/* Sheet Backdrop */
.sheet-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-overlay);
    opacity: 0;
    transition: opacity var(--transition-base);
    z-index: var(--z-sheet-backdrop);
    pointer-events: none;
}

.sheet-backdrop.visible {
    opacity: 1;
    pointer-events: auto;
}

/* Bottom Sheet */
.bottom-sheet {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-bg);
    border-radius: var(--radius-2xl) var(--radius-2xl) 0 0;
    transform: translateY(100%);
    transition: transform var(--transition-base);
    z-index: var(--z-sheet);
    max-height: 90vh;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-xl);
}

.bottom-sheet.visible {
    transform: translateY(0);
}

.bottom-sheet.transitioning {
    transition: none;
}

/* Sheet Handle */
.sheet-handle {
    width: 40px;
    height: 4px;
    background: var(--color-border);
    border-radius: var(--radius-full);
    margin: 12px auto 8px;
    cursor: grab;
    flex-shrink: 0;
}

.sheet-handle:active {
    cursor: grabbing;
}

/* Sheet Header */
.sheet-header {
    padding: var(--spacing-md) var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
    flex-shrink: 0;
}

.sheet-title {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-semibold);
    color: var(--color-text);
}

.sheet-subtitle {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    margin-top: var(--spacing-xs);
}

/* Sheet Content */
.sheet-content {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    overscroll-behavior: contain;
    -webkit-overflow-scrolling: touch;
}

.sheet-content-inner {
    padding: var(--spacing-lg);
}

/* Sheet Footer */
.sheet-footer {
    padding: var(--spacing-md) var(--spacing-lg);
    padding-bottom: calc(var(--spacing-md) + var(--safe-area-bottom));
    border-top: 1px solid var(--color-border);
    background: var(--color-bg);
    flex-shrink: 0;
}

/* Fullscreen Sheet */
.fullscreen-sheet {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-bg);
    transform: translateY(100%);
    transition: transform var(--transition-base);
    z-index: var(--z-sheet);
    display: flex;
    flex-direction: column;
}

.fullscreen-sheet.visible {
    transform: translateY(0);
}

.fullscreen-sheet .sheet-header {
    padding-top: calc(var(--spacing-md) + var(--safe-area-top));
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.fullscreen-sheet .sheet-close-btn {
    width: var(--touch-target-min);
    height: var(--touch-target-min);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.fullscreen-sheet .sheet-header-text {
    flex: 1;
}

/* Action Sheet */
.action-sheet {
    position: fixed;
    left: var(--spacing-md);
    right: var(--spacing-md);
    bottom: calc(var(--spacing-md) + var(--safe-area-bottom));
    background: var(--color-bg);
    border-radius: var(--radius-xl);
    transform: translateY(calc(100% + var(--spacing-md) + var(--safe-area-bottom)));
    transition: transform var(--transition-base);
    z-index: var(--z-sheet);
    overflow: hidden;
}

.action-sheet.visible {
    transform: translateY(0);
}

.action-sheet-header {
    padding: var(--spacing-lg);
    text-align: center;
    border-bottom: 1px solid var(--color-border);
}

.action-sheet-title {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-semibold);
    color: var(--color-text);
}

.action-sheet-message {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    margin-top: var(--spacing-xs);
    white-space: pre-line;
}

.action-sheet-actions {
    display: flex;
    flex-direction: column;
}

.action-sheet-button {
    padding: var(--spacing-md) var(--spacing-lg);
    text-align: center;
    font-size: var(--font-size-base);
    color: var(--color-text);
    border-bottom: 1px solid var(--color-border);
    min-height: var(--touch-target-min);
    display: flex;
    align-items: center;
    justify-content: center;
}

.action-sheet-button:last-child {
    border-bottom: none;
}

.action-sheet-button.primary {
    color: var(--color-primary);
    font-weight: var(--font-weight-semibold);
}

.action-sheet-button.destructive {
    color: var(--color-error);
}

.action-sheet-button.cancel {
    color: var(--color-text-secondary);
}

.action-sheet-button:active {
    background: var(--color-bg-secondary);
}

/* Modal */
.modal {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0.9);
    opacity: 0;
    transition: opacity var(--transition-base), transform var(--transition-base);
    z-index: var(--z-modal);
    background: var(--color-bg);
    border-radius: var(--radius-xl);
    min-width: 280px;
    max-width: calc(100% - var(--spacing-xl));
    max-height: calc(100% - var(--spacing-xl));
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-xl);
}

.modal.visible {
    transform: translate(-50%, -50%) scale(1);
    opacity: 1;
}

.modal-header {
    padding: var(--spacing-lg);
    text-align: center;
}

.modal-title {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-semibold);
    color: var(--color-text);
}

.modal-content {
    padding: 0 var(--spacing-lg) var(--spacing-lg);
    text-align: center;
    color: var(--color-text-secondary);
    flex: 1;
    overflow-y: auto;
}

.modal-actions {
    display: flex;
    border-top: 1px solid var(--color-border);
}

.modal-button {
    flex: 1;
    padding: var(--spacing-md);
    text-align: center;
    font-size: var(--font-size-base);
    color: var(--color-text);
    border-right: 1px solid var(--color-border);
    min-height: var(--touch-target-min);
}

.modal-button:last-child {
    border-right: none;
}

.modal-button.primary {
    color: var(--color-primary);
    font-weight: var(--font-weight-semibold);
}

.modal-button:active {
    background: var(--color-bg-secondary);
}

/* Toast */
.toast {
    position: fixed;
    bottom: calc(var(--spacing-xl) + var(--safe-area-bottom));
    left: 50%;
    transform: translateX(-50%) translateY(calc(100% + var(--spacing-xl)));
    transition: transform var(--transition-base);
    z-index: var(--z-toast);
    background: var(--color-text);
    color: var(--color-bg);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-lg);
    font-size: var(--font-size-sm);
    max-width: calc(100% - var(--spacing-xl));
    box-shadow: var(--shadow-lg);
}

.toast.visible {
    transform: translateX(-50%) translateY(0);
}

.toast.success {
    background: var(--color-success);
}

.toast.error {
    background: var(--color-error);
}

.toast.warning {
    background: var(--color-warning);
}

/* Loading */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: var(--z-loading);
    opacity: 0;
    transition: opacity var(--transition-fast);
    pointer-events: none;
}

.loading-overlay.visible {
    opacity: 1;
    pointer-events: auto;
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top-color: #ffffff;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.loading-text {
    margin-top: var(--spacing-md);
    color: #ffffff;
    font-size: var(--font-size-sm);
}