/* ==========================================================================
   MATEMÁTICA PREMIUM - ULTIMATE UI V3
   Focus: Glassmorphism, Modern Gradients & High Performance
   ========================================================================== 
*/

:root {
    /* --- Palette: Ocean & Space --- */
    --p-50: #eff6ff; --p-100: #dbeafe; --p-500: #3b82f6; --p-600: #2563eb; --p-700: #1d4ed8;
    
    /* --- Semantic Colors --- */
    --primary: #00a2ff;
    --primary-glow: rgba(0, 162, 255, 0.35);
    --secondary: #7c3aed; /* Violet accent */
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;

    /* --- Surfaces (Dark Mode Default) --- */
    --bg-main: #06070a;
    --bg-card: rgba(17, 20, 28, 0.6);
    --bg-elevated: rgba(25, 29, 41, 0.8);
    --border: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(255, 255, 255, 0.15);

    /* --- Text --- */
    --tx-main: #f8fafc;
    --tx-soft: #cbd5e1;
    --tx-muted: #64748b;

    /* --- Effects --- */
    --glass: blur(14px) saturate(160%);
    --shadow-soft: 0 8px 32px -4px rgba(0, 0, 0, 0.5);
    --shadow-flare: 0 0 20px rgba(0, 162, 255, 0.15);
    --radius-main: 16px;
    --radius-pill: 50px;
    
    /* --- Layout --- */
    --header-h: 72px;
    --container: 1140px;
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Light Theme Overrides */
html[data-theme="light"] {
    --bg-main: #f3f4f6;
    --bg-card: rgba(255, 255, 255, 0.8);
    --bg-elevated: #ffffff;
    --border: rgba(0, 0, 0, 0.06);
    --border-hover: rgba(0, 0, 0, 0.12);
    --tx-main: #0f172a;
    --tx-soft: #334155;
    --tx-muted: #94a3b8;
    --shadow-soft: 0 10px 25px -5px rgba(0, 0, 0, 0.05);
}

/* ==========================================================================
   BASE RESET
   ========================================================================== */
*, *::before, *::after { box-sizing: border-box; }

body {
    margin: 0;
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-main);
    color: var(--tx-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

/* Background Gradients (Aura) */
body::before, body::after {
    content: "";
    position: fixed;
    width: 40vw;
    height: 40vw;
    border-radius: 50%;
    z-index: -1;
    filter: blur(120px);
    opacity: 0.15;
    pointer-events: none;
}
body::before { top: -10%; right: -5%; background: var(--primary); }
body::after { bottom: -10%; left: -5%; background: var(--secondary); }

/* ==========================================================================
   GRID & LAYOUT
   ========================================================================== */
.container {
    width: min(100% - 40px, var(--container));
    margin-inline: auto;
}

.section-spacing { padding-block: 60px; }

.grid-auto {
    display: grid;
    gap: 24px;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

/* ==========================================================================
   COMPONENTS: CARDS & GLASS
   ========================================================================== */
.card {
    background: var(--bg-card);
    backdrop-filter: var(--glass);
    -webkit-backdrop-filter: var(--glass);
    border: 1px solid var(--border);
    border-radius: var(--radius-main);
    padding: 30px;
    transition: var(--transition);
    box-shadow: var(--shadow-soft);
}

.card:hover {
    border-color: var(--border-hover);
    transform: translateY(-5px);
    box-shadow: var(--shadow-soft), var(--shadow-flare);
}

/* ==========================================================================
   TYPOGRAPHY
   ========================================================================== */
h1, h2, h3 { 
    margin: 0; 
    line-height: 1.2; 
    font-weight: 800; 
    letter-spacing: -0.025em; 
}

.text-gradient {
    background: linear-gradient(135deg, #fff 30%, var(--primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* ==========================================================================
   BUTTONS (PREMIUM FEEL)
   ========================================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    border-radius: var(--radius-main);
    font-weight: 700;
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid transparent;
}

.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: 0 4px 15px var(--primary-glow);
}

.btn-primary:hover {
    background: #00b4ff;
    transform: scale(1.02);
    box-shadow: 0 6px 20px var(--primary-glow);
}

.btn-ghost {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border);
    color: var(--tx-main);
}

.btn-ghost:hover { background: rgba(255, 255, 255, 0.1); }

/* ==========================================================================
   HEADER (NAVBAR)
   ========================================================================== */
.header {
    position: sticky;
    top: 0;
    height: var(--header-h);
    background: rgba(6, 7, 10, 0.7);
    backdrop-filter: var(--glass);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    display: flex;
    align-items: center;
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: 12px;
    display: grid;
    place-items: center;
    color: white;
    font-weight: 900;
    font-size: 1.4rem;
}

/* ==========================================================================
   QUIZ OPTIONS (UI ENGINE)
   ========================================================================== */
.quiz-option {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 18px 24px;
    background: rgba(255, 255, 255, 0.03);
    border: 2px solid var(--border);
    border-radius: var(--radius-main);
    cursor: pointer;
    transition: var(--transition);
    margin-bottom: 12px;
}

.quiz-option:hover {
    background: rgba(255, 255, 255, 0.06);
    border-color: var(--primary);
}

.quiz-option.active {
    background: rgba(0, 162, 255, 0.1);
    border-color: var(--primary);
    box-shadow: inset 0 0 10px var(--primary-glow);
}

.quiz-option input[type="radio"] {
    width: 20px;
    height: 20px;
    accent-color: var(--primary);
}

/* ==========================================================================
   ANIMATIONS
   ========================================================================== */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.animate-in {
    animation: fadeIn 0.5s ease forwards;
}

/* ==========================================================================
   RESPONSIVE OVERRIDES
   ========================================================================== */
@media (max-width: 768px) {
    :root { --header-h: 64px; }
    
    .card { padding: 20px; }
    
    h1 { font-size: 2rem; }
    
    .mobile-hide { display: none; }
    
    .btn { width: 100%; padding-block: 14px; }
}

/* Custom Scrollbar */
::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: var(--bg-main); }
::-webkit-scrollbar-thumb { 
    background: var(--border-hover); 
    border-radius: 10px;
    border: 3px solid var(--bg-main);
}
::-webkit-scrollbar-thumb:hover { background: var(--tx-muted); }