:root {
    --accent: #6366f1; --accent-hover: #4f46e5;
    --bg: #09090b; --surface: #18181b;
    --text: #fafafa; --text-dim: #a1a1aa;
    --border: #27272a; --success: #22c55e;
    --danger: #ef4444; --card-bg: #111;
}

[data-theme="light"] {
    --accent: #4f46e5; --bg: #f4f4f5; --surface: #ffffff;
    --text: #09090b; --text-dim: #71717a; --border: #e4e4e7;
    --success: #16a34a; --card-bg: #fafafa;
}

[data-theme="inferno"] {
    --accent: #f97316; --bg: #0c0500; --surface: #1a0a00;
    --text: #fff7ed; --text-dim: #fdba74; --border: #431407;
    --success: #fbbf24; --card-bg: #2a0e00;
}

@keyframes flicker {
    0%, 100% { border-color: #431407; box-shadow: 0 0 5px rgba(249, 115, 22, 0.2); }
    50% { border-color: #f97316; box-shadow: 0 0 15px rgba(249, 115, 22, 0.5); }
}

* { box-sizing: border-box; transition: background 0.3s, color 0.3s, border-color 0.3s; }

body { 
    font-family: 'Inter', system-ui, -apple-system, sans-serif; 
    background: var(--bg); color: var(--text); 
    margin: 0; display: flex; height: 100vh; overflow: hidden; 
}

/* Sidebar Navigation */
.sidebar { 
    width: 320px; background: var(--surface); border-right: 1px solid var(--border); 
    padding: 24px; display: flex; flex-direction: column; gap: 20px; 
    overflow-y: auto; flex-shrink: 0;
}

.header-row { display: flex; justify-content: space-between; align-items: center; margin-bottom: 10px; }
h1 { font-size: 1.2rem; margin: 0; color: var(--accent); font-weight: 800; letter-spacing: -0.02em; }

.theme-toggle { 
    background: var(--bg); border: 1px solid var(--border); color: var(--text); 
    padding: 8px; border-radius: 8px; cursor: pointer; width: 40px; height: 40px; 
    display: flex; align-items: center; justify-content: center; font-size: 1.2rem;
}

.control-group { display: flex; flex-direction: column; gap: 8px; }
label { font-size: 0.7rem; font-weight: 700; color: var(--text-dim); text-transform: uppercase; letter-spacing: 0.05em; }

select, input[type="range"], input[type="file"] { width: 100%; }

.btn { 
    display: flex; align-items: center; justify-content: center; gap: 8px;
    padding: 12px; border-radius: 8px; font-weight: 600; cursor: pointer; border: none; 
    transition: 0.2s; font-size: 0.85rem; width: 100%;
}
.btn-primary { background: var(--accent); color: white; }
.btn-primary:hover { background: var(--accent-hover); }
.btn-success { background: var(--success); color: #000; }
.btn-outline { background: transparent; border: 1px solid var(--border); color: var(--text); }

/* Main Preview Area */
.main-content { flex-grow: 1; padding: 40px; overflow-y: auto; display: flex; flex-direction: column; align-items: center; }

.preview-grid { 
    display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); 
    gap: 30px; width: 100%; max-width: 1000px; 
}

.preview-card { 
    background: var(--surface); border-radius: 12px; border: 1px solid var(--border); 
    padding: 20px; display: flex; flex-direction: column; align-items: center; gap: 15px;
}
[data-theme="inferno"] .preview-card { animation: flicker 4s infinite alternate; }

.preview-card h3 { margin: 0; font-size: 0.8rem; color: var(--text-dim); text-transform: uppercase; }

canvas { 
    max-width: 100%; height: auto; border-radius: 4px; 
    background-image: 
        linear-gradient(45deg, #808080 25%, transparent 25%), 
        linear-gradient(-45deg, #808080 25%, transparent 25%), 
        linear-gradient(45deg, transparent 75%, #808080 75%), 
        linear-gradient(-45deg, transparent 75%, #808080 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
    background-color: #ccc;
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

.color-well { display: flex; align-items: center; gap: 10px; background: var(--bg); padding: 8px; border-radius: 8px; border: 1px solid var(--border); }
input[type="color"] { border: none; width: 30px; height: 30px; cursor: pointer; background: none; }

.instructions { 
    margin-top: 40px; padding: 20px; background: rgba(99, 102, 241, 0.05); 
    border-radius: 12px; border: 1px dashed var(--border); max-width: 1000px; font-size: 0.85rem; line-height: 1.6;
}

.hidden { display: none !important; }

@media (max-width: 800px) {
    body { flex-direction: column; overflow-y: auto; }
    .sidebar { width: 100%; height: auto; border-right: none; border-bottom: 1px solid var(--border); }
    .main-content { padding: 20px; }
}