/* === Buttons === */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: 0.5rem 1rem;
    font-family: var(--font-family);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    line-height: var(--line-height-tight);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    cursor: pointer;
    text-decoration: none;
    white-space: nowrap;
    transition: all var(--transition-fast);
    user-select: none;
}

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

.btn svg {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
}

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

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

.btn-secondary {
    background: var(--color-surface);
    color: var(--color-text);
    border-color: var(--color-border);
}

.btn-secondary:hover {
    background: var(--color-surface-hover);
    border-color: var(--color-muted);
}

.btn-success {
    background: var(--color-success);
    color: var(--color-inverse);
    border-color: var(--color-success);
}

.btn-success:hover {
    background: var(--color-success-hover);
    border-color: var(--color-success-hover);
}

.btn-danger {
    background: var(--color-danger);
    color: var(--color-inverse);
    border-color: var(--color-danger);
}

.btn-danger:hover {
    background: var(--color-danger-hover);
    border-color: var(--color-danger-hover);
}

.btn-ghost {
    background: transparent;
    color: var(--color-text-secondary);
    border-color: transparent;
}

.btn-ghost:hover {
    background: var(--color-bg);
    color: var(--color-text);
}

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

.btn-outline:hover {
    background: var(--color-primary);
    color: var(--color-inverse);
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: var(--font-size-xs);
}

.btn-lg {
    padding: 0.625rem 1.25rem;
    font-size: var(--font-size-base);
}

.btn-block {
    display: flex;
    width: 100%;
}

.btn-icon {
    padding: 0.5rem;
}

.btn.loading {
    position: relative;
    color: transparent;
    pointer-events: none;
}

.btn.loading::after {
    content: '';
    position: absolute;
    width: 16px;
    height: 16px;
    border: 2px solid currentColor;
    border-right-color: transparent;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
    color: var(--color-inverse);
}

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

/* === Alerts === */
.alert {
    display: flex;
    align-items: flex-start;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    margin-bottom: var(--space-4);
    border: 1px solid transparent;
}

.alert svg {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
    margin-top: 1px;
}

.alert-success {
    background: var(--color-success-light);
    color: #065F46;
    border-color: #A7F3D0;
}

.alert-danger {
    background: var(--color-danger-light);
    color: #991B1B;
    border-color: #FECACA;
}

.alert-warning {
    background: var(--color-warning-light);
    color: #92400E;
    border-color: #FDE68A;
}

.alert-info {
    background: var(--color-info-light);
    color: #3730A3;
    border-color: #C7D2FE;
}

.alert-dismissible {
    position: relative;
    padding-left: var(--space-10);
}

.alert-dismiss {
    position: absolute;
    left: var(--space-2);
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    cursor: pointer;
    color: inherit;
    opacity: 0.6;
    padding: var(--space-1);
}

.alert-dismiss:hover {
    opacity: 1;
}

/* === Status Badges === */
.badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-1);
    padding: 0.125rem 0.625rem;
    font-size: var(--font-size-xs);
    font-weight: var(--font-weight-medium);
    border-radius: var(--radius-full);
    white-space: nowrap;
    line-height: var(--line-height-normal);
}

.badge-primary {
    background: var(--color-primary-light);
    color: var(--color-primary-dark);
}

.badge-success {
    background: var(--color-success-light);
    color: #065F46;
}

.badge-warning {
    background: var(--color-warning-light);
    color: #92400E;
}

.badge-danger {
    background: var(--color-danger-light);
    color: #991B1B;
}

.badge-info {
    background: var(--color-info-light);
    color: #3730A3;
}

.badge-secondary {
    background: var(--color-bg);
    color: var(--color-muted);
}

/* Domain-specific status badges */
.status-pending {
    background: var(--color-warning-light);
    color: #92400E;
}

.status-approved, .status-active, .status-present {
    background: var(--color-success-light);
    color: #065F46;
}

.status-rejected, .status-cancelled, .status-failed, .status-absent {
    background: var(--color-danger-light);
    color: #991B1B;
}

.status-planned, .status-scheduled, .status-draft {
    background: var(--color-info-light);
    color: #3730A3;
}

.status-completed, .status-graded {
    background: var(--color-primary-light);
    color: var(--color-primary-dark);
}

.status-late {
    background: var(--color-warning-light);
    color: #92400E;
}

.status-excused {
    background: var(--color-bg);
    color: var(--color-muted);
}

.status-paid {
    background: var(--color-success-light);
    color: #065F46;
}

.status-unpaid, .status-debtor {
    background: var(--color-danger-light);
    color: #991B1B;
}

.status-credit {
    background: var(--color-info-light);
    color: #3730A3;
}

/* === Cards === */
.card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border-light);
}

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4) var(--space-5);
    border-bottom: 1px solid var(--color-border-light);
}

.card-header h3 {
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-semibold);
}

.card-body {
    padding: var(--space-5);
}

.card-footer {
    padding: var(--space-3) var(--space-5);
    border-top: 1px solid var(--color-border-light);
    background: var(--color-surface-hover);
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

/* === Empty State === */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-12) var(--space-6);
    text-align: center;
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    border: 1px dashed var(--color-border);
}

.empty-state svg {
    width: 48px;
    height: 48px;
    color: var(--color-muted);
    margin-bottom: var(--space-4);
    opacity: 0.5;
}

.empty-state h3 {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-semibold);
    color: var(--color-text);
    margin-bottom: var(--space-2);
}

.empty-state p {
    color: var(--color-muted);
    font-size: var(--font-size-sm);
    max-width: 400px;
    margin-bottom: var(--space-5);
}

/* === Modal / Dialog === */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: var(--z-modal);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-4);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 480px;
    max-height: 90vh;
    overflow-y: auto;
    transform: scale(0.95);
    transition: transform var(--transition-normal);
}

.modal-overlay.active .modal {
    transform: scale(1);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4) var(--space-5);
    border-bottom: 1px solid var(--color-border-light);
}

.modal-header h3 {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-semibold);
}

.modal-close {
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-1);
    color: var(--color-muted);
    border-radius: var(--radius-sm);
}

.modal-close:hover {
    background: var(--color-bg);
    color: var(--color-text);
}

.modal-body {
    padding: var(--space-5);
}

.modal-footer {
    display: flex;
    justify-content: flex-start;
    gap: var(--space-3);
    padding: var(--space-4) var(--space-5);
    border-top: 1px solid var(--color-border-light);
}

/* === Toast === */
.toast-container {
    position: fixed;
    top: calc(var(--header-height) + var(--space-4));
    left: 50%;
    transform: translateX(-50%);
    z-index: var(--z-toast);
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
    pointer-events: none;
}

.toast {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    background: var(--color-surface);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--color-border);
    font-size: var(--font-size-sm);
    pointer-events: auto;
    animation: toastIn 0.3s ease, toastOut 0.3s ease 2.7s forwards;
    max-width: 400px;
}

.toast-success { border-right: 3px solid var(--color-success); }
.toast-danger { border-right: 3px solid var(--color-danger); }
.toast-warning { border-right: 3px solid var(--color-warning); }
.toast-info { border-right: 3px solid var(--color-info); }

@keyframes toastIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes toastOut {
    from { opacity: 1; transform: translateY(0); }
    to { opacity: 0; transform: translateY(-10px); }
}

/* === Progress Bar === */
.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--color-bg);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--color-primary);
    border-radius: var(--radius-full);
    transition: width var(--transition-normal);
}

/* === Skeleton Loading === */
.skeleton {
    background: linear-gradient(90deg, var(--color-bg) 25%, var(--color-border-light) 50%, var(--color-bg) 75%);
    background-size: 200% 100%;
    animation: skeleton 1.5s ease-in-out infinite;
    border-radius: var(--radius-md);
}

@keyframes skeleton {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

.skeleton-text {
    height: 1rem;
    margin-bottom: var(--space-2);
}

.skeleton-title {
    height: 1.5rem;
    width: 60%;
    margin-bottom: var(--space-3);
}

.skeleton-card {
    height: 120px;
}