.bg-gradient {
  background:
    radial-gradient(ellipse at 30% 20%, rgba(139, 92, 246, 0.12) 0%, transparent 55%),
    radial-gradient(ellipse at 70% 80%, rgba(59, 130, 246, 0.08) 0%, transparent 55%);
}

[data-theme="light"] .bg-gradient {
  background:
    radial-gradient(ellipse at 30% 20%, rgba(139, 92, 246, 0.08) 0%, transparent 50%),
    radial-gradient(ellipse at 70% 80%, rgba(59, 130, 246, 0.05) 0%, transparent 50%);
  opacity: 0.3;
}

.container-wide {
  width: min(100%, 1240px);
}

header {
  margin-bottom: var(--space-6);
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-3);
}

.logo {
  font-size: 1.8rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent-purple), var(--accent-blue));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-links {
  display: flex;
  gap: var(--space-3);
  align-items: center;
  flex-wrap: wrap;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--accent-blue);
}

.theme-toggle {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 10px;
  width: 44px;
  height: 44px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
  position: relative;
}

.theme-icon {
  width: 20px;
  height: 20px;
  stroke-width: 2;
  color: var(--text-primary);
  position: absolute;
  transition: all 0.3s ease;
}

.sun-icon {
  opacity: 0;
  transform: rotate(90deg) scale(0.8);
}

.moon-icon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

[data-theme="light"] .sun-icon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

[data-theme="light"] .moon-icon {
  opacity: 0;
  transform: rotate(-90deg) scale(0.8);
}

.controls,
.student-list,
.qr-preview {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  margin-bottom: var(--space-5);
  box-shadow: var(--shadow-card);
}

.controls-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.form-group label {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.form-group input,
.form-group select,
.form-group textarea {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px 14px;
  color: var(--text-primary);
  font: inherit;
  transition: border-color 0.2s;
}

.form-group textarea {
  resize: vertical;
  min-height: 100px;
  font-family: "JetBrains Mono", monospace;
}

.btn-row {
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
}

.btn {
  background: var(--accent-blue);
  color: #fff;
  border: none;
  border-radius: var(--radius-md);
  padding: 12px 18px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.btn-secondary {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-success {
  background: var(--accent-green);
}

.search-input {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  color: var(--text-primary);
  font: inherit;
}

.pagination-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  margin-top: var(--space-4);
  flex-wrap: wrap;
}

.page-numbers {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.page-btn {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  color: var(--text-primary);
  font-size: 0.9rem;
  cursor: pointer;
  min-width: 36px;
}

.page-btn.active {
  background: var(--accent-blue);
  border-color: var(--accent-blue);
  color: #fff;
}

.page-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-4);
  flex-wrap: wrap;
  gap: var(--space-3);
}

.section-title {
  font-size: 1.2rem;
  font-weight: 600;
}

.student-count {
  background: var(--bg-secondary);
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.student-table {
  width: 100%;
  border-collapse: collapse;
}

.student-table th,
.student-table td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.student-table th {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.student-table tr:hover td {
  background: rgba(59, 130, 246, 0.05);
}

.student-id {
  font-family: "JetBrains Mono", monospace;
  color: var(--accent-blue);
}

.action-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 6px 10px;
  border-radius: var(--radius-sm);
}

.action-btn:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

.action-btn.delete:hover {
  color: var(--accent-red);
}

.preview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--space-4);
  margin-top: var(--space-4);
}

.qr-card {
  background: #ffffff;
  border-radius: 12px;
  padding: var(--space-4);
  text-align: center;
}

.qr-card canvas {
  max-width: 150px;
  height: auto;
}

.qr-card .name {
  margin-top: var(--space-3);
  font-weight: 700;
  color: #1a1a24;
}

.qr-card .id {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.85rem;
  color: #64748b;
  margin-top: 4px;
}

.empty-state {
  text-align: center;
  padding: var(--space-6) var(--space-4);
  color: var(--text-secondary);
}

.empty-state svg {
  width: 60px;
  height: 60px;
  margin-bottom: var(--space-3);
  opacity: 0.5;
}

.feedback {
  position: fixed;
  top: var(--space-4);
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  display: none;
  align-items: center;
  gap: var(--space-3);
  z-index: 200;
  max-width: calc(100% - 40px);
  box-shadow: var(--shadow-card);
}

.feedback.active {
  display: flex;
}

.feedback.success {
  border-color: var(--accent-green);
}

.feedback.error {
  border-color: var(--accent-red);
}

@media (max-width: 720px) {
  .header-content {
    flex-direction: column;
    align-items: flex-start;
  }

  .section-header {
    flex-direction: column;
    align-items: flex-start;
  }
}