:root {
  --bg: #fafafa;
  --ink: #0a0a0a;
  --muted: #71717a;
  --line: #e4e4e7;
  --card: #ffffff;
  --soft: #f4f4f5;
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  font-size: 16px;
  line-height: 1.6;
}

.top {
  max-width: 640px;
  margin: 0 auto;
  padding: 28px 24px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.brand {
  color: var(--ink);
  text-decoration: none;
  font-weight: 600;
  letter-spacing: -0.02em;
}
nav { display: flex; gap: 20px; }
nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 14px;
}
nav a[aria-current="page"] { color: var(--ink); }

main { max-width: 640px; margin: 0 auto; padding: 40px 24px 80px; }
.meta { margin: 0 0 8px; color: var(--muted); font-size: 14px; }
h1 { margin: 0 0 12px; font-size: 32px; font-weight: 600; letter-spacing: -0.03em; line-height: 1.25; }
.lead { margin: 0 0 28px; color: #3f3f46; }

.block { margin-top: 36px; padding-top: 28px; border-top: 1px solid var(--line); }
.kicker { margin: 0 0 8px; font-size: 13px; color: var(--muted); }
h2 { margin: 0 0 12px; font-size: 20px; font-weight: 600; letter-spacing: -0.02em; }

.steps { margin: 0 0 20px; padding-left: 18px; color: #3f3f46; }
.steps li { margin: 8px 0; }
.steps a { color: var(--ink); }

.btn, .choice {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 16px;
  border-radius: 8px;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: #fff;
  text-decoration: none;
  font: inherit;
  font-size: 15px;
  cursor: pointer;
}
.choice {
  display: flex;
  width: 100%;
  margin: 0 0 8px;
  justify-content: flex-start;
  background: #fff;
  color: var(--ink);
  border-color: var(--line);
  text-align: left;
}
.choice:hover { border-color: #a1a1aa; }
.choice.on { border-color: var(--ink); background: var(--soft); }
.row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }

.ask { margin: 22px 0 12px; font-weight: 600; }
.note { margin: 16px 0 0; color: var(--muted); font-size: 14px; }
.result {
  margin: 16px 0 0;
  padding: 14px 16px;
  background: var(--soft);
  border-radius: 8px;
}
.rule p { margin: 0 0 10px; color: #3f3f46; }
.done { margin-top: 28px; color: var(--muted); }

.week {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
  color: inherit;
  text-decoration: none;
}
.week span { color: var(--muted); font-size: 14px; }
.fact { margin: 0 0 18px; }
.fact strong { display: block; margin-bottom: 4px; }
input, select {
  width: 100%;
  margin-top: 6px;
  padding: 10px 0;
  border: none;
  border-bottom: 1px solid var(--line);
  background: transparent;
  font: inherit;
}
label { display: block; margin-top: 14px; font-size: 13px; color: var(--muted); }
.grid { display: grid; grid-template-columns: 1fr; gap: 8px; }
@media (min-width: 640px) {
  .grid.three { grid-template-columns: repeat(3, 1fr); gap: 16px; }
}