:root {
  --bg: #f5f7fb;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #e5e7eb;
  --primary: #2563eb;
  --primary-strong: #1d4ed8;
  --success-bg: #dcfce7;
  --success-text: #166534;
  --pending-bg: #fef3c7;
  --pending-text: #92400e;
  --absent-bg: #fee2e2;
  --absent-text: #991b1b;
  --complete-btn: #16a34a;
  --complete-btn-hover: #15803d;
  --absent-btn: #dc2626;
  --absent-btn-hover: #b91c1c;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
}

.topbar {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  padding: 20px;
}

.topbar h1 {
  margin: 0;
  font-size: 1.5rem;
}

.topbar p {
  margin: 6px 0 0;
  color: var(--muted);
}

.container {
  max-width: 1100px;
  margin: 20px auto;
  padding: 0 16px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px;
}

.overview-layout {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(260px, 1fr);
  gap: 14px;
  align-items: start;
}

.side-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px;
  background: #fbfdff;
}

.side-card h3 {
  margin: 0 0 6px;
}

.side-section {
  margin-top: 12px;
}

.side-section h4 {
  margin: 0 0 8px;
  font-size: 0.95rem;
}

.ready-list {
  margin-top: 10px;
  display: grid;
  gap: 8px;
}

.ready-item {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px;
  background: white;
}

.ready-item p {
  margin: 6px 0 0;
  font-size: 0.9rem;
}

.ready-item ul {
  margin: 6px 0 0;
  padding-left: 18px;
}

.ready-item .label {
  color: var(--muted);
}

.next-ready-highlight {
  margin-top: 8px;
  padding: 8px;
  border: 1px solid var(--pending-bg);
  border-radius: 8px;
  background: #fff9db;
}

.next-ready-highlight p {
  margin-top: 0;
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.actions {
  display: flex;
  gap: 8px;
}

.btn {
  border: 1px solid var(--primary);
  background: var(--primary);
  color: white;
  padding: 8px 12px;
  border-radius: 6px;
  cursor: pointer;
}

.btn:hover {
  background: var(--primary-strong);
}

.btn.secondary {
  background: white;
  color: var(--primary);
}

.btn.btn-complete {
  border-color: var(--complete-btn);
  background: var(--complete-btn);
  color: #ffffff;
}

.btn.btn-complete:hover {
  background: var(--complete-btn-hover);
}

.btn.btn-absent {
  border-color: var(--absent-btn);
  background: var(--absent-btn);
  color: #ffffff;
}

.btn.btn-absent:hover {
  background: var(--absent-btn-hover);
}

.summary {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 10px;
  margin: 16px 0;
}

.stat {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px;
  background: #fbfdff;
}

.stat h3 {
  margin: 0 0 6px;
  font-size: 0.9rem;
  color: var(--muted);
}

.stat strong {
  font-size: 1.25rem;
}

.panel-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 12px;
}

.panel-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px;
}

.panel-card h3 {
  margin: 0 0 8px;
}

.panel-card ul {
  margin: 8px 0 0;
  padding-left: 18px;
}

.tag {
  display: inline-block;
  border-radius: 999px;
  padding: 4px 8px;
  font-size: 0.8rem;
  margin-left: 6px;
}

.tag.pending {
  background: var(--pending-bg);
  color: var(--pending-text);
}

.tag.completed {
  background: var(--success-bg);
  color: var(--success-text);
}

.tag.absent {
  background: var(--absent-bg);
  color: var(--absent-text);
}

.panel-info,
.current-student,
.list {
  margin-top: 14px;
}

.current-student {
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fbfdff;
}

.student-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px;
  margin-bottom: 8px;
}

.student-meta {
  color: var(--muted);
  font-size: 0.9rem;
}

.note {
  color: var(--muted);
  font-size: 0.9rem;
}

@media (max-width: 900px) {
  .overview-layout {
    grid-template-columns: 1fr;
  }
}