:root {
  --bg: #f4f7fb;
  --card-bg: #ffffff;
  --text: #1f2a37;
  --muted: #64748b;
  --accent: #1d5fbf;
  --accent-light: #e5eefb;
  --border: #dde6f2;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
}

header.site-header {
  background: var(--accent);
  color: #fff;
  padding: 2.5rem 1.5rem 2rem;
  text-align: center;
}

header.site-header .course-title {
  font-size: 1.6rem;
  font-weight: 700;
  margin: 0 0 0.5rem;
}

header.site-header .course-meta {
  font-size: 0.95rem;
  opacity: 0.85;
}

header.site-header .placeholder {
  color: #fff;
  opacity: 0.9;
}

main {
  max-width: 760px;
  margin: 0 auto;
  padding: 2rem 1.5rem 3rem;
}

section.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem 1.75rem;
  margin-bottom: 1.5rem;
}

section.card h2 {
  margin-top: 0;
  font-size: 1.15rem;
  color: var(--accent);
  border-left: 4px solid var(--accent);
  padding-left: 0.6rem;
}

.placeholder {
  color: var(--muted);
  font-style: italic;
}

ul.info-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

ul.info-list li {
  padding: 0.4rem 0;
  border-bottom: 1px dashed var(--border);
}

ul.info-list li:last-child {
  border-bottom: none;
}

.person {
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--border);
}

.person:last-of-type {
  border-bottom: none;
}

.person-name {
  margin: 0 0 0.3rem;
  font-weight: 600;
  color: var(--text);
}

.table-wrap {
  overflow-x: auto;
}

table.schedule {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}

table.schedule th,
table.schedule td {
  padding: 0.6rem 0.7rem;
  border-bottom: 1px solid var(--border);
  text-align: left;
  white-space: nowrap;
}

table.schedule td:nth-child(4),
table.schedule td:nth-child(5) {
  white-space: normal;
  min-width: 10em;
}

table.schedule thead th {
  background: var(--accent-light);
  color: var(--accent);
  font-weight: 600;
  white-space: nowrap;
}

table.schedule tbody tr:last-child td {
  border-bottom: none;
}

table.schedule tbody tr:hover {
  background: var(--accent-light);
}

ul.info-list .label {
  display: inline-block;
  min-width: 5.5em;
  color: var(--muted);
}

.announcement {
  background: var(--accent-light);
  border-radius: 6px;
  padding: 0.75rem 1rem;
  margin-bottom: 0.75rem;
  font-size: 0.95rem;
}

.announcement:last-child {
  margin-bottom: 0;
}

.announcement .date {
  color: var(--accent);
  font-weight: 600;
  margin-right: 0.5em;
}

a {
  color: var(--accent);
}

footer {
  text-align: center;
  color: var(--muted);
  font-size: 0.85rem;
  padding: 1.5rem;
}

footer a {
  color: var(--muted);
}