:root {
    --bg-dark: #121212;
    --bg-surface: #1e1e1e;
    --bg-elevated: #2c2c2c;
    --border-color: #444444;
    --text-main: #e0e0e0;
    --text-dim: #a0a0a0;
    --accent: #bb86fc;
    --font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

* {
    box-sizing: border-box;
}

body, html {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: var(--font-family);
    overflow: hidden;
}

.app-container {
    display: grid;
    grid-template-columns: 300px 1fr 400px;
    height: 100vh;
    width: 100vw;
}

.pane-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
    background-color: var(--bg-surface);
}

.pane-header h2 {
    margin: 0;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Left Pane */
.left-pane {
    background-color: var(--bg-surface);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
}

.points-list {
    flex: 1;
    overflow-y: auto;
    padding: 1rem;
}

.point-item {
    position: relative;
    background-color: var(--bg-elevated);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 28px 0.75rem 0.75rem 0.75rem;
    margin-bottom: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    transition: opacity 0.2s, transform 0.2s, border-color 0.2s;
}

.point-color-bar {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 24px;
    border-radius: 4px 4px 0 0;
    display: flex;
    align-items: center;
    padding: 0 8px;
    z-index: 1;
}

.point-item-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    margin-bottom: 0;
}

.point-item.dragging {
    opacity: 0.5;
    transform: scale(0.98);
    border-color: var(--accent);
}

.point-item.drop-target {
    border-top: 3px solid var(--accent);
}

.point-item-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.25rem;
}

.point-item-left {
    display: flex;
    align-items: center;
    gap: 8px;
}

.drag-handle {
    cursor: grab;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2px;
    width: 12px;
    height: 12px;
}

.drag-handle span {
    width: 4px;
    height: 4px;
    background-color: currentColor;
    border-radius: 1px;
}

.remove-btn {
    background: transparent;
    border: none;
    color: currentColor;
    padding: 0;
    width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    line-height: 1;
    cursor: pointer;
    transition: transform 0.1s;
}

.remove-btn:hover {
    transform: scale(1.1);
}


.point-inputs {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.5rem;
}

.input-field input {
    background: var(--bg-dark);
    border: 1px solid var(--border-color);
    color: white;
    padding: 2px 4px;
    border-radius: 2px;
    font-family: monospace;
    width: 100%;
}


.input-field {
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
}

.input-field label {
    font-size: 0.7rem;
    color: var(--text-dim);
}

.input-field input {
    background: var(--bg-dark);
    border: 1px solid var(--border-color);
    color: white;
    padding: 2px 4px;
    border-radius: 2px;
    font-family: monospace;
}

.velocity-field {
    grid-column: span 3;
    margin-top: 0.5rem;
}

/* Middle Pane */
.middle-pane {
    display: flex;
    flex-direction: column;
    position: relative;
    overflow: hidden;
}

.canvas-container {
    flex: 1;
    background-color: #000;
    cursor: crosshair;
    position: relative;
    overflow: hidden;
    min-width: 0;
    min-height: 0;
}

.canvas-container canvas {
    display: block;
}

.properties-panel {
    background-color: var(--bg-surface);
    border-top: 1px solid var(--border-color);
    padding: 1rem;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    overflow-y: auto;
}

.prop-section {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    padding-right: 1rem;
    border-right: 1px solid var(--border-color);
}

.prop-section:last-child {
    border-right: none;
}

.prop-section.actions {
    justify-content: center;
    gap: 0.75rem;
}

.prop-group {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.range-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.range-group span {
    font-family: monospace;
    font-size: 0.8rem;
    min-width: 20px;
    text-align: right;
}

.prop-group label {
    font-size: 0.75rem;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

#func-editor {
    background-color: var(--bg-dark);
    color: #aaffaa;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-family: 'Consolas', 'Monaco', monospace;
    padding: 0.5rem;
    resize: vertical;
    height: 100px;
}

/* Right Pane */
.right-pane {
    background-color: var(--bg-surface);
    border-left: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
}

.previews-container {
    flex: 1;
    display: flex;
    padding: 1rem;
    gap: 1rem;
    overflow: hidden;
}

.approximation-container {
    padding: 1rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.approx-gradient {
    flex: 1;
    border-radius: 4px;
    border: 1px solid var(--border-color);
    background: var(--bg-dark);
    cursor: pointer;
}

.gradient-preview {
    flex: 1;
    border-radius: 4px;
    border: 1px solid var(--border-color);
    background: linear-gradient(to bottom, #000, #fff);
}

.palette-preview {
    width: 60px;
    display: flex;
    flex-direction: column;
    gap: 2px;
    overflow: hidden;
}

.palette-swatch {
    width: 100%;
    flex: 1;
    border: 1px solid var(--border-color);
    border-radius: 2px;
}

/* UI Elements */
button {
    background-color: var(--bg-elevated);
    color: white;
    border: 1px solid var(--border-color);
    padding: 0.4rem 0.8rem;
    border-radius: 4px;
    cursor: pointer;
    transition: background 0.2s;
}

button:hover {
    background-color: #3d3d3d;
}

input[type="range"] {
    cursor: pointer;
}