/* AhaTxt 官网样式 —— 极简产品风（Things 3 / iA Writer 式）：
   白底黑字、一处品牌蓝、无渐变无光效，真实截图是唯一的视觉主角。
   色值沿用 Apple 官网文字色（#1d1d1f / #6e6e73），accent 取软件 neat 皮肤蓝 */

:root {
  --bg: #ffffff;
  --bg-alt: #f5f6f2;
  --text-primary: #1d1d1f;
  --text-secondary: #6e6e73;
  --text-faint: #86868b;
  --accent: #3b6ef5;
  --border: #ebebe8;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue", "Segoe UI", sans-serif;
  color: var(--text-primary);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; text-underline-offset: 3px; }
a:hover { text-decoration: underline; }

::selection { background: rgba(59, 110, 245, 0.14); }

/* ===== 导航 ===== */

.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  -webkit-backdrop-filter: saturate(1.8) blur(14px);
  backdrop-filter: saturate(1.8) blur(14px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: 1020px;
  margin: 0 auto;
  padding: 11px 24px;
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-weight: 600;
  font-size: 17px;
  color: var(--text-primary);
}

.nav-brand:hover { text-decoration: none; }

.nav-brand img { width: 24px; height: 24px; }

.nav-links {
  display: flex;
  gap: 24px;
  margin-left: auto;
}

.nav-links a {
  font-size: 14px;
  color: var(--text-secondary);
}

.nav-links a:hover { color: var(--text-primary); text-decoration: none; }

.nav-download {
  padding: 6px 18px;
  border-radius: 980px;
  background: var(--text-primary);
  color: #fff;
  font-size: 14px;
  font-weight: 500;
  transition: opacity 0.15s ease;
}

.nav-download:hover { text-decoration: none; opacity: 0.82; }

/* ===== 首屏 ===== */

.hero {
  max-width: 1020px;
  margin: 0 auto;
  padding: 104px 24px 88px;
  text-align: center;
}

.hero h1 {
  font-size: 52px;
  font-weight: 700;
  letter-spacing: -1px;
  margin-bottom: 18px;
}

.sub {
  font-size: 19px;
  color: var(--text-secondary);
  margin-bottom: 34px;
}

.download-group {
  display: flex;
  justify-content: center;
  gap: 16px;
}

.download-btn {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding: 10px 26px;
  border-radius: 980px;
  background: var(--text-primary);
  color: #fff;
  transition: opacity 0.15s ease, transform 0.15s ease, box-shadow 0.15s ease;
}

.download-btn:hover {
  text-decoration: none;
  opacity: 0.88;
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.16);
}

.download-main {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}

.download-btn svg {
  width: 15px;
  height: 15px;
}

.download-label { font-size: 14px; font-weight: 600; }

.download-meta { font-size: 11px; opacity: 0.75; font-weight: 400; }

.download-note {
  margin-top: 16px;
  font-size: 13px;
  color: var(--text-faint);
}

.download-count {
  margin-top: 4px;
  font-size: 13px;
  color: var(--text-secondary);
}

.download-count strong {
  color: var(--accent);
  font-weight: 700;
}

/* 首屏主截图：微出血感，轻边框 */

.hero-shot {
  margin: 52px -24px 0;
}

.hero-shot img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 14px;
  border: 1px solid var(--border);
  box-shadow:
    0 1px 2px rgba(0, 0, 0, 0.04),
    0 4px 12px rgba(0, 0, 0, 0.05),
    0 28px 72px -20px rgba(0, 0, 0, 0.16);
  transition: transform 0.2s ease;
}

.hero-shot:hover img { transform: translateY(-3px); }

/* ===== 功能：图文交替（偶数行浅灰底全宽横贯） ===== */

.feature-row-alt { background: var(--bg-alt); }

.row-inner {
  max-width: 1020px;
  margin: 0 auto;
  padding: 96px 24px;
  display: grid;
  grid-template-columns: 1.12fr 1fr;
  gap: 64px;
  align-items: center;
}

.feature-shot img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 12px;
  border: 1px solid var(--border);
  box-shadow:
    0 1px 2px rgba(0, 0, 0, 0.04),
    0 18px 48px -16px rgba(0, 0, 0, 0.12);
  transition: transform 0.2s ease;
}

.feature-shot:hover img { transform: translateY(-2px); }

.feature-text p { max-width: 40em; }

.kicker {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
}

.feature-text h2 {
  font-size: 30px;
  font-weight: 700;
  letter-spacing: -0.3px;
  line-height: 1.3;
  margin-bottom: 16px;
  text-align: left;
}

.feature-text p {
  font-size: 16px;
  color: var(--text-secondary);
}

/* ===== 格式带 ===== */

.formats {
  padding: 88px 24px;
  text-align: center;
}

.format-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  max-width: 760px;
  margin: 0 auto 18px;
}

.chip {
  font-family: "SF Mono", ui-monospace, Menlo, Consolas, monospace;
  font-size: 13px;
  color: var(--text-secondary);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 7px;
  padding: 4px 12px;
  transition: color 0.15s ease, background 0.15s ease, border-color 0.15s ease;
}

.chip:hover {
  color: #fff;
  background: var(--accent);
  border-color: var(--accent);
}

.format-note {
  font-size: 15px;
  color: var(--text-faint);
}

/* ===== 对比表 ===== */

.compare {
  background: var(--bg-alt);
  padding: 96px 24px;
}

.compare h2 {
  text-align: center;
  margin-bottom: 48px;
}

.compare-table-wrap {
  max-width: 820px;
  margin: 0 auto;
  overflow-x: auto;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 10px 4px;
  box-shadow:
    0 1px 2px rgba(0, 0, 0, 0.03),
    0 16px 48px -20px rgba(0, 0, 0, 0.10);
}

.compare-table {
  width: 100%;
  min-width: 640px;
  border-collapse: collapse;
  font-size: 14.5px;
}

.compare-table th,
.compare-table td {
  padding: 13px 16px;
  text-align: center;
  border-bottom: 1px solid #e3e5df;
}

.compare-table th:first-child,
.compare-table td:first-child {
  text-align: left;
  font-weight: 500;
  color: var(--text-primary);
  white-space: nowrap;
}

.compare-table thead th {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
  border-bottom: 2px solid #d8dad4;
}

/* AhaTxt 列强调：淡底 + 主色勾 */
.col-ours {
  background: rgba(59, 110, 245, 0.06);
  color: var(--accent);
  font-weight: 600;
}

.compare-table thead .col-ours { color: var(--accent); }

.compare-table td:not(.col-ours) { color: var(--text-faint); }

.compare-table tbody tr:hover td:not(.col-ours) { background: rgba(0, 0, 0, 0.025); }

.compare-note {
  max-width: 820px;
  margin: 18px auto 0;
  font-size: 12.5px;
  color: var(--text-faint);
  text-align: center;
}

/* ===== 系统要求 + 购买 ===== */

.bottom-info {
  max-width: 1020px;
  margin: 0 auto;
  padding: 0 24px 96px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
}

.info-block {
  padding-top: 28px;
  border-top: 1px solid var(--border);
}

.info-block h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 10px;
}

.info-block h3::before {
  content: "";
  display: inline-block;
  width: 18px;
  height: 3px;
  border-radius: 2px;
  background: var(--accent);
  margin-right: 10px;
  vertical-align: 4px;
}

.info-block p {
  font-size: 14.5px;
  color: var(--text-secondary);
}

/* ===== 常见问题（details/summary 原生折叠，极简定制） ===== */

.faq {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 24px 96px;
}

.faq h2 {
  text-align: center;
  margin-bottom: 40px;
}

.faq details {
  border-bottom: 1px solid var(--border);
}

.faq details:first-of-type { border-top: 1px solid var(--border); }

.faq summary {
  padding: 18px 4px;
  font-size: 15.5px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  position: relative;
  padding-right: 36px;
  transition: color 0.15s ease;
}

.faq summary::-webkit-details-marker { display: none; }

.faq summary:hover { color: var(--accent); }

/* 右侧 + 折叠指示，展开转 × */
.faq summary::after {
  content: "+";
  position: absolute;
  right: 6px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 20px;
  font-weight: 400;
  color: var(--text-faint);
  transition: transform 0.2s ease;
}

.faq details[open] summary::after { content: "–"; }

.faq details p {
  padding: 0 4px 20px;
  font-size: 14.5px;
  color: var(--text-secondary);
  max-width: 44em;
}

/* ===== 页脚 ===== */

.site-footer {
  border-top: 1px solid var(--border);
  padding: 36px 24px 44px;
  text-align: center;
  font-size: 13px;
  color: var(--text-faint);
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.footer-brand img { width: 22px; height: 22px; }

.site-footer p { margin-bottom: 5px; }

.site-footer a { color: var(--text-secondary); }

a.icp { color: var(--text-faint); }

.footer-sep { color: var(--border); }

/* ===== 响应式 ===== */

@media (max-width: 860px) {
  .row-inner {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 64px 24px;
  }
  .feature-text h2 { text-align: left; }
  .bottom-info { grid-template-columns: 1fr; gap: 32px; }
  .nav-links { display: none; }
  .hero { padding-top: 72px; }
  .hero h1 { font-size: 34px; }
  .sub { font-size: 17px; }
  .download-group { flex-direction: column; align-items: center; }
}