:root {
    --bg-window: rgba(18, 18, 20, 0.75);
    --bg-card: rgba(30, 30, 35, 0.6);
    --border-color: rgba(255, 255, 255, 0.07);
    --text-main: #f3f4f6;
    --text-muted: #9ca3af;
    --primary: #3b82f6;
    --primary-glow: rgba(59, 130, 246, 0.3);
    --danger: #ef4444;
    --danger-hover: #dc2626;
    --success: #10b981;
    --font-stack: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

body { 
    margin: 0; 
    overflow: hidden; 
    background-color: #0f0f11; 
    font-family: var(--font-stack);
    -webkit-font-smoothing: antialiased;
}

canvas { display: block; outline: none; }

/* Conteneur UI Principal - Glassmorphic minimal */
#ui-container {
    position: absolute; 
    top: 20px; 
    left: 20px;
    color: var(--text-main); 
    background: var(--bg-window);
    backdrop-filter: blur(20px); 
    -webkit-backdrop-filter: blur(20px);
    padding: 18px; 
    border-radius: 16px;
    pointer-events: auto; 
    user-select: none; 
    width: 290px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
    max-height: calc(100vh - 40px); 
    overflow-y: auto; 
    border: 1px solid var(--border-color);
}

/* Custom Scrollbar */
#ui-container::-webkit-scrollbar { width: 4px; }
#ui-container::-webkit-scrollbar-track { background: transparent; }
#ui-container::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.1); border-radius: 10px; }

.studio-header {
    display: flex; 
    align-items: center; 
    justify-content: space-between;
    margin-bottom: 20px; 
    padding-bottom: 12px; 
    border-bottom: 1px solid var(--border-color);
}
.studio-header h2 { 
    margin: 0; 
    font-size: 0.85em; 
    font-weight: 800; 
    color: #ffffff; 
    letter-spacing: 2px; 
}
.version-tag {
    font-size: 0.65em;
    background: rgba(255,255,255,0.1);
    padding: 2px 6px;
    border-radius: 20px;
    color: var(--text-muted);
}

/* Sections Collapsibles */
.section { 
    background: var(--bg-card); 
    border-radius: 10px; 
    margin-bottom: 10px; 
    border: 1px solid var(--border-color);
    overflow: hidden;
}
.collapsible-header {
    display: flex; 
    justify-content: space-between; 
    align-items: center;
    padding: 12px 14px; 
    font-size: 0.8em; 
    font-weight: 600; 
    cursor: pointer;
    background: rgba(255, 255, 255, 0.02);
    transition: background 0.2s;
}
.collapsible-header:hover { background: rgba(255, 255, 255, 0.05); }
.collapsible-header .arrow { font-size: 16px; transition: transform 0.2s; color: var(--text-muted); }
.section.collapsed .collapsible-content { display: none; }
.section.collapsed .arrow { transform: rotate(-90deg); }
.collapsible-content { padding: 14px; border-top: 1px solid var(--border-color); }

/* Groupe d'Outils */
.tool-group { display: flex; gap: 6px; }
.tool-btn {
    flex: 1; 
    display: flex; 
    flex-direction: column; 
    align-items: center; 
    gap: 6px;
    background: rgba(255,255,255,0.03); 
    border: 1px solid var(--border-color);
    color: var(--text-muted); 
    padding: 10px 0; 
    border-radius: 8px;
    cursor: pointer; 
    font-size: 0.7em; 
    font-family: var(--font-stack);
    font-weight: 500;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}
.tool-btn span { font-size: 18px; }
.tool-btn:hover { color: #fff; background: rgba(255,255,255,0.07); }
.tool-btn.active {
    background: var(--primary); 
    color: #ffffff; 
    border-color: var(--primary);
    box-shadow: 0 0 12px var(--primary-glow);
}

/* Inventaire des briques */
.inventory { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; }
.inv-item {
    aspect-ratio: 1; 
    background: rgba(255,255,255,0.03); 
    border: 1px solid var(--border-color);
    border-radius: 8px; 
    cursor: pointer; 
    display: flex; 
    align-items: center;
    justify-content: center; 
    font-size: 0.65em; 
    color: var(--text-muted);
    transition: all 0.2s;
}
.inv-item:hover { background: rgba(255,255,255,0.08); color: #fff; border-color: rgba(255,255,255,0.2); }
.inv-item.active { background: #fff; color: #000; border-color: #fff; font-weight: bold; }

/* Palette de couleurs */
.color-picker { display: grid; grid-template-columns: repeat(5, 1fr); gap: 8px; }
.color-swatch {
    aspect-ratio: 1; 
    border-radius: 50%; 
    cursor: pointer; 
    position: relative;
    border: 2px solid transparent; 
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.3);
    transition: transform 0.15s, border-color 0.15s;
}
.color-swatch:hover { transform: scale(1.1); }
.color-swatch.active { border-color: #ffffff; transform: scale(1.05); box-shadow: 0 0 10px rgba(255,255,255,0.4); }

/* Range Sliders customisés */
.control-row { margin-bottom: 12px; }
.control-row:last-child { margin-bottom: 0; }
.control-label { display: flex; justify-content: space-between; font-size: 0.72em; color: var(--text-muted); margin-bottom: 5px; }
.val-display { color: var(--primary); font-family: monospace; font-weight: 600; }

input[type="range"] {
    -webkit-appearance: none; width: 100%; height: 4px; background: rgba(255,255,255,0.1);
    border-radius: 2px; outline: none; cursor: pointer;
}
input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none; width: 12px; height: 12px; border-radius: 50%;
    background: #ffffff; transition: transform 0.1s; box-shadow: 0 0 4px rgba(0,0,0,0.5);
}
input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.2); background: var(--primary); }
input[type="color"] { 
    width: 100%; height: 28px; border: 1px solid var(--border-color); 
    border-radius: 6px; background: none; cursor: pointer; padding: 0;
}

/* Custom Switches (Toggle) */
.checkbox-wrapper { display: flex; flex-direction: column; gap: 8px; margin-bottom: 14px; }
.switch-row { display: flex; align-items: center; gap: 10px; cursor: pointer; font-size: 0.72em; color: var(--text-muted); }
.switch-row input { display: none; }
.switch-slider {
    width: 28px; height: 16px; background: rgba(255,255,255,0.1); border-radius: 20px;
    position: relative; transition: background 0.2s; display: inline-block;
}
.switch-slider::before {
    content: ""; position: absolute; width: 12px; height: 12px; left: 2px; bottom: 2px;
    background: #fff; border-radius: 50%; transition: transform 0.2s;
}
input:checked + .switch-slider { background: var(--primary); }
input:checked + .switch-slider::before { transform: translateX(12px); }
input:checked ~ .label-text { color: var(--text-main); }

.divider { height: 1px; background: var(--border-color); margin: 14px 0; }

/* Boutons d'actions */
.action-btns { margin-top: 14px; display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.btn-action {
    display: flex; align-items: center; justify-content: center; gap: 6px;
    border: none; padding: 10px; border-radius: 8px; font-family: var(--font-stack);
    font-size: 0.72em; font-weight: 600; cursor: pointer; transition: background 0.2s, transform 0.1s;
}
.btn-action span { font-size: 16px; }
.btn-action:active { transform: scale(0.98); }
.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: #2563eb; }
.btn-secondary { background: rgba(255,255,255,0.06); color: var(--text-main); border: 1px solid var(--border-color); }
.btn-secondary:hover { background: rgba(255,255,255,0.1); }
.btn-danger { background: rgba(239, 68, 68, 0.15); color: #f87171; border: 1px solid rgba(239, 68, 68, 0.2); grid-column: span 2; }
.btn-danger:hover { background: var(--danger); color: white; }

/* Guide / Raccourcis */
.hint { margin-top: 16px; padding: 12px; background: rgba(0,0,0,0.2); border-radius: 8px; border: 1px solid var(--border-color); }
.hint-header { display: flex; align-items: center; gap: 6px; font-size: 0.7em; font-weight: 700; color: #fff; margin-bottom: 8px; text-transform: uppercase; letter-spacing: 0.5px; }
.hint-header span { font-size: 14px; color: var(--primary); }
.hint ul { margin: 0; padding: 0; list-style: none; display: flex; flex-direction: column; gap: 6px; }
.hint li { font-size: 0.68em; color: var(--text-muted); display: flex; justify-content: space-between; align-items: center; }
kbd { background: rgba(255,255,255,0.1); padding: 2px 5px; border-radius: 4px; color: #fff; font-family: monospace; font-size: 0.95em; border-bottom: 2px solid rgba(0,0,0,0.3); }