:root {
    --bg: #0f0f0f;
    --card: #1a1a1a;
    --accent: #00f2ff;
    --accent-glow: rgba(0, 242, 255, 0.4);
    --lime: #39ff14;
    --text: #ffffff;
    --text-dim: #888;
}

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

body {
    background-color: var(--bg);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    display: flex;
    justify-content: center;
    padding: 15px;
}

.calculator-card {
    background: var(--card);
    width: 100%;
    max-width: 420px;
    border-radius: 28px;
    padding: 24px;
    border: 1px solid rgba(255,255,255,0.05);
}

header h1 { font-size: 1.5rem; letter-spacing: -1px; margin-bottom: 4px; }
.accent { color: var(--accent); }
.subtitle { color: var(--text-dim); font-size: 0.8rem; margin-bottom: 20px; }

.section-group { margin-bottom: 15px; }
.row { display: flex; justify-content: space-between; align-items: center; margin-bottom: 10px; }

select {
    background: #2a2a2a;
    border: 1px solid #444;
    color: white;
    padding: 8px 12px;
    border-radius: 12px;
    font-size: 0.9rem;
}

.control-box {
    background: rgba(255,255,255,0.03);
    border-radius: 20px;
    padding: 16px;
    margin-bottom: 12px;
}

.highlight { border: 1px solid var(--accent); background: rgba(0, 242, 255, 0.05); }

label { font-size: 0.85rem; color: var(--text-dim); display: block; margin-bottom: 10px; }

.badge { font-weight: bold; color: var(--lime); font-size: 1rem; margin-top: 8px; text-align: center; }

/* Sliders */
input[type="range"] {
    width: 100%;
    height: 6px;
    background: #333;
    border-radius: 5px;
    appearance: none;
    accent-color: var(--accent);
}

/* Doble Slider Custom */
.double-slider-wrapper {
    position: relative;
    height: 30px;
    display: flex;
    align-items: center;
}

.double-slider-wrapper input[type="range"] {
    position: absolute;
    pointer-events: none;
    background: none;
    z-index: 2;
}

.double-slider-wrapper input::-webkit-slider-thumb {
    pointer-events: auto;
    appearance: none;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: var(--text);
    border: 3px solid var(--accent);
    cursor: pointer;
}

/* Botones Presets */
.preset-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 6px;
    margin-bottom: 12px;
}

.preset-grid button {
    background: #2a2a2a;
    border: 1px solid #444;
    color: white;
    padding: 6px;
    border-radius: 8px;
    font-size: 0.7rem;
    cursor: pointer;
    transition: 0.2s;
}

.preset-grid button:active { background: var(--accent); color: #000; }

.autonomy-display {
    text-align: center;
    font-size: 3.5rem;
    font-weight: 800;
    color: var(--accent);
    text-shadow: 0 0 20px var(--accent-glow);
}

.autonomy-display small { font-size: 1.2rem; color: var(--text-dim); font-weight: 400; }

.divider { border: 0; border-top: 1px solid #333; margin: 15px 0; }