/**
 * Merge System Tool - Zhween Classroom Tools
 *
 * Document merge tool for creating personalized certificates and badges
 * Supports RTL languages and dark mode
 */

/* ==========================================================================
   CSS Custom Properties
   ========================================================================== */

:root {
    /* Brand Colors */
    --merge-primary: #15aebf;
    --merge-primary-hover: #0e9aa8;
    --merge-primary-light: rgba(21, 174, 191, 0.1);

    /* Surface Colors */
    --merge-bg: #f8fafc;
    --merge-surface: #ffffff;

    /* Text Colors */
    --merge-text: #1e293b;
    --merge-text-secondary: #64748b;
    --merge-text-muted: #94a3b8;

    /* Border & Dividers */
    --merge-border: #e2e8f0;
    --merge-border-light: #f1f5f9;

    /* Feedback Colors */
    --merge-success: #22c55e;
    --merge-success-light: rgba(34, 197, 94, 0.1);
    --merge-danger: #ef4444;
    --merge-danger-light: rgba(239, 68, 68, 0.1);

    /* Shadows */
    --merge-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
    --merge-shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);

    /* Spacing */
    --merge-panel-width: 280px;
    --merge-gap: 1rem;
    --merge-radius: 12px;
    --merge-radius-sm: 8px;

    /* Transitions */
    --merge-transition: 150ms ease;
}

/* Dark Mode */
@media (prefers-color-scheme: dark) {
    :root {
        --merge-bg: #0f172a;
        --merge-surface: #1e293b;
        --merge-text: #f1f5f9;
        --merge-text-secondary: #94a3b8;
        --merge-text-muted: #64748b;
        --merge-border: #334155;
        --merge-border-light: #1e293b;
        --merge-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
        --merge-shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.4);
    }
}

/* ==========================================================================
   Base Container
   ========================================================================== */

.merge {
    display: flex;
    flex-direction: column;
    background: var(--merge-bg);
    color: var(--merge-text);
    font-family: 'Nunito', -apple-system, BlinkMacSystemFont, sans-serif;
    overflow-x: hidden;
}

/* ==========================================================================
   Body Layout
   ========================================================================== */

.merge__body {
    display: flex;
    flex: 1 1 auto;
    gap: var(--merge-gap);
    padding: var(--merge-gap);
    overflow: auto;
}

/* ==========================================================================
   Left Panel
   ========================================================================== */

.merge__panel {
    width: var(--merge-panel-width);
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    overflow-y: auto;
}

/* ==========================================================================
   Sections
   ========================================================================== */

.merge__section {
    background: var(--merge-surface);
    border-radius: var(--merge-radius);
    padding: 0.75rem;
    border: 1px solid var(--merge-border);
}

.merge__section--actions {
    margin-top: auto;
}

.merge__section-title {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--merge-text);
    margin: 0 0 0.625rem 0;
}

.merge__step-badge {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
    background: var(--merge-primary);
    color: white;
    border-radius: 50%;
    font-size: 0.65rem;
    font-weight: 700;
}

/* ==========================================================================
   Upload Zone
   ========================================================================== */

.merge__upload {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 0.75rem;
    border: 2px dashed var(--merge-border);
    border-radius: var(--merge-radius-sm);
    background: var(--merge-border-light);
    cursor: pointer;
    transition: all var(--merge-transition);
    text-align: center;
}

.merge__upload:hover,
.merge__upload--dragover {
    border-color: var(--merge-primary);
    background: var(--merge-primary-light);
}

.merge__upload--small {
    padding: 0.625rem;
}

.merge__upload-icon {
    color: var(--merge-text-muted);
    margin-bottom: 0.25rem;
    transition: color var(--merge-transition);
}

.merge__upload:hover .merge__upload-icon {
    color: var(--merge-primary);
}

.merge__upload-text {
    margin: 0;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--merge-text);
}

.merge__upload-hint {
    font-size: 0.65rem;
    color: var(--merge-text-muted);
    margin-top: 0.125rem;
}

/* ==========================================================================
   Input Methods
   ========================================================================== */

.merge__methods {
    display: flex;
    gap: 0.375rem;
    margin-bottom: 0.5rem;
}

.merge__method {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.25rem;
    padding: 0.375rem;
    font-size: 0.7rem;
    font-weight: 600;
    font-family: inherit;
    color: var(--merge-text-secondary);
    background: var(--merge-border-light);
    border: 1px solid var(--merge-border);
    border-radius: var(--merge-radius-sm);
    cursor: pointer;
    transition: all var(--merge-transition);
}

.merge__method:hover {
    border-color: var(--merge-primary);
    color: var(--merge-primary);
}

.merge__method--active {
    background: var(--merge-primary-light);
    border-color: var(--merge-primary);
    color: var(--merge-primary);
}

.merge__method svg {
    flex-shrink: 0;
}

/* ==========================================================================
   Textarea
   ========================================================================== */

.merge__textarea {
    width: 100%;
    min-height: 70px;
    padding: 0.5rem;
    font-size: 0.8rem;
    font-family: inherit;
    line-height: 1.4;
    color: var(--merge-text);
    background: var(--merge-surface);
    border: 1px solid var(--merge-border);
    border-radius: var(--merge-radius-sm);
    resize: vertical;
    transition: border-color var(--merge-transition), box-shadow var(--merge-transition);
}

.merge__textarea:focus {
    outline: none;
    border-color: var(--merge-primary);
    box-shadow: 0 0 0 3px var(--merge-primary-light);
}

.merge__textarea::placeholder {
    color: var(--merge-text-muted);
}

/* ==========================================================================
   Actions
   ========================================================================== */

.merge__actions {
    display: flex;
    gap: 0.375rem;
    margin-top: 0.5rem;
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.merge__btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.375rem;
    padding: 0.5rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 600;
    font-family: inherit;
    border: none;
    border-radius: var(--merge-radius-sm);
    cursor: pointer;
    transition: all var(--merge-transition);
}

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

.merge__btn--primary {
    background: var(--merge-primary);
    color: white;
}

.merge__btn--primary:hover:not(:disabled) {
    background: var(--merge-primary-hover);
    transform: translateY(-1px);
}

.merge__btn--secondary {
    background: var(--merge-border-light);
    color: var(--merge-text);
}

.merge__btn--secondary:hover:not(:disabled) {
    background: var(--merge-border);
}

.merge__btn--ghost {
    background: transparent;
    color: var(--merge-text-secondary);
    padding: 0.5rem 0.75rem;
}

.merge__btn--ghost:hover:not(:disabled) {
    background: var(--merge-border-light);
    color: var(--merge-text);
}

.merge__btn--danger {
    background: var(--merge-danger-light);
    color: var(--merge-danger);
}

.merge__btn--danger:hover:not(:disabled) {
    background: var(--merge-danger);
    color: white;
}

.merge__btn--full {
    width: 100%;
}

.merge__btn + .merge__btn {
    margin-top: 0.375rem;
}

/* ==========================================================================
   Status
   ========================================================================== */

.merge__status {
    display: none;
    padding: 0.5rem 0.625rem;
    margin-top: 0.5rem;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--merge-radius-sm);
}

.merge__status--visible {
    display: block;
}

.merge__status--info {
    background: var(--merge-primary-light);
    color: var(--merge-primary);
}

.merge__status--success {
    background: var(--merge-success-light);
    color: var(--merge-success);
}

/* ==========================================================================
   Main Content Area
   ========================================================================== */

.merge__main {
    flex: 1 1 auto;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    min-height: 0;
}

/* ==========================================================================
   Empty State
   ========================================================================== */

.merge__empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
    background: var(--merge-surface);
    border-radius: var(--merge-radius);
    border: 1px solid var(--merge-border);
    text-align: center;
    flex: 1;
}

.merge__empty svg {
    color: var(--merge-text-muted);
    margin-bottom: 1rem;
}

.merge__empty h3 {
    margin: 0 0 0.5rem;
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--merge-text);
}

.merge__empty p {
    margin: 0;
    font-size: 0.875rem;
    color: var(--merge-text-secondary);
}

/* ==========================================================================
   Canvas Container
   ========================================================================== */

.merge__canvas-wrap {
    position: relative;
    background: var(--merge-surface);
    border-radius: var(--merge-radius);
    border: 1px solid var(--merge-border);
    overflow: auto;
    max-height: 550px;
}

.merge__canvas-wrap canvas {
    display: block;
    margin: 0 auto;
    cursor: crosshair;
    background: white;
    box-shadow: var(--merge-shadow);
    touch-action: none;
    -webkit-user-select: none;
    user-select: none;
}

/* ==========================================================================
   Canvas Toolbar
   ========================================================================== */

.merge__toolbar {
    position: absolute;
    top: 1rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.375rem;
    background: var(--merge-surface);
    border-radius: var(--merge-radius-sm);
    box-shadow: var(--merge-shadow-lg);
    border: 1px solid var(--merge-border);
    z-index: 10;
}

.merge__tool {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    padding: 0;
    background: transparent;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    color: var(--merge-text-secondary);
    transition: all var(--merge-transition);
}

.merge__tool:hover {
    background: var(--merge-border-light);
    color: var(--merge-primary);
}

.merge__tool--danger:hover {
    background: var(--merge-danger-light);
    color: var(--merge-danger);
}

.merge__tool-divider {
    width: 1px;
    height: 24px;
    background: var(--merge-border);
    margin: 0 0.25rem;
}

/* ==========================================================================
   Settings Panel
   ========================================================================== */

.merge__settings {
    background: var(--merge-surface);
    border-radius: var(--merge-radius);
    border: 1px solid var(--merge-border);
    padding: 1rem;
}

.merge__settings-title {
    margin: 0 0 1rem;
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--merge-text);
}

.merge__settings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 1rem;
}

.merge__settings-actions {
    display: flex;
    gap: 0.5rem;
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--merge-border);
}

/* ==========================================================================
   Form Fields
   ========================================================================== */

.merge__field {
    display: flex;
    flex-direction: column;
    gap: 0.375rem;
}

.merge__field label {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--merge-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.025em;
}

.merge__field select,
.merge__field input[type="text"] {
    width: 100%;
    padding: 0.5rem 0.625rem;
    font-size: 0.875rem;
    font-family: inherit;
    color: var(--merge-text);
    background: var(--merge-surface);
    border: 1px solid var(--merge-border);
    border-radius: 6px;
    transition: border-color var(--merge-transition);
}

.merge__field select:focus,
.merge__field input[type="text"]:focus {
    outline: none;
    border-color: var(--merge-primary);
}

.merge__field input[type="color"] {
    width: 100%;
    height: 36px;
    padding: 2px;
    border: 1px solid var(--merge-border);
    border-radius: 6px;
    cursor: pointer;
}

.merge__range-wrap {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.merge__range-wrap input[type="range"] {
    flex: 1;
    height: 4px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--merge-border);
    border-radius: 2px;
    cursor: pointer;
}

.merge__range-wrap input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    background: var(--merge-primary);
    border-radius: 50%;
    cursor: pointer;
}

.merge__range-wrap input[type="range"]::-moz-range-thumb {
    width: 16px;
    height: 16px;
    background: var(--merge-primary);
    border: none;
    border-radius: 50%;
    cursor: pointer;
}

.merge__range-value {
    flex-shrink: 0;
    min-width: 45px;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--merge-primary);
    text-align: right;
}

/* ==========================================================================
   Results Area
   ========================================================================== */

.merge__results {
    background: var(--merge-surface);
    border-radius: var(--merge-radius);
    border: 1px solid var(--merge-border);
    padding: 1rem;
}

.merge__results-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 1rem;
}

.merge__results-header h3 {
    margin: 0;
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--merge-text);
}

.merge__file-list {
    display: grid;
    gap: 0.5rem;
    max-height: 300px;
    overflow-y: auto;
}

.merge__file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    padding: 0.625rem 0.75rem;
    background: var(--merge-border-light);
    border-radius: 6px;
    font-size: 0.875rem;
}

.merge__file-item span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--merge-text);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.merge__file-item a {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: var(--merge-primary);
    color: white;
    border-radius: 6px;
    text-decoration: none;
    transition: background var(--merge-transition);
}

.merge__file-item a:hover {
    background: var(--merge-primary-hover);
}

/* ==========================================================================
   Modal
   ========================================================================== */

.merge__modal {
    position: fixed;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 1rem;
}

.merge__modal[hidden] {
    display: none;
}

.merge__modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
}

.merge__modal-content {
    position: relative;
    max-width: 400px;
    width: 100%;
    padding: 1.5rem;
    background: var(--merge-surface);
    border-radius: var(--merge-radius);
    box-shadow: var(--merge-shadow-lg);
    animation: merge-modal-in 0.2s ease;
}

@keyframes merge-modal-in {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.merge__modal-content h3 {
    margin: 0 0 0.25rem;
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--merge-text);
}

.merge__modal-content > p {
    margin: 0 0 1.25rem;
    font-size: 0.875rem;
    color: var(--merge-text-secondary);
}

.merge__modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 0.5rem;
    margin-top: 1.25rem;
}

/* ==========================================================================
   Responsive Design
   ========================================================================== */

@media (max-width: 900px) {
    .merge__body {
        flex-direction: column;
    }

    .merge__panel {
        width: 100%;
        flex-direction: row;
        flex-wrap: wrap;
        gap: 0.5rem;
    }

    .merge__section {
        flex: 1 1 calc(50% - 0.25rem);
        min-width: 200px;
    }

    .merge__section--actions {
        flex-basis: 100%;
        margin-top: 0;
    }

    .merge__empty,
    .merge__canvas-wrap {
        min-height: 250px;
    }
}

@media (max-width: 600px) {
    :root {
        --merge-panel-width: 100%;
        --merge-gap: 0.75rem;
    }

    .merge__section {
        flex-basis: 100%;
    }

    .merge__methods {
        flex-direction: column;
    }

    .merge__settings-grid {
        grid-template-columns: 1fr;
    }

    .merge__results-header {
        flex-direction: column;
        align-items: stretch;
    }

    .merge__toolbar {
        position: static;
        transform: none;
        margin: 0.5rem;
        justify-content: center;
    }
}

/* ==========================================================================
   Reduced Motion
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
    .merge__modal-content {
        animation: none;
    }

    .merge__btn:hover,
    .merge__tool:hover,
    .merge__upload:hover {
        transform: none;
    }
}

/* ==========================================================================
   RTL Support
   ========================================================================== */

[dir="rtl"] .merge__section-title {
    flex-direction: row-reverse;
}

[dir="rtl"] .merge__method {
    flex-direction: row-reverse;
}

[dir="rtl"] .merge__btn {
    flex-direction: row-reverse;
}

[dir="rtl"] .merge__range-value {
    text-align: left;
}

[dir="rtl"] .merge__file-item {
    flex-direction: row-reverse;
}

/* ==========================================================================
   Print Styles
   ========================================================================== */

@media print {
    .merge__panel,
    .merge__modal,
    .merge__toolbar {
        display: none !important;
    }

    .merge__body {
        display: block;
        padding: 0;
    }

    .merge__main {
        page-break-inside: avoid;
    }
}