/* 移动优先 + 响应式；触控目标 ≥44px；375px 与宽屏双视口验收 */
:root {
  --ink: #16202b;
  --ink-soft: #51606f;
  --bg: #ffffff;
  --bg-soft: #f4f7fa;
  --accent: #0b66ff;
  --accent-ink: #ffffff;
  --line: #e3e9ef;
  --radius: 12px;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
}

a { color: var(--accent); text-decoration: none; }
a:hover, a:focus-visible { text-decoration: underline; }

/* ---------- header ---------- */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--line);
}
.brand { font-size: 22px; font-weight: 800; color: var(--ink); letter-spacing: -0.02em; }
.brand span { color: var(--accent); }
.site-header nav { display: flex; gap: 4px; }
.site-header nav a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 12px;
  color: var(--ink-soft);
  font-weight: 600;
  border-radius: 8px;
}
.site-header nav a[aria-current="page"] { color: var(--ink); background: var(--bg-soft); }

main { max-width: 1040px; margin: 0 auto; padding: 0 20px; }

/* ---------- hero ---------- */
.hero { padding: 56px 0 40px; text-align: center; }
.hero-small { padding: 40px 0 8px; }
.badge {
  display: inline-block;
  padding: 6px 14px;
  border-radius: 999px;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  color: var(--ink-soft);
  font-size: 14px;
  font-weight: 600;
}
h1 { font-size: 34px; line-height: 1.15; letter-spacing: -0.02em; margin: 18px 0 12px; }
.lead { font-size: 18px; color: var(--ink-soft); max-width: 620px; margin: 0 auto; }

/* ---------- subscribe form：窄屏堆叠，≥640px 并排 ---------- */
.subscribe-form {
  display: flex;
  flex-direction: column;
  gap: 10px;
  max-width: 460px;
  margin: 26px auto 0;
}
.subscribe-form input[type="email"] {
  min-height: 48px;
  padding: 0 16px;
  font-size: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  width: 100%;
}
.subscribe-form input[type="email"]:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; border-color: var(--accent); }
.subscribe-form button {
  min-height: 48px;
  padding: 0 22px;
  font-size: 16px;
  font-weight: 700;
  color: var(--accent-ink);
  background: var(--accent);
  border: 0;
  border-radius: var(--radius);
  cursor: pointer;
}
.subscribe-form button:hover { filter: brightness(1.08); }
.subscribe-form button:disabled { opacity: 0.6; cursor: wait; }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; opacity: 0; }
.form-msg { min-height: 1.4em; margin: 10px 0 0; font-weight: 600; text-align: center; }
.form-msg.ok { color: #0a7a40; }
.form-msg.err { color: #c0382b; }
.consent { font-size: 13px; color: var(--ink-soft); text-align: center; margin-top: 6px; }

@media (min-width: 640px) {
  h1 { font-size: 48px; }
  .subscribe-form { flex-direction: row; }
  .subscribe-form input[type="email"] { flex: 1; }
}

/* ---------- features ---------- */
.features {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  padding: 28px 0;
}
.card {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
}
.card h3 { margin: 0 0 8px; font-size: 18px; }
.card p { margin: 0; color: var(--ink-soft); }

@media (min-width: 768px) {
  .features { grid-template-columns: repeat(3, 1fr); gap: 20px; padding: 40px 0; }
}

/* ---------- prose（产品页正文） ---------- */
.prose { max-width: 720px; margin: 0 auto; padding: 8px 0 24px; }
.prose h2 { font-size: 24px; margin: 36px 0 10px; }
.steps { padding-left: 20px; color: var(--ink-soft); }
.steps li { margin: 10px 0; }
.steps strong { color: var(--ink); }

/* 表格窄屏横向滚动兜底，不撑破布局 */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 12px 14px; border-bottom: 1px solid var(--line); }
th { width: 40%; color: var(--ink-soft); font-weight: 600; white-space: nowrap; }

/* ---------- cta / footer ---------- */
.cta { text-align: center; padding: 36px 0 56px; }
.cta h2 { font-size: 26px; margin: 0 0 8px; }
.cta p { color: var(--ink-soft); }
.btn-link { display: inline-flex; align-items: center; min-height: 44px; font-weight: 700; }

.site-footer {
  border-top: 1px solid var(--line);
  padding: 22px 20px;
  text-align: center;
  color: var(--ink-soft);
  font-size: 14px;
}
.site-footer .follow { margin: 0 0 6px; font-weight: 700; color: var(--ink); }
.site-footer .social { margin-bottom: 10px; line-height: 2; }
.site-footer .social a {
  display: inline-block;
  min-height: 44px;
  line-height: 44px;
  padding: 0 6px;
  font-weight: 600;
}

/* ---------- 通知页（confirmed / unsubscribed / link_invalid） ---------- */
.notice-page { display: flex; align-items: center; justify-content: center; min-height: 100vh; padding: 20px; }
.notice-card {
  max-width: 460px;
  text-align: center;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 36px 26px;
}
.notice-card h1 { font-size: 28px; margin: 0 0 12px; }
.notice-card p { color: var(--ink-soft); }