:root {
    --bg-color: #0f1115;
    --panel-bg: rgba(22, 25, 33, 0.7);
    --panel-border: rgba(255, 255, 255, 0.08);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-color: #3b82f6;
    --accent-hover: #60a5fa;
    --danger-color: #ef4444;
    --danger-hover: #f87171;
    --glow-color: rgba(59, 130, 246, 0.5);
    
    --point-color: #10b981;
    --link-color: #e2e8f0;
    --trace-color: #8b5cf6;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    overflow: hidden;
    width: 100vw;
    height: 100vh;
}

#main-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    cursor: crosshair;
}

#ui-layer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 10;
    pointer-events: none;
    display: flex;
    flex-direction: column;
}

header {
    padding: 2rem;
    pointer-events: auto;
    background: linear-gradient(to bottom, rgba(15, 17, 21, 0.9), transparent);
}

h1 {
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    margin-bottom: 0.5rem;
}

header p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    max-width: 400px;
}

#controls-panel {
    position: absolute;
    top: 2rem;
    right: 2rem;
    width: 320px;
    max-height: calc(100vh - 4rem);
    overflow-y: auto;
    background: var(--panel-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--panel-border);
    border-radius: 16px;
    padding: 1.5rem;
    pointer-events: auto;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

#status-text {
    font-size: 1.1rem;
    font-weight: 500;
}

/* Analytical Controls */
#analytical-controls {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.control-group label {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.dropdown {
    width: 100%;
    padding: 0.5rem;
    background: rgba(255,255,255,0.1);
    color: var(--text-primary);
    border: 1px solid var(--panel-border);
    border-radius: 4px;
    font-family: inherit;
    font-size: 0.9rem;
}

input[type=range] {
    width: 100%;
    accent-color: var(--accent-color);
}

.btn-group {
    display: flex;
    gap: 0.75rem;
    flex-direction: column;
}

button {
    width: 100%;
    padding: 0.875rem;
    border: none;
    border-radius: 8px;
    font-family: inherit;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

button:focus {
    outline: 2px solid var(--text-primary);
    outline-offset: 2px;
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

#btn-synthesize {
    background-color: var(--accent-color);
    color: white;
}

#btn-synthesize:not(:disabled):hover {
    background-color: var(--accent-hover);
    box-shadow: 0 0 15px var(--glow-color);
}

#btn-clear.secondary, .secondary {
    background-color: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--panel-border);
}

#btn-clear.secondary:hover, .secondary:hover {
    color: var(--text-primary);
    border-color: rgba(255, 255, 255, 0.3);
    background-color: rgba(255, 255, 255, 0.05);
}

.sol-nav-btn {
    min-width: 36px !important;
}

.mech-badge {
    display: inline-block;
    padding: 1px 6px;
    border-radius: 4px;
    font-size: 0.85em;
}
.mech-badge.crank-rocker { background: rgba(16,185,129,0.2); color: #34d399; }
.mech-badge.double-crank { background: rgba(251,191,36,0.2); color: #fbbf24; }
.mech-badge.rocker-crank { background: rgba(96,165,250,0.2); color: #60a5fa; }
.mech-badge.double-rocker { background: rgba(239,68,68,0.2); color: #f87171; }

#main-canvas.drawing-mode {
    cursor: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24'%3E%3Ccircle cx='12' cy='12' r='4' fill='%23f59e0b'/%3E%3C/svg%3E") 12 12, crosshair;
}

#stats {
    padding-top: 1.5rem;
    border-top: 1px solid var(--panel-border);
    font-size: 0.85rem;
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.stat-row {
    display: flex;
    justify-content: space-between;
}

.stat-row span:last-child {
    color: var(--text-primary);
    font-variant-numeric: tabular-nums;
}

.hidden {
    display: none !important;
}

.instructions-pill {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    background: var(--panel-bg);
    backdrop-filter: blur(12px);
    border: 1px solid var(--panel-border);
    padding: 0.75rem 1.25rem;
    border-radius: 9999px;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 0.9rem;
}

.dot {
    width: 8px;
    height: 8px;
    background-color: var(--accent-color);
    border-radius: 50%;
    box-shadow: 0 0 8px var(--glow-color);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(59, 130, 246, 0.7); }
    70% { box-shadow: 0 0 0 10px rgba(59, 130, 246, 0); }
    100% { box-shadow: 0 0 0 0 rgba(59, 130, 246, 0); }
}