:root {
  --brand: #3b82f6;
  --brand-d: #2563eb;
  --bg: #f5f6f8;
  --ink: #1f2937;
  --mut: #6b7280;
  --card: #ffffff;
  --shadow: 0 6px 24px rgba(30, 41, 59, 0.08);
}

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

body {
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
  background: linear-gradient(180deg, rgba(59, 130, 246, 0.10), var(--bg) 240px);
  color: var(--ink);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

.topbar {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 22px 20px 18px;
  max-width: 880px;
  margin: 0 auto;
}
.brand { font-size: 22px; font-weight: 700; letter-spacing: .5px; }
.sub { color: var(--mut); font-size: 14px; }

main { max-width: 880px; margin: 0 auto; padding: 8px 20px 40px; }

.cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}
@media (max-width: 560px) { .cards { grid-template-columns: 1fr; } }

.card {
  background: var(--card);
  border-radius: 18px;
  padding: 22px 20px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
}
.card-icon { font-size: 40px; line-height: 1; }
.card-title { font-size: 18px; font-weight: 700; }
.card-ver { color: var(--mut); font-size: 13px; min-height: 18px; }

.btn {
  display: inline-block;
  text-decoration: none;
  border: none;
  cursor: pointer;
  font-size: 15px;
  font-weight: 600;
  padding: 11px 20px;
  border-radius: 12px;
  transition: transform .08s ease, background .15s ease;
  width: 100%;
  text-align: center;
}
.btn:active { transform: scale(.98); }
.btn.primary { background: var(--brand); color: #fff; }
.btn.primary:hover { background: var(--brand-d); }
.btn.ghost { background: #eef2ff; color: var(--brand-d); margin-top: 2px; }

.hist {
  list-style: none;
  width: 100%;
  max-height: 0;
  overflow: hidden;
  transition: max-height .25s ease;
}
.hist.open { max-height: 600px; }
.hist li {
  padding: 10px 0;
  border-top: 1px solid #eef0f4;
  font-size: 14px;
}
.hist li a { color: var(--brand-d); font-weight: 600; text-decoration: none; }
.hist li a:hover { text-decoration: underline; }
.hist .date { color: var(--mut); font-size: 12px; margin-left: 8px; }
.hist .notes {
  color: var(--mut);
  font-size: 12.5px;
  margin-top: 4px;
  white-space: pre-wrap;
  line-height: 1.5;
}
.hist .empty { color: var(--mut); }

.foot {
  text-align: center;
  color: var(--mut);
  font-size: 12.5px;
  margin-top: 28px;
}
.foot code { background: #eef2ff; padding: 1px 6px; border-radius: 5px; color: var(--brand-d); }