/* ==========================================================================
   1. HERO SECTION (Fluid Typography & Sleek Layout)
   ========================================================================== */
.hero-section {
    min-height: 60vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 4rem 2rem;
    position: relative;
}

.hero-container {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

/* Fluid Heading Scaling from Design Guide */
.hero-title {
    font-size: clamp(2.5rem, 5vw + 1rem, 4.5rem);
    line-height: 1.1;
    letter-spacing: -1px;
    background: linear-gradient(135deg, var(--color-text-main) 30%, var(--color-text-muted));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: clamp(1.1rem, 2vw, 1.4rem);
    color: var(--color-text-muted);
    max-width: 700px;
    text-wrap: balance;
}

/* Central Neon Action Button */
.btn-start {
    margin-top: 1rem;
    font-family: var(--font-heading);
    font-size: 1.1rem;
    font-weight: 700;
    color: #000;
    background: var(--color-accent-in);
    padding: 1rem 2.5rem;
    border-radius: 50px;
    box-shadow: 0 0 20px oklch(0.75 0.15 250 / 0.4);
    transition: all var(--transition-base);
}

.btn-start:hover {
    transform: translateY(-3px);
    box-shadow: 0 0 35px var(--color-accent-in);
    filter: brightness(1.1);
}

/* ==========================================================================
   2. LEVEL SELECTION CARDS (Glassmorphism & Neon Borders)
   ========================================================================== */
.levels-section {
    max-width: 1400px;
    margin: 0 auto;
    padding: 5rem 2rem;
}

.section-title {
    font-size: clamp(1.8rem, 3vw, 2.8rem);
    text-align: center;
    margin-bottom: 3.5rem;
    letter-spacing: -0.5px;
}

/* 4-Column Responsive Grid Layout */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
}

/* Glassmorphism Panel Engineering */
.level-card {
    background: var(--color-bg-surface);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: var(--glass-border);
    box-shadow: var(--glass-shadow);
    border-radius: 20px;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    gap: 1.5rem;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.level-card:hover {
    transform: translateY(-8px) scale(1.02);
}

/* Card Header & Badges */
.card-header {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.level-badge {
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 1.1rem;
    padding: 0.3rem 0.8rem;
    border-radius: 8px;
    color: #000;
}

.level-card h3 {
    font-size: 1.3rem;
    color: var(--color-text-main);
}

.card-description {
    font-size: 0.95rem;
    color: var(--color-text-muted);
    line-height: 1.5;
}

/* Specific Card Custom Colors (OKLCH Neon Accents) */
.badge-a1 { background: var(--color-accent-in); }
.border-a1:hover { box-shadow: 0 0 25px oklch(0.75 0.15 250 / 0.25); border-color: var(--color-accent-in); }

.badge-a2 { background: var(--color-accent-on); }
.border-a2:hover { box-shadow: 0 0 25px oklch(0.75 0.18 310 / 0.25); border-color: var(--color-accent-on); }

.badge-b1 { background: var(--color-accent-at); }
.border-b1:hover { box-shadow: 0 0 25px oklch(0.8 0.18 150 / 0.25); border-color: var(--color-accent-at); }

.badge-b2 { background: var(--color-success); }
.border-b2:hover { box-shadow: 0 0 25px oklch(0.75 0.2 150 / 0.25); border-color: var(--color-success); }

/* Card Call to Action Buttons */
.btn-card {
    display: block;
    text-align: center;
    background: oklch(1 0 0 / 0.05);
    border: 1px solid oklch(1 0 0 / 0.1);
    padding: 0.8rem 1rem;
    border-radius: 12px;
    font-weight: 600;
    font-size: 0.9rem;
    transition: all var(--transition-base);
}

.level-card:hover .btn-card {
    background: var(--color-text-main);
    color: #000;
    border-color: var(--color-text-main);
}

/* ==========================================================================
   3. HOW IT WORKS SECTION (Sequential Steps)
   ========================================================================== */
.how-it-works-section {
    max-width: 1400px;
    margin: 0 auto;
    padding: 5rem 2rem 8rem 2rem;
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 3rem;
}

.step-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 1rem;
}

.step-number {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 800;
    width: 50px;
    height: 50px;
    background: oklch(1 0 0 / 0.03);
    border: var(--glass-border);
    color: var(--color-accent-in);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    box-shadow: var(--glass-shadow);
}

.step-item h3 {
    font-size: 1.25rem;
    color: var(--color-text-main);
}

.step-item p {
    font-size: 0.95rem;
    color: var(--color-text-muted);
    max-width: 320px;
}

/* ==========================================================================
   4. WIP SYSTEM SPECIFIC UTILITIES
   ========================================================================== */
.btn-close-modal {
    background: var(--color-accent-on);
    color: #000;
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 700;
    padding: 0.75rem 2rem;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    box-shadow: 0 0 15px oklch(0.75 0.18 310 / 0.3);
    transition: all var(--transition-base);
}

.btn-close-modal:hover {
    transform: scale(1.03);
    box-shadow: 0 0 25px var(--color-accent-on);
}

/* ==========================================================================
   5. RESPONSIVE BREAKPOINT GRID STRATEGY (Mobile-First Adjustments)
   ========================================================================== */
@media (max-width: 1024px) {
    .cards-grid {
        grid-template-columns: repeat(2, 1fr); /* 2x2 grid layout on laptops/tablets */
    }
}

@media (max-width: 768px) {
    .cards-grid, .steps-grid {
        grid-template-columns: 1fr; /* Full single column stack layout on smartphones */
        gap: 1.5rem;
    }
    
    .how-it-works-section {
        padding-bottom: 4rem;
    }
}

/* ==========================================================================
   6. AUTHENTICATION SYSTEM MODAL STYLES
   ========================================================================== */
.auth-tab {
    transition: all var(--transition-base);
}
.auth-tab.active {
    border-bottom: 2px solid var(--color-accent-in) !important;
    color: var(--color-text-main) !important;
}
.auth-tab:not(.active):hover {
    color: var(--color-text-main) !important;
}

#auth-form select {
    appearance: none;
    -webkit-appearance: none;
    background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 1rem center;
    background-size: 1rem;
    padding-right: 2.5rem !important;
}

#auth-form select option {
    background: oklch(0.12 0.01 260);
    color: var(--color-text-main);
}

/* ==========================================================================
   MODAL UI POLISH
   ========================================================================== */
.btn-close-icon {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    background: oklch(1 0 0 / 0.05);
    border: 1px solid oklch(1 0 0 / 0.1);
    color: var(--color-text-main);
    width: 36px;
    height: 36px;
    border-radius: 50%;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-base);
}

.btn-close-icon:hover {
    background: oklch(0.65 0.2 25 / 0.2);
    color: var(--color-error);
    border-color: var(--color-error);
    transform: rotate(90deg);
}