:root {
    --primary: #0B2545;
    --primary-light: #134074;
    --secondary: #1390E5;
    --accent: #00B4D8;
    --success: #10B981;
    --warning: #F59E0B;
    --danger: #EF4444;
    --dark: #0F172A;
    --light-bg: #F8FAFC;
    --card-bg: #FFFFFF;
    --border-color: #E2E8F0;
    --text-main: #1E293B;
    --text-muted: #64748B;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 18px;
    --shadow-subtle: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
}

body {
    background-color: var(--light-bg);
    color: var(--text-main);
    font-family: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Navbar PRONABEC */
.navbar-pronabec {
    background: linear-gradient(135deg, #0B2545 0%, #134074 100%);
    box-shadow: 0 4px 20px rgba(11, 37, 69, 0.15);
    padding: 0.8rem 0;
}

.navbar-brand-badge {
    background: rgba(255, 255, 255, 0.15);
    color: #fff;
    font-size: 0.75rem;
    padding: 3px 8px;
    border-radius: 6px;
    font-weight: 600;
    letter-spacing: 0.5px;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.nav-link {
    font-weight: 500;
    color: rgba(255, 255, 255, 0.85) !important;
    padding: 0.5rem 1rem !important;
    border-radius: var(--radius-sm);
    transition: all 0.2s ease;
}

.nav-link:hover, .nav-link.active {
    color: #ffffff !important;
    background: rgba(255, 255, 255, 0.12);
}

/* Cards & Containers */
.card-custom {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-subtle);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card-custom:hover {
    box-shadow: var(--shadow-hover);
}

.card-stat {
    border-left: 4px solid var(--secondary);
}

/* Buttons */
.btn-primary-pronabec {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: #fff;
    border: none;
    font-weight: 600;
    border-radius: var(--radius-sm);
    padding: 0.55rem 1.25rem;
    transition: all 0.2s ease;
}

.btn-primary-pronabec:hover {
    background: linear-gradient(135deg, #07192f 0%, #0d2f55 100%);
    color: #fff;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(11, 37, 69, 0.25);
}

.btn-accent {
    background: linear-gradient(135deg, var(--secondary) 0%, var(--accent) 100%);
    color: #fff;
    border: none;
    font-weight: 600;
    border-radius: var(--radius-sm);
    padding: 0.55rem 1.25rem;
}

.btn-accent:hover {
    color: #fff;
    box-shadow: 0 4px 12px rgba(19, 144, 229, 0.3);
}

/* Badges */
.badge-mat {
    background-color: #e0f2fe;
    color: #0369a1;
    font-weight: 600;
    border: 1px solid #bae6fd;
}

.badge-lec {
    background-color: #fef3c7;
    color: #b45309;
    font-weight: 600;
    border: 1px solid #fde68a;
}

.badge-diff-basico {
    background-color: #dcfce7;
    color: #15803d;
}

.badge-diff-intermedio {
    background-color: #ffedd5;
    color: #c2410c;
}

.badge-diff-avanzado {
    background-color: #fee2e2;
    color: #b91c1c;
}

/* Question Option Styling */
.option-item {
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 0.9rem 1.15rem;
    margin-bottom: 0.65rem;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    background: #fff;
}

.option-item:hover {
    border-color: var(--secondary);
    background-color: #f0f9ff;
}

.option-item.selected {
    border-color: var(--secondary);
    background-color: #e0f2fe;
    font-weight: 600;
}

.option-item.correct-answer {
    border-color: var(--success);
    background-color: #ecfdf5;
}

.option-item.wrong-answer {
    border-color: var(--danger);
    background-color: #fef2f2;
}

.option-letter {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: #f1f5f9;
    color: var(--text-main);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    margin-right: 0.85rem;
    flex-shrink: 0;
    transition: all 0.2s;
}

.option-item.selected .option-letter {
    background: var(--secondary);
    color: #fff;
}

.option-item.correct-answer .option-letter {
    background: var(--success);
    color: #fff;
}

.option-item.wrong-answer .option-letter {
    background: var(--danger);
    color: #fff;
}

/* Simulador UI Navigation Grid */
.exam-grid-btn {
    width: 38px;
    height: 38px;
    padding: 0;
    font-size: 0.85rem;
    font-weight: 700;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: #ffffff;
    color: var(--text-muted);
    transition: all 0.15s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.exam-grid-btn:hover {
    border-color: var(--secondary);
    color: var(--secondary);
}

.exam-grid-btn.active {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
    font-weight: 800;
}

.exam-grid-btn.answered {
    background: var(--secondary);
    color: #ffffff;
    border-color: var(--secondary);
}

.exam-grid-btn.flagged {
    background: var(--warning);
    color: #ffffff;
    border-color: var(--warning);
}

/* Timer Display */
.timer-badge {
    font-family: 'Courier New', Courier, monospace;
    font-size: 1.35rem;
    font-weight: 700;
    letter-spacing: 1px;
    background: #0F172A;
    color: #38BDF8;
    padding: 0.4rem 0.9rem;
    border-radius: var(--radius-sm);
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.5);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.timer-badge.warning {
    color: #FBBF24;
}

.timer-badge.danger {
    color: #F87171;
    animation: pulse-danger 0.8s infinite;
}

@keyframes pulse-danger {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.04); }
}

/* Solucionario Pedagógico */
.solution-box {
    background: #f8fafc;
    border-left: 4px solid var(--secondary);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    padding: 1.25rem;
    margin-top: 1rem;
}

.solution-step {
    line-height: 1.7;
    font-size: 0.98rem;
}

/* Footer */
footer {
    margin-top: auto;
    background: #0B2545;
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.85rem;
    padding: 1.5rem 0;
}