:root {
    --bg: #f5f5f7;
    --panel: #ffffff;
    --border: #d0d0d8;
    --primary: #4a6cf7;
    --primary-hover: #3a56d4;
    --danger: #e74c3c;
    --text: #1e1e2f;
    --text-light: #6e6e7e;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    --radius: 10px;
    --font: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    height: 100vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}
header {
    background: var(--panel);
    border-bottom: 1px solid var(--border);
    padding: 8px 16px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    box-shadow: var(--shadow);
    z-index: 10;
    flex-shrink: 0;
}
header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-right: 8px;
    white-space: nowrap;
    background: linear-gradient(135deg, #4a6cf7, #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.toolbar { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; flex: 1; }
.size-control { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }
.size-control label { font-size: 0.85rem; color: var(--text-light); }
.size-control input[type="number"] { width: 60px; padding: 6px 8px; border: 1px solid var(--border); border-radius: 6px; font-size: 0.9rem; text-align: center; }
.size-control button { padding: 6px 12px; border: 1px solid var(--border); background: #f0f0f4; border-radius: 6px; cursor: pointer; font-size: 0.85rem; transition: all 0.15s; white-space: nowrap; }
.size-control button:hover { background: #e2e2e8; }
.size-control button.primary { background: var(--primary); color: white; border-color: var(--primary); font-weight: 600; }
.size-control button.primary:hover { background: var(--primary-hover); }
.actions { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-left: auto; }
.actions button { padding: 7px 14px; border: 1px solid var(--border); background: #f8f8fc; border-radius: 6px; cursor: pointer; font-size: 0.85rem; transition: all 0.15s; white-space: nowrap; font-weight: 500; }
.actions button:hover { background: #e8e8f0; }
.actions button.danger { color: var(--danger); border-color: #f5c6c6; }
.actions button.danger:hover { background: #fde8e8; }
.actions label { display: flex; align-items: center; gap: 4px; font-size: 0.8rem; color: var(--text-light); cursor: pointer; white-space: nowrap; }
.actions input[type="checkbox"] { width: 16px; height: 16px; cursor: pointer; }
.tab-bar {
    background: #f0f0f4;
    border-bottom: 1px solid var(--border);
    padding: 0 8px;
    display: flex;
    align-items: center;
    overflow-x: auto;
    white-space: nowrap;
    flex-shrink: 0;
    box-shadow: 0 2px 4px rgba(0,0,0,0.04);
    min-height: 40px;
}
.tab {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 12px;
    cursor: pointer;
    border: none;
    background: transparent;
    font-size: 0.9rem;
    color: var(--text-light);
    border-bottom: 2px solid transparent;
    transition: all 0.15s;
    white-space: nowrap;
    flex-shrink: 0;
}
.tab:hover { background: #e8e8f0; }
.tab.active { background: var(--panel); color: var(--text); border-bottom-color: var(--primary); font-weight: 500; }
.tab-close { cursor: pointer; font-size: 1rem; line-height: 1; padding: 0 4px; border-radius: 4px; color: #999; }
.tab-close:hover { background: #ddd; color: #333; }
main { flex: 1; display: flex; overflow: hidden; gap: 0; min-height: 0; }
.panel {
    background: var(--panel);
    padding: 14px;
    overflow-y: auto;
    border-right: 1px solid var(--border);
    width: 230px;
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    gap: 14px;
}
.panel.left { border-right: 1px solid var(--border); }
.panel h2 { font-size: 0.95rem; font-weight: 600; color: var(--text-light); text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 4px; }
.current-color { display: flex; align-items: center; gap: 8px; }
.current-color input[type="color"] {
    width: 50px;
    height: 38px;
    border: 1px solid var(--border);
    border-radius: 6px;
    cursor: pointer;
    background: white;
    padding: 2px;
    flex-shrink: 0;          /* 禁止颜色选择器被压缩 */
}
.current-color input[type="text"].hex-input {
    width: 80px;              /* 固定宽度，不挤压颜色选择器 */
    flex-shrink: 0;
    padding: 7px 10px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.9rem;
    font-family: monospace;
    text-transform: uppercase;
}
.default-colors { display: grid; grid-template-columns: repeat(8, 1fr); gap: 6px; }
.default-colors .color-swatch { aspect-ratio: 1; border-radius: 5px; cursor: pointer; border: 2px solid transparent; transition: all 0.12s; box-shadow: 0 1px 4px rgba(0,0,0,0.12); position: relative; }
.default-colors .color-swatch:hover { transform: scale(1.12); border-color: #333; z-index: 2; }
.default-colors .color-swatch.active { border-color: #1e1e2f; box-shadow: 0 0 0 2px white, 0 0 0 4px #1e1e2f; }
.default-colors .color-swatch.transparent {
    background: repeating-linear-gradient(45deg, #fff, #fff 4px, #ccc 4px, #ccc 8px);
}
.default-colors .color-swatch.transparent::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    width: 100%;
    height: 2px;
    background: #ff0000;
    transform: translateY(-50%) rotate(45deg);
}
.tool-buttons { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; }
.tool-buttons button { padding: 8px 6px; border: 1px solid var(--border); background: #f8f8fc; border-radius: 6px; cursor: pointer; font-size: 0.82rem; font-weight: 500; transition: all 0.15s; text-align: center; }
.tool-buttons button:hover { background: #e8e8f0; }
.tool-buttons button.active { background: var(--primary); color: white; border-color: var(--primary); box-shadow: 0 2px 6px rgba(74,108,247,0.3); }
.tool-settings {
    display: none;
    flex-direction: column;
    gap: 4px;
    margin-top: 6px;
    font-size: 0.85rem;
    color: var(--text-light);
}
.tool-settings.active {
    display: flex;
}
.tool-settings label {
    display: flex;
    align-items: center;
    gap: 6px;
}
.tool-settings input[type="number"] {
    width: 60px;
    padding: 4px 6px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.9rem;
    text-align: center;
}
.tool-settings input[type="checkbox"] {
    width: 16px;
    height: 16px;
    cursor: pointer;
}
.selection-actions, .batch-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
.selection-actions button, .batch-actions button { padding: 8px 6px; border: 1px solid var(--border); background: #f8f8fc; border-radius: 6px; cursor: pointer; font-size: 0.8rem; transition: all 0.15s; font-weight: 500; }
.selection-actions button:hover, .batch-actions button:hover { background: #e8e8f0; }
.batch-actions button.paint { background: #e8f0fe; border-color: #b8c8f0; color: #2a4a8a; }
.batch-actions button.paint:hover { background: #d8e4fc; }
.batch-actions button.delete { background: #fde8e8; border-color: #f5c6c6; color: #a03030; }
.batch-actions button.delete:hover { background: #fbd0d0; }
.status { display: flex; flex-direction: column; gap: 4px; font-size: 0.78rem; color: var(--text-light); border-top: 1px solid var(--border); padding-top: 10px; margin-top: auto; }
.status span { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

/* ========== Canvas 区域 ========== */
.canvas-wrap {
    flex: 1;
    min-width: 0;
    background: #e9e9ef;
    overflow: auto;
    padding: 16px;
    position: relative;
}
#canvasSpacer {
    display: block;
    width: 0;
    height: 0;
}
#canvas {
    position: absolute;
    top: 0;
    left: 0;
    background: white;
    border-radius: 4px;
    box-shadow: none;
    touch-action: none;
    cursor: crosshair;
    display: block;
    flex-shrink: 0;
}

/* ========== 缩放控件 - 固定于视口底部 ========== */
.zoom-controls {
    position: fixed;
    bottom: 12px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 100;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 4px 12px;
    display: flex;
    align-items: center;
    gap: 8px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.2);
    white-space: nowrap;
    font-size: 0.9rem;
    pointer-events: auto;
}
.zoom-controls button {
    background: transparent;
    border: none;
    font-size: 1.2rem;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.15s;
    color: var(--text);
}
.zoom-controls button:hover { background: rgba(0, 0, 0, 0.08); }
.zoom-controls button:active { background: rgba(0, 0, 0, 0.15); }
.zoom-controls input[type="range"] {
    width: 120px;
    height: 4px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--border);
    border-radius: 2px;
    outline: none;
    cursor: pointer;
}
.zoom-controls input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    border: 2px solid white;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}
.zoom-controls input[type="range"]::-moz-range-thumb {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    border: 2px solid white;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}
.zoom-controls #zoomPercent {
    min-width: 48px;
    text-align: center;
    font-weight: 500;
    font-size: 0.9rem;
    color: var(--text);
}
.zoom-controls #zoomInput {
    width: 60px;
    padding: 4px 6px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.9rem;
    text-align: center;
    background: white;
    color: var(--text);
}
.zoom-controls #zoomInput:focus { outline: none; border-color: var(--primary); }
.zoom-controls #zoomResetBtn { font-size: 1rem; }

input[type="file"] { display: none; }
.save-indicator { display: inline-block; width: 10px; height: 10px; border-radius: 50%; margin-left: 6px; flex-shrink: 0; }
.save-indicator.saved { background: #2ecc71; }
.save-indicator.dirty { background: #f39c12; }

/* ========== 模态框 ========== */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 200;
}
.modal-content {
    background: white;
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.3);
    width: 320px;
    max-width: 90%;
}
.modal-content h3 { margin-bottom: 12px; }
.modal-content p { margin-bottom: 8px; }
.modal-content .import-fields {
    display: flex;
    gap: 12px;
    margin: 12px 0;
}
.modal-content .import-fields label {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.9rem;
}
.modal-content .import-fields input {
    width: 70px;
    padding: 6px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.9rem;
    text-align: center;
}
.modal-content .import-ratio {
    margin: 8px 0;
}
.modal-content .import-ratio label {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.9rem;
    cursor: pointer;
}
.modal-content .hint {
    color: var(--text-light);
    font-size: 0.8rem;
    margin-bottom: 12px;
}
.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 8px;
}
.modal-actions button {
    padding: 8px 16px;
    border: 1px solid var(--border);
    background: #f8f8fc;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
}
.modal-actions button.primary {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}
.modal-actions button.primary:hover { background: var(--primary-hover); }

/* ========== 响应式 ========== */
@media (max-width: 768px) {
    body { overflow: auto; height: auto; }
    header { padding: 8px; gap: 6px; }
    header h1 { font-size: 1.2rem; }
    .toolbar { gap: 6px; }
    .size-control input[type="number"] { width: 48px; padding: 5px 4px; }
    .actions button { padding: 6px 10px; font-size: 0.75rem; }
    main { flex-direction: column; overflow: visible; }
    .panel {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--border);
        flex-direction: row;
        flex-wrap: wrap;
        gap: 10px;
        padding: 10px;
        max-height: none;
        overflow-y: visible;
    }
    .panel.left { order: 2; }
    .canvas-wrap {
        order: 1;
        height: 55vh;
        min-height: 300px;
        padding: 12px;
    }
    .panel h2 { font-size: 0.8rem; margin-bottom: 2px; }
    .default-colors { grid-template-columns: repeat(12, 1fr); }
    .tool-buttons { grid-template-columns: repeat(3, 1fr); }
    .selection-actions, .batch-actions { grid-template-columns: repeat(4, 1fr); }
    .status { flex-direction: row; gap: 12px; border-top: none; padding-top: 0; }
    .zoom-controls input[type="range"] { width: 80px; }
    .zoom-controls { bottom: 8px; padding: 4px 10px; gap: 4px; font-size: 0.8rem; }
    .zoom-controls button { width: 24px; height: 24px; font-size: 1rem; }
    .zoom-controls #zoomInput { width: 50px; font-size: 0.8rem; }
    .current-color input[type="text"].hex-input { width: 60px; } /* 移动端稍窄 */
}