/* ==========================================================================
   易组卷官网 — 苹果风设计系统
   ========================================================================== */

:root {
  --font: -apple-system, BlinkMacSystemFont, "SF Pro SC", "PingFang SC",
    "Microsoft YaHei", "Noto Sans SC", "Helvetica Neue", Arial, sans-serif;

  --bg-white: #ffffff;
  --bg-gray: #f5f5f7;
  --bg-dark: #161617;

  --text-primary: #1d1d1f;
  --text-secondary: #6e6e73;
  --text-tertiary: #86868b;
  --text-on-dark: #ffffff;
  --text-on-dark-secondary: #a1a1a6;

  --accent: #3f51b5;
  --accent-hover: #3949ab;
  --accent-soft: #5c6bc0;
  --accent-light: #a5b4fc;

  --divider: #d2d2d7;
  --divider-dark: #333336;

  --radius-sm: 12px;
  --radius-md: 18px;
  --radius-lg: 28px;
  --radius-pill: 980px;

  --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 12px 32px rgba(0, 0, 0, 0.10);
  --shadow-lg: 0 24px 60px rgba(0, 0, 0, 0.14);

  --nav-h: 52px;
  --container: 1080px;
  --narrow: 720px;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img { max-width: 100%; display: block; }
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }
h1, h2, h3, h4, p { margin: 0; }

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

/* ---------- 导航 ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 1000;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color 0.35s ease, border-color 0.35s ease;
}
.nav.scrolled {
  background: rgba(255, 255, 255, 0.78);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  backdrop-filter: saturate(180%) blur(20px);
  border-bottom-color: var(--divider);
}
.nav-inner {
  max-width: var(--container);
  margin: 0 auto;
  height: 100%;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-primary);
  font-weight: 600;
  font-size: 17px;
  letter-spacing: -0.01em;
}
.brand:hover { color: var(--text-primary); }
.brand-logo { width: 30px; height: 30px; }
.brand-name { white-space: nowrap; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-link {
  display: inline-block;
  padding: 8px 14px;
  color: var(--text-primary);
  font-size: 14px;
  font-weight: 400;
  border-radius: var(--radius-pill);
  transition: color 0.2s ease, background-color 0.2s ease;
}
.nav-link:hover { color: var(--text-primary); background: rgba(0, 0, 0, 0.05); }
.nav-link.active { color: var(--accent); font-weight: 500; }

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

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px; height: 40px;
  padding: 8px;
  background: transparent;
  border: none;
  cursor: pointer;
}
.nav-toggle-bar {
  display: block;
  width: 100%; height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 26px;
  font-size: 16px;
  font-weight: 500;
  line-height: 1.2;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  cursor: pointer;
  text-align: center;
  transition: transform 0.2s ease, background-color 0.2s ease,
    color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}
.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 8px 20px rgba(63, 81, 181, 0.35);
}
.btn-secondary {
  background: transparent;
  color: var(--accent);
  border-color: var(--accent);
}
.btn-secondary:hover {
  background: rgba(63, 81, 181, 0.06);
  color: var(--accent);
  transform: translateY(-1px);
}
.btn-dark {
  background: var(--bg-dark);
  color: #fff;
}
.btn-dark:hover { background: #000; color: #fff; transform: translateY(-1px); }
.btn-lg { padding: 16px 34px; font-size: 18px; }
.btn-nav { padding: 9px 20px; font-size: 14px; }

/* ---------- 分节 ---------- */
.section { padding: 96px 0; }
.section-gray { background: var(--bg-gray); }
.section-dark {
  background: var(--bg-dark);
  color: var(--text-on-dark);
}
.section-dark .section-title { color: var(--text-on-dark); }
.section-dark .section-lead { color: var(--text-on-dark-secondary); }
.section-dark .section-eyebrow { color: var(--accent-light); }
.section-tight { padding: 72px 0; }

.section-eyebrow {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 16px;
}
.section-title {
  font-size: clamp(30px, 4.5vw, 45px);
  font-weight: 700;
  line-height: 1.22;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: 20px;
}
.section-lead {
  font-size: 19px;
  line-height: 1.6;
  color: var(--text-secondary);
}
.text-center { text-align: center; }
.mx-auto { margin-left: auto; margin-right: auto; }

/* ---------- 网格与卡片 ---------- */
.grid { display: grid; gap: 20px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-5 { grid-template-columns: repeat(5, 1fr); }

.card {
  background: var(--bg-white);
  border-radius: var(--radius-md);
  padding: 32px;
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(0, 0, 0, 0.04);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }

/* ---------- Hero ---------- */
.hero {
  padding: calc(var(--nav-h) + 88px) 0 80px;
  background: var(--bg-white);
  text-align: center;
}
.hero-title {
  font-size: clamp(35px, 6.5vw, 50px);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  margin-bottom: 24px;
}
.hero-subtitle {
  font-size: clamp(18px, 2.2vw, 21px);
  line-height: 1.6;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto 32px;
}
.hero-cta {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 28px;
}
.hero-features {
  font-size: 15px;
  color: var(--text-tertiary);
}

/* ---------- 痛点卡片 ---------- */
.pain-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  box-shadow: var(--shadow-sm);
}
.pain-card h3 {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 12px;
}
.pain-card p { color: var(--text-secondary); font-size: 16px; }

/* ---------- 工作流时间线 ---------- */
.workflow {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 12px;
  margin-top: 56px;
}
.workflow-step { text-align: center; }
.workflow-dot {
  width: 44px; height: 44px;
  margin: 0 auto 14px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 600;
  position: relative;
}
.workflow-step:not(:last-child) .workflow-dot::after {
  content: "";
  position: absolute;
  top: 50%;
  left: calc(100% + 6px);
  width: calc(100% - 12px);
  height: 1px;
  background: var(--divider);
  transform: translateY(-50%);
}
.workflow-step p { font-size: 14px; color: var(--text-secondary); }

/* ---------- 图文左右交错 ---------- */
.feature-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.feature-row.reverse .feature-media { order: -1; }
.feature-text .section-title { font-size: clamp(28px, 3.4vw, 40px); margin-bottom: 16px; }
.feature-text p { color: var(--text-secondary); margin-bottom: 16px; }
.feature-list { list-style: none; padding: 0; margin: 0; }
.feature-list li {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  margin-bottom: 12px;
  color: var(--text-secondary);
}
.feature-list li::before {
  content: "✓";
  color: var(--accent);
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 1px;
}

/* ---------- 截图占位 ---------- */
.shot-frame {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: linear-gradient(135deg, #eef0f8 0%, #e3e7f5 100%);
  border: 1px solid rgba(0, 0, 0, 0.05);
  box-shadow: var(--shadow-md);
}
.ratio-16-9 { aspect-ratio: 16 / 9; }
.ratio-3-2 { aspect-ratio: 3 / 2; }
.shot-frame img { width: 100%; height: 100%; object-fit: cover; }
.shot-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 24px;
  text-align: center;
  color: var(--text-secondary);
}
.shot-empty img { display: none; }
.shot-loaded .shot-overlay { display: none; }
.shot-loaded.shot-frame { aspect-ratio: auto; }
.shot-loaded.shot-frame img { width: 100%; height: auto; object-fit: contain; display: block; }
.shot-icon { color: var(--accent-soft); opacity: 0.6; }
.shot-label { font-size: 17px; font-weight: 600; color: var(--text-secondary); }
.shot-meta { font-size: 13px; color: var(--text-tertiary); }

/* ---------- 对比表 ---------- */
.compare-table {
  margin-top: 48px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--divider);
  background: var(--bg-white);
}
.compare-row {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  border-bottom: 1px solid var(--divider);
}
.compare-row:last-child { border-bottom: none; }
.compare-row.header { background: var(--bg-gray); }
.compare-cell {
  padding: 20px 24px;
  font-size: 16px;
  color: var(--text-secondary);
}
.compare-cell:not(:last-child) { border-right: 1px solid var(--divider); }
.compare-row.header .compare-cell {
  font-weight: 600;
  color: var(--text-primary);
  font-size: 17px;
}
.compare-cell.before { color: var(--text-tertiary); }
.compare-cell.after {
  color: var(--text-primary);
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 8px;
}
.compare-cell.after::before {
  content: "";
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--accent);
  flex-shrink: 0;
}
.compare-cell.lead {
  font-weight: 600;
  color: var(--text-primary);
}

/* ---------- 品牌段 ---------- */
.brand-section {
  background: var(--bg-dark);
  color: var(--text-on-dark);
  padding: 140px 0;
  text-align: center;
}
.brand-quote {
  font-size: clamp(30px, 4vw, 48px);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.02em;
  max-width: 860px;
  margin: 0 auto 24px;
}
.brand-sub {
  color: var(--text-on-dark-secondary);
  font-size: 19px;
  max-width: 680px;
  margin: 0 auto;
}

/* ---------- 最终 CTA ---------- */
.cta-section { padding: 120px 0; text-align: center; }
.cta-title {
  font-size: clamp(34px, 4.5vw, 52px);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}
.cta-sub {
  font-size: 19px;
  color: var(--text-secondary);
  max-width: 640px;
  margin: 0 auto 36px;
}
.cta-meta { margin-top: 20px; font-size: 15px; color: var(--text-tertiary); }

/* ---------- FAQ ---------- */
.faq { max-width: 760px; margin: 0 auto; }
.faq-item {
  border-bottom: 1px solid var(--divider);
}
.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 22px 0;
  cursor: pointer;
  list-style: none;
  font-size: 18px;
  font-weight: 500;
  color: var(--text-primary);
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  font-size: 24px;
  font-weight: 300;
  color: var(--text-tertiary);
  transition: transform 0.25s ease;
}
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item .faq-body {
  padding: 0 0 24px;
  color: var(--text-secondary);
  font-size: 16px;
}

/* ---------- 内页标题头 ---------- */
.page-head {
  padding: calc(var(--nav-h) + 72px) 0 48px;
  text-align: center;
}
.page-head .section-title { margin-bottom: 16px; }

/* ---------- 页脚 ---------- */
.footer { background: var(--bg-dark); color: var(--text-on-dark); padding: 72px 0 32px; }
.footer-inner { max-width: var(--container); margin: 0 auto; padding: 0 24px; }
.footer-top {
  display: flex;
  justify-content: space-between;
  gap: 48px;
  flex-wrap: wrap;
  padding-bottom: 48px;
  border-bottom: 1px solid var(--divider-dark);
}
.footer-brand-row { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
.footer-brand-name { font-size: 20px; font-weight: 600; }
.footer-tagline { color: var(--text-on-dark-secondary); font-size: 15px; max-width: 280px; }
.footer-cols { display: flex; gap: 64px; flex-wrap: wrap; }
.footer-col { display: flex; flex-direction: column; gap: 12px; }
.footer-col h4 { font-size: 14px; font-weight: 600; color: var(--text-on-dark); margin-bottom: 4px; }
.footer-col a, .footer-static { color: var(--text-on-dark-secondary); font-size: 14px; }
.footer-col a:hover { color: var(--text-on-dark); }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  padding-top: 28px;
  color: var(--text-on-dark-secondary);
  font-size: 13px;
}

/* ---------- 渐显动画 ---------- */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.6s cubic-bezier(0.22, 1, 0.36, 1), transform 0.6s cubic-bezier(0.22, 1, 0.36, 1); }
.reveal.visible { opacity: 1; transform: none; }

/* ---------- 下载页组件 ---------- */
.download-hero { text-align: center; padding: calc(var(--nav-h) + 72px) 0 40px; }
.version-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border-radius: var(--radius-pill);
  background: rgba(63, 81, 181, 0.08);
  color: var(--accent);
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 24px;
}
.req-card { text-align: center; }
.req-card .req-icon { font-size: 32px; margin-bottom: 16px; }
.req-card h3 { font-size: 20px; font-weight: 600; margin-bottom: 10px; }
.req-card p { color: var(--text-secondary); font-size: 15px; }
.changelog {
  list-style: none;
  padding: 0;
  margin: 0;
  max-width: 640px;
}
.changelog li {
  display: flex;
  gap: 16px;
  padding: 20px 0;
  border-bottom: 1px solid var(--divider);
}
.changelog .ver { font-weight: 600; color: var(--accent); min-width: 64px; flex-shrink: 0; }
.changelog .desc { color: var(--text-secondary); font-size: 15px; }

/* ---------- 使用场景卡片 ---------- */
.scenario-card { text-align: left; }
.scenario-card .scenario-icon { font-size: 30px; margin-bottom: 16px; }
.scenario-card h3 { font-size: 21px; font-weight: 600; margin-bottom: 12px; }
.scenario-card p { color: var(--text-secondary); font-size: 15px; }

/* ---------- 帮助中心步骤 ---------- */
.help-steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.help-step { text-align: center; padding: 32px 20px; background: var(--bg-white); border-radius: var(--radius-md); box-shadow: var(--shadow-sm); }
.help-step .step-num {
  width: 40px; height: 40px;
  margin: 0 auto 16px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700;
}
.help-step h3 { font-size: 18px; font-weight: 600; margin-bottom: 10px; }
.help-step p { color: var(--text-secondary); font-size: 14px; }

/* ---------- 响应式 ---------- */
@media (max-width: 1068px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-5 { grid-template-columns: repeat(3, 1fr); }
  .workflow { grid-template-columns: repeat(4, 1fr); row-gap: 28px; }
  .workflow-step:nth-child(4) .workflow-dot::after { display: none; }
  .feature-row { gap: 40px; }
  .help-steps { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 734px) {
  body { font-size: 16px; }
  .section { padding: 64px 0; }
  .hero { padding-top: calc(var(--nav-h) + 56px); }
  .grid-2, .grid-3, .grid-4, .grid-5 { grid-template-columns: 1fr; }
  .workflow { grid-template-columns: 1fr 1fr; row-gap: 24px; }
  .workflow-step .workflow-dot::after { display: none !important; }
  .feature-row { grid-template-columns: 1fr; gap: 28px; }
  .feature-row.reverse .feature-media { order: 0; }
  .help-steps { grid-template-columns: 1fr; }
  .compare-row { grid-template-columns: 1fr; }
  .compare-cell { border-right: none !important; border-bottom: 1px solid var(--divider); padding: 14px 18px; }
  .compare-row.header { display: none; }

  /* 移动端导航抽屉 */
  .nav-links {
    position: fixed;
    top: var(--nav-h);
    left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    background: var(--bg-white);
    padding: 12px 24px 24px;
    border-bottom: 1px solid var(--divider);
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.25s ease, opacity 0.25s ease, visibility 0.25s ease;
  }
  .nav-links.open { transform: none; opacity: 1; visibility: visible; }
  .nav-link { padding: 14px 8px; font-size: 16px; border-bottom: 1px solid var(--divider); border-radius: 0; }
  .nav-link:last-child { border-bottom: none; }
  .nav-toggle { display: flex; }
  .btn-nav { display: none; }
  .footer-top { flex-direction: column; }
  .footer-bottom { flex-direction: column; }
}