/* Maodouchat homepage. Product-first visual system. */

:root {
  color-scheme: light;
  --bg: #f7f4ec;
  --bg-soft: #eeeadf;
  --surface: #fffef8;
  --surface-2: #f2efe6;
  --surface-3: #e9e4d7;
  --ink: #151a16;
  --ink-2: #39433d;
  --muted: #6a756e;
  --line: rgba(23, 35, 27, .12);
  --line-strong: rgba(23, 35, 27, .22);
  --brand: #087f5b;
  --brand-strong: #086849;
  --brand-ink: #103f30;
  --brand-soft: rgba(8, 127, 91, .12);
  --on-brand: #f8fff8;
  --accent: #e65a3f;
  --accent-strong: #bd3c27;
  --accent-soft: rgba(230, 90, 63, .12);
  --blue: #1769a8;
  --blue-soft: rgba(23, 105, 168, .12);
  --lemon: #d9e36b;
  --lemon-soft: rgba(217, 227, 107, .2);
  --danger: #c43d55;
  --danger-soft: rgba(196, 61, 85, .12);
  --nav-bg: rgba(247, 244, 236, .88);
  --code-bg: #151b17;
  --code-text: #eef3ed;
  --code-comment: #89dbb4;
  --shadow-sm: 0 1px 2px rgba(23, 35, 27, .06);
  --shadow-md: 0 18px 42px rgba(23, 35, 27, .12);
  --shadow-lg: 0 30px 70px rgba(23, 35, 27, .18);
  --radius: 8px;
  --radius-lg: 18px;
  --t-fast: 150ms ease;
  --t-normal: 280ms cubic-bezier(.2, .8, .2, 1);
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #11140f;
  --bg-soft: #171b15;
  --surface: #1b211b;
  --surface-2: #232a23;
  --surface-3: #293129;
  --ink: #f0f4ee;
  --ink-2: #bfcbc1;
  --muted: #93a096;
  --line: rgba(228, 240, 229, .12);
  --line-strong: rgba(228, 240, 229, .22);
  --brand: #55d59a;
  --brand-strong: #83e8b5;
  --brand-ink: #b9f2d5;
  --brand-soft: rgba(85, 213, 154, .14);
  --on-brand: #07140d;
  --accent: #ff8a68;
  --accent-strong: #ffb09a;
  --accent-soft: rgba(255, 138, 104, .14);
  --blue: #6ec8ef;
  --blue-soft: rgba(110, 200, 239, .14);
  --lemon: #dfe977;
  --lemon-soft: rgba(223, 233, 119, .18);
  --danger: #ff8fa4;
  --danger-soft: rgba(255, 143, 164, .14);
  --nav-bg: rgba(17, 20, 15, .86);
  --code-bg: #0b0f0b;
  --code-text: #eef3ed;
  --code-comment: #89dbb4;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, .2);
  --shadow-md: 0 18px 42px rgba(0, 0, 0, .28);
  --shadow-lg: 0 30px 70px rgba(0, 0, 0, .4);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 94px;
}

body {
  min-width: 320px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  opacity: .24;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: linear-gradient(to bottom, black, transparent 78%);
  -webkit-mask-image: linear-gradient(to bottom, black, transparent 78%);
}

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

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

h1,
h2,
h3,
h4,
p {
  overflow-wrap: break-word;
}

.hidden,
[hidden] {
  display: none !important;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 200;
  padding: 10px 14px;
  border-radius: 6px;
  background: var(--brand);
  color: var(--on-brand);
  transform: translateY(-150%);
  transition: transform var(--t-fast);
}

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

.container {
  width: 100%;
  max-width: 1220px;
  margin: 0 auto;
  padding: 0 28px;
}

.container-wide {
  width: 100%;
  max-width: 1320px;
  margin: 0 auto;
  padding: 0 28px;
}

.theme-toggle {
  position: fixed;
  top: 11px;
  right: 26px;
  z-index: 90;
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  background: var(--surface);
  color: var(--ink-2);
  box-shadow: var(--shadow-sm);
  transition: color var(--t-fast), border-color var(--t-fast), transform var(--t-fast), background var(--t-fast);
}

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

.theme-toggle svg {
  width: 19px;
  height: 19px;
}

.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 70;
  height: 66px;
  border-bottom: 1px solid var(--line);
  background: var(--nav-bg);
  -webkit-backdrop-filter: blur(20px) saturate(1.25);
  backdrop-filter: blur(20px) saturate(1.25);
  box-shadow: var(--shadow-sm);
  transition: border-color var(--t-normal), box-shadow var(--t-normal);
}

.site-nav.scrolled {
  border-color: var(--line-strong);
  box-shadow: var(--shadow-md);
}

.nav-inner {
  height: 100%;
  max-width: 1320px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 0 72px 0 32px;
}

.nav-brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  color: var(--ink);
  font-weight: 800;
  white-space: nowrap;
}

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

.nav-brand img {
  width: 38px;
  height: 38px;
  border-radius: 11px;
  box-shadow: 0 8px 20px var(--brand-soft);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-links a {
  position: relative;
  padding: 9px 12px;
  border-radius: 7px;
  color: var(--ink-2);
  font-size: 14px;
  font-weight: 680;
  transition: color var(--t-fast), background var(--t-fast);
}

.nav-links a:hover {
  color: var(--ink);
  background: var(--surface-2);
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 13px;
  right: 13px;
  bottom: 4px;
  height: 2px;
  border-radius: 999px;
  background: var(--brand);
  opacity: 0;
  transform: scaleX(.4);
  transition: opacity var(--t-fast), transform var(--t-fast);
}

.nav-links a:hover::after,
.nav-links a:focus-visible::after {
  opacity: 1;
  transform: scaleX(1);
}

.nav-links .nav-cta {
  margin-left: 8px;
  padding: 10px 17px;
  border-radius: 999px;
  background: var(--ink);
  color: var(--surface);
  box-shadow: 0 10px 24px rgba(20, 31, 24, .14);
}

.nav-links .nav-cta::after {
  display: none;
}

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

[data-theme="dark"] .nav-links .nav-cta {
  background: var(--brand);
  color: var(--on-brand);
}

[data-theme="dark"] .nav-links .nav-cta: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: 8px;
  background: var(--surface);
  color: var(--ink);
}

.nav-mobile svg {
  width: 20px;
  height: 20px;
}

.btn {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 12px 20px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-weight: 760;
  white-space: nowrap;
  transition: transform var(--t-fast), box-shadow var(--t-fast), border-color var(--t-fast), background var(--t-fast), color var(--t-fast);
}

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

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--brand);
  color: var(--on-brand);
  box-shadow: 0 12px 28px var(--brand-soft);
}

.btn-primary:hover {
  background: var(--brand-strong);
  color: var(--on-brand);
  box-shadow: 0 16px 34px var(--brand-soft);
}

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

.btn-ghost:hover {
  border-color: var(--brand);
  background: var(--surface-2);
  color: var(--ink);
}

.btn-block {
  width: 100%;
}

.hero {
  position: relative;
  min-height: 900px;
  padding: 154px 0 90px;
  overflow: hidden;
}

.hero::before {
  content: "PRIVATE";
  position: absolute;
  top: 66px;
  left: -12px;
  z-index: 0;
  color: var(--surface-3);
  font-size: 188px;
  font-weight: 900;
  letter-spacing: -7px;
  line-height: .84;
  pointer-events: none;
  white-space: nowrap;
  opacity: .7;
}

[data-theme="dark"] .hero::before {
  color: var(--surface-3);
}

.hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, .86fr) minmax(540px, 1.14fr);
  align-items: center;
  gap: 62px;
}

.hero-copy {
  position: relative;
  z-index: 2;
}

.hero-badges {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.hero-status,
.hero-chip {
  min-height: 32px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 11px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  color: var(--ink-2);
  font-size: 12px;
  font-weight: 720;
  box-shadow: var(--shadow-sm);
}

.hero-chip {
  color: var(--brand-strong);
  background: var(--brand-soft);
  border-color: transparent;
}

.status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #9aa69e;
  box-shadow: 0 0 0 4px rgba(154, 166, 158, .12);
}

.service-status[data-state="online"] .status-dot {
  background: var(--brand);
  box-shadow: 0 0 0 4px var(--brand-soft);
}

.service-status[data-state="offline"] .status-dot {
  background: var(--danger);
  box-shadow: 0 0 0 4px var(--danger-soft);
}

.hero-title {
  max-width: 760px;
  margin-bottom: 26px;
  font-size: 78px;
  line-height: .98;
  font-weight: 880;
  letter-spacing: 0;
}

.hero-title .text-accent {
  position: relative;
  display: inline-block;
  color: var(--brand);
}

.hero-title .text-accent::after {
  content: "";
  position: absolute;
  left: -4px;
  right: -4px;
  bottom: 3px;
  height: 11px;
  z-index: -1;
  border-radius: 999px;
  background: var(--lemon-soft);
  transform: rotate(-1deg);
}

.hero-desc {
  max-width: 610px;
  margin-bottom: 30px;
  color: var(--ink-2);
  font-size: 18px;
  line-height: 1.75;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 34px;
  flex-wrap: wrap;
}

.hero-proof {
  display: flex;
  align-items: center;
  gap: 9px;
  flex-wrap: wrap;
  color: var(--muted);
  font-size: 12px;
}

.hero-proof span {
  min-height: 30px;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  color: var(--ink-2);
}

.hero-proof svg {
  width: 14px;
  height: 14px;
  color: var(--brand);
}

.hero-visual {
  position: relative;
  min-height: 650px;
}

.hero-visual::before {
  content: "";
  position: absolute;
  inset: 46px 26px 0 60px;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: linear-gradient(135deg, transparent 3%, black 46%, black 78%, transparent);
  -webkit-mask-image: linear-gradient(135deg, transparent 3%, black 46%, black 78%, transparent);
  opacity: .65;
}

.app-window {
  position: absolute;
  top: 0;
  right: 0;
  width: min(660px, 100%);
  border: 1px solid var(--line-strong);
  border-radius: 20px;
  background: var(--surface);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  transform: rotate(-1.5deg);
}

.app-window-bar {
  height: 48px;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 16px;
  border-bottom: 1px solid var(--line);
  background: var(--surface-3);
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

.window-dots {
  display: flex;
  gap: 5px;
}

.window-dots i {
  width: 9px;
  height: 9px;
  display: block;
  border-radius: 50%;
  background: #e06c5c;
}

.window-dots i:nth-child(2) {
  background: #dfa43c;
}

.window-dots i:nth-child(3) {
  background: #4fb477;
}

.window-secure {
  margin-left: auto;
  padding: 4px 7px;
  border-radius: 999px;
  background: var(--brand-soft);
  color: var(--brand-strong);
  font-size: 10px;
}

.app-window-body {
  min-height: 585px;
  display: grid;
  grid-template-columns: 190px minmax(0, 1fr);
}

.app-sidebar {
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--line);
  background: var(--surface-2);
}

.app-profile {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 20px 14px 16px;
  border-bottom: 1px solid var(--line);
}

.app-avatar {
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  flex-shrink: 0;
  border-radius: 10px;
  background: var(--brand-soft);
  color: var(--brand-strong);
  font-weight: 820;
}

.app-avatar.small {
  width: 31px;
  height: 31px;
  border-radius: 9px;
  font-size: 12px;
}

.app-avatar.green {
  background: var(--brand-soft);
  color: var(--brand-strong);
}

.app-avatar.orange {
  background: var(--accent-soft);
  color: var(--accent);
}

.app-profile strong,
.sidebar-item strong {
  display: block;
  color: var(--ink);
  font-size: 12px;
  line-height: 1.3;
}

.app-profile span,
.sidebar-item span {
  display: block;
  color: var(--muted);
  font-size: 10px;
  line-height: 1.4;
}

.sidebar-search {
  margin: 14px 12px 8px;
  padding: 9px 11px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--muted);
  font-size: 11px;
}

.sidebar-list {
  display: grid;
  gap: 4px;
  padding: 0 10px;
}

.sidebar-item {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 9px;
  border-radius: 8px;
}

.sidebar-item.active {
  background: var(--brand-soft);
}

.sidebar-bottom {
  margin-top: auto;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 15px 14px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 10px;
}

.sidebar-bottom svg {
  width: 15px;
  height: 15px;
  color: var(--brand);
}

.app-chat {
  display: flex;
  flex-direction: column;
  background: var(--surface);
}

.app-chat-top {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 15px 18px;
  border-bottom: 1px solid var(--line);
}

.app-chat-top strong {
  display: block;
  color: var(--ink);
  font-size: 14px;
}

.app-chat-top span {
  display: block;
  color: var(--muted);
  font-size: 11px;
}

.app-chat-top svg {
  width: 19px;
  height: 19px;
  color: var(--brand);
}

.app-messages {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: 11px;
  padding: 24px 18px;
}

.message {
  max-width: 74%;
  padding: 10px 12px;
  border-radius: 13px 13px 13px 4px;
  background: var(--surface-2);
  color: var(--ink);
  font-size: 12px;
  line-height: 1.55;
}

.message.outgoing {
  align-self: flex-end;
  border-radius: 13px 13px 4px 13px;
  background: var(--brand);
  color: var(--on-brand);
}

.message.compact {
  align-self: center;
  max-width: 140px;
  padding: 6px 9px;
  border-radius: 999px;
  color: var(--muted);
  font-size: 10px;
  text-align: center;
}

.app-composer {
  min-height: 58px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 12px 14px;
  border-top: 1px solid var(--line);
}

.app-composer > span {
  color: var(--muted);
  font-size: 12px;
}

.composer-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.composer-actions svg {
  width: 17px;
  height: 17px;
  color: var(--muted);
}

.composer-actions svg:last-child {
  color: var(--brand);
}

.float-note {
  position: absolute;
  z-index: 3;
  min-width: 198px;
  display: flex;
  align-items: center;
  gap: 11px;
  padding: 13px 14px;
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  background: var(--surface);
  box-shadow: var(--shadow-md);
}

.float-note svg {
  width: 22px;
  height: 22px;
  color: var(--brand);
}

.float-note strong,
.float-note span {
  display: block;
}

.float-note strong {
  color: var(--ink);
  font-size: 12px;
}

.float-note span {
  color: var(--muted);
  font-size: 10px;
}

.note-top {
  top: 88px;
  left: 10px;
}

.note-bottom {
  right: 34px;
  bottom: 26px;
}

/* ---------- Hero 视觉区入场：渐显 + 平滑步进上移 ---------- */
@keyframes maodou-rise {
  from {
    opacity: 0;
    transform: translateY(26px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes maodou-fade-in {
  from {
    opacity: 0;
  }

  to {
    opacity: 1;
  }
}

/* 侧边栏搜索 */
.hero-visual .sidebar-search {
  opacity: 0;
  animation: maodou-rise .5s cubic-bezier(.22, .61, .36, 1) .08s both;
}

/* 侧边栏会话列表项 */
.hero-visual .sidebar-item {
  opacity: 0;
  animation: maodou-rise .5s cubic-bezier(.22, .61, .36, 1) both;
}

.hero-visual .sidebar-item:nth-child(1) { animation-delay: .18s; }
.hero-visual .sidebar-item:nth-child(2) { animation-delay: .28s; }
.hero-visual .sidebar-item:nth-child(3) { animation-delay: .38s; }

/* 消息列表容器(纯淡入,避免与气泡位移叠加) */
.hero-visual .app-messages {
  animation: maodou-fade-in .4s ease .2s both;
}

/* 消息气泡逐个步进上移 */
.hero-visual .app-messages .message {
  opacity: 0;
  animation: maodou-rise .45s cubic-bezier(.22, .61, .36, 1) both;
}

.hero-visual .app-messages .message:nth-child(1) { animation-delay: .48s; }
.hero-visual .app-messages .message:nth-child(2) { animation-delay: .6s; }
.hero-visual .app-messages .message:nth-child(3) { animation-delay: .72s; }
.hero-visual .app-messages .message:nth-child(4) { animation-delay: .84s; }
.hero-visual .app-messages .message:nth-child(5) { animation-delay: .96s; }

/* 悬浮卡片 */
.hero-visual .float-note.note-top {
  animation: maodou-rise .55s cubic-bezier(.22, .61, .36, 1) .7s both;
}

.hero-visual .float-note.note-bottom {
  animation: maodou-rise .55s cubic-bezier(.22, .61, .36, 1) .85s both;
}

.section {
  position: relative;
  padding: 112px 0;
}

.section-alt {
  background: var(--bg-soft);
}

.section-head {
  max-width: 780px;
  margin-bottom: 58px;
}

.kicker {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
  color: var(--brand-strong);
  font-size: 12px;
  font-weight: 850;
}

.kicker::before {
  content: "";
  width: 28px;
  height: 3px;
  border-radius: 999px;
  background: var(--brand);
}

.section-title {
  max-width: 800px;
  margin-bottom: 16px;
  font-size: 52px;
  line-height: 1.05;
  font-weight: 860;
  letter-spacing: 0;
}

.section-desc {
  max-width: 680px;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.78;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 16px;
}

.feature-card {
  --card-accent: var(--brand);
  position: relative;
  grid-column: span 3;
  min-height: 285px;
  display: flex;
  flex-direction: column;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  overflow: hidden;
  transition: transform var(--t-normal), border-color var(--t-normal), box-shadow var(--t-normal), background var(--t-normal);
}

.feature-card-large {
  grid-column: span 6;
  min-height: 340px;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--card-accent);
  opacity: .75;
}

.feature-card:nth-child(2) {
  --card-accent: var(--blue);
}

.feature-card:nth-child(3) {
  --card-accent: var(--accent);
}

.feature-card:nth-child(4) {
  --card-accent: var(--blue);
}

.feature-card:nth-child(5) {
  --card-accent: var(--accent);
}

.feature-card:hover {
  transform: translateY(-6px);
  border-color: var(--card-accent);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  width: 50px;
  height: 50px;
  display: grid;
  place-items: center;
  margin-bottom: 24px;
  border-radius: var(--radius);
  background: var(--brand-soft);
  color: var(--brand-strong);
}

.feature-card:nth-child(2) .feature-icon,
.feature-card:nth-child(4) .feature-icon {
  background: var(--blue-soft);
  color: var(--blue);
}

.feature-card:nth-child(3) .feature-icon,
.feature-card:nth-child(5) .feature-icon {
  background: var(--accent-soft);
  color: var(--accent);
}

.feature-icon svg {
  width: 24px;
  height: 24px;
}

.feature-content {
  max-width: 620px;
}

.feature-label {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 11px;
  font-weight: 820;
}

.feature-card h3 {
  margin-bottom: 10px;
  color: var(--ink);
  font-size: 23px;
  font-weight: 850;
}

.feature-card p {
  color: var(--ink-2);
  font-size: 14px;
  line-height: 1.75;
}

.feature-points {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: auto;
  padding-top: 24px;
  list-style: none;
}

.feature-points li {
  padding: 7px 10px;
  border-radius: 999px;
  background: var(--surface-2);
  color: var(--ink-2);
  font-size: 11px;
}

.security-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, .68fr);
  gap: 58px;
  align-items: center;
}

.security-flow {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 12px;
}

.flow-step {
  position: relative;
  min-height: 184px;
  padding: 20px 14px;
  border-top: 3px solid var(--brand);
  border-radius: var(--radius);
  background: var(--surface);
  transition: transform var(--t-normal), box-shadow var(--t-normal);
}

.flow-step:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.flow-step-icon {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  margin-bottom: 18px;
  border-radius: var(--radius);
  background: var(--brand-soft);
  color: var(--brand-strong);
}

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

.flow-step-label {
  margin-bottom: 7px;
  color: var(--ink);
  font-size: 15px;
  font-weight: 850;
}

.flow-step-desc {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.65;
}

.security-note {
  position: relative;
  padding: 30px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow-sm);
}

.security-note-mark {
  position: absolute;
  top: 20px;
  right: 20px;
  padding: 6px 9px;
  border-radius: 999px;
  background: var(--brand-soft);
  color: var(--brand-strong);
  font-size: 11px;
  font-weight: 850;
}

.security-note h3 {
  max-width: 360px;
  margin-bottom: 14px;
  color: var(--ink);
  font-size: 25px;
  line-height: 1.25;
  font-weight: 850;
}

.security-note p {
  color: var(--ink-2);
  font-size: 14px;
  line-height: 1.78;
}

.security-metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 20px;
  margin-top: 34px;
}

.metric {
  padding-top: 20px;
  border-top: 1px solid var(--line-strong);
}

.metric strong,
.metric span {
  display: block;
}

.metric strong {
  margin-bottom: 7px;
  color: var(--ink);
  font-size: 29px;
  font-weight: 850;
}

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

.ai-wrap {
  display: grid;
  grid-template-columns: minmax(0, .82fr) minmax(0, 1.18fr);
  gap: 68px;
  align-items: center;
}

.ai-copy .section-title {
  margin-top: 2px;
}

.ai-control {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 26px;
}

.ai-control span {
  padding: 7px 11px;
  border-radius: 999px;
  background: var(--surface-2);
  color: var(--ink-2);
  font-size: 12px;
}

.ai-control span:first-child {
  background: var(--danger-soft);
  color: var(--danger);
}

.ai-list {
  display: grid;
}

.ai-item {
  display: grid;
  grid-template-columns: 50px minmax(0, 1fr);
  gap: 16px;
  padding: 24px 0;
  border-bottom: 1px solid var(--line);
}

.ai-item:first-child {
  border-top: 1px solid var(--line);
}

.ai-icon {
  width: 50px;
  height: 50px;
  display: grid;
  place-items: center;
  border-radius: var(--radius);
  background: var(--accent-soft);
  color: var(--accent);
}

.ai-icon svg {
  width: 23px;
  height: 23px;
}

.ai-item h3 {
  margin-bottom: 7px;
  color: var(--ink);
  font-size: 19px;
  font-weight: 850;
}

.ai-item p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

.preview-shell {
  display: grid;
  grid-template-columns: 330px minmax(0, 1fr);
  gap: 72px;
  align-items: center;
}

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

.preview-tab {
  min-height: 60px;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink-2);
  font-weight: 760;
  text-align: left;
  transition: border-color var(--t-fast), background var(--t-fast), color var(--t-fast), transform var(--t-fast);
}

.preview-tab svg {
  width: 20px;
  height: 20px;
  color: var(--muted);
}

.preview-tab:hover {
  transform: translateX(4px);
  border-color: var(--brand);
  color: var(--ink);
}

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

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

.phone {
  width: min(370px, 78vw);
  margin: 0 auto;
  padding: 10px;
  border: 1px solid var(--line-strong);
  border-radius: 34px;
  background: var(--surface);
  box-shadow: var(--shadow-lg);
}

.phone-screen {
  display: none;
  min-height: 540px;
  overflow: hidden;
  border-radius: 25px;
  background: var(--bg);
}

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

.screen-top {
  min-height: 78px;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 20px 16px 14px;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}

.screen-top .chat-avatar {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 10px;
  background: var(--brand-soft);
  color: var(--brand-strong);
  font-weight: 850;
}

.screen-top .chat-avatar.orange {
  background: var(--accent-soft);
  color: var(--accent);
}

.screen-top .chat-avatar.blue {
  background: var(--blue-soft);
  color: var(--blue);
}

.screen-top strong,
.screen-top span {
  display: block;
}

.screen-top strong {
  color: var(--ink);
  font-size: 15px;
}

.screen-top span {
  color: var(--muted);
  font-size: 11px;
}

.screen-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 12px;
  padding: 24px 16px;
}

.screen-caption {
  align-self: center;
  max-width: 220px;
  padding: 7px 10px;
  border-radius: 999px;
  background: var(--surface-2);
  color: var(--muted);
  font-size: 11px;
  text-align: center;
}

.screen-bubble {
  max-width: 78%;
  align-self: flex-start;
  padding: 11px 13px;
  border-radius: 14px 14px 14px 4px;
  background: var(--surface);
  color: var(--ink);
  font-size: 13px;
  line-height: 1.55;
}

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

.screen-bubble.ai {
  border: 1px solid var(--accent);
  background: var(--accent-soft);
  color: var(--ink);
}

.screen-toolbar {
  min-height: 66px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 14px;
  border-top: 1px solid var(--line);
  background: var(--surface);
}

.screen-action {
  min-height: 34px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 10px;
  border-radius: 7px;
  background: var(--surface-2);
  color: var(--ink-2);
  font-size: 10px;
  white-space: nowrap;
}

.screen-action svg {
  width: 14px;
  height: 14px;
  color: var(--brand);
}

.dev-wrap {
  display: grid;
  grid-template-columns: minmax(0, .86fr) minmax(440px, 1.14fr);
  gap: 68px;
  align-items: center;
}

.dev-info .section-title {
  margin-top: 2px;
}

.dev-info > p {
  color: var(--ink-2);
  font-size: 16px;
  line-height: 1.78;
}

.dev-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 24px 0;
}

.dev-chips span {
  padding: 7px 10px;
  border-radius: 999px;
  background: var(--surface-2);
  color: var(--ink-2);
  font-size: 12px;
}

.dev-code {
  overflow: hidden;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-lg);
  background: var(--code-bg);
  color: var(--code-text);
  box-shadow: var(--shadow-lg);
}

.dev-code-header {
  height: 48px;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 16px;
  border-bottom: 1px solid rgba(255, 255, 255, .12);
  color: rgba(238, 243, 237, .68);
  font-size: 12px;
}

.dev-code pre {
  padding: 28px;
  overflow-x: auto;
  font-size: 13px;
  line-height: 1.75;
}

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

.download-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.download-card {
  min-height: 260px;
  display: flex;
  flex-direction: column;
  padding: 28px;
  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);
}

.download-card:hover {
  transform: translateY(-5px);
  border-color: var(--brand);
  box-shadow: var(--shadow-md);
}

.download-card.featured {
  border-color: var(--brand);
  background: var(--brand-soft);
}

.download-card-top {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
}

.download-logo {
  width: 56px;
  height: 56px;
  display: grid;
  place-items: center;
  border-radius: 13px;
  background: var(--brand);
  color: var(--on-brand);
  font-size: 25px;
  font-weight: 860;
}

.download-logo.alt {
  background: var(--surface-2);
  color: var(--brand);
}

.download-label {
  display: block;
  margin-bottom: 6px;
  color: var(--brand-strong);
  font-size: 11px;
  font-weight: 850;
}

.download-card h3 {
  margin-bottom: 8px;
  color: var(--ink);
  font-size: 24px;
  font-weight: 850;
}

.download-card p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

.download-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0 24px;
}

.download-tags span {
  padding: 7px 10px;
  border-radius: 999px;
  background: var(--surface-2);
  color: var(--ink-2);
  font-size: 11px;
}

.download-card .btn {
  margin-top: auto;
}

.version-line {
  margin-top: 28px;
  color: var(--muted);
  font-size: 13px;
}

.faq-list {
  max-width: 820px;
}

.faq-item {
  margin-bottom: 12px;
  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: 18px;
  padding: 18px 20px;
  color: var(--ink);
  font-weight: 760;
  cursor: pointer;
  list-style: none;
}

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

.faq-item summary::after {
  content: "+";
  color: var(--brand);
  font-size: 22px;
  line-height: 1;
}

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

.faq-a {
  padding: 0 20px 20px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.78;
}

.faq-more {
  max-width: 820px;
  margin-top: 20px;
  color: var(--muted);
  font-size: 14px;
}

.footer {
  padding: 76px 0 30px;
  border-top: 1px solid var(--line);
  background: var(--bg-soft);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.7fr 1fr 1fr 1fr;
  gap: 40px;
}

.footer-brand .nav-brand {
  margin-bottom: 16px;
}

.footer-brand p {
  max-width: 360px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
}

.footer-col {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
}

.footer-col h4 {
  margin-bottom: 6px;
  color: var(--ink);
  font-size: 13px;
  font-weight: 850;
}

.footer-col a {
  color: var(--muted);
  font-size: 13px;
}

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

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-top: 46px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .55s ease, transform .55s ease;
}

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

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}

@media (max-width: 1120px) {
  .hero-inner {
    grid-template-columns: minmax(0, .9fr) minmax(440px, 1.1fr);
    gap: 38px;
  }

  .hero-title {
    font-size: 66px;
  }

  .app-window {
    right: -12px;
  }

  .note-top {
    left: -4px;
  }

  .note-bottom {
    right: 8px;
  }

  .feature-card-large {
    grid-column: span 12;
  }

  .feature-card {
    grid-column: span 4;
  }

  .security-wrap,
  .ai-wrap,
  .dev-wrap {
    grid-template-columns: 1fr;
    gap: 44px;
  }

  .security-note,
  .ai-copy,
  .dev-info {
    max-width: 720px;
  }

  .preview-shell {
    grid-template-columns: 280px minmax(0, 1fr);
    gap: 42px;
  }
}

@media (max-width: 880px) {
  .nav-inner {
    padding-right: 74px;
  }

  .hero {
    min-height: auto;
    padding-top: 132px;
  }

  .hero-inner {
    grid-template-columns: 1fr;
    gap: 56px;
  }

  .hero-copy {
    max-width: 760px;
  }

  .hero-visual {
    width: min(650px, 100%);
    min-height: 640px;
    margin: 0 auto;
  }

  .hero-visual::before {
    inset: 34px 10px 0 18px;
  }

  .app-window {
    position: relative;
    right: auto;
    width: 100%;
  }

  .note-top {
    left: -6px;
  }

  .note-bottom {
    right: -4px;
  }

  .section {
    padding: 86px 0;
  }

  .section-title {
    font-size: 46px;
  }

  .feature-card,
  .feature-card-large {
    grid-column: span 12;
  }

  .feature-card-large {
    min-height: auto;
  }

  .security-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .security-metrics {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .preview-shell {
    grid-template-columns: 1fr;
    gap: 28px;
  }

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

  .preview-tab {
    width: auto;
  }

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

@media (max-width: 720px) {
  .site-nav {
    height: 64px;
  }

  .nav-inner {
    padding-right: 16px;
  }

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

  .nav-links {
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 5px;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: 12px;
    background: var(--surface);
    box-shadow: var(--shadow-md);
  }

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

  .nav-links a {
    padding: 12px 13px;
  }

  .nav-links .nav-cta {
    margin: 8px 0 0;
    text-align: center;
  }

  .theme-toggle {
    top: 11px;
    right: 74px;
  }

  .hero-title {
    font-size: 56px;
  }

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

  .hero-actions {
    align-items: stretch;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .hero-visual {
    min-height: 580px;
  }

  .app-window-body {
    grid-template-columns: 1fr;
  }

  .app-sidebar {
    display: none;
  }

  .app-window {
    width: min(460px, 100%);
  }

  .float-note {
    min-width: 170px;
    padding: 11px 12px;
  }

  .note-top {
    top: 78px;
    left: -8px;
  }

  .note-bottom {
    right: -8px;
  }

  .section-head {
    margin-bottom: 42px;
  }

  .section-title {
    font-size: 40px;
  }

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

  .flow-step {
    min-height: auto;
  }

  .download-card {
    padding: 24px;
  }

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

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
}

@media (max-width: 480px) {
  .container,
  .container-wide {
    padding: 0 16px;
  }

  .theme-toggle {
    top: 11px;
    right: 66px;
    width: 40px;
    height: 40px;
  }

  .nav-brand span {
    font-size: 16px;
  }

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

  .hero {
    padding: 112px 0 66px;
  }

  .hero-title {
    font-size: 47px;
    line-height: 1.04;
  }

  .hero-desc {
    line-height: 1.7;
  }

  .hero-proof {
    gap: 7px;
  }

  .hero-visual {
    min-height: 500px;
  }

  .app-window-bar {
    padding: 0 12px;
  }

  .app-chat-top {
    min-height: 66px;
    padding: 13px 14px;
  }

  .app-messages {
    padding: 20px 14px;
  }

  .message {
    max-width: 82%;
    font-size: 11px;
  }

  .float-note {
    min-width: 150px;
    font-size: 11px;
  }

  .note-top {
    top: 66px;
    left: -2px;
  }

  .note-bottom {
    right: -2px;
  }

  .section-title {
    font-size: 35px;
  }

  .section-desc {
    font-size: 15px;
  }

  .feature-card,
  .feature-card-large {
    padding: 24px;
  }

  .security-metrics {
    gap: 16px;
  }

  .metric strong {
    font-size: 24px;
  }

  .security-note {
    padding: 24px;
  }

  .security-note-mark {
    top: 14px;
    right: 14px;
  }

  .ai-control {
    align-items: stretch;
    flex-direction: column;
  }

  .ai-control span {
    text-align: center;
  }

  .preview-tab {
    flex: 1 0 100%;
  }

  .dev-code pre {
    padding: 20px;
    font-size: 12px;
  }

  .download-card-top {
    grid-template-columns: 46px minmax(0, 1fr);
    gap: 12px;
  }

  .download-logo {
    width: 46px;
    height: 46px;
    border-radius: 10px;
    font-size: 20px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }
}