/**
 * formulacion-inorganica.css
 *
 * Hoja de Estilos para la aplicación de Formulación Inorgánica.
 * Versión profesional con tema oscuro por defecto.
 */

/* --- 1. VARIABLES GLOBALES Y RESET --- */
:root {
    /* Paleta de colores (consistente con las otras apps) */
    --color-bg-start: #1b2735;
    --color-bg-end: #090a0f;
    --color-surface: #161b22;
    --color-border: #30363d;
    --color-text-primary: #f0f2f5;
    --color-text-secondary: #a8b2c1;
    --color-accent: #3498db;
    --color-accent-hover: #58a6ff;
    --color-success: #2ecc71;
    --color-warning: #f39c12;
    --color-danger: #e74c3c;
    --color-shadow: rgba(0, 0, 0, 0.5);
    --color-surface-interactive: #2c3e50;

    /* Tipografía y espaciado */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    --radius-md: 12px;
    --radius-sm: 8px;
    --shadow-md: 0 4px 12px var(--color-shadow);
    --transition-speed: 0.2s;
}

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

body {
    font-family: var(--font-family);
    background: linear-gradient(135deg, var(--color-bg-start) 0%, var(--color-bg-end) 100%);
    color: var(--color-text-primary);
    min-height: 100vh;
    padding: 1rem;
    font-size: 16px;
}

/* --- 2. LAYOUT Y COMPONENTES PRINCIPALES --- */
.container {
    max-width: 900px;
    margin-inline: auto;
    padding: 1rem;
}

.main-header {
    text-align: center;
    margin-bottom: 2.5rem;
}

.main-header h1 {
    font-size: clamp(1.75rem, 5vw, 2.5rem);
    letter-spacing: 1px;
    text-shadow: 0 2px 4px var(--color-shadow);
    margin-bottom: 0.5rem;
}

.main-header .subtitle {
    font-size: clamp(1rem, 2.5vw, 1.1rem);
    color: var(--color-text-secondary);
    max-width: 60ch;
    margin-inline: auto;
}

/* --- 3. FORMULARIO DE OPCIONES --- */
.options-form {
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    margin-bottom: 2.5rem;
}

.settings-panel {
    border: none;
    padding: 0;
    margin: 0;
}
.settings-panel:not(:last-child) {
    margin-bottom: 2rem;
}

.settings-panel legend {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    width: 100%;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--color-border);
}

.checkbox-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 0.75rem;
}

.checkbox-item, .radio-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    background-color: var(--color-surface-interactive);
    padding: 0.75rem;
    border-radius: var(--radius-sm);
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}

.checkbox-item:hover, .radio-item:hover {
    transform: scale(1.02);
    box-shadow: 0 0 10px rgba(52, 152, 219, 0.2);
}

.checkbox-item input, .radio-item input {
    width: 1.25em;
    height: 1.25em;
    accent-color: var(--color-accent);
    flex-shrink: 0;
    cursor: pointer;
}
.checkbox-item label, .radio-item label {
    cursor: pointer;
    width: 100%;
}

.select-all-container {
    margin-top: 1rem;
    border-top: 1px dashed var(--color-border);
    padding-top: 1rem;
}

.preferences-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}
@media (min-width: 600px) {
    .preferences-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

.preference-group h3 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    color: var(--color-text-secondary);
}
.preference-group {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.form-actions {
    text-align: center;
    margin-top: 2rem;
}

.button {
    font-family: inherit;
    font-size: 1rem;
    padding: 0.75rem 2rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    background-color: var(--color-surface-interactive);
    color: var(--color-text-primary);
    font-weight: 600;
    cursor: pointer;
    transition: background-color var(--transition-speed), transform var(--transition-speed);
}
.button:hover {
    transform: translateY(-2px);
}
.button.button-primary {
    background-color: var(--color-accent);
    border-color: var(--color-accent);
}
.button.button-primary:hover {
    background-color: var(--color-accent-hover);
    border-color: var(--color-accent-hover);
}

/* --- 4. SECCIÓN DE EJERCICIOS --- */
.exercise-section {
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
}

.table-wrapper {
    overflow-x: auto;
}

#exercise-table {
    width: 100%;
    border-collapse: collapse;
    min-width: 700px;
}
#exercise-table th, #exercise-table td {
    padding: 0.75rem 1rem;
    text-align: left;
    border: 1px solid var(--color-border);
    vertical-align: middle;
}
#exercise-table thead th {
    background-color: var(--color-surface-interactive);
    font-weight: 600;
}
#exercise-table tbody tr:nth-child(even) {
    background-color: rgba(0,0,0,0.2);
}
#exercise-table input[type="text"] {
    width: 100%;
    padding: 0.5rem;
    font-family: inherit;
    font-size: 1rem;
    background-color: var(--color-bg);
    border: 2px solid var(--color-border);
    color: var(--color-text-primary);
    border-radius: var(--radius-sm);
    transition: border-color var(--transition-speed), background-color var(--transition-speed);
}
#exercise-table input[type="text"]:focus {
    outline: none;
    border-color: var(--color-accent);
}
#exercise-table .correct {
    background-color: rgba(46, 204, 113, 0.1);
    border-color: var(--color-success);
}
#exercise-table .incorrect {
    background-color: rgba(231, 76, 60, 0.1);
    border-color: var(--color-danger);
}
#exercise-table .solution {
    font-size: 0.9rem;
    color: var(--color-success);
    margin-top: 0.25rem;
    display: block;
}

.correction-controls {
    text-align: center;
    margin-top: 1.5rem;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}
#check-answers-btn { background-color: var(--color-warning); color: #000; border-color: var(--color-warning); }
#check-answers-btn:hover { background-color: #d4ac0d; border-color: #d4ac0d; }
#try-again-btn { background-color: var(--color-success); border-color: var(--color-success); }
#try-again-btn:hover { background-color: #27ae60; border-color: #27ae60; }

.score-display {
    font-size: 1.25rem;
    font-weight: bold;
    padding: 0.5rem 1.5rem;
    border-radius: var(--radius-sm);
    background-color: var(--color-surface-interactive);
    border: 1px solid var(--color-border);
}

/* --- 5. UTILIDADES (LOADER, ERRORES) --- */
.loader, .error-message {
    text-align: center;
    padding: 1.5rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    margin-bottom: 2rem;
}
.error-message {
    color: var(--color-danger);
    background-color: rgba(231, 76, 60, 0.1);
    border: 1px solid var(--color-danger);
}
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}
[hidden] {
    display: none !important;
}