/* ========================================
   ThatBioTutor Proposal — Multi-Page Design
   ======================================== */

:root {
    --primary: #10b981;
    --primary-dark: #059669;
    --primary-light: #d1fae5;
    --accent: #6366f1;
    --accent-light: #a5b4fc;
    --dark: #0f172a;
    --dark-light: #1e293b;
    --dark-medium: #334155;
    --gray: #64748b;
    --gray-light: #94a3b8;
    --light: #f8fafc;
    --white: #ffffff;
    --warning: #f59e0b;
    --error: #ef4444;
    --radius: 16px;
    --radius-sm: 8px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --shadow-glow: 0 0 40px rgba(16, 185, 129, 0.15);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    color: var(--light);
    line-height: 1.6;
    min-height: 100vh;
}

/* ========================================
   Navigation
   ======================================== */

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(15, 23, 42, 0.9);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    z-index: 1000;
    padding: 16px 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--white);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

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

.nav-links {
    display: flex;
    gap: 32px;
    list-style: none;
}

.nav-links a {
    color: var(--gray-light);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.2s;
    position: relative;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--white);
}

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary);
    border-radius: 2px;
}

.nav-cta {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: var(--white);
    padding: 10px 20px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.85rem;
    transition: transform 0.2s, box-shadow 0.2s;
}

.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 40px -10px rgba(16, 185, 129, 0.5);
}

/* ========================================
   Layout
   ======================================== */

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 120px 24px 60px;
}

.container-wide {
    max-width: 1100px;
}

/* ========================================
   Hero
   ======================================== */

.hero {
    text-align: center;
    padding: 80px 20px;
    margin-bottom: 40px;
}

.hero-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: var(--white);
    padding: 8px 20px;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 24px;
    animation: pulse 2s infinite;
}

@keyframes pulse {

    0%,
    100% {
        box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.4);
    }

    50% {
        box-shadow: 0 0 0 15px rgba(16, 185, 129, 0);
    }
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--white), var(--gray-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 16px;
    line-height: 1.1;
}

.hero-subtitle {
    color: var(--gray-light);
    font-size: 1.2rem;
    max-width: 600px;
    margin: 0 auto 32px;
}

.hero-cta-group {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 16px 32px;
    border-radius: 50px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s;
    font-size: 1rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: var(--white);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 40px -10px rgba(16, 185, 129, 0.5);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.15);
    color: var(--white);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.25);
}

/* ========================================
   Cards
   ======================================== */

.card {
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius);
    padding: 32px;
    margin-bottom: 24px;
    transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.card-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
}

.card-icon {
    font-size: 1.5rem;
}

.card h2 {
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--white);
}

.card h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--primary);
    margin: 20px 0 12px;
}

.card p {
    color: var(--gray-light);
    margin-bottom: 16px;
}

/* ========================================
   Page Headers
   ======================================== */

.page-header {
    text-align: center;
    margin-bottom: 48px;
}

.page-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 12px;
}

.page-header p {
    color: var(--gray-light);
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto;
}

/* ========================================
   Stats Grid
   ======================================== */

.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin: 40px 0;
}

.stat-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius);
    padding: 32px;
    text-align: center;
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 8px;
}

.stat-label {
    color: var(--gray-light);
    font-size: 0.9rem;
}

/* ========================================
   Problem/Solution Boxes
   ======================================== */

.problem-box {
    background: rgba(239, 68, 68, 0.1);
    border-left: 3px solid var(--error);
    padding: 20px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin-bottom: 24px;
}

.problem-box h4 {
    color: #fca5a5;
    margin-bottom: 8px;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.problem-box p {
    color: #fca5a5;
    margin: 0;
}

.solution-box {
    background: rgba(16, 185, 129, 0.1);
    border-left: 3px solid var(--primary);
    padding: 20px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin-bottom: 24px;
}

.solution-box h4 {
    color: var(--primary-light);
    margin-bottom: 8px;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.solution-box p {
    color: var(--primary-light);
    margin: 0;
}

/* ========================================
   Tables
   ======================================== */

.data-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

.data-table th,
.data-table td {
    padding: 16px;
    text-align: left;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.data-table th {
    color: var(--gray-light);
    font-weight: 500;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.data-table td {
    color: var(--light);
}

.data-table tbody tr:hover {
    background: rgba(255, 255, 255, 0.02);
}

/* ========================================
   Timeline
   ======================================== */

.timeline {
    position: relative;
    padding-left: 32px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(to bottom, var(--primary), var(--accent));
}

.timeline-item {
    position: relative;
    padding-bottom: 32px;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -37px;
    top: 4px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--primary);
    border: 2px solid var(--dark);
}

.timeline-item h4 {
    color: var(--white);
    font-size: 1rem;
    margin-bottom: 8px;
}

.timeline-item p {
    color: var(--gray-light);
    font-size: 0.9rem;
    margin: 0;
}

.timeline-item .timeline-tag {
    display: inline-block;
    background: rgba(16, 185, 129, 0.2);
    color: var(--primary);
    padding: 4px 12px;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-top: 8px;
}

/* ========================================
   Pricing
   ======================================== */

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
    margin: 40px 0;
}

.pricing-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius);
    padding: 40px;
    text-align: center;
    position: relative;
    transition: transform 0.2s, box-shadow 0.2s;
}

.pricing-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-glow);
}

.pricing-card.featured {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.1), rgba(99, 102, 241, 0.1));
    border-color: var(--primary);
}

.pricing-badge {
    position: absolute;
    top: -14px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: var(--white);
    padding: 6px 20px;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.pricing-tier {
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--gray-light);
    margin-bottom: 12px;
}

.pricing-amount {
    font-size: 3rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 8px;
}

.pricing-amount span {
    font-size: 1rem;
    font-weight: 400;
    color: var(--gray-light);
}

.pricing-description {
    color: var(--gray-light);
    font-size: 0.9rem;
    margin-bottom: 32px;
}

.pricing-features {
    list-style: none;
    text-align: left;
    margin-bottom: 32px;
}

.pricing-features li {
    padding: 12px 0;
    color: var(--light);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    align-items: center;
    gap: 12px;
}

.pricing-features li::before {
    content: '✓';
    color: var(--primary);
    font-weight: 700;
}

.pricing-features li:last-child {
    border-bottom: none;
}

.pricing-card .btn {
    width: 100%;
    justify-content: center;
}

/* ========================================
   CTA Section
   ======================================== */

.cta-section {
    text-align: center;
    padding: 80px 40px;
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.1), rgba(99, 102, 241, 0.1));
    border-radius: var(--radius);
    margin: 60px 0;
    position: relative;
    overflow: hidden;
}

.cta-section::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(16, 185, 129, 0.1) 0%, transparent 50%);
    animation: rotate 20s linear infinite;
}

@keyframes rotate {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

.cta-section h2 {
    font-size: 2.5rem;
    margin-bottom: 16px;
    position: relative;
}

.cta-section p {
    color: var(--gray-light);
    margin-bottom: 32px;
    font-size: 1.1rem;
    position: relative;
}

.cta-section .btn {
    position: relative;
}

/* ========================================
   Footer
   ======================================== */

.footer {
    text-align: center;
    padding: 40px 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    color: var(--gray);
    font-size: 0.85rem;
}

/* ========================================
   Download Button
   ======================================== */

.download-btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.15);
    color: var(--white);
    padding: 14px 28px;
    border-radius: var(--radius-sm);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s;
}

.download-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--primary);
}

.download-btn svg {
    width: 20px;
    height: 20px;
}

/* ========================================
   Accessibility
   ======================================== */

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ========================================
   Mobile Navigation
   ======================================== */

.nav-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--white);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 8px;
}

.nav-mobile {
    display: none;
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    background: rgba(15, 23, 42, 0.98);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    padding: 20px;
    z-index: 999;
}

.nav-mobile.active {
    display: block;
}

.nav-mobile a {
    display: block;
    padding: 16px 20px;
    color: var(--light);
    text-decoration: none;
    font-weight: 500;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.nav-mobile a:hover,
.nav-mobile a.active {
    color: var(--primary);
}

/* ========================================
   Reduced Motion
   ======================================== */

@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* ========================================
   Responsive
   ======================================== */

@media (max-width: 768px) {
    .nav-toggle {
        display: block;
    }

    .nav-links {
        display: none;
    }

    .hero h1 {
        font-size: 2.2rem;
    }

    .stats-grid,
    .pricing-grid {
        grid-template-columns: 1fr;
    }

    .container {
        padding: 100px 16px 40px;
    }

    .card {
        padding: 24px;
    }

    .hero-cta-group {
        flex-direction: column;
        align-items: center;
    }
}