/* =========================================================
   极速IM 官网样式
   视觉基调：品牌蓝 #2B6CF6 · 克制留白 · 细线分隔 · 信息密度优先
   ========================================================= */

:root {
  /* 品牌色 */
  --brand:      #2B6CF6;
  --brand-600:  #1B55D6;
  --brand-700:  #1643A8;
  --brand-50:   #EFF5FF;
  --brand-100:  #DCE9FF;

  /* 中性色 */
  --ink:        #1B1F27;
  --ink-2:      #3E4653;
  --muted:      #5A6373;
  --faint:      #7C8798;
  --line:       #E2E6ED;
  --line-soft:  #EDF0F5;
  --bg:         #FFFFFF;
  --bg-soft:    #F7F9FC;
  --bg-tint:    #F2F6FF;

  --success:    #16A34A;

  --radius-sm:  6px;
  --radius:     12px;
  --radius-lg:  18px;

  --shadow-sm:  0 1px 2px rgba(27,31,39,.05);
  --shadow:     0 6px 20px -8px rgba(27,31,39,.14);
  --shadow-lg:  0 30px 60px -28px rgba(20,54,128,.32);

  --container:  1160px;
  --nav-h:      68px;

  --sans: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei",
          "Hiragino Sans GB", "Source Han Sans SC", "Noto Sans SC",
          -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas,
          "Liberation Mono", monospace;

  --ease: cubic-bezier(.22,.61,.36,1);
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 12px);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--ink-2);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4 { color: var(--ink); margin: 0; line-height: 1.25; letter-spacing: -.01em; }
p { margin: 0; }
ul { margin: 0; padding: 0; list-style: none; }
button { font-family: inherit; }

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===================== 按钮 ===================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  white-space: nowrap;
  transition: background .18s var(--ease), border-color .18s var(--ease),
              color .18s var(--ease), transform .18s var(--ease), box-shadow .18s var(--ease);
}
.btn-lg { padding: 14px 26px; font-size: 16px; }

.btn-primary { background: var(--brand); color: #fff; box-shadow: 0 1px 2px rgba(43,108,246,.25); }
.btn-primary:hover { background: var(--brand-600); transform: translateY(-1px); box-shadow: 0 8px 20px -8px rgba(43,108,246,.6); }

.btn-ghost { background: #fff; color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--brand); color: var(--brand); }

.btn-white { background: #fff; color: var(--brand-700); }
.btn-white:hover { transform: translateY(-1px); }

.btn-outline-white { background: transparent; color: #fff; border-color: rgba(255,255,255,.5); }
.btn-outline-white:hover { background: rgba(255,255,255,.12); border-color: #fff; }

/* ===================== 导航 ===================== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,.82);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s var(--ease), background .2s var(--ease);
}
.nav.is-scrolled { border-bottom-color: var(--line); background: rgba(255,255,255,.94); }

.nav-inner {
  max-width: var(--container);
  height: var(--nav-h);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 24px;
}
.brand-logo { height: 30px; width: auto; }

.nav-links {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 6px;
}
.nav-links > a {
  padding: 8px 14px;
  font-size: 15px;
  color: var(--muted);
  border-radius: var(--radius-sm);
  transition: color .16s var(--ease), background .16s var(--ease);
}
.nav-links > a:hover { color: var(--ink); background: var(--bg-soft); }
.nav-links .nav-cta { margin-left: 10px; color: #fff; }
.nav-links .nav-cta:hover { color: #fff; background: var(--brand-600); }

.nav-toggle {
  display: none;
  margin-left: auto;
  width: 42px; height: 42px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: #fff;
  cursor: pointer;
  padding: 0;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}
.nav-toggle span {
  display: block; width: 18px; height: 1.5px;
  background: var(--ink); border-radius: 2px;
  transition: transform .2s var(--ease), opacity .2s var(--ease);
}

/* ===================== 首屏 ===================== */
.hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(900px 420px at 78% -8%, var(--brand-50) 0%, rgba(239,245,255,0) 62%),
    linear-gradient(180deg, #FCFDFF 0%, #FFFFFF 100%);
}
.hero-grid-bg {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(to right, rgba(27,31,39,.045) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(27,31,39,.045) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(120% 80% at 50% 0%, #000 30%, transparent 78%);
  -webkit-mask-image: radial-gradient(120% 80% at 50% 0%, #000 30%, transparent 78%);
  pointer-events: none;
}
.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  align-items: center;
  gap: 56px;
  padding-top: 88px;
  padding-bottom: 96px;
}

.eyebrow {
  display: inline-flex; align-items: center; gap: 9px;
  margin: 0 0 22px;
  padding: 6px 14px 6px 11px;
  font-size: 13.5px; color: var(--brand-700);
  background: #fff;
  border: 1px solid var(--brand-100);
  border-radius: 999px;
  box-shadow: var(--shadow-sm);
}
.eyebrow .dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 0 3px rgba(22,163,74,.15);
}

.hero h1 {
  font-size: clamp(38px, 4.6vw, 60px);
  font-weight: 700;
  letter-spacing: -.028em;
  color: var(--ink);
}
.hero .lead {
  margin-top: 22px;
  max-width: 32em;
  font-size: 17px;
  color: var(--muted);
}
.hero-actions {
  display: flex; flex-wrap: wrap; gap: 12px;
  margin-top: 34px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  margin: 46px 0 0;
  padding-top: 28px;
  border-top: 1px solid var(--line);
}
.hero-stats > div { padding-right: 16px; }
.hero-stats dt {
  font-family: var(--mono);
  font-size: 30px; font-weight: 600; color: var(--ink);
  letter-spacing: -.02em; line-height: 1.1;
}
.hero-stats dt small { font-size: 14px; font-weight: 500; color: var(--brand); margin-left: 2px; }
.hero-stats dd { margin: 6px 0 0; font-size: 13.5px; color: var(--faint); }

/* ---- 聊天界面示意 ---- */
.hero-visual { display: flex; justify-content: center; }
.chat-mock {
  position: relative;
  width: 100%; max-width: 400px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}
.chat-head {
  display: flex; align-items: center; gap: 12px;
  padding: 15px 18px;
  border-bottom: 1px solid var(--line-soft);
  background: #FCFDFF;
}
.chat-avatar {
  width: 38px; height: 38px; border-radius: 10px;
  background: linear-gradient(135deg, var(--brand) 0%, var(--brand-700) 100%);
  color: #fff; font-size: 15px; font-weight: 600;
  display: flex; align-items: center; justify-content: center;
}
.chat-meta { display: flex; flex-direction: column; line-height: 1.35; }
.chat-meta strong { font-size: 15px; color: var(--ink); }
.chat-meta span { font-size: 12px; color: var(--success); }
.chat-dots { margin-left: auto; display: flex; gap: 3px; }
.chat-dots i { width: 3.5px; height: 3.5px; border-radius: 50%; background: var(--faint); }

.chat-body {
  padding: 20px 18px;
  display: flex; flex-direction: column; gap: 12px;
  background:
    linear-gradient(180deg, #FAFBFD 0%, #FFFFFF 100%);
}
.msg { display: flex; }
.msg.in { justify-content: flex-start; }
.msg.out { justify-content: flex-end; }
.bubble {
  max-width: 78%;
  padding: 10px 14px;
  font-size: 14px; line-height: 1.55;
  border-radius: 14px;
}
.msg.in .bubble {
  background: #fff; color: var(--ink-2);
  border: 1px solid var(--line);
  border-bottom-left-radius: 5px;
}
.msg.out .bubble {
  background: var(--brand); color: #fff;
  border-bottom-right-radius: 5px;
  box-shadow: 0 4px 12px -6px rgba(43,108,246,.6);
}
.msg.typing .bubble {
  display: inline-flex; gap: 4px; align-items: center;
  padding: 13px 14px;
}
.msg.typing .bubble span {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--faint);
  animation: blink 1.3s infinite ease-in-out;
}
.msg.typing .bubble span:nth-child(2) { animation-delay: .18s; }
.msg.typing .bubble span:nth-child(3) { animation-delay: .36s; }
@keyframes blink { 0%,60%,100% { opacity: .28; } 30% { opacity: 1; } }

.chat-input {
  display: flex; align-items: center; gap: 10px;
  padding: 13px 18px;
  border-top: 1px solid var(--line-soft);
  font-size: 14px; color: var(--faint);
}
.chat-input span { flex: 1; }
.send-ico {
  width: 26px; height: 26px; border-radius: 8px;
  background: var(--brand-50);
  position: relative;
}
.send-ico::after {
  content: ""; position: absolute; inset: 0;
  border-top: 2px solid var(--brand);
  border-right: 2px solid var(--brand);
  width: 8px; height: 8px;
  transform: rotate(45deg) translate(-1px, 4px);
  margin: auto;
}

.chat-badge {
  position: absolute;
  right: -18px; bottom: 74px;
  display: flex; flex-direction: column; align-items: flex-start;
  padding: 10px 16px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.chat-badge b { font-family: var(--mono); font-size: 22px; color: var(--brand); line-height: 1; }
.chat-badge small { margin-top: 3px; font-size: 11.5px; color: var(--faint); }

/* ===================== 通用区块 ===================== */
.section { padding: 96px 0; }
.section-soft { background: var(--bg-soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }

.section-head { max-width: 720px; margin-bottom: 52px; }
.eyebrow-mono {
  margin: 0 0 16px;
  font-family: var(--mono);
  font-size: 12.5px; letter-spacing: .08em;
  color: var(--brand); text-transform: uppercase;
}
.section-head h2 {
  font-size: clamp(28px, 3.2vw, 40px);
  font-weight: 700;
  letter-spacing: -.025em;
}
.section-sub { margin-top: 16px; font-size: 16.5px; color: var(--muted); }

/* 网格 */
.grid { display: grid; gap: 20px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

/* 卡片 */
.card {
  position: relative;
  padding: 28px 26px 30px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color .2s var(--ease), transform .2s var(--ease), box-shadow .2s var(--ease);
}
.card::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 2px;
  background: var(--brand);
  transform: scaleY(0); transform-origin: top;
  transition: transform .28s var(--ease);
}
.card:hover { transform: translateY(-3px); border-color: var(--brand-100); box-shadow: var(--shadow); }
.card:hover::before { transform: scaleY(1); }

.card-ico {
  width: 42px; height: 42px;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 18px;
  font-size: 19px; color: var(--brand);
  background: var(--brand-50);
  border: 1px solid var(--brand-100);
  border-radius: 10px;
}
.card h3 { font-size: 18px; font-weight: 600; margin-bottom: 10px; }
.card p { font-size: 14.5px; color: var(--muted); line-height: 1.72; }

/* ===================== 功能标签页 ===================== */
.tabs {
  display: flex; flex-wrap: wrap; gap: 8px;
  padding-bottom: 22px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 32px;
}
.tab {
  padding: 9px 18px;
  font-size: 14.5px;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 999px;
  cursor: pointer;
  transition: all .18s var(--ease);
}
.tab:hover { color: var(--ink); border-color: var(--faint); }
.tab.is-active { color: #fff; background: var(--ink); border-color: var(--ink); }

.tab-panels .panel { display: none; }
.tab-panels .panel.is-active {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0 40px;
  animation: fadeUp .34s var(--ease) both;
}
@keyframes fadeUp { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

.panel li {
  position: relative;
  padding: 13px 0 13px 26px;
  font-size: 15px;
  color: var(--ink-2);
  border-bottom: 1px dashed var(--line);
}
.panel li::before {
  content: ""; position: absolute; left: 2px; top: 21px;
  width: 6px; height: 6px;
  border-radius: 2px;
  background: var(--brand);
  transform: rotate(45deg);
}

/* ===================== 架构图 ===================== */
.arch { display: flex; flex-direction: column; }
.arch-layer {
  display: flex; align-items: stretch; gap: 0;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.arch-tag {
  flex: 0 0 120px;
  display: flex; align-items: center; justify-content: center;
  padding: 18px 10px;
  font-family: var(--mono);
  font-size: 12.5px; letter-spacing: .04em;
  color: var(--brand-700);
  background: var(--brand-50);
  border-right: 1px solid var(--brand-100);
}
.arch-body {
  flex: 1;
  padding: 18px 22px;
  display: flex; flex-direction: column; gap: 4px;
  justify-content: center;
}
.arch-body b { font-size: 15.5px; color: var(--ink); font-weight: 600; }
.arch-body > span { font-size: 13.5px; color: var(--muted); }
.arch-split {
  flex-direction: row;
  gap: 28px;
  flex-wrap: wrap;
  padding: 16px 22px;
}
.arch-split > div { display: flex; flex-direction: column; gap: 2px; }
.arch-split b { font-size: 14.5px; }
.arch-split span { font-size: 12.5px; color: var(--faint); }

.arch-link {
  display: flex; align-items: center; gap: 12px;
  padding: 9px 0 9px 150px;
  font-family: var(--mono);
  font-size: 12px; color: var(--faint);
}
.arch-link i {
  flex: 0 0 1px; height: 16px;
  background: var(--line);
}

.stack-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-top: 28px;
}
.stack-chip {
  padding: 14px 16px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  display: flex; flex-direction: column; gap: 3px;
}
.stack-chip span { font-size: 11.5px; color: var(--faint); letter-spacing: .02em; }
.stack-chip b { font-size: 14px; color: var(--ink); font-weight: 600; }

/* ===================== 性能与部署 ===================== */
.deploy-grid {
  display: grid;
  grid-template-columns: .85fr 1.15fr;
  gap: 24px;
  align-items: start;
}
.metric-card, .deploy-steps {
  padding: 32px 30px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
}
.metric-card h3, .deploy-steps h3 {
  font-size: 18px; font-weight: 600;
  padding-bottom: 18px; margin-bottom: 6px;
  border-bottom: 1px solid var(--line);
}
.metric-table { width: 100%; border-collapse: collapse; }
.metric-table th, .metric-table td {
  padding: 15px 0;
  font-size: 14.5px;
  text-align: left;
  border-bottom: 1px solid var(--line-soft);
}
.metric-table tr:last-child th, .metric-table tr:last-child td { border-bottom: 0; }
.metric-table th { font-weight: 400; color: var(--muted); }
.metric-table td {
  text-align: right;
  font-family: var(--mono);
  font-size: 14px;
  color: var(--ink);
  font-weight: 500;
}

.deploy-steps h3 { margin-bottom: 20px; }
.step { display: flex; gap: 16px; padding: 12px 0; }
.step-n {
  flex: 0 0 26px; height: 26px;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--mono); font-size: 13px; font-weight: 600;
  color: var(--brand);
  background: var(--brand-50);
  border-radius: 50%;
}
.step b { display: block; font-size: 15px; color: var(--ink); margin-bottom: 3px; }
.step p { font-size: 14px; color: var(--muted); line-height: 1.65; }

.code-block {
  margin-top: 20px;
  background: #161A22;
  border-radius: var(--radius);
  overflow: hidden;
}
.code-head {
  display: flex; align-items: center; gap: 6px;
  padding: 11px 14px;
  background: rgba(255,255,255,.04);
  border-bottom: 1px solid rgba(255,255,255,.07);
}
.code-head i { width: 9px; height: 9px; border-radius: 50%; background: rgba(255,255,255,.18); }
.code-head span { margin-left: 8px; font-family: var(--mono); font-size: 12px; color: rgba(255,255,255,.45); }
.code-block pre { margin: 0; padding: 18px; overflow-x: auto; }
.code-block code {
  font-family: var(--mono);
  font-size: 13.5px;
  line-height: 1.85;
  color: #C9D4E6;
  white-space: pre;
}
.code-block .c-p { color: #5A90FB; }
.code-block .c-c { color: #6B7A90; }

/* ===================== 演示 ===================== */
.demo-grid {
  display: grid;
  grid-template-columns: 1.25fr .9fr;
  gap: 24px;
  align-items: start;
}
.demo-main {
  padding: 36px 34px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}
.demo-main h3 { font-size: 21px; font-weight: 700; }
.demo-main > p { margin-top: 12px; font-size: 15.5px; color: var(--muted); }

.cred {
  display: grid; grid-template-columns: 1fr 1fr; gap: 12px;
  margin: 26px 0;
}
.cred > div {
  padding: 14px 18px;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  display: flex; flex-direction: column; gap: 5px;
}
.cred span { font-size: 12.5px; color: var(--faint); }
.cred b { font-family: var(--mono); font-size: 16px; color: var(--ink); letter-spacing: .02em; }

.demo-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.demo-note { margin-top: 18px; font-size: 13px; color: var(--faint); }

.demo-side { display: flex; flex-direction: column; gap: 16px; }
.side-card {
  padding: 24px 26px;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.side-card h4 { font-size: 16px; font-weight: 600; margin-bottom: 8px; }
.side-card p { font-size: 14px; color: var(--muted); line-height: 1.68; margin-bottom: 14px; }
.side-card.is-plain p { margin-bottom: 0; }
.link-arrow {
  display: inline-flex; align-items: center; gap: 7px;
  font-size: 14.5px; font-weight: 500; color: var(--brand);
}
.link-arrow span { transition: transform .2s var(--ease); }
.link-arrow:hover span { transform: translateX(4px); }

/* ---- 各端下载 ---- */
.dl-block {
  margin-top: 44px;
  padding-top: 36px;
  border-top: 1px solid var(--line);
}
.dl-head {
  display: flex; align-items: baseline; justify-content: space-between;
  gap: 8px 28px; flex-wrap: wrap;
}
.dl-head h3 { font-size: 19px; font-weight: 600; }
.dl-head p { font-size: 14px; color: var(--muted); max-width: 56ch; }

.dl-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 186px), 1fr));
  gap: 14px;
  margin-top: 24px;
}
.dl-item {
  position: relative;
  display: flex; flex-direction: column; gap: 3px;
  padding: 22px 20px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color .2s var(--ease), transform .2s var(--ease), box-shadow .2s var(--ease);
}
.dl-item:not(.is-pending):hover {
  transform: translateY(-3px);
  border-color: var(--brand-100);
  box-shadow: var(--shadow);
}
.dl-name { font-size: 16px; font-weight: 600; color: var(--ink); }
.dl-type {
  font-family: var(--mono);
  font-size: 11px; letter-spacing: .06em;
  color: var(--brand);
}
.dl-note { margin-top: 2px; font-size: 12.5px; color: var(--faint); }
.dl-state {
  margin-top: 16px;
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 13.5px; font-weight: 500; color: var(--brand);
}
.dl-item:not(.is-pending) .dl-state::after { content: "→"; transition: transform .2s var(--ease); }
.dl-item:not(.is-pending):hover .dl-state::after { transform: translateX(3px); }

.dl-item.is-pending {
  background: var(--bg-soft);
  border-style: dashed;
  cursor: not-allowed;
}
.dl-item.is-pending .dl-name,
.dl-item.is-pending .dl-type,
.dl-item.is-pending .dl-state { color: var(--faint); }
.dl-item.is-pending .dl-state { font-weight: 400; }

/* ===================== 联系 ===================== */
/* auto-fit：卡片数量与屏宽变化时自动重排 */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 230px), 1fr));
  gap: 16px;
}
.contact-card {
  display: flex; flex-direction: column; gap: 8px;
  padding: 26px 24px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  min-width: 0;
  transition: border-color .2s var(--ease), transform .2s var(--ease), box-shadow .2s var(--ease);
}
.contact-card:not(.is-static):hover {
  transform: translateY(-3px);
  border-color: var(--brand-100);
  box-shadow: var(--shadow);
}
.contact-card.is-primary {
  border-color: var(--brand-100);
  background: linear-gradient(180deg, var(--brand-50) 0%, #fff 62%);
}
.contact-card.is-primary:hover { border-color: var(--brand); }
.contact-k {
  font-family: var(--mono);
  font-size: 12px; letter-spacing: .06em;
  color: var(--brand);
}
.contact-card b {
  font-size: 17px; font-weight: 600; color: var(--ink);
  overflow-wrap: anywhere; word-break: break-word;
}
.contact-card i { font-style: normal; font-size: 13px; color: var(--faint); }
.contact-card.is-static { background: var(--bg-soft); }

/* ===================== CTA 色带 ===================== */
.cta-band {
  background: linear-gradient(120deg, var(--brand-600) 0%, var(--brand-700) 55%, #10245C 100%);
  color: #fff;
  position: relative;
  overflow: hidden;
}
.cta-band::after {
  content: ""; position: absolute; inset: 0;
  background-image:
    linear-gradient(to right, rgba(255,255,255,.06) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255,255,255,.06) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(90% 100% at 20% 50%, #000 0%, transparent 70%);
  -webkit-mask-image: radial-gradient(90% 100% at 20% 50%, #000 0%, transparent 70%);
}
.cta-inner {
  position: relative;
  display: flex; align-items: center; justify-content: space-between;
  gap: 32px; flex-wrap: wrap;
  padding-top: 66px; padding-bottom: 66px;
}
.cta-inner h2 { color: #fff; font-size: clamp(24px, 2.8vw, 34px); font-weight: 700; letter-spacing: -.02em; }
.cta-actions { display: flex; gap: 12px; flex-wrap: wrap; }

/* ===================== 页脚 ===================== */
.footer {
  background: #131722;
  color: rgba(255,255,255,.55);
  padding: 56px 0 34px;
}
.footer-inner { display: flex; flex-direction: column; gap: 28px; }
.footer-brand img { height: 30px; width: auto; filter: brightness(0) invert(1); opacity: .92; }
.footer-brand p { margin-top: 14px; font-size: 14px; }

.footer-nav { display: flex; flex-wrap: wrap; gap: 8px 26px; }
.footer-nav a { font-size: 14px; color: rgba(255,255,255,.6); transition: color .16s var(--ease); }
.footer-nav a:hover { color: #fff; }

.footer-meta {
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px;
  padding-top: 26px;
  border-top: 1px solid rgba(255,255,255,.08);
  font-size: 13px; color: rgba(255,255,255,.4);
}
.footer-meta a {
  color: rgba(255,255,255,.62);
  overflow-wrap: anywhere;
  transition: color .16s var(--ease);
}
.footer-meta a:hover { color: #fff; }

/* ===================== 提示条 ===================== */
.toast {
  position: fixed;
  left: 50%; bottom: 32px;
  transform: translate(-50%, 20px);
  padding: 12px 22px;
  background: var(--ink);
  color: #fff;
  font-size: 14px;
  border-radius: var(--radius-sm);
  box-shadow: 0 12px 30px -10px rgba(0,0,0,.5);
  opacity: 0;
  pointer-events: none;
  transition: opacity .24s var(--ease), transform .24s var(--ease);
  z-index: 999;
}
.toast.is-show { opacity: 1; transform: translate(-50%, 0); }

/* ===================== 入场动画 ===================== */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .7s var(--ease), transform .7s var(--ease);
  transition-delay: var(--delay, 0s);
}
.reveal.is-in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
  .msg.typing .bubble span { animation: none; }
}

/* ===================== 响应式 ===================== */
@media (max-width: 1024px) {
  .hero-inner { grid-template-columns: 1fr; gap: 48px; padding-top: 64px; padding-bottom: 76px; }
  .hero-visual { justify-content: flex-start; }
  .chat-badge { right: 0; }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .stack-row { grid-template-columns: repeat(2, 1fr); }
  .deploy-grid, .demo-grid { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  :root { --nav-h: 60px; }
  .section { padding: 68px 0; }
  .container { padding: 0 18px; }
  .nav-inner { padding: 0 18px; }

  .nav-links {
    position: fixed;
    top: var(--nav-h); left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 14px 18px 22px;
    background: rgba(255,255,255,.98);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 16px 30px -20px rgba(27,31,39,.4);
    transform: translateY(-12px);
    opacity: 0; visibility: hidden;
    transition: opacity .2s var(--ease), transform .2s var(--ease), visibility .2s;
  }
  .nav-links.is-open { opacity: 1; visibility: visible; transform: none; }
  .nav-links > a { padding: 13px 12px; font-size: 16px; }
  .nav-links .nav-cta { margin: 8px 0 0; }

  .nav-toggle { display: flex; }
  .nav.is-open .nav-toggle span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
  .nav.is-open .nav-toggle span:nth-child(2) { opacity: 0; }
  .nav.is-open .nav-toggle span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

  .hero h1 { font-size: clamp(30px, 8.4vw, 40px); }
  .hero .lead { font-size: 16px; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 22px 0; }
  .hero-stats > div { padding-right: 12px; }
  .hero-actions .btn { flex: 1 1 auto; }

  .grid-3 { grid-template-columns: 1fr; }
  .tab-panels .panel.is-active { grid-template-columns: 1fr; }
  .arch-tag { flex: 0 0 84px; font-size: 11.5px; }
  .arch-link { padding-left: 96px; }
  .stack-row { grid-template-columns: 1fr 1fr; }
  .cred { grid-template-columns: 1fr; }
  .demo-actions .btn { width: 100%; }
  .cta-inner { flex-direction: column; align-items: flex-start; }
  .cta-actions { width: 100%; }
  .cta-actions .btn { flex: 1 1 auto; }
  .footer-meta { flex-direction: column; }
}