:root {
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-primary: #38bdf8;
    --accent-secondary: #818cf8;
    --color-unit: #10b981;
    --color-expansion: #38bdf8;
    --color-partition: #fb7185;
    --border-radius: 12px;
}

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

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.5;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 1200px;
    /* Altura fija relativa para estabilidad */
    height: 85vh;
    max-height: 800px;
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.3), 0 10px 10px -5px rgba(0, 0, 0, 0.2);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    position: relative;
}

@media (max-height: 600px) {
    .container {
        height: 95vh;
    }
}

#fullscreen-btn {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: rgba(15, 23, 42, 0.6);
    backdrop-filter: blur(4px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-secondary);
    padding: 0.5rem;
    border-radius: 8px;
    cursor: pointer;
    z-index: 100;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

#fullscreen-btn:hover {
    background: rgba(15, 23, 42, 0.9);
    color: var(--text-primary);
    transform: scale(1.1);
}

.container:fullscreen {
    max-width: none;
    max-height: none;
    width: 100vw;
    height: 100vh;
    border-radius: 0;
}

.container:fullscreen main {
    flex: 1;
}

header {
    padding: 1.5rem 2rem;
    background: linear-gradient(to right, #1e293b, #334155);
    border-bottom: 1px solid #334155;
    text-align: center;
    flex-shrink: 0;
}

header h1 {
    font-size: 1.875rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    background: linear-gradient(to right, #38bdf8, #818cf8);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

header p {
    color: var(--text-secondary);
}

#math-display {
    color: var(--text-primary);
    font-family: 'Courier New', Courier, monospace;
    font-weight: bold;
    font-size: 1.5rem;
}

.equation-container {
    margin-top: 1rem;
    background-color: rgba(0, 0, 0, 0.2);
    display: inline-block;
    padding: 0.5rem 1.5rem;
    border-radius: 20px;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.cancellation-note {
    font-size: 0.8rem;
    padding: 1rem;
    background-color: rgba(16, 185, 129, 0.1);
    border-radius: 8px;
    border-left: 4px solid var(--color-unit);
    color: var(--text-secondary);
}

.cancellation-note strong {
    color: var(--color-unit);
    display: block;
    margin-bottom: 0.25rem;
}

main {
    display: flex;
    flex-direction: row;
    padding: 1.5rem;
    gap: 1.5rem;
    flex: 1;
}

@media (max-width: 900px) {
    body {
        align-items: flex-start;
        padding: 10px;
    }

    .container {
        height: auto;
        max-height: none;
        overflow-y: auto;
    }

    main {
        flex-direction: column;
    }

    .canvas-container {
        flex: none;
        height: 350px;
        min-height: 350px;
    }

    .controls {
        flex: none;
        overflow-y: visible;
    }
}

.canvas-container {
    flex: 2;
    background-color: #020617;
    border-radius: var(--border-radius);
    border: 1px solid #334155;
    position: relative;
    min-height: 400px;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

canvas {
    width: 100%;
    height: 100%;
    display: block;
}

.controls {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    background-color: #0f172a66;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    border: 1px solid #334155;
    /* Permitir scroll si los controles son muchos */
    overflow-y: auto;
}

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

label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
}

input[type="number"] {
    background-color: #1e293b;
    border: 1px solid #334155;
    color: white;
    padding: 0.5rem;
    border-radius: 6px;
    font-size: 1rem;
}

input[type="range"] {
    width: 100%;
    cursor: pointer;
}

.info-panel {
    background-color: #33415544;
    padding: 1rem;
    border-radius: 8px;
    border-left: 4px solid var(--accent-primary);
}

#formula-explanation {
    margin-bottom: 0.5rem;
    font-family: monospace;
}

#result-explanation {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

footer {
    padding: 1rem;
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-secondary);
    border-top: 1px solid #334155;
    background-color: rgba(0, 0, 0, 0.1);
}

footer p {
    margin-bottom: 0.25rem;
}

footer a {
    color: var(--accent-primary);
    text-decoration: none;
    transition: color 0.2s ease;
}

footer a:hover {
    color: var(--accent-secondary);
    text-decoration: underline;
}