/* ============================================================
   PPT AI 工作台 · 落地页样式
   配色与界面复用产品 navy(dark) 主题（web/src/styles/theme-navy.css）
   首屏窗口为「生图 → 图转网页 → 打开编辑 → 保存」四步连播演示
   ============================================================ */
:root {
  --font-sans: "Noto Sans SC", "Source Han Sans SC", "Noto Sans CJK SC", ui-sans-serif, system-ui, sans-serif;
  --font-serif: "Noto Serif SC", "Source Han Serif SC", ui-serif, serif;
  --bg: oklch(0.17 0.008 250);
  --bg-2: oklch(0.205 0.018 255);
  --card: oklch(0.225 0.012 250);
  --card-2: oklch(0.205 0.011 250);
  --sidebar: oklch(0.155 0.01 250);
  --surface-2: oklch(0.265 0.012 250);
  --border: oklch(1 0 0 / 12%);
  --border-soft: oklch(1 0 0 / 7%);
  --fg: oklch(0.94 0.006 250);
  --muted: oklch(0.72 0.012 248);
  --muted-2: oklch(0.6 0.012 250);
  --primary: oklch(0.72 0.105 184);
  --primary-strong: oklch(0.78 0.12 184);
  --chat-user: oklch(0.34 0.052 205);
  --accent: oklch(0.82 0.12 80);
  --accent-strong: oklch(0.86 0.14 82);
  --accent-fg: oklch(0.24 0.05 70);
  --radius: 16px;
  --shadow-pop: 0 26px 70px rgb(0 0 0 / 48%);
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}
body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  color: var(--fg);
  background:
    radial-gradient(1100px 600px at 80% -8%, oklch(0.32 0.07 184 / 36%), transparent 60%),
    radial-gradient(900px 600px at 6% 110%, oklch(0.3 0.06 80 / 20%), transparent 55%),
    linear-gradient(180deg, var(--bg-2), var(--bg) 38%);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a {
  color: inherit;
  text-decoration: none;
}
.wrap {
  width: min(1200px, 100% - 48px);
  margin-inline: auto;
}

/* ---------------- 顶部导航 ---------------- */
header.nav {
  position: sticky;
  top: 0;
  z-index: 30;
  backdrop-filter: blur(12px);
  background: oklch(0.17 0.008 250 / 62%);
  border-bottom: 1px solid var(--border-soft);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  letter-spacing: 0.2px;
}
.brand .logo {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border-radius: 7px;
  box-shadow: 0 6px 18px oklch(0.72 0.105 184 / 35%);
}
.brand .logo img {
  display: block;
  width: 30px;
  height: 30px;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 22px;
  font-size: 14px;
  color: var(--muted);
}
.nav-links a:hover {
  color: var(--fg);
}
.btn {
  --b: var(--accent);
  --bs: var(--accent-strong);
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 12px 20px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 15px;
  border: none;
  cursor: pointer;
  color: var(--accent-fg);
  background: linear-gradient(135deg, var(--bs), var(--b));
  box-shadow: 0 10px 26px oklch(0.82 0.12 80 / 28%);
  transition:
    transform 180ms var(--ease),
    box-shadow 180ms var(--ease),
    filter 180ms var(--ease);
}
.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 16px 34px oklch(0.82 0.12 80 / 38%);
  filter: saturate(1.05);
}
.btn:active {
  transform: translateY(0);
}
.btn.sm {
  padding: 9px 16px;
  font-size: 14px;
}
.btn.ghost {
  background: oklch(1 0 0 / 6%);
  color: var(--fg);
  box-shadow: none;
  border: 1px solid oklch(1 0 0 / 12%);
}
.btn.ghost:hover {
  background: oklch(1 0 0 / 10%);
  box-shadow: none;
}
.lang-toggle {
  font-family: inherit;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 13px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.3px;
  cursor: pointer;
  color: var(--fg);
  background: oklch(1 0 0 / 6%);
  border: 1px solid oklch(1 0 0 / 12%);
  transition:
    background 180ms var(--ease),
    color 180ms var(--ease);
}
.lang-toggle:hover {
  background: oklch(1 0 0 / 12%);
}
.lang-toggle svg {
  opacity: 0.8;
}

/* ---------------- Hero ---------------- */
.hero {
  display: grid;
  grid-template-columns: 0.88fr 1.12fr;
  gap: 52px;
  align-items: center;
  min-height: calc(100vh - 64px);
  padding: 38px 0 56px;
}
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 13px;
  color: var(--primary-strong);
  background: oklch(0.72 0.105 184 / 12%);
  border: 1px solid oklch(0.72 0.105 184 / 28%);
}
.eyebrow .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--primary-strong);
  animation: pulse 2.4s var(--ease) infinite;
}
@keyframes pulse {
  0% {
    box-shadow: 0 0 0 0 oklch(0.72 0.105 184 / 55%);
  }
  70%,
  100% {
    box-shadow: 0 0 0 9px oklch(0.72 0.105 184 / 0%);
  }
}
h1 {
  margin: 22px 0 0;
  font-size: clamp(32px, 4.6vw, 54px);
  line-height: 1.1;
  letter-spacing: -0.5px;
  font-weight: 800;
}
h1 .grad {
  background: linear-gradient(120deg, var(--primary-strong), oklch(0.85 0.11 200) 45%, var(--accent-strong));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.sub {
  margin: 20px 0 0;
  max-width: 30em;
  font-size: clamp(15px, 1.6vw, 18px);
  line-height: 1.7;
  color: var(--muted);
}
.cta {
  margin-top: 30px;
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}
.cta .platform {
  font-size: 13px;
  color: var(--muted);
}
.cta .platform strong {
  color: var(--fg);
  font-weight: 600;
}
.stats {
  margin-top: 34px;
  display: flex;
  gap: 32px;
  flex-wrap: wrap;
}
.stats .item .n {
  font-size: 20px;
  font-weight: 800;
  color: var(--fg);
}
.stats .item .l {
  font-size: 13px;
  color: var(--muted);
  margin-top: 2px;
}