%;
  left: -24px;
  width: 20px;
  height: 2px;
  background: var(--brand);
  opacity: .55;
}

.flow-step-icon {
  width: 42px;
  height: 42px;
  margin: 0 auto 12px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--brand-soft);
  color: var(--brand-strong);
}

.flow-step-icon svg {
  width: 20px;
  height: 20px;
}

.flow-step-label {
  margin-bottom: 4px;
  font-size: 14px;
  font-weight: 700;
  color: var(--text);
}

.flow-step-desc {
  font-size: 12px;
  line-height: 1.55;
  color: var(--text-3);
}

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

.metric {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  text-align: center;
}

.metric strong {
  display: block;
  margin-bottom: 4px;
  font-size: 22px;
  color: var(--brand-strong);
}

.metric span {
  font-size: 12px;
  color: var(--text-3);
}

/* ═══ AI ═══ */
.ai-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 14px;
}

.ai-card {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  transition: transform var(--t-normal), border-color var(--t-normal), box-shadow var(--t-normal);
}

.ai-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}

.ai-card-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}

.ai-icon {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  border-radius: var(--radius);
  background: var(--accent-soft);
  color: var(--accent);
}

.ai-icon svg {
  width: 20px;
  height: 20px;
}

.ai-card h3 {
  font-size: 16px;
  font-weight: 750;
  color: var(--text);
}

.ai-card > p {
  margin-bottom: 16px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-2);
}

.ai-demo {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--bg-soft);
  font-family: "SF Mono", "Fira Code", monospace;
  font-size: 12px;
  line-height: 1.75;
  overflow-x: auto;
  white-space: nowrap;
  color: var(--text-3);
}

.code-keyword {
  color: var(--accent);
  font-weight: 700;
}

.code-url {
  color: var(--brand-strong);
}

.code-string {
  color: var(--info);
}

.code-comment {
  color: var(--text-3);
}

/* ═══ Product preview ═══ */
.preview-shell {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 48px;
  align-items: center;
}

.preview-tabs {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.preview-tab {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text-2);
  text-align: left;
  font-weight: 650;
  transition: border-color var(--t-fast), background var(--t-fast), color var(--t-fast);
}

.preview-tab svg {
  width: 19px;
  height: 19px;
  color: var(--text-3);
}

.preview-tab:hover {
  border-color: var(--brand);
  color: var(--text);
}

.preview-tab.active {
  border-color: var(--brand);
  background: var(--brand-soft);
  color: var(--brand-strong);
}

.preview-tab.active svg {
  color: var(--brand);
}

.preview-tab span {
  display: block;
  font-size: 12px;
  color: var(--text-3);
  font-weight: 500;
}

.phone {
  position: relative;
  width: min(340px, 78vw);
  aspect-ratio: 9 / 19.4;
  margin: 0 auto;
  padding: 12px;
  border: 1px solid var(--line-strong);
  border-radius: 30px;
  background: var(--surface);
  box-shadow: var(--shadow-lg);
}

.phone::before {
  content: "";
  position: absolute;
  top: 22px;
  left: 50%;
  width: 84px;
  height: 22px;
  transform: translateX(-50%);
  border-radius: 999px;
  background: var(--bg);
  z-index: 3;
}

.phone-screen {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
  border-radius: 20px;
  background: var(--bg-soft);
  display: none;
  flex-direction: column;
}

.phone-screen.active {
  display: flex;
}

.screen-top {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 38px 14px 12px;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}

.screen-top .chat-avatar {
  width: 34px;
  height: 34px;
}

.screen-top strong {
  display: block;
  font-size: 14px;
  color: var(--text);
}

.screen-top span {
  display: block;
  font-size: 11px;
  color: var(--text-3);
}

.screen-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: 12px;
  padding: 18px 14px;
}

.screen-bubble {
  align-self: flex-start;
  max-width: 82%;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 14px 14px 14px 4px;
  background: var(--surface);
  color: var(--text-2);
  font-size: 12px;
  line-height: 1.55;
}

.screen-bubble.out {
  align-self: flex-end;
  border: 1px solid transparent;
  border-radius: 14px 14px 4px 14px;
  background: var(--brand);
  color: var(--on-brand);
}

.screen-toolbar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  padding: 10px 14px 14px;
  border-top: 1px solid var(--line);
  background: var(--surface);
}

.screen-action {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 8px 4px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface-2);
  color: var(--text-3);
  font-size: 10px;
}

.screen-action svg {
  width: 16px;
  height: 16px;
  color: var(--brand-strong);
}

.screen-list {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 46px 14px 18px;
}

.screen-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.screen-row .chat-avatar {
  width: 30px;
  height: 30px;
}

.screen-row strong {
  display: block;
  font-size: 13px;
  color: var(--text);
}

.screen-row span {
  display: block;
  font-size: 11px;
  color: var(--text-3);
}

.screen-row .screen-dot {
  margin-left: auto;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--brand);
}

.screen-caption {
  max-width: 460px;
  margin-top: 18px;
  color: var(--text-3);
  font-size: 13px;
  line-height: 1.7;
  text-align: center;
}

/* ═══ Developer ═══ */
.dev-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
}

.dev-info h3 {
  margin-bottom: 14px;
  font-size: 22px;
  font-weight: 800;
  color: var(--text);
}

.dev-info > p {
  margin-bottom: 18px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-2);
}

.dev-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 24px;
}

.dev-chip {
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text-2);
  font-size: 12px;
  font-weight: 600;
}

.dev-code {
  overflow: hidden;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow-md);
}

.dev-code-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--line);
  background: var(--surface-2);
}

.dev-code-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.dev-code-dot.r { background: #e06c5c; }
.dev-code-dot.y { background: #dfa43c; }
.dev-code-dot.g { background: #4fb477; }

.dev-code-header span {
  margin-left: 6px;
  font-size: 12px;
  color: var(--text-3);
}

.dev-code pre {
  padding: 20px;
  overflow-x: auto;
  font-family: "SF Mono", "Fira Code", monospace;
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-2);
}

/* ═══ Comparison ═══ */
.compare-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.compare-table {
  width: 100%;
  min-width: 720px;
  border-collapse: collapse;
}

.compare-table th,
.compare-table td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
  text-align: center;
  font-size: 14px;
}

.compare-table thead th {
  color: var(--text);
  font-weight: 750;
  background: var(--surface-2);
}

.compare-table th:first-child,
.compare-table td:first-child {
  text-align: left;
  color: var(--text-2);
}

.compare-table tbody tr:hover {
  background: var(--brand-soft);
}

.compare-table .col-maodou {
  color: var(--brand-strong);
  font-weight: 750;
}

.compare-yes {
  color: var(--success);
  font-weight: 700;
}

.compare-maybe {
  color: var(--accent);
  font-size: 12px;
}

.compare-no {
  color: var(--text-3);
}

.compare-note {
  margin-top: 14px;
  color: var(--text-3);
  font-size: 12px;
  text-align: center;
}

/* ═══ FAQ ═══ */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-width: 820px;
  margin: 0 auto;
}

.faq-cat {
  margin: 28px 0 6px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  font-size: 18px;
  font-weight: 800;
  color: var(--text);
}

.faq-cat:first-child {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.faq-item {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  transition: border-color var(--t-fast), background var(--t-fast);
}

.faq-item[open] {
  border-color: var(--brand);
  background: var(--surface-2);
}

.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 16px 18px;
  list-style: none;
  cursor: pointer;
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  flex-shrink: 0;
  font-size: 22px;
  font-weight: 400;
  color: var(--brand-strong);
  transition: transform var(--t-normal);
}

.faq-item[open] summary::after {
  transform: rotate(45deg);
}

.faq-a {
  padding: 0 18px 16px;
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.75;
}

.faq-more {
  margin-top: 30px;
  text-align: center;
}

/* ═══ Download ═══ */
.download-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: start;
}

.download-platforms {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.dl-card {
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  text-align: center;
  transition: transform var(--t-normal), border-color var(--t-normal), box-shadow var(--t-normal);
}

.dl-card:hover {
  transform: translateY(-4px);
  border-color: var(--brand);
  box-shadow: var(--shadow-md);
}

.dl-icon {
  width: 44px;
  height: 44px;
  margin: 0 auto 12px;
  display: grid;
  place-items: center;
  border-radius: var(--radius);
  background: var(--brand-soft);
  color: var(--brand-strong);
}

.dl-icon svg {
  width: 22px;
  height: 22px;
}

.dl-name {
  margin-bottom: 6px;
  font-size: 15px;
  font-weight: 800;
  color: var(--text);
}

.dl-status {
  margin-bottom: 14px;
  color: var(--text-3);
  font-size: 12px;
}

.dl-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  padding: 10px 14px;
  border-radius: var(--radius);
  background: var(--brand);
  color: var(--on-brand);
  font-size: 13px;
  font-weight: 700;
}

.dl-btn:hover {
  background: var(--brand-strong);
  color: var(--on-brand);
}

.dl-card.disabled {
  filter: saturate(.7);
}

.dl-card.disabled .dl-btn {
  background: var(--surface-2);
  color: var(--text-3);
  cursor: not-allowed;
}

.download-features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}

.download-feature {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text-2);
  font-size: 13px;
  font-weight: 600;
}

.download-feature-icon {
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border-radius: var(--radius-sm);
  background: var(--brand-soft);
  color: var(--brand-strong);
}

.download-feature-icon svg {
  width: 16px;
  height: 16px;
}

.version-line {
  margin-top: 34px;
  color: var(--text-3);
  font-size: 14px;
  text-align: center;
}

.version-line strong {
  color: var(--text);
}

.pill {
  display: inline-block;
  padding: 4px 9px;
  border-radius: 999px;
  background: var(--brand-soft);
  color: var(--brand-strong);
  font-size: 11px;
  font-weight: 700;
}

.pill-soon {
  background: var(--accent-soft);
  color: var(--accent);
}

.pill-plan {
  background: var(--surface-2);
  color: var(--text-3);
}

/* ═══ Footer ═══ */
.footer {
  border-top: 1px solid var(--line);
  background: var(--bg-soft);
  padding: 56px 0 28px;
}

.footer-cols {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 36px;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

.footer-brand {
  margin-bottom: 12px;
  font-size: 17px;
  font-weight: 800;
  color: var(--text);
}

.footer-col p {
  color: var(--text-3);
  font-size: 13px;
  line-height: 1.75;
}

.footer-col h4 {
  margin-bottom: 12px;
  color: var(--text);
  font-size: 13px;
  font-weight: 800;
  text-transform: uppercase;
}

.footer-col a {
  display: block;
  padding: 4px 0;
  color: var(--text-3);
  font-size: 13px;
}

.footer-col a:hover {
  color: var(--brand-strong);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  max-width: var(--max-w);
  margin: 36px auto 0;
  padding: 20px 24px 0;
  border-top: 1px solid var(--line);
  color: var(--text-3);
  font-size: 13px;
}

/* ═══ Sub-pages ═══ */
.page-hero {
  position: relative;
  padding: 132px 24px 52px;
  text-align: center;
}

.page-hero h1 {
  margin-bottom: 12px;
  font-size: 44px;
  line-height: 1.15;
  font-weight: 850;
  color: var(--text);
}

.page-hero p {
  max-width: 640px;
  margin: 0 auto;
  color: var(--text-2);
  font-size: 16px;
}

.page-container {
  max-width: 860px;
  margin: 0 auto;
  padding: 0 24px 80px;
}

.doc-meta {
  margin-bottom: 10px;
  color: var(--text-3);
  font-size: 13px;
}

.toc {
  margin: 24px 0 8px;
  padding: 18px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.toc h4 {
  margin-bottom: 10px;
  color: var(--text-3);
  font-size: 13px;
  font-weight: 800;
  text-transform: uppercase;
}

.toc ul {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 4px 24px;
  list-style: none;
}

.toc a {
  color: var(--text-2);
  font-size: 14px;
}

.toc a:hover {
  color: var(--brand-strong);
}

.prose {
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.8;
}

.prose h2 {
  margin: 42px 0 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  color: var(--text);
  font-size: 24px;
  font-weight: 800;
}

.prose h3 {
  margin: 28px 0 12px;
  color: var(--text);
  font-size: 18px;
  font-weight: 750;
}

.prose p {
  margin-bottom: 14px;
}

.prose ul,
.prose ol {
  margin-bottom: 16px;
  padding-left: 22px;
}

.prose li {
  margin-bottom: 8px;
}

.prose a {
  color: var(--brand-strong);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.prose strong {
  color: var(--text);
}

.prose code {
  padding: 2px 6px;
  border-radius: 4px;
  background: var(--surface);
  color: var(--brand-strong);
  font-family: "SF Mono", "Fira Code", monospace;
  font-size: 13px;
}

.callout {
  margin: 20px 0;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--brand);
  border-radius: var(--radius);
  background: var(--surface);
  font-size: 14px;
}

.callout-info {
  border-left-color: var(--info);
}

.callout-warning {
  border-left-color: var(--accent);
}

.callout-title {
  margin-bottom: 6px;
  color: var(--text);
  font-weight: 800;
}

.cta-back {
  margin-top: 48px;
  text-align: center;
}

.cta-back a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: var(--radius);
  background: var(--brand);
  color: var(--on-brand);
  font-weight: 700;
  transition: background var(--t-fast), transform var(--t-fast);
}

.cta-back a:hover {
  background: var(--brand-strong);
  color: var(--on-brand);
  transform: translateY(-1px);
}

/* ═══ Reduced motion ═══ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }
}

/* ═══ Responsive ═══ */
@media (max-width: 1024px) {
  .hero-scene {
    right: -180px;
    opacity: .72;
  }

  .hero-chat.front {
    right: 120px;
  }

  .hero {
    min-height: 0;
    flex-direction: column;
    padding: 118px 20px 72px;
  }

  .hero-copy {
    max-width: 640px;
  }

  .hero-title {
    font-size: 44px;
  }

  .hero-desc {
    font-size: 16px;
  }

  .hero-scene {
    position: relative;
    top: auto;
    right: auto;
    width: min(360px, 88vw);
    height: auto;
    margin: 48px auto 0;
    transform: none;
    opacity: 1;
  }

  .hero-scene::before {
    inset: -36px;
  }

  .hero-chat.back {
    display: none;
  }

  .hero-chat.front {
    position: relative;
    top: auto;
    right: auto;
    width: 100%;
    height: 470px;
    transform: none;
  }

  .chat-pill {
    left: -16px;
    top: 180px;
  }

  .security-flow {
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
  }

  .flow-step + .flow-step {
    margin-left: 0;
  }

  .flow-step + .flow-step::before {
    display: none;
  }

  .preview-shell {
    grid-template-columns: 1fr;
  }

  .preview-tabs {
    flex-direction: row;
    flex-wrap: wrap;
  }

  .preview-tab {
    width: auto;
  }

  .dev-grid {
    grid-template-columns: 1fr;
  }

  .download-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  .nav-inner {
    padding: 0 18px;
  }

  .nav-links {
    position: fixed;
    top: 64px;
    left: 14px;
    right: 14px;
    z-index: 60;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 6px;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: var(--surface);
    box-shadow: var(--shadow-lg);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links a {
    justify-content: center;
    padding: 12px;
  }

  .nav-links .btn-download {
    margin-left: 0;
  }

  .nav-mobile {
    display: inline-flex;
  }

  .theme-toggle {
    position: fixed;
    top: 11px;
    right: 70px;
    width: 40px;
    height: 40px;
  }

  .section {
    padding: 72px 0;
  }

  .section-head {
    margin-bottom: 40px;
  }

  .section-title {
    font-size: 31px;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .security-flow {
    grid-template-columns: 1fr;
  }

  .security-metrics {
    grid-template-columns: repeat(2, 1fr);
  }

  .ai-grid {
    grid-template-columns: 1fr;
  }

  .download-features {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-cols {
    grid-template-columns: 1fr 1fr;
  }

  .toc ul {
    grid-template-columns: 1fr;
  }

  .page-hero h1 {
    font-size: 34px;
  }
}

@media (max-width: 480px) {
  .hero-actions .btn {
    width: 100%;
  }

  .download-features {
    grid-template-columns: 1fr;
  }

  .footer-cols {
    grid-template-columns: 1fr;
  }

  .footer-bottom {
    justify-content: center;
    text-align: center;
  }
}