/* ==========================================================================
   PQ Mail 官网样式 - 蓝色调 · 简洁 · 白色背景
   ========================================================================== */

:root {
  --blue: #2563eb;
  --blue-dark: #1d4ed8;
  --blue-deep: #1e40af;
  --blue-soft: #eff6ff;
  --blue-soft-2: #dbeafe;
  --ink: #0f172a;
  --ink-2: #334155;
  --ink-3: #64748b;
  --line: #e2e8f0;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --radius: 14px;
  --radius-lg: 20px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, .06);
  --shadow-md: 0 8px 24px rgba(37, 99, 235, .10);
  --shadow-lg: 0 16px 40px rgba(15, 23, 42, .12);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
          "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", sans-serif;
}

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

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

body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
  overflow-x: clip;
}

img { display: block; max-width: 100%; }
a { text-decoration: none; color: inherit; }

.container { width: min(1120px, calc(100% - 48px)); margin: 0 auto; }
.container-narrow { width: min(760px, calc(100% - 48px)); margin: 0 auto; }

.text-blue { color: var(--blue); }

/* --------------------------------------------------------------------------
   按钮
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 600;
  font-size: 15px;
  border-radius: 10px;
  padding: 12px 26px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background .2s ease, color .2s ease, box-shadow .2s ease,
              border-color .2s ease, transform .2s ease;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }

.btn-primary {
  background: var(--blue);
  color: #fff;
  box-shadow: 0 6px 18px rgba(37, 99, 235, .28);
}
.btn-primary:hover {
  background: var(--blue-dark);
  box-shadow: 0 8px 22px rgba(37, 99, 235, .36);
}

.btn-ghost {
  background: #fff;
  color: var(--ink-2);
  border-color: var(--line);
}
.btn-ghost:hover {
  color: var(--blue);
  border-color: var(--blue);
  background: var(--blue-soft);
}

.btn-white {
  background: #fff;
  color: var(--blue);
  box-shadow: 0 8px 22px rgba(15, 23, 42, .18);
}
.btn-white:hover { background: var(--blue-soft); }

.btn-lg { padding: 15px 34px; font-size: 16px; border-radius: 12px; }
.btn-sm { padding: 8px 18px; font-size: 14px; }

/* --------------------------------------------------------------------------
   导航
   -------------------------------------------------------------------------- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, .86);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
  transition: box-shadow .25s ease;
}
.site-nav.is-scrolled { box-shadow: var(--shadow-sm); }

.nav-inner {
  display: flex;
  align-items: center;
  gap: 28px;
  height: 64px;
}

.nav-brand { display: flex; align-items: center; gap: 10px; }

.nav-logo {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  object-fit: cover;
}

.nav-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: .2px;
}
.nav-title em {
  font-style: normal;
  color: var(--blue);
  margin-right: 2px;
}

.nav-links {
  display: flex;
  gap: 26px;
  margin-left: auto;
}
.nav-links a {
  font-size: 14.5px;
  color: var(--ink-2);
  font-weight: 500;
  transition: color .2s ease;
}
.nav-links a:hover { color: var(--blue); }

/* --------------------------------------------------------------------------
   Hero
   -------------------------------------------------------------------------- */
.hero {
  padding: 96px 0 84px;
  background:
    radial-gradient(1000px 420px at 50% -10%, var(--blue-soft) 0%, rgba(239, 246, 255, 0) 70%),
    var(--bg);
  text-align: center;
  overflow: hidden;
}

.hero-inner { max-width: 820px; }

.hero-badge {
  display: inline-block;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--blue-deep);
  background: var(--blue-soft-2);
  border: 1px solid rgba(37, 99, 235, .18);
  padding: 6px 16px;
  border-radius: 999px;
  margin-bottom: 26px;
  letter-spacing: .5px;
}

.hero h1 {
  font-size: clamp(38px, 6.4vw, 60px);
  line-height: 1.18;
  font-weight: 800;
  letter-spacing: 1px;
  margin-bottom: 22px;
}

.hero-sub {
  font-size: 17.5px;
  color: var(--ink-3);
  max-width: 640px;
  margin: 0 auto 36px;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.hero-platforms {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 10px;
  font-size: 13.5px;
  color: var(--ink-3);
}

.platform-tag {
  font-weight: 600;
  color: var(--blue-deep);
  background: #fff;
  border: 1px solid var(--blue-soft-2);
  border-radius: 8px;
  padding: 4px 12px;
  box-shadow: var(--shadow-sm);
}

/* --------------------------------------------------------------------------
   通用 Section
   -------------------------------------------------------------------------- */
.section { padding: 88px 0; }
.section-alt { background: var(--bg-alt); }

.section-head {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 52px;
}
.section-head h2 {
  font-size: clamp(26px, 4vw, 34px);
  font-weight: 800;
  letter-spacing: .5px;
  margin-bottom: 12px;
}
.section-head p { color: var(--ink-3); font-size: 16px; }

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

.feature-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 24px;
  transition: transform .22s ease, box-shadow .22s ease, border-color .22s ease;
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(37, 99, 235, .35);
}

.feature-icon {
  width: 46px;
  height: 46px;
  border-radius: 12px;
  background: var(--blue-soft);
  color: var(--blue);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
}
.feature-icon svg { width: 24px; height: 24px; }

.feature-card h3 {
  font-size: 16.5px;
  font-weight: 700;
  margin-bottom: 8px;
}
.feature-card p {
  font-size: 14.5px;
  color: var(--ink-3);
  line-height: 1.75;
}

/* --------------------------------------------------------------------------
   效果展示
   -------------------------------------------------------------------------- */
.showcase-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 20px;
  align-items: stretch;
}

.showcase-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform .22s ease, box-shadow .22s ease;
}
.showcase-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.showcase-tag {
  align-self: flex-start;
  margin: 18px 18px 0;
  font-size: 13px;
  font-weight: 700;
  color: #fff;
  background: var(--blue);
  padding: 4px 14px;
  border-radius: 999px;
  letter-spacing: .5px;
}

.showcase-shots {
  padding: 16px 18px 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
  flex: 1;
}
.showcase-shots img {
  width: 100%;
  height: auto;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: #fff;
}

.showcase-desc {
  text-align: center;
  font-size: 14px;
  color: var(--ink-3);
  padding: 14px 18px 20px;
}

/* --------------------------------------------------------------------------
   常见问题
   -------------------------------------------------------------------------- */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color .2s ease, box-shadow .2s ease;
}
.faq-item[open] {
  border-color: rgba(37, 99, 235, .35);
  box-shadow: var(--shadow-md);
}

.faq-item summary {
  list-style: none;
  cursor: pointer;
  padding: 18px 22px;
  font-size: 15.5px;
  font-weight: 600;
  color: var(--ink);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  user-select: none;
}
.faq-item summary::-webkit-details-marker { display: none; }

.faq-arrow {
  position: relative;
  width: 10px;
  height: 10px;
  flex: 0 0 10px;
}
.faq-arrow::before,
.faq-arrow::after {
  content: "";
  position: absolute;
  background: var(--blue);
  border-radius: 2px;
  transition: transform .25s ease;
}
.faq-arrow::before {
  width: 10px; height: 2px;
  left: 0; top: 4px;
}
.faq-arrow::after {
  width: 2px; height: 10px;
  left: 4px; top: 0;
}
.faq-item[open] .faq-arrow::after { transform: scaleY(0); }

.faq-answer {
  padding: 0 22px 20px;
  font-size: 14.5px;
  color: var(--ink-3);
  line-height: 1.8;
}

/* --------------------------------------------------------------------------
   CTA
   -------------------------------------------------------------------------- */
.cta-section {
  background: linear-gradient(135deg, var(--blue) 0%, var(--blue-deep) 100%);
  padding: 76px 0;
}
.cta-inner {
  text-align: center;
  color: #fff;
  max-width: 700px;
}
.cta-inner h2 {
  font-size: clamp(24px, 3.6vw, 32px);
  font-weight: 800;
  margin-bottom: 14px;
  letter-spacing: .5px;
}
.cta-inner p {
  font-size: 16px;
  opacity: .92;
  margin-bottom: 32px;
}
.cta-inner .btn-white { padding: 14px 36px; font-size: 16px; }

/* --------------------------------------------------------------------------
   页脚
   -------------------------------------------------------------------------- */
.site-footer {
  background: var(--ink);
  color: #cbd5e1;
  padding: 56px 0 28px;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 32px;
  padding-bottom: 36px;
  border-bottom: 1px solid rgba(148, 163, 184, .18);
  flex-wrap: wrap;
}

.footer-brand {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  max-width: 460px;
}
.footer-brand img {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  flex: 0 0 46px;
}

.footer-name {
  color: #fff;
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 6px;
}
.footer-name em { font-style: normal; color: #60a5fa; margin-right: 2px; }

.footer-desc { font-size: 14px; color: #94a3b8; line-height: 1.75; }

.footer-links {
  display: grid;
  grid-template-columns: repeat(2, minmax(120px, 1fr));
  gap: 12px 40px;
}
.footer-links a {
  font-size: 14.5px;
  color: #cbd5e1;
  transition: color .2s ease;
}
.footer-links a:hover { color: #60a5fa; }

.footer-bottom {
  padding-top: 24px;
  text-align: center;
}
.footer-bottom p { font-size: 13px; color: #64748b; }

/* --------------------------------------------------------------------------
   响应式与移动端优化
   -------------------------------------------------------------------------- */
@media (max-width: 960px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .showcase-grid {
    grid-template-columns: 1fr;
    max-width: 640px;
    margin: 0 auto;
  }
}

@media (max-width: 640px) {
  body { font-size: 15px; }

  /* 导航：收紧高度，锚点保留、字号缩小 */
  .nav-inner { height: 56px; gap: 12px; }
  .nav-logo { width: 30px; height: 30px; border-radius: 8px; }
  .nav-title { font-size: 15.5px; }
  .nav-links { gap: 14px; margin-left: auto; }
  .nav-links a { font-size: 13px; }
  .nav-inner .btn { margin-left: 2px; }

  /* Hero：更紧凑，两个按钮等宽铺满、易点 */
  .hero { padding: 52px 0 54px; }
  .hero-badge { font-size: 12.5px; padding: 5px 14px; margin-bottom: 20px; }
  .hero h1 { margin-bottom: 16px; }
  .hero-sub { font-size: 15.5px; margin-bottom: 28px; }
  .hero-actions { gap: 10px; margin-bottom: 30px; }
  .hero-actions .btn-lg { flex: 1 1 0; min-width: 0; padding: 14px 10px; }
  .hero-platforms { font-size: 12.5px; gap: 8px; }
  .platform-tag { padding: 3px 10px; }

  /* 区块与功能卡片 */
  .section { padding: 58px 0; }
  .section-head { margin-bottom: 36px; }
  .section-head h2 { letter-spacing: 0; }
  .section-head p { font-size: 14.5px; }
  .feature-grid { grid-template-columns: 1fr; gap: 14px; }
  .feature-card { padding: 22px 20px; }
  .feature-icon { width: 42px; height: 42px; margin-bottom: 14px; }
  .feature-card h3 { font-size: 15.5px; }
  .feature-card p { font-size: 14px; }

  /* 效果展示 */
  .showcase-card { border-radius: 16px; }
  .showcase-tag { margin: 14px 14px 0; font-size: 12px; }
  .showcase-shots { padding: 12px 12px 0; gap: 8px; }
  .showcase-shots img { border-radius: 8px; }
  .showcase-desc { padding: 12px 14px 16px; font-size: 13.5px; }

  /* FAQ：增大触控面积 */
  .faq-item summary { padding: 16px 18px; font-size: 14.5px; }
  .faq-answer { padding: 0 18px 18px; font-size: 14px; }

  /* CTA 与页脚 */
  .cta-section { padding: 54px 0; }
  .cta-inner .btn-white { width: 100%; max-width: 320px; }
  .site-footer { padding: 44px 0 22px; }
  .footer-inner { flex-direction: column; gap: 28px; padding-bottom: 28px; }
  .footer-brand { flex-direction: column; text-align: center; align-items: center; }
  .footer-links {
    grid-template-columns: repeat(4, auto);
    gap: 10px 18px;
    justify-content: center;
    width: 100%;
  }
}

/* 触屏设备：禁用悬停位移，避免点击后卡片“弹一下” */
@media (hover: none) {
  .feature-card:hover,
  .showcase-card:hover { transform: none; }
}

/* 动效降级 */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}