:root {
  --lms-bg: #f4f7fb;
  --lms-surface: #ffffff;
  --lms-surface-2: #f8fafc;
  --lms-border: #dbe3ef;
  --lms-text: #172033;
  --lms-muted: #5f6b85;

  --lms-primary: #2563eb;
  --lms-primary-soft: #eaf2ff;

  --lms-secondary: #64748b;
  --lms-secondary-soft: #f1f5f9;

  --lms-success: #0f9f6e;
  --lms-success-soft: #eafaf3;

  --lms-warning: #f2b200;
  --lms-warning-soft: #fff7db;

  --lms-danger: #e11d48;
  --lms-danger-soft: #fff1f4;

  --lms-dark: #1f2937;
  --lms-shadow: 0 8px 24px rgba(15, 23, 42, 0.06);
  --lms-radius: 16px;
}

body {
  background: var(--lms-bg);
  color: var(--lms-text);
}

.app-topbar {
  height: 56px;
  background: var(--lms-surface);
  border-color: var(--lms-border) !important;
}

.app-layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  min-height: calc(100vh - 56px);
}

.app-sidebar {
  background: var(--lms-surface);
  border-color: var(--lms-border) !important;
}

.app-main {
  background: var(--lms-bg);
  min-width: 0;
  text-align: left;
}

/* Карточки и списки */
.card,
.list-group-item,
.table,
.alert,
.border,
.rounded {
  border-color: var(--lms-border) !important;
}

.card,
.list-group-item {
  border-radius: var(--lms-radius) !important;
  box-shadow: var(--lms-shadow);
}

.list-group-item {
  background: var(--lms-surface);
}

.list-group-item-action {
  border-radius: 12px;
  margin-bottom: 8px;
}

.list-group-item-action:hover {
  background: var(--lms-primary-soft);
}

/* Таблицы */
.table {
  --bs-table-bg: transparent;
}

.table > :not(caption) > * > * {
  border-bottom-color: var(--lms-border);
}

.table thead th {
  color: var(--lms-text);
  font-weight: 700;
}

/* Текст */
.text-muted,
.small.text-muted,
.form-text {
  color: var(--lms-muted) !important;
}

/* Кнопки */
.btn {
  border-radius: 12px;
  font-weight: 500;
  box-shadow: none !important;
}

.btn-sm {
  border-radius: 10px;
}

.btn-sm i,
.btn i {
  margin-right: 4px;
}

.btn-primary {
  background: var(--lms-primary);
  border-color: var(--lms-primary);
}

.btn-primary:hover,
.btn-primary:focus {
  background: #1d4ed8;
  border-color: #1d4ed8;
}

.btn-outline-primary {
  color: var(--lms-primary);
  border-color: var(--lms-primary);
  background: #fff;
}

.btn-outline-primary:hover,
.btn-outline-primary:focus {
  color: #fff;
  background: var(--lms-primary);
  border-color: var(--lms-primary);
}

.btn-outline-secondary {
  color: var(--lms-secondary);
  border-color: var(--lms-secondary);
  background: #fff;
}

.btn-outline-secondary:hover,
.btn-outline-secondary:focus {
  color: #fff;
  background: var(--lms-secondary);
  border-color: var(--lms-secondary);
}

.btn-outline-success {
  color: var(--lms-success);
  border-color: var(--lms-success);
  background: #fff;
}

.btn-outline-success:hover,
.btn-outline-success:focus {
  color: #fff;
  background: var(--lms-success);
  border-color: var(--lms-success);
}

.btn-warning {
  color: #3b2f00;
  background: var(--lms-warning);
  border-color: var(--lms-warning);
}

.btn-warning:hover,
.btn-warning:focus {
  color: #3b2f00;
  background: #dfaa00;
  border-color: #dfaa00;
}

.btn-outline-danger {
  color: var(--lms-danger);
  border-color: var(--lms-danger);
  background: #fff;
}

.btn-outline-danger:hover,
.btn-outline-danger:focus {
  color: #fff;
  background: var(--lms-danger);
  border-color: var(--lms-danger);
}

.btn-outline-dark {
  color: var(--lms-dark);
  border-color: var(--lms-dark);
  background: #fff;
}

.btn-outline-dark:hover,
.btn-outline-dark:focus {
  color: #fff;
  background: var(--lms-dark);
  border-color: var(--lms-dark);
}

/* Поля формы */
.form-control,
.form-select {
  border-radius: 12px;
  border-color: var(--lms-border);
  background: #fff;
}

.form-control:focus,
.form-select:focus {
  border-color: #93c5fd;
  box-shadow: 0 0 0 0.2rem rgba(37, 99, 235, 0.12);
}

/* Боковое меню */
.list-group-flush > .list-group-item,
.list-group-item-action {
  border-radius: 12px !important;
}

.list-group-item.active {
  background: var(--lms-primary);
  border-color: var(--lms-primary);
}

/* Значки/бейджи */
.badge {
  border-radius: 10px;
}

/* Адаптив */
@media (max-width: 991px) {
  .app-layout {
    grid-template-columns: 1fr;
  }
}
/* === Student lesson page: unified document style (Notion-like) === */

/* === Student lesson page: unified document style === */

.lesson-sheet {
  background: #ffffff;
  border: 1px solid var(--lms-border);
  border-radius: 18px;
  box-shadow: var(--lms-shadow);
  overflow: hidden;
  padding: 18px 0;
}

.lesson-divider {
  height: 22px;
  border-top: 1px solid #eef2f7;
  margin: 0 28px;
}

.lesson-block {
  background: #ffffff;
  padding: 0 28px;
  line-height: 1.65;
}

.lesson-block-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--lms-text);
  margin-bottom: 14px;
}

.lesson-block > * {
  margin: 0 0 18px 0;
}

.lesson-block > *:last-child {
  margin-bottom: 0;
}

.lesson-block h1,
.lesson-block h2,
.lesson-block h3,
.lesson-block h4,
.lesson-block h5,
.lesson-block h6 {
  line-height: 1.3;
}

.lesson-code {
  padding: 14px 16px;
  border: 1px solid var(--lms-border);
  border-radius: 12px;
  background: #f8fafc;
  white-space: pre;
  overflow: auto;
}

.lesson-sheet img {
  display: block;
  max-width: 100%;
  max-height: 520px;
  object-fit: contain;
  border-radius: 12px;
}