:root {
  --bg: #f9f2e7;
  --panel: #fffaf3;
  --text: #3a2416;
  --muted: #7a5740;
  --primary: #a34f1f;
  --primary-strong: #7f3a14;
  --border: #e6c9a8;
  --ok: #2f7a2f;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.4;
  font-size: 20px;
}

.app-header {
  padding: 20px 18px 10px;
  background: var(--panel);
  border-bottom: 2px solid var(--border);
  text-align: center;
  position: relative;
  z-index: 1;
}

.app-header h1 {
  margin: 0;
  font-size: 34px;
}

.subtitle {
  margin: 8px 0 0;
  color: var(--muted);
}

.app-main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px;
  position: relative;
  z-index: 1;
}

.controls {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
  align-items: end;
  background: var(--panel);
  border: 2px solid var(--border);
  border-radius: 14px;
  padding: 14px;
}

.control-field {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.control-field span {
  font-weight: 700;
}

input,
select,
button {
  font-size: 20px;
}

input,
select {
  min-height: 52px;
  border: 2px solid var(--border);
  border-radius: 10px;
  padding: 8px 12px;
  background: #fff;
}

input:focus,
select:focus,
button:focus {
  outline: 4px solid #f1c35a;
  outline-offset: 2px;
}

button {
  min-height: 52px;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  padding: 8px 14px;
  font-weight: 700;
}

.secondary-btn {
  background: #f0dfcd;
  color: var(--text);
}

.secondary-btn:hover {
  background: #e9d2b8;
}

.status-row {
  margin: 14px 0;
  padding: 12px 14px;
  background: var(--panel);
  border: 2px solid var(--border);
  border-radius: 12px;
  color: var(--muted);
}

.group-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 14px;
}

.group-card {
  display: block;
  width: 100%;
  text-align: left;
  padding: 16px;
  border: 2px solid var(--border);
  border-radius: 14px;
  background: var(--panel);
}

.group-card:hover {
  border-color: var(--primary);
}

.group-card h3 {
  margin: 0 0 8px;
  font-size: 25px;
}

.group-meta {
  color: var(--muted);
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
}

.group-meta strong {
  color: var(--ok);
}

.detail-panel {
  margin-top: 18px;
  padding: 16px;
  border: 2px solid var(--border);
  border-radius: 14px;
  background: var(--panel);
}

.detail-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.detail-header h2 {
  margin: 0;
  font-size: 30px;
}

.detail-meta {
  margin-top: 8px;
  color: var(--muted);
}

.event-block {
  margin-top: 16px;
  border-top: 2px solid var(--border);
  padding-top: 14px;
}

.event-title {
  margin: 0 0 8px;
  font-weight: 700;
}

.time-slot-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 10px;
}

.time-slot-btn {
  border: 2px solid var(--border);
  background: #f9fbff;
  color: var(--text);
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.time-slot-btn.is-active {
  border-color: var(--primary);
  background: #fff0de;
}

.free-label {
  display: inline-block;
  background: #e9f9ea;
  color: var(--ok);
  border: 1px solid #8fd08f;
  border-radius: 999px;
  padding: 2px 10px;
  font-size: 17px;
  font-weight: 700;
}

.assignment-list {
  margin: 0;
  padding-left: 1.2em;
}

.assignment-list li {
  margin-bottom: 14px;
}

.open-link {
  display: inline-block;
  margin-top: 10px;
  color: var(--primary-strong);
  font-weight: 700;
}

.app-footer {
  margin: 24px 16px;
  text-align: center;
}

.app-footer a {
  color: var(--primary-strong);
  font-weight: 700;
}