/* ============================================================================
   SMART TEACHER PWA — Lesson Detail (Horizontal Grade Table)
   ============================================================================ */

.lesson-detail {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.lesson-detail__status {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.lesson-detail__info {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-4);
}

.lesson-detail__info span {
  margin-right: var(--space-4);
}

/* --- Grade Table Container --- */
.grade-table-container {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  flex: 1;
}

.grade-table-scroll {
  overflow-x: auto;
  overflow-y: auto;
  max-height: calc(100vh - 280px);
  -webkit-overflow-scrolling: touch;
}

/* --- Grade Table --- */
.grade-table {
  width: 100%;
  min-width: 700px;
  border-collapse: separate;
  border-spacing: 0;
  table-layout: fixed;
}

/* Header row */
.grade-table thead th {
  position: sticky;
  top: 0;
  background: var(--color-bg-secondary);
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
  padding: var(--space-3) var(--space-2);
  text-align: center;
  border-bottom: 2px solid var(--color-border);
  z-index: 2;
  white-space: nowrap;
}

/* Sticky first column (student names) */
.grade-table thead th:first-child,
.grade-table tbody td:first-child {
  position: sticky;
  left: 0;
  z-index: 3;
  background: var(--color-surface);
  text-align: left;
  min-width: 160px;
  max-width: 200px;
  width: 200px;
  padding-left: var(--space-4);
  border-right: 2px solid var(--color-border);
}

.grade-table thead th:first-child {
  z-index: 4;
  background: var(--color-bg-secondary);
}

/* Module columns */
.grade-table thead th:not(:first-child) {
  width: calc((100% - 200px) / 6);
  min-width: 90px;
}

/* Body rows */
.grade-table tbody tr {
  transition: background-color var(--duration-fast) var(--ease-default);
}

.grade-table tbody tr:hover td {
  background-color: var(--color-surface-hover);
}

.grade-table tbody tr:hover td:first-child {
  background-color: var(--color-surface-hover);
}

.grade-table tbody td {
  padding: var(--space-1);
  text-align: center;
  border-bottom: 1px solid var(--color-divider);
  background: var(--color-surface);
}

/* Student name in table */
.grade-table__student-name {
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--color-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Grade cell button */
.grade-cell-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 42px;
  padding: var(--space-2);
  border: none;
  border-radius: var(--radius-md);
  background: transparent;
  cursor: pointer;
  font-size: var(--text-md);
  font-weight: var(--weight-semibold);
  transition: background-color var(--duration-fast) var(--ease-default),
              color var(--duration-fast) var(--ease-default);
  color: var(--color-text-tertiary);
}

.grade-cell-btn:hover {
  background: var(--color-bg-tertiary);
}

.grade-cell-btn--empty {
  color: var(--color-text-tertiary);
  font-weight: var(--weight-normal);
}

.grade-cell-btn--filled {
  color: var(--color-text);
}

/* Color coding for grades */
.grade-cell-btn--high {
  color: var(--color-success-600);
}

.grade-cell-btn--mid {
  color: var(--color-warning-600);
}

.grade-cell-btn--low {
  color: var(--color-danger-600);
}

/* Completed lesson — cells not clickable */
.grade-table--completed .grade-cell-btn {
  cursor: default;
  pointer-events: none;
}

/* Disabled grade cell (no prev HW) */
.grade-cell-btn--disabled {
  opacity: 0.3;
  cursor: not-allowed;
  pointer-events: none;
}

/* --- Responsive --- */
@media (max-width: 767px) {
  .grade-table-scroll {
    max-height: calc(100vh - 240px);
  }

  .grade-table thead th:first-child,
  .grade-table tbody td:first-child {
    min-width: 120px;
    max-width: 140px;
    width: 140px;
    padding-left: var(--space-3);
  }

  .grade-table thead th:not(:first-child) {
    min-width: 75px;
  }

  .grade-table thead th {
    font-size: 10px;
    padding: var(--space-2) var(--space-1);
  }

  .grade-cell-btn {
    min-height: 38px;
    font-size: var(--text-base);
  }
}

/* Module column header abbreviation on mobile */
@media (max-width: 480px) {
  .grade-table thead th:first-child,
  .grade-table tbody td:first-child {
    min-width: 100px;
    max-width: 120px;
    width: 120px;
  }

  .grade-table__student-name {
    font-size: var(--text-xs);
  }
}