/**
 * GradeGPT Beta - Stripe-inspired Landing Page Styles
 * Version: 2.0.7 - Logos always in one row
 * 
 * Design Philosophy:
 * - Premium, polished aesthetic inspired by Stripe
 * - Gradient mesh backgrounds with animated blobs
 * - Subtle depth through layered shadows
 * - Smooth micro-interactions
 * - Professional typography with personality
 */

/* ============================================
   CSS Custom Properties (Design Tokens)
   ============================================ */
:root {
    /* Primary Colors - Brand navy blue based on #121c50 */
    --color-primary-900: #0a1030;
    --color-primary-800: #0f1743;
    --color-primary-700: #121c50;
    --color-primary-600: #1a2766;
    --color-primary-500: #23337d;
    --color-primary-400: #3d5199;
    --color-primary-300: #6b80c4;
    --color-primary-200: #a0b2d9;
    --color-primary-100: #d5deef;
    
    /* Accent Colors - Warm gold */
    --color-accent-500: #f59e0b;
    --color-accent-400: #fbbf24;
    --color-accent-300: #fcd34d;
    
    /* Success Green */
    --color-success-500: #10b981;
    --color-success-400: #34d399;
    
    /* Neutrals */
    --color-white: #ffffff;
    --color-gray-50: #f9fafa;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-300: #d1d5db;
    --color-gray-400: #9ca3af;
    --color-gray-500: #6b7280;
    --color-gray-600: #4b5563;
    --color-gray-700: #374151;
    --color-gray-800: #1f2937;
    --color-gray-900: #111827;
    
    /* Typography */
    --font-display: 'Sora', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-body: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    
    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --shadow-glow: 0 0 40px rgba(18, 28, 80, 0.3);
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============================================
   Reset & Base Styles
   ============================================ */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-body);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-gray-800);
    background: var(--color-gray-50);
    min-height: 100vh;
    overflow-x: hidden;
}

/* ============================================
   Background - Night Sky with Stars & Meteors
   ============================================ */
.page-background {
    position: fixed;
    inset: 0;
    z-index: -1;
    overflow: hidden;
    background: linear-gradient(180deg, #1a1a2e 0%, #2d2d44 40%, #3d3d5c 70%, #4a4a6a 100%);
}

.page-background canvas {
    display: block;
    position: absolute;
    top: 0;
    left: 0;
}

/* ============================================
   Typography
   ============================================ */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.2;
    color: var(--color-gray-900);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 1.875rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
    color: var(--color-gray-600);
}

.text-gradient {
    background: linear-gradient(135deg, var(--color-primary-300), var(--color-accent-400));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ============================================
   Layout
   ============================================ */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.section {
    padding: var(--space-16) 0;
}

/* ============================================
   Navigation
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: var(--space-4) 0;
    background: #f9fafa;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

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

.logo {
    position: relative;
    display: flex;
    align-items: center;
    text-decoration: none;
}

.logo-img {
    height: 48px;
    width: auto;
    object-fit: contain;
}

.logo-beta-badge {
    position: absolute;
    top: -4px;
    right: -28px;
    padding: 1px 6px;
    background: var(--color-primary-700);
    color: white;
    font-size: 0.6rem;
    font-weight: 700;
    font-family: var(--font-display);
    border-radius: var(--radius-full);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-8);
    list-style: none;
}

.nav-links a {
    color: var(--color-gray-600);
    text-decoration: none;
    font-size: 0.9375rem;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.nav-links a:hover {
    color: var(--color-primary-600);
}

.nav-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-1);
    padding: var(--space-1) var(--space-3);
    background: linear-gradient(135deg, var(--color-success-500), var(--color-success-400));
    color: white;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    padding-top: calc(80px + var(--space-16));
    padding-bottom: var(--space-16);
    text-align: center;
}

.hero h1 {
    color: #ffffff;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: var(--space-6);
    animation: fade-in-up 0.6s ease-out;
}

.hero-badge .pulse {
    width: 8px;
    height: 8px;
    background: var(--color-success-500);
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(1.2); }
}

.hero h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    margin-bottom: var(--space-4);
    animation: fade-in-up 0.6s ease-out 0.1s backwards;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.65);
    max-width: 600px;
    margin: 0 auto var(--space-8);
    animation: fade-in-up 0.6s ease-out 0.2s backwards;
}

@keyframes fade-in-up {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============================================
   Confirmation Card
   ============================================ */
.confirmation-card {
    max-width: 560px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(16px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: var(--radius-2xl);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3), var(--shadow-glow);
    padding: var(--space-10);
    text-align: left;
    animation: card-appear 0.8s ease-out 0.3s backwards;
}

@keyframes card-appear {
    from {
        opacity: 0;
        transform: translateY(30px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.card-header {
    display: flex;
    align-items: flex-start;
    gap: var(--space-4);
    margin-bottom: var(--space-6);
}

.success-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--color-success-500), var(--color-success-400));
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.success-icon svg {
    width: 28px;
    height: 28px;
    color: white;
}

.card-header-text h2 {
    font-size: 1.5rem;
    margin-bottom: var(--space-1);
}

.card-header-text p {
    font-size: 0.9375rem;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-4);
    margin-bottom: var(--space-6);
    padding: var(--space-5);
    background: var(--color-gray-50);
    border-radius: var(--radius-xl);
}

.stat-item {
    text-align: center;
}

.stat-icon {
    font-size: 1.25rem;
    margin-bottom: var(--space-1);
}

.stat-value {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-gray-900);
}

.stat-label {
    font-size: 0.75rem;
    color: var(--color-gray-500);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Progress Bar */
.progress-section {
    margin-bottom: var(--space-6);
}

.progress-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-2);
}

.progress-label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-gray-700);
}

.progress-percentage {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-primary-600);
}

.progress-bar {
    height: 8px;
    background: var(--color-gray-200);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary-600), var(--color-primary-400));
    border-radius: var(--radius-full);
    transition: width 1s ease-out;
    animation: progress-animate 2s ease-out forwards;
}

@keyframes progress-animate {
    from { width: 0; }
    to { width: var(--progress-width, 67%); }
}

/* CTA Button */
.cta-button {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    width: 100%;
    padding: var(--space-4) var(--space-6);
    background: #121c50;
    color: white;
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-xl);
    cursor: pointer;
    transition: all var(--transition-base);
    box-shadow: 0 4px 14px rgba(18, 28, 80, 0.4);
}

.cta-button:hover {
    transform: translateY(-2px);
    background: #1a2766;
    box-shadow: 0 6px 20px rgba(18, 28, 80, 0.5);
}

.cta-button:active {
    transform: translateY(0);
}

.cta-button svg {
    width: 20px;
    height: 20px;
}

/* Email confirmation */
.email-confirmation {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    margin-top: var(--space-4);
    font-size: 0.875rem;
    color: var(--color-gray-500);
}

.email-confirmation svg {
    width: 16px;
    height: 16px;
    color: var(--color-success-500);
}

/* ============================================
   Activity Feed
   ============================================ */
.activity-feed {
    max-width: 560px;
    margin: var(--space-8) auto 0;
    animation: fade-in-up 0.6s ease-out 0.5s backwards;
}

.activity-header {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: 0.75rem;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.6);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-3);
}

.activity-header .live-dot {
    width: 6px;
    height: 6px;
    background: var(--color-success-500);
    border-radius: 50%;
    animation: pulse 1.5s ease-in-out infinite;
}

.activity-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
    overflow: hidden;
}

.activity-item {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    background: rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    font-size: 0.875rem;
    animation: slide-in 0.4s ease-out backwards;
}

.activity-item:nth-child(1) { animation-delay: 0.6s; }
.activity-item:nth-child(2) { animation-delay: 0.7s; }
.activity-item:nth-child(3) { animation-delay: 0.8s; }
.activity-item:nth-child(4) { animation-delay: 0.9s; }

@keyframes slide-in {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.activity-avatar {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-full);
    object-fit: cover;
    flex-shrink: 0;
}

.activity-text {
    flex: 1;
    color: rgba(255, 255, 255, 0.7);
}

.activity-text strong {
    color: #ffffff;
}

.activity-time {
    font-size: 0.75rem;
    color: rgba(255, 255, 255, 0.4);
}

/* ============================================
   Features Section
   ============================================ */
.features-section {
    background: var(--color-white);
    border-top: 1px solid var(--color-gray-100);
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-12);
}

.section-header h2 {
    margin-bottom: var(--space-4);
}

.section-header p {
    max-width: 600px;
    margin: 0 auto;
    font-size: 1.125rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-8);
}

.feature-card {
    padding: var(--space-8);
    background: var(--color-gray-50);
    border-radius: var(--radius-xl);
    transition: all var(--transition-base);
}

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

.feature-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--color-primary-600), var(--color-primary-400));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: var(--space-4);
}

.feature-card h3 {
    margin-bottom: var(--space-2);
}

.feature-card p {
    font-size: 0.9375rem;
}

/* ============================================
   Social Proof / Logos
   ============================================ */
.logos-section {
    text-align: center;
    padding: var(--space-12) 0;
    border-bottom: 1px solid var(--color-gray-100);
    background: var(--color-white);
}

.logos-label {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--color-gray-400);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-6);
}

.logos-grid {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-6);
    flex-wrap: nowrap;
    margin: 0 auto;
}

.logos-grid img {
    display: block;
}

.university-logo {
    height: 44px !important;
    max-height: 44px !important;
    width: 120px !important;
    max-width: 120px !important;
    object-fit: contain !important;
    filter: grayscale(100%);
    opacity: 0.6;
    transition: all var(--transition-base);
    flex-shrink: 0 !important;
}

.university-logo:hover {
    filter: grayscale(0%);
    opacity: 1;
}

/* ============================================
   Testimonial
   ============================================ */
.testimonial-section {
    background: linear-gradient(135deg, var(--color-primary-900), var(--color-primary-800));
    color: white;
}

.testimonial-card {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
}

.testimonial-quote {
    font-size: 1.5rem;
    font-weight: 400;
    line-height: 1.5;
    margin-bottom: var(--space-6);
    color: rgba(255, 255, 255, 0.95);
}

.testimonial-author {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-4);
}

.author-avatar {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-full);
    object-fit: cover;
}

.author-info {
    text-align: left;
}

.author-name {
    font-weight: 600;
    color: white;
}

.author-role {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.7);
}

/* ============================================
   FAQ Section
   ============================================ */
.faq-section {
    background: var(--color-white);
}

.faq-grid {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border-bottom: 1px solid var(--color-gray-200);
    padding: var(--space-6) 0;
}

.faq-question {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-family: var(--font-display);
    font-size: 1.0625rem;
    font-weight: 600;
    color: var(--color-gray-900);
    cursor: pointer;
    transition: color var(--transition-fast);
}

.faq-question:hover {
    color: var(--color-primary-600);
}

.faq-question svg {
    width: 20px;
    height: 20px;
    color: var(--color-gray-400);
    transition: transform var(--transition-base);
}

.faq-item.open .faq-question svg {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-slow);
}

.faq-item.open .faq-answer {
    max-height: 200px;
}

.faq-answer p {
    padding-top: var(--space-4);
    font-size: 0.9375rem;
}

/* ============================================
   Countdown Timer
   ============================================ */
.countdown-section {
    text-align: center;
    padding: var(--space-10);
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.05), rgba(245, 158, 11, 0.05));
    border-radius: var(--radius-2xl);
    margin-top: var(--space-12);
}

.countdown-label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-gray-500);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-4);
}

.countdown-timer {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-4);
}

.countdown-unit {
    text-align: center;
}

.countdown-value {
    font-family: var(--font-mono);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-gray-900);
    background: var(--color-white);
    padding: var(--space-3) var(--space-5);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    min-width: 80px;
}

.countdown-unit-label {
    font-size: 0.75rem;
    color: var(--color-gray-500);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-top: var(--space-2);
}

.countdown-separator {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-gray-300);
}

.countdown-separator-ms {
    font-size: 1.5rem;
    color: var(--color-primary-400);
}

.countdown-value-ms {
    color: var(--color-primary-600);
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(99, 102, 241, 0.05));
}

.countdown-unit-ms .countdown-unit-label {
    color: var(--color-primary-500);
}

/* ============================================
   Footer
   ============================================ */
.footer {
    background: var(--color-gray-900);
    color: var(--color-gray-400);
    padding: var(--space-12) 0 var(--space-8);
}

.footer-content {
    display: flex;
    justify-content: center;
    align-items: center;
}

.footer-links {
    display: flex;
    gap: var(--space-6);
}

.footer-links a {
    color: var(--color-gray-400);
    text-decoration: none;
    font-size: 0.875rem;
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: white;
}

.footer-copyright {
    width: 100%;
    text-align: center;
    padding-top: var(--space-4);
    margin-top: var(--space-4);
    font-size: 0.875rem;
}

.footer-domain {
    color: var(--color-gray-400);
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-domain:hover {
    color: var(--color-primary-300);
}

/* ============================================
   Modal
   ============================================ */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: white;
    border-radius: var(--radius-2xl);
    padding: var(--space-10);
    max-width: 440px;
    width: 90%;
    text-align: center;
    transform: scale(0.9) translateY(20px);
    transition: transform var(--transition-base);
}

.modal-overlay.active .modal-content {
    transform: scale(1) translateY(0);
}

.modal-icon {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--color-primary-100), var(--color-primary-200));
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-5);
    font-size: 1.75rem;
}

.modal-content h3 {
    margin-bottom: var(--space-3);
}

.modal-content p {
    margin-bottom: var(--space-6);
}

.modal-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-3) var(--space-8);
    background: #121c50;
    color: white;
    font-family: var(--font-display);
    font-weight: 600;
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.modal-button:hover {
    background: #1a2766;
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    
    .nav-links {
        display: none;
    }
    
    .hero {
        padding-top: calc(70px + var(--space-10));
    }
    
    .confirmation-card {
        padding: var(--space-6);
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
        gap: var(--space-3);
    }
    
    .countdown-timer {
        flex-wrap: wrap;
    }
    
    .countdown-value {
        font-size: 1.75rem;
        padding: var(--space-2) var(--space-4);
        min-width: 60px;
    }
}