/* Custom Utility Classes Using Design Tokens */

/* Spacing Utilities - Reduced from defaults */
.compact-spacing {
    --spacing-scale: 0.75; /* 75% of design token spacing */
}

/* Card Styles */
.card {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border-primary);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-4);
}

.card-header {
    padding: var(--spacing-3) var(--spacing-4);
    border-bottom: 1px solid var(--color-border-secondary);
}

.card-body {
    padding: var(--spacing-4);
}

/* Metrics Card */
.metric-card {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border-primary);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-4);
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    transition: all var(--duration-fast) var(--easing-standard);
}

.metric-card-clickable {
    text-decoration: none;
    color: inherit;
    cursor: pointer;
}

.metric-card-clickable:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--color-primary-400);
}

.metric-card-clickable:active {
    transform: translateY(0);
}

.metric-card-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--border-radius-md);
    flex-shrink: 0;
}

.metric-card-content {
    flex: 1;
    min-width: 0;
}

.metric-card-title {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-1);
}

.metric-card-value {
    font-size: var(--font-size-3xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-text-primary);
    font-family: var(--font-family-mono);
}

.metric-card-subtitle {
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
    margin-top: var(--spacing-1);
}

/* Class List Item */
.class-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-3);
    background-color: var(--color-bg-tertiary);
    border-radius: var(--border-radius-md);
    transition: background-color var(--transition-fast);
}

.class-item:hover {
    background-color: var(--color-bg-hover);
}

.class-item-title {
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-medium);
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-1);
}

.class-item-subtitle {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.class-item-meta {
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
    margin-top: var(--spacing-1);
}

/* Student Avatar List */
.student-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    padding: var(--spacing-2) 0;
}

.student-avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--border-radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: var(--font-weight-semibold);
    color: white;
    flex-shrink: 0;
}

.student-info-name {
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-medium);
    color: var(--color-text-primary);
}

.student-info-class {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

/* Page Header */
.page-header {
    margin-bottom: var(--spacing-6);
}

.page-title {
    font-size: var(--font-size-3xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-2);
}

.page-subtitle {
    font-size: var(--font-size-base);
    color: var(--color-text-secondary);
}

/* Grid System - Tighter spacing */
.grid-compact {
    display: grid;
    gap: var(--spacing-4);
}

.grid-compact-sm {
    display: grid;
    gap: var(--spacing-3);
}

@media (min-width: 1024px) {
    .grid-compact {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .grid-2-col {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Link Styles */
.link-primary {
    color: var(--color-text-link);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    transition: color var(--transition-fast);
}

.link-primary:hover {
    color: var(--color-text-link-hover);
}

/* Button Styles */
.btn-link {
    padding: var(--spacing-2) var(--spacing-4);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    color: var(--color-text-link);
    background: transparent;
    border: none;
    cursor: pointer;
    transition: color var(--transition-fast);
}

.btn-link:hover {
    color: var(--color-text-link-hover);
}

/* Loading State */
.loading-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 256px;
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 3px solid var(--color-border-primary);
    border-top-color: var(--color-primary-600);
    border-radius: var(--border-radius-full);
    animation: spin var(--transition-base) linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-text {
    margin-top: var(--spacing-4);
    color: var(--color-text-secondary);
    font-size: var(--font-size-base);
}

/* Error State */
.error-container {
    background-color: var(--color-status-error-light);
    border: 1px solid var(--color-status-error);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-4);
}

.error-text {
    color: var(--color-status-error-dark);
    font-size: var(--font-size-sm);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: var(--spacing-8) var(--spacing-4);
    color: var(--color-text-tertiary);
}