* {
    box-sizing: border-box;
}

:root {
    --bg-color: #f6f8fa;
    --text-color: #24292f;
    --control-bg: #ffffff;
    --border-color: #d0d7de;
    --accent-color: #0969da;
    --canvas-bg: #fff;
    --display-bg: #f9f9f9;
    --display-text: #0550ae;
    --select-bg: #fff;
    --legend-bg: rgba(255, 255, 255, 0.9);
}

.dark-mode {
    --bg-color: #0f111a;
    --text-color: #e0e0e0;
    --control-bg: #1a1c25;
    --border-color: #30363d;
    --accent-color: #4db8ff;
    --canvas-bg: #000;
    --display-bg: #1a1a1a;
    --display-text: #00ff00;
    --select-bg: #222;
    --legend-bg: rgba(26, 28, 37, 0.9);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 20px;
    padding-bottom: 50px;
    transition: background-color 0.3s, color 0.3s;
}

.controls {
    background-color: var(--control-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 15px;
    margin-bottom: 20px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    display: flex;
    gap: 25px;
    align-items: flex-start;
}

.control-row {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin-bottom: 15px;
    align-items: center;
}

.control-row:last-child {
    margin-bottom: 0;
}

.slider-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

select,
input[type="file"],
button {
    background-color: var(--select-bg);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    padding: 6px 10px;
    border-radius: 4px;
    font-size: 13px;
}

button {
    cursor: pointer;
    background-color: var(--accent-color);
    color: white;
    border: none;
    transition: opacity 0.2s;
}

button:hover {
    opacity: 0.8;
}

#statusMessage {
    font-size: 13px;
    color: #888;
    opacity: 1;
}

.fade-out {
    transition: opacity 0.5s ease-in-out;
    opacity: 0 !important;
}

canvas {
    border: 1px solid var(--border-color);
    background-color: var(--canvas-bg);
    image-rendering: pixelated;
    cursor: default;
}

#cellInfo {
    position: fixed;
    background: rgba(0, 0, 0, 0.85);
    color: #fff;
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 12px;
    pointer-events: none;
    display: none;
    z-index: 1001;
    border: 1px solid #444;
    box-shadow: 0 4px 8px rgba(0,0,0,0.5);
    line-height: 1.4;
}

#dataDisplay {
    height: 160px;
    background-color: var(--display-bg);
    color: var(--display-text);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 8px;
    font-family: monospace;
    font-size: 13px;
    resize: none;
    cursor: pointer;
}

#structSize {
    width: 100%;
    height: 160px;
    background-color: var(--select-bg);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 0;
    overflow: hidden;
    outline: none;
    display: block;
    font-family: inherit;
    font-size: 13px;
}

/* Legend Styling (Used inside modal) */
.legend-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 12px;
}

.legend-color {
    width: 14px;
    height: 14px;
    border-radius: 3px;
    border: 1px solid rgba(0,0,0,0.1);
}

/* Footer Styling */
footer {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 8px 20px;
    background: var(--control-bg);
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
    align-items: center;
    z-index: 1000;
}

.help-btn {
    background: #444;
    font-size: 11px;
    padding: 3px 10px;
}

/* Modal Styling */
.modal {
    display: none;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: var(--control-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 25px;
    z-index: 2000;
    box-shadow: 0 10px 40px rgba(0,0,0,0.4);
    max-width: 500px;
    width: 90%;
}

.modal-header {
    font-weight: bold;
    font-size: 18px;
    margin-bottom: 20px;
    color: var(--accent-color);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 12px;
}

.modal-content {
    font-size: 13px;
    line-height: 1.6;
}

.modal-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 15px;
    padding-top: 15px;
    border-top: 1px solid var(--border-color);
}

.shortcut-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-top: 5px;
}

.shortcut-item {
    display: flex;
    justify-content: space-between;
}

.kbd {
    background: #555;
    color: #fff;
    padding: 2px 6px;
    border-radius: 4px;
    font-family: monospace;
    font-size: 11px;
}

.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    z-index: 1999;
}