:root {
  --primary-color: #326ce5;
  --secondary-color: #f0f4f8;
  --text-color: #333;
  --border-color: #ddd;
  --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  --plenum-color: #ff6b6b;
  --workshop-color: #48bb78;
  --bg-color: #f8f9fa;
  --card-bg: white;
  --muted-text: #666;
  --description-text: #555;
  --error-bg: #fee;
  --error-text: #c33;
  --plenum-gradient-start: #fff5f5;
  --workshop-gradient-start: #f0fff4;
}

[data-theme="dark"] {
  --primary-color: #5b9aff;
  --secondary-color: #2d3748;
  --text-color: #e2e8f0;
  --border-color: #4a5568;
  --shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
  --plenum-color: #ff8787;
  --workshop-color: #68d391;
  --bg-color: #1a202c;
  --card-bg: #2d3748;
  --muted-text: #a0aec0;
  --description-text: #cbd5e0;
  --error-bg: #742a2a;
  --error-text: #fc8181;
  --plenum-gradient-start: #3d2626;
  --workshop-gradient-start: #22543d;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
    Ubuntu, Cantarell, sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  background-color: var(--bg-color);
  transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 10px;
}

/* Header */
header {
  position: relative;
  background: linear-gradient(135deg, var(--primary-color), #4a80f0);
  color: white;
  padding: 1.5rem 0;
  box-shadow: var(--shadow);
  overflow: hidden;
}

header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: url("images/cover.png");
  background-size: cover;
  background-position: center;
  opacity: 0.25;
  pointer-events: none;
  z-index: 0;
}

.header-content {
  position: relative;
  z-index: 1;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
}

.header-logo {
  max-height: 100px;
  height: auto;
  max-width: 100%;
  object-fit: contain;
}

.theme-toggle {
  background: rgba(255, 255, 255, 0.2);
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s ease;
  color: white;
  flex-shrink: 0;
}

.theme-toggle:hover {
  background: rgba(255, 255, 255, 0.3);
  transform: scale(1.1);
}

.theme-toggle svg {
  width: 14px;
  height: 14px;
}

.theme-toggle .moon-icon {
  display: none;
}

[data-theme="dark"] .theme-toggle .sun-icon {
  display: none;
}

[data-theme="dark"] .theme-toggle .moon-icon {
  display: block;
}

/* Main Content */
main {
  padding: 2rem 0;
  min-height: 60vh;
}

#loading {
  text-align: center;
  font-size: 1.2rem;
  padding: 3rem;
  color: var(--muted-text);
}

#error {
  background-color: var(--error-bg);
  color: var(--error-text);
  padding: 1rem;
  border-radius: 8px;
  margin: 1rem 0;
  border-left: 4px solid var(--error-text);
}

/* Filters */
#filter-container {
  margin-bottom: 0rem;
  margin-top: 0.5rem;
}

.filter-toggle {
  width: 100%;
  background: var(--card-bg);
  border: 2px solid var(--border-color);
  border-radius: 8px;
  padding: 0.75rem 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  font-size: 1rem;
  color: var(--text-color);
  font-weight: 600;
  transition: all 0.3s ease;
  box-shadow: var(--shadow);
}

.filter-toggle:hover {
  border-color: var(--primary-color);
  background: var(--secondary-color);
}

.filter-toggle svg:first-child {
  color: var(--primary-color);
}

.filter-toggle span {
  flex: 1;
  text-align: left;
}

.filter-toggle .chevron {
  transition: transform 0.3s ease;
  color: var(--muted-text);
}

.filter-toggle.active .chevron {
  transform: rotate(180deg);
}

#filters {
  background: var(--card-bg);
  padding: 0.5rem;
  border-radius: 8px;
  margin-top: 0.5rem;
  box-shadow: var(--shadow);
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
  overflow: hidden;
  transition: max-height 0.3s ease, opacity 0.3s ease, padding 0.3s ease;
}

.filters-collapsed {
  max-height: 0;
  opacity: 0;
  padding: 0;
  margin-top: 0;
}

.filters-expanded {
  max-height: 500px;
  opacity: 1;
}

.filter-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.filter-group label {
  font-weight: 600;
  color: var(--text-color);
}

.filter-group select {
  padding: 0.5rem 1rem;
  border: 2px solid var(--border-color);
  border-radius: 6px;
  font-size: 1rem;
  background-color: var(--card-bg);
  color: var(--text-color);
  cursor: pointer;
  transition: border-color 0.3s;
}

.filter-group select:hover,
.filter-group select:focus {
  border-color: var(--primary-color);
  outline: none;
}

.search-group {
  flex: 1;
  min-width: 250px;
}

.filter-group input[type="text"] {
  padding: 0.5rem 1rem;
  border: 2px solid var(--border-color);
  border-radius: 6px;
  font-size: 1rem;
  background-color: var(--card-bg);
  color: var(--text-color);
  transition: border-color 0.3s;
}

.filter-group input[type="text"]:hover,
.filter-group input[type="text"]:focus {
  border-color: var(--primary-color);
  outline: none;
}

.filter-group input[type="text"]::placeholder {
  color: var(--muted-text);
  opacity: 0.7;
}

/* Checkbox group for type filter */
.checkbox-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  font-weight: normal;
  color: var(--text-color);
}

.checkbox-label input[type="checkbox"] {
  cursor: pointer;
  width: 18px;
  height: 18px;
  accent-color: var(--primary-color);
}

.checkbox-label:hover {
  color: var(--primary-color);
}

/* Schedule */
.day-section {
  margin-bottom: 3rem;
}

.day-section h2 {
  color: var(--primary-color);
  font-size: 1.8rem;
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 3px solid var(--primary-color);
}

.day-section > .session-card {
  margin-bottom: 1.5rem;
}

.time-slot {
  margin-bottom: 1.5rem;
  padding: 0.5rem;
  border-radius: 6px;
  border: 1px dashed var(--border-color);
}

.time-header {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--primary-color);
  margin-bottom: 1rem;
  padding: 0.5rem 0;
}

.sessions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: 1rem;
}

/* Session Cards */
.session-card {
  background: var(--card-bg);
  border-radius: 8px;
  padding: 1rem;
  padding-bottom: 2rem;
  box-shadow: var(--shadow);
  transition: transform 0.2s, box-shadow 0.2s;
  border-left: 4px solid var(--primary-color);
  cursor: pointer;
  position: relative;
}

.session-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
}

.session-card.plenum {
  border-left-color: var(--plenum-color);
  background: linear-gradient(
    to right,
    var(--plenum-gradient-start),
    var(--card-bg)
  );
}

.session-card.workshop {
  border-left-color: var(--workshop-color);
  background: linear-gradient(
    to right,
    var(--workshop-gradient-start),
    var(--card-bg)
  );
}

/* West room styling - border on right */
.session-card.room-west {
  border-left: none;
  border-right: 4px solid var(--primary-color);
}

.session-card.room-west.plenum {
  border-right-color: var(--plenum-color);
  background: linear-gradient(
    to left,
    var(--plenum-gradient-start),
    var(--card-bg)
  );
}

.session-card.room-west.workshop {
  border-right-color: var(--workshop-color);
  background: linear-gradient(
    to left,
    var(--workshop-gradient-start),
    var(--card-bg)
  );
}

/* West room layout - right-aligned */
.session-card.room-west .session-title {
  text-align: right;
}

.session-card.room-west .session-meta {
  flex-direction: row-reverse;
  justify-content: flex-start;
}

.session-card.room-west .session-speakers-compact {
  flex-direction: row-reverse;
}

.session-card.room-west .speaker-compact {
  flex-direction: row-reverse;
}

.session-header {
  margin-bottom: 0.5rem;
}

.session-title {
  font-size: 1.1rem;
  color: var(--text-color);
  margin: 0;
}

/* Session metadata line (speakers, time, room) */
.session-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  font-size: 0.9rem;
}

.session-time {
  color: var(--muted-text);
  font-weight: 500;
  white-space: nowrap;
}

.session-room {
  background-color: var(--secondary-color);
  color: var(--primary-color);
  padding: 0.25rem 0.7rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  white-space: nowrap;
}

/* Compact speaker view (collapsed state) */
.session-speakers-compact {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.speaker-compact {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.speaker-compact img {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--border-color);
}

.speaker-compact .speaker-name {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-color);
}

/* Expanded session details */
.session-details {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.session-card.expanded .session-details {
  max-height: 2000px;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
}

.session-description {
  color: var(--description-text);
  margin-bottom: 1rem;
  line-height: 1.6;
  font-size: 0.95rem;
}

.session-speakers-full {
  margin-top: 0.75rem;
}

.session-speakers-full .speaker-tagline {
  font-size: 0.85rem;
  color: var(--muted-text);
  margin-bottom: 0.5rem;
  line-height: 1.4;
}

.session-speakers-full .speaker-tagline:last-child {
  margin-bottom: 0;
}

/* Expand indicator */
.expand-indicator {
  position: absolute;
  bottom: 0.5rem;
  right: 0.75rem;
  color: var(--primary-color);
  transition: transform 0.3s ease;
}

.session-card.expanded .expand-indicator {
  transform: rotate(180deg);
}

.session-card.room-west .expand-indicator {
  right: auto;
  left: 0.75rem;
}

/* Footer */
footer {
  background-color: #2d3748;
  color: white;
  text-align: center;
  padding: 2rem 0;
  margin-top: 3rem;
}

.footer-link {
  color: #5b9aff;
}

.footer-link:hover {
  color: #c33;
}

/* Responsive */
@media (max-width: 768px) {
  .header-logo {
    max-height: 50px;
  }

  .sessions-grid {
    grid-template-columns: 1fr;
  }

  #filters {
    flex-direction: column;
    gap: 1rem;
  }
}