:root {
    --bg: #f0f2f5;
    --panel-bg: #ffffff;
    --border: #e0e0e0;
    --text: #333333;
    --text-secondary: #666666;
    --accent: #4a6cf7;
    --accent-hover: #3b5de7;
    --danger: #e74c3c;
    --danger-hover: #c0392b;
    --success: #27ae60;
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --radius: 10px;
    --radius-sm: 6px;
    --transition: 0.2s ease;
    --font-mono: 'SF Mono', 'Cascadia Code', 'Consolas', monospace;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

/* Header */
.app-header {
    background: var(--panel-bg);
    border-bottom: 1px solid var(--border);
    padding: 14px 28px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.04);
    position: sticky;
    top: 0;
    z-index: 100;
}
.app-header .logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    color: var(--accent);
    letter-spacing: -0.5px;
}
.app-header .logo svg {
    width: 32px;
    height: 32px;
}
.header-actions {
    display: flex;
    gap: 10px;
}

/* Main Layout */
.app-container {
    display: flex;
    height: calc(100vh - 65px);
    gap: 0;
}

/* Left Panel */
.left-panel {
    width: 440px;
    min-width: 440px;
    background: var(--panel-bg);
    border-right: 1px solid var(--border);
    overflow-y: auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 18px;
    box-shadow: 2px 0 8px rgba(0, 0, 0, 0.03);
    z-index: 10;
}
.left-panel::-webkit-scrollbar {
    width: 5px;
}
.left-panel::-webkit-scrollbar-thumb {
    background: #d0d0d0;
    border-radius: 10px;
}

/* Right Panel - Preview */
.right-panel {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: #e8eaef;
    overflow: hidden;
}
.preview-header {
    padding: 14px 20px;
    background: #fafafa;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    flex-shrink: 0;
}
.preview-header .info {
    font-size: 13px;
    color: var(--text-secondary);
}
.preview-area {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    overflow: auto;
    position: relative;
}
.preview-area .empty-state {
    text-align: center;
    color: #bbb;
    user-select: none;
}
.preview-area .empty-state svg {
    width: 80px;
    height: 80px;
    margin-bottom: 16px;
    opacity: 0.5;
}
.preview-area .empty-state p {
    font-size: 15px;
    margin: 4px 0;
}
.preview-canvas-wrapper {
    position: relative;
    display: inline-block;
    box-shadow: var(--shadow-lg);
    border-radius: 4px;
    background: #fff;
    max-width: 100%;
    max-height: 100%;
}
.preview-canvas-wrapper img,
.preview-canvas-wrapper canvas {
    display: block;
    max-width: 100%;
    max-height: 70vh;
    border-radius: 4px;
    object-fit: contain;
}
.preview-canvas-wrapper canvas {
    transition: cursor 0.15s;
}
.preview-badge {
    position: absolute;
    top: 10px;
    right: 10px;
    background: var(--accent);
    color: #fff;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.5px;
    pointer-events: none;
}

/* Image list for multiple uploads */
.image-thumb-list {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    padding: 4px 0;
    max-height: 100px;
    overflow-y: auto;
}
.image-thumb {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-sm);
    border: 2px solid transparent;
    cursor: pointer;
    object-fit: cover;
    transition: var(--transition);
    flex-shrink: 0;
}
.image-thumb:hover {
    border-color: #bbb;
}
.image-thumb.active {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(74, 108, 247, 0.15);
}
.image-thumb-count {
    font-size: 11px;
    color: var(--text-secondary);
    text-align: center;
    margin-top: 2px;
}

/* Section titles */
.section-title {
    font-size: 13px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-secondary);
    margin-bottom: 4px;
    display: flex;
    align-items: center;
    gap: 6px;
}
.section-title::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--border);
}

/* Upload area */
.upload-zone {
    border: 2px dashed #d0d5e0;
    border-radius: var(--radius);
    padding: 24px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    background: #fafbfc;
    position: relative;
}
.upload-zone:hover {
    border-color: var(--accent);
    background: #f5f7ff;
}
.upload-zone.drag-over {
    border-color: var(--accent);
    background: #eef1ff;
    box-shadow: 0 0 0 4px rgba(74, 108, 247, 0.1);
}
.upload-zone .icon {
    font-size: 36px;
    margin-bottom: 8px;
}
.upload-zone p {
    font-size: 13px;
    color: var(--text-secondary);
    margin: 2px 0;
}
.upload-zone .btn-browse {
    display: inline-block;
    margin-top: 8px;
    padding: 8px 18px;
    background: var(--accent);
    color: #fff;
    border-radius: 20px;
    font-size: 13px;
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}
.upload-zone .btn-browse:hover {
    background: var(--accent-hover);
}
.upload-zone input[type="file"] {
    display: none;
}

/* Form controls */
.form-group {
    display: flex;
    flex-direction: column;
    gap: 4px;
}
.form-group label {
    font-size: 12px;
    font-weight: 600;
    color: var(--text-secondary);
    letter-spacing: 0.3px;
}
.form-row {
    display: flex;
    gap: 10px;
    align-items: flex-end;
}
.form-row .form-group {
    flex: 1;
}
select,
input[type="text"],
input[type="number"],
input[type="color"],
textarea {
    padding: 9px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 13px;
    font-family: inherit;
    transition: var(--transition);
    background: #fafbfc;
    color: var(--text);
    width: 100%;
    resize: vertical;
}
select:focus,
input[type="text"]:focus,
input[type="number"]:focus,
textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(74, 108, 247, 0.08);
    background: #fff;
}
input[type="color"] {
    padding: 4px 6px;
    width: 42px;
    height: 38px;
    cursor: pointer;
    border-radius: var(--radius-sm);
}
input[type="range"] {
    width: 100%;
    accent-color: var(--accent);
    cursor: pointer;
}
/* Inline value edit inputs (click slider labels to edit) */
.inline-value-input {
    width: 58px;
    text-align: right;
    font-family: var(--font-mono);
    font-size: 12px;
    font-weight: 600;
    color: var(--accent);
    padding: 2px 4px;
    border: 1.5px solid var(--accent);
    border-radius: 4px;
    background: #fff;
    outline: none;
}
.inline-value-input:focus {
    box-shadow: 0 0 0 3px rgba(74, 108, 247, 0.15);
}
.range-with-value {
    display: flex;
    align-items: center;
    gap: 8px;
}
.range-with-value span {
    font-size: 12px;
    font-weight: 600;
    color: var(--accent);
    min-width: 38px;
    text-align: right;
    font-family: var(--font-mono);
}

/* Position grid */
.position-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);
    gap: 3px;
    width: 120px;
    height: 120px;
    background: #e8eaef;
    border-radius: var(--radius-sm);
    padding: 3px;
    flex-shrink: 0;
}
.position-cell {
    background: #fff;
    border-radius: 3px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 10px;
    color: #ccc;
    font-weight: 600;
    user-select: none;
}
.position-cell:hover {
    background: #eef1ff;
    color: var(--accent);
}
.position-cell.active {
    background: var(--accent);
    color: #fff;
    box-shadow: 0 2px 6px rgba(74, 108, 247, 0.3);
}

/* Buttons */
.btn {
    padding: 10px 18px;
    border-radius: var(--radius-sm);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: var(--transition);
    letter-spacing: 0.3px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    white-space: nowrap;
}
.btn-primary {
    background: var(--accent);
    color: #fff;
}
.btn-primary:hover {
    background: var(--accent-hover);
    box-shadow: 0 4px 12px rgba(74, 108, 247, 0.3);
}
.btn-outline {
    background: #fff;
    color: var(--accent);
    border: 1.5px solid var(--accent);
}
.btn-outline:hover {
    background: #f5f7ff;
}
.btn-danger {
    background: #fff;
    color: var(--danger);
    border: 1.5px solid var(--danger);
}
.btn-danger:hover {
    background: #fff5f5;
}
.btn-sm {
    padding: 6px 12px;
    font-size: 11px;
    border-radius: 16px;
}
.btn-xs {
    padding: 3px 8px;
    font-size: 10px;
    border-radius: 12px;
}
.btn-success {
    background: var(--success);
    color: #fff;
}
.btn-success:hover {
    background: #219a52;
}
.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

/* Template card */
.template-card {
    border: 1.5px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 10px 12px;
    cursor: pointer;
    transition: var(--transition);
    background: #fafbfc;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
}
.template-card:hover {
    border-color: var(--accent);
    background: #f8f9ff;
}
.template-card.active {
    border-color: var(--accent);
    background: #eef2ff;
    box-shadow: 0 0 0 3px rgba(74, 108, 247, 0.08);
}
.template-card .tpl-info {
    flex: 1;
    min-width: 0;
}
.template-card .tpl-name {
    font-weight: 600;
    font-size: 13px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.template-card .tpl-preview {
    font-size: 11px;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.template-actions {
    display: flex;
    gap: 3px;
    flex-shrink: 0;
}

/* Template editor modal */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 200;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: fadeIn 0.2s ease;
}
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}
.modal {
    background: #fff;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    width: 520px;
    max-width: 95vw;
    max-height: 85vh;
    overflow-y: auto;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.modal h3 {
    font-size: 17px;
    letter-spacing: -0.3px;
}
.modal .modal-actions {
    display: flex;
    gap: 8px;
    justify-content: flex-end;
}
.template-row-item {
    display: flex;
    gap: 6px;
    align-items: center;
    padding: 8px;
    background: #f9fafb;
    border-radius: var(--radius-sm);
    flex-wrap: wrap;
}
.template-row-item input {
    flex: 1;
    min-width: 80px;
    padding: 7px 10px;
    font-size: 12px;
}
.badge {
    display: inline-block;
    padding: 3px 8px;
    border-radius: 10px;
    font-size: 10px;
    font-weight: 600;
    letter-spacing: 0.5px;
    background: #eef2ff;
    color: var(--accent);
}

/* Toast */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    background: #333;
    color: #fff;
    padding: 10px 20px;
    border-radius: 20px;
    font-size: 13px;
    z-index: 999;
    animation: slideUp 0.3s ease;
    pointer-events: none;
    box-shadow: var(--shadow-lg);
}
@keyframes slideUp {
    from {
        transform: translateX(-50%) translateY(20px);
        opacity: 0;
    }
    to {
        transform: translateX(-50%) translateY(0);
        opacity: 1;
    }
}

/* Responsive */
@media (max-width: 900px) {
    .app-container {
        flex-direction: column;
    }
    .left-panel {
        width: 100%;
        min-width: 100%;
        max-height: 45vh;
        flex-shrink: 0;
    }
    .right-panel {
        flex: 1;
    }
    .preview-canvas-wrapper img,
    .preview-canvas-wrapper canvas {
        max-height: 40vh;
    }
}