/* ============================================
   Hindsight Landing - 中文版
   亮色暖调 · 基于 logo 橙→紫渐变
   ============================================ */

:root {
  /* 配色 */
  --bg: #ffffff;
  --bg-warm: #faf8f5;
  --text: #1a1a1a;
  --text-mute: #6b6b6b;
  --text-faded: #a0a0a0;
  --accent: #f88b5c;
  --accent-hover: #e5764a;
  --accent-2: #b47ce6;
  --border: #e8e5e0;

  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.12);
  --shadow-cta: 0 4px 12px rgba(248, 139, 92, 0.30);

  /* 渐变 */
  --gradient: linear-gradient(135deg, #f88b5c 0%, #ff7b9c 50%, #b47ce6 100%);
  --gradient-soft: linear-gradient(180deg, #fff8f2 0%, #ffffff 100%);

  /* 字体 */
  --font-cn: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui,
    -apple-system, sans-serif;
  --font-en: "Inter", "SF Pro Display", -apple-system, BlinkMacSystemFont,
    system-ui, sans-serif;

  /* 圆角 */
  --r-btn: 12px;
  --r-card: 16px;
  --r-img: 14px;

  /* 动画 */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --trans-fast: 150ms var(--ease-out);
  --trans-base: 250ms var(--ease-out);
}

/* ============================================
   Reset & Base
   ============================================ */

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-cn);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--trans-fast);
}

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

ul {
  list-style: none;
}

/* ============================================
   Layout helpers
   ============================================ */

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
}

.container.narrow {
  max-width: 800px;
}

/* ============================================
   Typography
   ============================================ */

/* 流式字号 —— clamp(min, preferred, max)，让所有屏幕宽度都能顺滑过渡，
   不在断点处突变。preferred = X vw 跟随视口宽度。 */
.display {
  font-family: var(--font-en);
  /* 加大到 88px，更有视觉冲击 —— 跟 Linear / Stripe hero 标题尺寸一致 */
  font-size: clamp(48px, 6.2vw, 88px);
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: -0.03em;
  background: var(--gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  /* 跟下方副标题留足呼吸感 */
  margin-bottom: 28px;
  /* padding-bottom 让 background-clip:text 在 g/j 下伸时不被自身行盒裁切 */
  padding-bottom: 0.05em;
}

h1,
h2,
h3,
h4 {
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -0.01em;
}

.section-title {
  font-size: clamp(28px, 3.2vw, 42px);
  line-height: 1.15;
  font-weight: 700;
  text-align: center;
  margin-bottom: clamp(36px, 4.5vw, 56px);
  letter-spacing: -0.02em;
}

.subtitle {
  font-size: clamp(18px, 1.8vw, 22px);
  font-weight: 500;
  line-height: 1.4;
  color: var(--text);
  margin-bottom: 20px;
}

.intro,
.lead {
  font-size: clamp(15px, 1.4vw, 17px);
  line-height: 1.7;
  color: var(--text-mute);
  margin-bottom: 32px;
}

.lead {
  margin-bottom: 32px;
}

.caption {
  font-size: 14px;
  color: var(--text-mute);
  text-align: center;
  margin-top: 16px;
}

.eyebrow {
  font-family: var(--font-en);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 20px;
}

.trust {
  font-size: 13px;
  color: var(--text-faded);
  margin-top: 20px;
}

.muted {
  color: var(--text-mute);
  font-size: 13px;
}

/* ============================================
   Buttons
   ============================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 0;
  border-radius: var(--r-btn);
  font-family: inherit;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--trans-base);
  white-space: nowrap;
  user-select: none;
}

.btn-sm {
  font-size: 14px;
  padding: 8px 18px;
}

.btn-lg {
  font-size: 16px;
  padding: 14px 28px;
}

.btn-primary {
  background: var(--accent);
  color: white;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

.btn-primary:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-cta);
}

.btn-ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-ghost:hover {
  border-color: var(--text-mute);
  background: var(--bg-warm);
}

/* HTML hidden 属性优先 —— .btn-platform 的 display: inline-flex
   类规则会覆盖默认 display: none，必须显式给 [hidden] 高优先级 */
[hidden] {
  display: none !important;
}

/* 平台下载按钮 —— 图标 + 两行文字，Windows / macOS 同款外观，仅图标区分 */
.btn-platform {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 12px 22px;
  border-radius: var(--r-btn);
  background: var(--accent);
  color: white;
  cursor: pointer;
  transition: all var(--trans-base);
  border: 0;
  text-decoration: none;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

.btn-platform:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-cta);
}

.btn-platform-icon {
  width: 22px;
  height: 22px;
  flex-shrink: 0;
}

.btn-platform-text {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  line-height: 1.2;
}

.btn-platform-name {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.btn-platform-meta {
  font-size: 12px;
  font-weight: 400;
  opacity: 0.78;
  font-family: var(--font-en);
  margin-top: 2px;
}

/* Final CTA 卡片内的平台按钮（白底 → 反色） */
.btn-platform-light {
  background: white;
  color: var(--accent-hover);
}

.btn-platform-light:hover {
  background: #fff5ee;
  color: var(--accent-hover);
}

.cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.trust-link {
  color: var(--text-mute);
  font-weight: 500;
  transition: color var(--trans-fast);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.trust-link:hover {
  color: var(--accent);
}

/* GitHub Octocat 图标 */
.trust-gh {
  color: var(--text-mute);
  transition: color var(--trans-fast);
}

.trust-link:hover .trust-gh {
  color: var(--text);
}


/* ============================================
   Nav
   ============================================ */

.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid rgba(232, 229, 224, 0.5);
}

.nav-inner {
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0;
  padding-bottom: 0;
}

/* Nav 左半区：logo + section 跳转锚点（为什么 / 演示）*/
.nav-left {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 18px;
}

.nav-logo {
  width: 28px;
  height: 28px;
  border-radius: 7px;
}

.nav-name {
  font-family: var(--font-en);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 20px;
}

/* Section 跳转锚点（为什么 / 演示） */
.nav-anchors {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-anchor {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-mute);
  transition: color var(--trans-fast);
  position: relative;
}

.nav-anchor::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width var(--trans-fast);
}

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

.nav-anchor:hover::after {
  width: 100%;
}

.lang-switch {
  font-size: 13px;
  color: var(--text-faded);
  display: flex;
  align-items: center;
  gap: 6px;
}

.lang-icon {
  color: var(--text-mute);
  margin-right: 2px;
  flex-shrink: 0;
}

.lang-active {
  color: var(--text);
  font-weight: 500;
}

.lang-switch a {
  color: var(--text-mute);
}

.lang-switch a:hover {
  color: var(--accent);
}

.lang-sep {
  opacity: 0.5;
}

.nav-github {
  display: flex;
  align-items: center;
  color: var(--text-mute);
  transition: color var(--trans-fast);
}

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

/* ============================================
   Hero
   ============================================ */

.hero {
  position: relative;
  padding: 80px 0 100px;
  background: var(--gradient-soft);
  overflow: hidden;
}

/* Hero 用独立加宽 container —— 1440px，让 iframe 有桌面级宽度
   其它 section 仍用全局 .container (1200px) */
.hero > .container {
  max-width: 1440px;
}

.hero-grid {
  display: grid;
  /* 默认 (≥ 1280px)：1 : 2.4 → iframe 占 ~72% ≈ 980px@1440 viewport
     gap 用 clamp 跟随宽度收缩 */
  grid-template-columns: minmax(0, 1fr) minmax(0, 2.4fr);
  gap: clamp(32px, 4vw, 56px);
  align-items: center;
}

.hero-text {
  max-width: 440px;
}

.hero-visual {
  position: relative;
}

/* 双色渐变光晕：橙 + 紫错位，比单色更有空间感 */
.hero-blob {
  position: absolute;
  inset: -15% -15% -15% 0;
  z-index: 0;
  pointer-events: none;
}

.hero-blob::before,
.hero-blob::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
}

.hero-blob::before {
  width: 65%;
  height: 65%;
  top: -10%;
  right: -10%;
  background: #f88b5c;
  opacity: 0.32;
}

.hero-blob::after {
  width: 55%;
  height: 55%;
  bottom: -10%;
  left: 5%;
  background: #b47ce6;
  opacity: 0.28;
}

/* Hero iframe —— 真应用 demo 嵌入；首屏即加载
   宽高比 16:11 接近真实桌面窗口，给应用 sidebar + 主面板足够呼吸空间 */
.hero-demo-frame {
  position: relative;
  z-index: 1;
  width: 100%;
  aspect-ratio: 16 / 11;
  border: 1px solid #e8e5e0;
  border-radius: var(--r-img);
  background: white;
  display: block;
  box-shadow:
    0 2px 4px rgba(0, 0, 0, 0.04),
    0 8px 16px rgba(0, 0, 0, 0.06),
    0 24px 48px rgba(0, 0, 0, 0.10),
    0 48px 96px -20px rgba(248, 139, 92, 0.28),
    0 72px 144px -32px rgba(180, 124, 230, 0.20);
}

@media (max-width: 900px) {
  .hero-demo-frame {
    aspect-ratio: 4 / 3;
  }
}

/* ============================================
   Why Hindsight
   ============================================ */

.why {
  padding: 100px 0;
}

.why .section-title {
  text-align: left;
  margin-bottom: 32px;
}

.why-list {
  margin: 32px 0 32px 0;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.why-list li {
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-mute);
  padding-left: 24px;
  position: relative;
}

.why-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--gradient);
}

.why-list strong {
  color: var(--text);
  font-weight: 600;
}

.why-closing {
  font-size: 19px;
  font-weight: 600;
  color: var(--text);
  margin-top: 16px;
}

/* ============================================
   Demo (video)
   ============================================ */

.demo {
  padding: 80px 0 100px;
  background: var(--bg-warm);
}

.video-frame {
  max-width: 960px;
  margin: 0 auto;
  border-radius: var(--r-img);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  background: black;
}

.video-frame video {
  display: block;
  width: 100%;
  height: auto;
}

.demo .caption {
  margin-top: 20px;
}

/* ============================================
   Features
   ============================================ */

.features {
  padding: 100px 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  max-width: 1000px;
  margin: 0 auto;
}

.feature-card {
  background: white;
  border: 1px solid var(--border);
  border-radius: var(--r-card);
  padding: 32px 28px;
  transition: transform var(--trans-base), box-shadow var(--trans-base),
    border-color var(--trans-base);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(248, 139, 92, 0.3);
}

.feature-icon {
  font-size: 36px;
  margin-bottom: 16px;
  display: inline-block;
}

.feature-card h3 {
  font-size: 22px;
  margin-bottom: 10px;
}

.feature-card p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-mute);
}

/* ============================================
   Showcase
   ============================================ */

.showcase {
  padding: 100px 0;
  background: var(--bg-warm);
}

.showcase-item {
  text-align: center;
  margin-bottom: 96px;
}

.showcase-item:last-child {
  margin-bottom: 0;
}

.showcase-item h2 {
  font-size: clamp(24px, 2.8vw, 36px);
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.showcase-item .caption {
  max-width: 640px;
  margin: 0 auto 32px;
  font-size: 16px;
}

.screenshot-large {
  max-width: 1000px;
  margin: 0 auto;
  border-radius: var(--r-img);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
}

.screenshot-large img {
  width: 100%;
  display: block;
}

/* ============================================
   Final CTA
   ============================================ */

.final-cta {
  padding: 100px 0;
}

.cta-card {
  background: var(--gradient);
  border-radius: 24px;
  padding: clamp(40px, 5vw, 72px) clamp(24px, 4vw, 48px);
  text-align: center;
  color: white;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(248, 139, 92, 0.25);
}

.cta-card h2 {
  font-size: clamp(28px, 3.4vw, 44px);
  line-height: 1.15;
  margin-bottom: 12px;
  color: white;
}

.cta-card p {
  font-size: clamp(15px, 1.4vw, 18px);
  margin-bottom: 32px;
  opacity: 0.92;
}

.cta-card .cta-group {
  justify-content: center;
}

.cta-card .btn-primary {
  background: white;
  color: var(--accent-hover);
}

.cta-card .btn-primary:hover {
  background: #fff5ee;
  transform: translateY(-1px);
}

.cta-card .btn-ghost {
  border-color: rgba(255, 255, 255, 0.6);
  color: white;
}

.cta-card .btn-ghost:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: white;
}

/* ============================================
   Footer
   ============================================ */

.footer {
  background: var(--bg-warm);
  padding: 64px 0 32px;
  border-top: 1px solid var(--border);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: clamp(32px, 4vw, 48px);
  margin-bottom: 48px;
}

.footer-brand {
  max-width: 320px;
}

.footer-logo-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.footer-logo {
  width: 28px;
  height: 28px;
  border-radius: 7px;
}

.footer-brand h3 {
  font-family: var(--font-en);
  font-size: 20px;
  font-weight: 700;
}

.footer-brand p {
  font-size: 14px;
  color: var(--text-mute);
  line-height: 1.6;
  margin-bottom: 16px;
}

.footer-col h4 {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--text);
  margin-bottom: 16px;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-col a {
  font-size: 14px;
  color: var(--text-mute);
}

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

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 24px;
  text-align: center;
  font-size: 13px;
  color: var(--text-faded);
}

.footer-bottom a {
  color: var(--text-mute);
}

.footer-bottom a:hover {
  color: var(--accent);
}

/* ============================================
   Responsive —— 多档断点
   - 1100-1280px：中等屏（小笔记本 / 大平板横屏）—— hero 比例放宽给文字
   - 900-1099px：平板 —— hero 仍侧排但更紧
   - <= 900px：手机 / 小平板 —— 全部垂直堆叠
   - <= 500px：小屏手机 —— 字号再降一档
   ============================================ */

/* 中等屏：hero 文字需要更多空间，iframe 仍占主导 */
@media (max-width: 1280px) {
  .hero-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.9fr);
  }
}

@media (max-width: 1100px) {
  .hero-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.5fr);
    gap: 40px;
  }
  .hero-text {
    max-width: 420px;
  }
  /* Footer 4 列在中等屏会挤，改成 brand 行 + 3 列子菜单 */
  .footer-grid {
    grid-template-columns: 1fr 1fr 1fr;
  }
  .footer-brand {
    grid-column: 1 / -1;
    max-width: none;
  }
}

@media (max-width: 900px) {
  .container {
    padding: 0 20px;
  }

  /* Typography 缩小 */
  .display {
    font-size: 48px;
  }

  .section-title {
    font-size: 32px;
    margin-bottom: 40px;
  }

  .subtitle {
    font-size: 19px;
  }

  /* Nav 简化：窄屏只保留 logo + 下载按钮 */
  .lang-switch {
    display: none;
  }

  .nav-github {
    display: none;
  }

  .nav-anchors {
    display: none;
  }

  /* Hero 改成纵向 */
  .hero {
    padding: 56px 0 72px;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .hero-text {
    max-width: none;
    text-align: center;
  }

  .hero-text .cta-group {
    justify-content: center;
  }

  /* Features 1 列 */
  .features-grid {
    grid-template-columns: 1fr;
  }

  .feature-card {
    padding: 28px 24px;
  }

  /* Section padding 缩小 */
  .why,
  .features,
  .showcase,
  .final-cta {
    padding: 64px 0;
  }

  .demo {
    padding: 56px 0 72px;
  }

  .showcase-item {
    margin-bottom: 64px;
  }

  .showcase-item h2 {
    font-size: 28px;
  }

  /* Final CTA 卡片 */
  .cta-card {
    padding: 48px 24px;
  }

  .cta-card h2 {
    font-size: 32px;
  }

  .cta-card p {
    font-size: 16px;
  }

  /* Footer 1 列 */
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  /* CTA group 移动端按钮变全宽 */
  .cta-group {
    flex-direction: column;
    align-items: stretch;
  }

  .cta-group .btn {
    justify-content: center;
  }
}

@media (max-width: 500px) {
  .display {
    font-size: 40px;
  }

  .section-title {
    font-size: 26px;
  }

  .why .section-title {
    font-size: 28px;
  }
}