:root {
        --bg: #f5f5f5;
        --panel: #ffffff;
        --border: #d9d9d9;
        --border-light: #f0f0f0;
        --text: rgba(0, 0, 0, 0.88);
        --text-secondary: rgba(0, 0, 0, 0.65);
        --text-tertiary: rgba(0, 0, 0, 0.45);
        --accent: #ff4d4f;
        --primary: #7BCB9E;
        --primary-hover: #97D9B4;
        --primary-active: #5CAD80;
        --primary-bg: #EAF8EF;
        --radius: 8px;
        --radius-sm: 6px;
        --shadow-card: 0 1px 2px rgba(0, 0, 0, 0.03), 0 1px 6px -1px rgba(0, 0, 0, 0.02), 0 2px 4px rgba(0, 0, 0, 0.02);
    }
    * { box-sizing: border-box; }
    body {
        margin: 0;
        font-size: 16px;
        background: var(--bg);
        color: var(--text);
        padding: 32px;
        -webkit-font-smoothing: antialiased;
    }
    .page {
        max-width: 1560px;
        margin: 0 auto;
    }
    .page-header {
        margin-bottom: 20px;
    }
    h1 {
        font-size: 28px;
        font-weight: 600;
        letter-spacing: -0.2px;
        margin: 0 0 4px;
        color: var(--text);
    }
    .subtitle {
        font-size: 16px;
        color: var(--text-tertiary);
        margin: 0;
    }
    .layout {
        display: flex;
        gap: 24px;
        align-items: flex-start;
        flex-wrap: wrap;
    }
    .panel {
        background: var(--panel);
        border: 1px solid var(--border-light);
        border-radius: var(--radius);
        box-shadow: var(--shadow-card);
        padding: 24px;
    }
    .side-stack {
        flex-shrink: 0;
        display: flex;
        flex-direction: column;
        gap: 12px;
    }
    .side-stack.side-stack-controls { width: 320px; }
    .side-stack.side-stack-shortcuts { width: 270px; }
    .controls {
        display: flex;
        flex-direction: column;
        gap: 22px;
    }
    .section + .section {
        padding-top: 18px;
        border-top: 1px solid var(--border-light);
    }
    .controls h2 {
        font-size: 14px;
        font-weight: 600;
        letter-spacing: 0.2px;
        margin: 0 0 12px;
        color: var(--text-tertiary);
        text-transform: uppercase;
    }
    .field {
        display: flex;
        flex-direction: column;
        gap: 9px;
        font-size: 16px;
    }
    .field.field-inline {
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
    }
    .field + .field { margin-top: 14px; }
    .field label {
        color: var(--text-secondary);
        display: flex;
        justify-content: space-between;
    }
    .field label span:last-child { color: var(--text); font-weight: 500; }
    .field input[type="text"] {
        width: 100%;
        border: 1px solid var(--border);
        border-radius: var(--radius-sm);
        padding: 9px 12px;
        font-size: 15px;
        font-family: inherit;
        color: var(--text);
        background: #ffffff;
    }
    .field input[type="text"]:focus {
        outline: none;
        border-color: var(--primary);
        box-shadow: 0 0 0 3px var(--primary-bg);
    }
    .row {
        display: flex;
        gap: 8px;
    }
    .row button {
        flex: 1 1 0;
        min-width: 0;
    }

    button, .file-btn {
        cursor: pointer;
        border: 1px solid var(--border);
        background: #ffffff;
        color: var(--text);
        border-radius: var(--radius-sm);
        padding: 11px 18px;
        font-size: 16px;
        font-family: inherit;
        line-height: 1.4;
        text-align: center;
        transition: color 0.15s, border-color 0.15s, background 0.15s;
    }
    .file-btn {
        display: flex;
        align-items: center;
        justify-content: center;
        width: 100%;
    }
    button:hover, .file-btn:hover {
        color: var(--primary-hover);
        border-color: var(--primary-hover);
    }
    button:active {
        color: var(--primary-active);
        border-color: var(--primary-active);
    }
    button:focus-visible, .file-btn:focus-within {
        outline: none;
        box-shadow: 0 0 0 3px var(--primary-bg);
        border-color: var(--primary);
    }
    button.primary {
        background: #ffffff;
        color: var(--primary);
        border-color: var(--primary);
        font-weight: 500;
    }
    button.primary:hover {
        background: var(--primary-bg);
        color: var(--primary-hover);
        border-color: var(--primary-hover);
    }
    button.primary:active {
        background: #CFF0DC;
        color: var(--primary-active);
        border-color: var(--primary-active);
    }
    button:disabled, button:disabled:hover {
        color: var(--text-tertiary);
        background: rgba(0, 0, 0, 0.02);
        border-color: var(--border-light);
        cursor: not-allowed;
    }

    .color-picker {
        display: flex;
        align-items: center;
        gap: 10px;
    }
    .color-swatch {
        position: relative;
        display: block;
        width: 26px;
        height: 26px;
        border-radius: 50%;
        overflow: hidden;
        flex-shrink: 0;
        cursor: pointer;
        box-shadow: 0 0 0 2px #fff, 0 0 0 3px var(--border), 0 1px 2px rgba(0, 0, 0, 0.1);
        transition: box-shadow 0.15s;
    }
    .color-swatch:hover {
        box-shadow: 0 0 0 2px #fff, 0 0 0 3px var(--primary-hover), 0 1px 2px rgba(0, 0, 0, 0.1);
    }
    .color-swatch input[type="color"] {
        position: absolute;
        top: 50%;
        left: 50%;
        width: 180%;
        height: 180%;
        margin: -90% 0 0 -90%;
        border: none;
        padding: 0;
        background: none;
        cursor: pointer;
    }
    .color-hex {
        font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
        font-size: 15px;
        letter-spacing: 0.3px;
        color: var(--text-secondary);
    }

    input[type="range"] {
        width: 100%;
        height: 5px;
        margin: 9px 0;
        -webkit-appearance: none;
        appearance: none;
        border-radius: 2px;
        background: linear-gradient(to right, var(--primary) 0%, var(--primary) var(--val, 0%), var(--border-light) var(--val, 0%), var(--border-light) 100%);
        outline: none;
    }
    input[type="range"]::-webkit-slider-thumb {
        -webkit-appearance: none;
        width: 18px;
        height: 18px;
        border-radius: 50%;
        background: #fff;
        border: 2px solid var(--primary);
        box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
        cursor: pointer;
        transition: box-shadow 0.15s;
    }
    input[type="range"]::-webkit-slider-thumb:hover {
        box-shadow: 0 0 0 4px var(--primary-bg);
    }
    input[type="range"]::-moz-range-track {
        height: 5px;
        border-radius: 2px;
        background: var(--border-light);
    }
    input[type="range"]::-moz-range-progress {
        height: 5px;
        border-radius: 2px;
        background: var(--primary);
    }
    input[type="range"]::-moz-range-thumb {
        width: 18px;
        height: 18px;
        border-radius: 50%;
        background: #fff;
        border: 2px solid var(--primary);
        box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
        cursor: pointer;
    }

    .canvas-wrap {
        flex: 1;
        min-width: 420px;
        display: flex;
        justify-content: center;
    }
    .canvas-stack {
        width: 100%;
        max-width: 1200px;
        display: flex;
        flex-direction: column;
        gap: 12px;
    }
    #dropzone {
        position: relative;
        border: 1px dashed var(--border);
        border-radius: var(--radius);
        min-height: 680px;
        width: 100%;
        max-width: 1200px;
        display: flex;
        align-items: center;
        justify-content: center;
        background: #fff;
        box-shadow: var(--shadow-card);
        overflow: hidden;
        transition: border-color 0.15s, background 0.15s;
    }
    #dropzone.drag-over {
        border-color: var(--primary);
        background: var(--primary-bg);
    }
    #placeholder {
        text-align: center;
        color: var(--text-tertiary);
        font-size: 18px;
        line-height: 1.7;
        padding: 52px;
    }
    #placeholder b { color: var(--primary); font-weight: 600; }
    #canvas {
        display: none;
        max-width: 100%;
        width: auto;
        max-height: 88vh;
        height: auto;
        cursor: crosshair;
        touch-action: none;
    }

    #boxList {
        list-style: none;
        margin: 0;
        padding: 0;
        display: flex;
        flex-direction: column;
        max-height: 220px;
        overflow-y: auto;
    }
    #boxList li {
        display: flex;
        justify-content: space-between;
        align-items: center;
        font-size: 15px;
        color: var(--text-secondary);
        padding: 9px 2px;
        border-bottom: 1px solid var(--border-light);
    }
    #boxList li:last-child { border-bottom: none; }
    #boxList li button {
        border: none;
        background: none;
        padding: 2px 6px;
        font-size: 15px;
        color: var(--text-tertiary);
    }
    #boxList li button:hover {
        color: var(--accent);
        border-color: transparent;
        background: none;
    }

    .empty-note {
        font-size: 14px;
        color: var(--text-tertiary);
        padding: 4px 2px;
    }

    .shortcut-list {
        list-style: none;
        margin: 0;
        padding: 0;
        display: flex;
        flex-direction: column;
    }
    .shortcut-list li {
        display: flex;
        justify-content: space-between;
        align-items: center;
        gap: 10px;
        font-size: 15px;
        color: var(--text-secondary);
        padding: 10px 2px;
        border-bottom: 1px solid var(--border-light);
    }
    .shortcut-list li:last-child { border-bottom: none; }
    .kbd-group {
        display: flex;
        align-items: center;
        gap: 3px;
        flex-shrink: 0;
        font-size: 13px;
        color: var(--text-tertiary);
        white-space: nowrap;
    }
    kbd {
        font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
        font-size: 12px;
        color: var(--text-secondary);
        background: var(--bg);
        border: 1px solid var(--border);
        border-bottom-width: 2px;
        border-radius: 4px;
        padding: 2px 6px;
        line-height: 1.4;
    }