/* ==========================================================================
   CSS Custom Properties & Base Setup
   ========================================================================== */
:root {
    /* Exatoo/Premium Dark Theme Colors - Ultra High-End */
    --bg-main: #050505; /* Absolut black */
    --bg-secondary: #0a0a0f;
    --bg-card: rgba(15, 15, 20, 0.7);
    
    --text-primary: #ffffff;
    --text-secondary: #8a8a9a;
    
    /* Vibrant Accents */
    --accent-primary: #8a2be2; /* Purple */
    --accent-secondary: #00d2ff; /* Cyan */
    --accent-glow: rgba(138, 43, 226, 0.4);
    
    --border-color: rgba(255, 255, 255, 0.08);
    
    /* Typography */
    --font-sans: 'Inter', sans-serif;
    --font-heading: 'Outfit', sans-serif;
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-main);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

html {
    scroll-behavior: smooth;
}

a {
    text-decoration: none;
    color: inherit;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ==========================================================================
   Typography & Utilities
   ========================================================================== */
h1, h2, h3, h4 {
    font-family: var(--font-heading);
    line-height: 1.2;
    margin-bottom: 1rem;
}

.highlight {
    color: var(--accent-primary);
}

.gradient-text {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.glass-card {
    background: var(--bg-card);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--border-color);
    border-radius: 20px;
}

.hidden {
    display: none !important;
}

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.7rem 1.4rem;
    border-radius: 50px;
    font-weight: 500;
    font-size: 0.95rem;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
    font-family: var(--font-sans);
}

.btn-badge {
    background: var(--accent-secondary);
    color: #000;
    font-size: 0.65rem;
    font-weight: 800;
    padding: 0.15rem 0.5rem;
    border-radius: 10px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-left: 0.2rem;
}

.btn-primary {
    background-color: var(--text-primary);
    color: var(--bg-main);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(255, 255, 255, 0.2);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.2);
}

.btn-outline {
    background-color: transparent;
    color: var(--accent-primary);
    border: 1px solid var(--accent-primary);
}

.btn-outline:hover {
    background-color: rgba(138, 43, 226, 0.1);
}

.btn-gradient {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: white;
    border: none;
}

.btn-gradient:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px var(--accent-glow);
}

.btn-glow {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: white;
    border: none;
    box-shadow: 0 4px 15px rgba(138, 43, 226, 0.3);
    transition: all 0.3s ease;
}

.btn-glow:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(138, 43, 226, 0.5);
}

/* ==========================================================================
   Navigation
   ========================================================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 1.5rem 0;
    z-index: 100;
    background: rgba(10, 10, 15, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
}

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

.logo-text {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 400;
    letter-spacing: -0.5px;
}

.logo-text strong {
    font-weight: 800;
    color: var(--accent-primary);
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--text-primary);
}

.nav-cta {
    background: rgba(138, 43, 226, 0.1);
    color: var(--accent-primary) !important;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    border: 1px solid rgba(138, 43, 226, 0.3);
}

.nav-cta:hover {
    background: rgba(138, 43, 226, 0.2);
}

/* ==========================================================================
   Hero Section - Ultra Premium
   ========================================================================== */
.hero {
    min-height: 85vh; /* Tighter on mobile/desktop */
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 100px;
    padding-bottom: 2rem;
    position: relative;
    overflow: hidden;
}

/* Background effects */
.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, rgba(138,43,226,0.15) 0%, transparent 60%);
    filter: blur(80px);
    z-index: -1;
    pointer-events: none;
}

.hero-content.text-center {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
}

.badge {
    display: inline-block;
    padding: 0.5rem 1.2rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 2rem;
    letter-spacing: 1px;
    text-transform: uppercase;
    color: var(--text-secondary);
    backdrop-filter: blur(10px);
}

.ultra-title {
    font-size: 4.5rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 2rem;
    letter-spacing: -2px;
}

.hero-subtitle {
    font-size: 1.3rem;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    max-width: 600px;
    line-height: 1.6;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
}

.hero-buttons .btn {
    padding: 0.8rem 1.5rem; /* Still delicate, but a tiny bit larger than standard buttons */
}

/* ==========================================================================
   Challenge Section
   ========================================================================== */
.challenge-section {
    padding: 6rem 0;
    position: relative;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: 2.5rem;
}

.section-header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.challenge-card {
    max-width: 800px;
    margin: 0 auto;
    padding: 3rem;
    position: relative;
}

.challenge-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.challenge-date {
    color: var(--text-secondary);
    font-weight: 500;
}

.difficulty.hard {
    background: rgba(255, 69, 58, 0.15);
    color: #ff453a;
    padding: 0.3rem 0.8rem;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 600;
}

.challenge-body h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
}

.challenge-body p {
    font-size: 1.1rem;
    line-height: 1.8;
}

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

.challenge-solution {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px dashed var(--border-color);
    animation: fadeIn 0.5s ease;
}

.challenge-solution h4 {
    color: var(--accent-primary);
    margin-bottom: 1rem;
}

.challenge-solution p {
    margin-bottom: 0.8rem;
    color: var(--text-secondary);
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

.challenge-loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 3rem 0;
    color: var(--text-secondary);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    border-top-color: var(--accent-primary);
    animation: spin 1s ease-in-out infinite;
    margin-bottom: 1rem;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.enem-alternatives {
    list-style: none;
    margin-top: 2rem;
}

.enem-alternative {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: 0.8rem;
    transition: all 0.2s;
}

.enem-alternative:hover {
    background: rgba(255, 255, 255, 0.06);
}

.alt-letter {
    font-weight: bold;
    color: var(--accent-secondary);
    background: rgba(0, 210, 255, 0.1);
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    flex-shrink: 0;
}

.alt-text {
    font-size: 1.05rem;
    line-height: 1.5;
}

/* ==========================================================================
   Exatoo Promotion Section - "Infinite Card" Look
   ========================================================================== */
.exatoo-section {
    padding: 2rem 0 6rem;
}

.infinite-card {
    background: linear-gradient(180deg, var(--bg-secondary) 0%, #000 100%);
    border: 1px solid rgba(255,255,255,0.05);
    border-radius: 32px;
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 4rem 2rem;
    text-align: center;
    overflow: hidden; /* Added to constrain feature grid */
}

.premium-glow {
    box-shadow: 0 30px 60px rgba(0,0,0,0.6), inset 0 1px 0 rgba(255,255,255,0.1), 0 0 80px rgba(138, 43, 226, 0.05);
}

.exatoo-text {
    max-width: 800px;
    padding: 0 2rem;
    z-index: 10;
}

.exatoo-text h2 {
    font-size: 3.5rem;
    margin-bottom: 2rem;
    letter-spacing: -1px;
}

.exatoo-subtitle {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    line-height: 1.6;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
    width: 100%;
}

.feature-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 16px;
    padding: 1.5rem;
    text-align: left;
    transition: all 0.3s ease;
}

.feature-card:hover {
    background: rgba(255, 255, 255, 0.06);
    border-color: rgba(138, 43, 226, 0.3);
    transform: translateY(-5px);
}

.feature-icon {
    width: 48px;
    height: 48px;
    background: rgba(138, 43, 226, 0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-secondary);
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.feature-card p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 0;
    line-height: 1.4;
}

.exatoo-cta-buttons {
    margin-top: 1rem;
}

.exatoo-mockup-wrapper {
    width: 100%;
    display: flex;
    justify-content: center;
    margin-bottom: 2.5rem;
    position: relative;
}

.mockup-frame {
    background: linear-gradient(180deg, rgba(255,255,255,0.05) 0%, transparent 100%);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 24px;
    padding: 0.5rem;
    max-width: 350px;
    width: 100%;
    box-shadow: 0 10px 40px rgba(138, 43, 226, 0.15);
    display: flex;
    justify-content: center;
}

.mockup-img-infinite {
    width: 100%;
    height: auto;
    border-radius: 20px;
    display: block;
}

.vip-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.vip-form input {
    padding: 1rem;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    color: white;
    font-family: var(--font-sans);
    font-size: 1rem;
}

.vip-form input:focus {
    outline: none;
    border-color: var(--accent-primary);
}

.form-success {
    margin-top: 1rem;
    color: #34c759 !important;
    font-weight: 500;
}

/* ==========================================================================
   Footer
   ========================================================================== */
footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 4rem 0 2rem;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
}

.footer-brand p {
    color: var(--text-secondary);
    margin-top: 0.5rem;
    font-size: 0.9rem;
}

.footer-social {
    display: flex;
    gap: 1rem;
}

.footer-social a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.05);
    transition: all 0.2s;
}

.footer-social a:hover {
    background: var(--accent-primary);
    transform: translateY(-2px);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* ==========================================================================
   Responsive Design
   ========================================================================== */
@media (max-width: 992px) {
    .ultra-title {
        font-size: 4rem;
    }
    
    .hero-subtitle {
        font-size: 1.2rem;
    }
    
    .exatoo-text h2 {
        font-size: 2.8rem;
    }
}

@media (max-width: 768px) {
    /* 1. Área Útil e Espaçamentos */
    .container {
        padding: 0 1rem;
    }
    
    .challenge-section, .exatoo-section {
        padding: 3rem 0;
    }

    .challenge-card {
        padding: 1.5rem;
        border-radius: 16px;
    }
    
    .exatoo-content {
        padding: 1.5rem;
        border-radius: 16px;
        gap: 2rem;
    }

    .section-header {
        margin-bottom: 2rem;
    }

    /* 2. Tipografia */
    .ultra-title {
        font-size: 2.8rem;
        letter-spacing: -1px;
    }
    
    .hero-subtitle {
        font-size: 1.1rem;
        padding: 0 1rem;
        margin-bottom: 2rem;
    }
    
    .section-header h2, .exatoo-text h2 {
        font-size: 2rem;
    }

    /* 3. Hero Section */
    .hero {
        padding-top: 100px;
        min-height: auto;
    }

    .hero-buttons {
        flex-direction: column;
        width: 100%;
        gap: 0.8rem;
    }
    
    .hero-buttons .btn {
        width: 100%;
    }

    /* 4. Challenge Box */
    .challenge-actions {
        flex-direction: column;
        width: 100%;
        gap: 1rem !important;
    }
    
    .challenge-actions .btn {
        width: 100%;
    }
    
    .enem-alternative {
        padding: 0.8rem;
        gap: 0.8rem;
    }
    
    .alt-letter {
        width: 25px;
        height: 25px;
        font-size: 0.9rem;
    }

    /* 5. Exatoo Box */
    .infinite-card {
        padding: 2.5rem 1.5rem;
        border-radius: 24px;
        width: 100%;
        box-sizing: border-box;
    }
    
    .exatoo-text {
        padding: 0;
        width: 100%;
        box-sizing: border-box;
    }
    
    .exatoo-subtitle {
        font-size: 0.95rem;
    }
    
    .feature-grid {
        display: flex;
        flex-direction: row;
        overflow-x: auto;
        overflow-y: hidden;
        scroll-snap-type: x mandatory;
        padding: 0 1.5rem 1.5rem 1.5rem; /* internal padding so cards don't touch edges */
        margin: 0 -1.5rem; /* negative margin to touch screen edges */
        gap: 1rem;
        -webkit-overflow-scrolling: touch;
        width: calc(100% + 3rem); /* compensate negative margins */
    }
    
    .feature-grid::-webkit-scrollbar {
        display: none;
    }

    .feature-card {
        flex: 0 0 85%;
        scroll-snap-align: center;
    }
    
    .feature-card:last-child {
        margin-right: 1.5rem; /* ensure scroll reaches the end */
    }
    
    .exatoo-cta-buttons {
        width: 100%;
    }

    .exatoo-cta-buttons .btn {
        width: 100%;
    }
    
    .mockup-frame {
        max-width: 250px;
        margin: 0 auto;
    }

    .feature-list li {
        font-size: 0.95rem;
        margin-bottom: 0.8rem;
    }

    /* 6. Footer & Nav */
    .nav-links {
        display: none;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 1.5rem;
        text-align: center;
    }
}