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

:root {
    /* Colors */
    --primary-red: #da233e;
    --primary-black: #231f20;
    --primary-white: #f5f5f5;
    --soft-grey: #F8F9FA;
    --medium-grey: #6C757D;
    --light-grey: #E9ECEF;
    --accent-blue: #ffd021;
    --accent-purple: #845EC2;
    
    /* Typography */
    --font-xs: 0.75rem;
    --font-sm: 0.875rem;
    --font-base: 1rem;
    --font-lg: 1.125rem;
    --font-xl: 1.25rem;
    --font-2xl: 1.5rem;
    --font-3xl: 1.875rem;
    --font-4xl: 2.25rem;
    --font-5xl: 3rem;
    --font-6xl: 3.75rem;
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    --space-4xl: 5rem;
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
}

body {
    font-family: 'Open Sans', sans-serif;
    line-height: 1.6;
    color: var(--primary-black);
    scroll-behavior: smooth;
    font-size: var(--font-base);
}

/* Navigation */
nav {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(15px);
    z-index: 1000;
    padding: var(--space-md) var(--space-xl);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

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

.logo-container {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.logo-img {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
    transition: all 0.3s ease;
}

.logo-img:hover {
    transform: rotate(360deg) scale(1.1);
}

.logo {
    font-size: var(--font-xl);
    font-weight: 700;
    color: var(--primary-red);
    transition: all 0.3s ease;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: var(--space-lg);
}

.nav-links a {
    text-decoration: none;
    color: var(--primary-black);
    font-weight: 500;
    font-size: var(--font-sm);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

.nav-links a:hover {
    color: var(--primary-red);
    transform: translateY(-2px);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-red);
    transition: width 0.3s ease;
}

.nav-links a:hover::after {
    width: 100%;
}

.register-btn {
    background: var(--primary-black);
    color: var(--primary-white);
    padding: var(--space-sm) var(--space-lg);
    border: none;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: var(--font-sm);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-decoration: none;
}

.register-btn:hover {
    background: var(--primary-red);
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(230, 57, 70, 0.3);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-white) 0%, var(--soft-grey) 50%, rgba(230, 57, 70, 0.05) 100%);
    text-align: center;
    padding: var(--space-xl);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="1" fill="rgba(230,57,70,0.1)"/></svg>') repeat;
    animation: float 20s infinite linear;
    pointer-events: none;
}

.hero-content {
    max-width: 700px;
    position: relative;
    z-index: 1;
}

.hero h1 {
    font-size: clamp(var(--font-4xl), 8vw, var(--font-6xl));
    font-weight: 800;
    margin-bottom: var(--space-md);
    color: var(--primary-black);
    animation: slideUpFade 1.2s cubic-bezier(0.4, 0, 0.2, 1) 0.3s both;
}

.hero-subtitle {
    font-size: var(--font-lg);
    color: var(--medium-grey);
    margin-bottom: var(--space-2xl);
    font-weight: 400;
    animation: slideUpFade 1.2s cubic-bezier(0.4, 0, 0.2, 1) 0.6s both;
}

.hero-buttons {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
    animation: slideUpFade 1.2s cubic-bezier(0.4, 0, 0.2, 1) 0.9s both;
}

.btn-primary {
    background: var(--primary-red);
    color: var(--primary-white);
    padding: var(--space-md) var(--space-xl);
    border: none;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: var(--font-base);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-decoration: none;
    display: inline-block;
    position: relative;
    overflow: hidden;
}

.btn-primary::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    transition: left 0.6s;
}

.btn-primary:hover::before {
    left: 100%;
}

.btn-primary:hover {
    background: #d32f3f;
    transform: translateY(-4px);
    box-shadow: 0 12px 30px rgba(230, 57, 70, 0.4);
}

.btn-secondary {
    background: transparent;
    color: var(--primary-black);
    padding: var(--space-md) var(--space-xl);
    border: 2px solid var(--primary-black);
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: var(--font-base);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-decoration: none;
    display: inline-block;
}

.btn-secondary:hover {
    background: var(--primary-black);
    color: var(--primary-white);
    transform: translateY(-4px);
    box-shadow: 0 8px 25px rgba(26, 26, 26, 0.2);
}

/* Sections */
.section {
    padding: var(--space-4xl) var(--space-xl);
    max-width: 1200px;
    margin: 0 auto;
}

.section-title {
    font-size: clamp(var(--font-3xl), 5vw, var(--font-4xl));
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--space-2xl);
    color: var(--primary-black);
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-red), var(--accent-purple));
    border-radius: 2px;
}

/* What is Relay Hack */
.about-description {
    font-size: var(--font-lg);
    text-align: center;
    max-width: 700px;
    margin: 0 auto var(--space-3xl);
    color: var(--medium-grey);
    line-height: 1.8;
}

.icon-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: var(--space-lg);
    margin-top: var(--space-2xl);
}

.icon-card {
    background: var(--primary-white);
    padding: var(--space-xl);
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid var(--light-grey);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.icon-card::before {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    background: linear-gradient(45deg, var(--primary-red), var(--accent-blue), var(--accent-purple));
    border-radius: var(--radius-lg);
    z-index: -1;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.icon-card:hover::before {
    opacity: 1;
}

.icon-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 20px 40px rgba(230, 57, 70, 0.15);
}

.icon-card .emoji {
    font-size: var(--font-4xl);
    margin-bottom: var(--space-md);
    display: block;
    transition: all 0.3s ease;
}

.icon-card:hover .emoji {
    transform: scale(1.2);
}

.icon-card h3 {
    font-size: var(--font-base);
    font-weight: 600;
    color: var(--primary-black);
}

/* Past Sprints */
.past-sprints {
    /* background: var(--soft-grey); */
    position: relative;
}

.sprint-case {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--space-3xl);
    align-items: center;
    max-width: 1000px;
    margin: 0 auto;
}

.partner-logo {
    /* background: var(--primary-white); */
    background-color:#ffdd00 ;
    padding: var(--space-2xl);
    border-radius: var(--radius-xl);
    text-align: center;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
    transition: all 0.4s ease;
    position: relative;
    overflow: hidden;
}

.partner-logo::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(230, 57, 70, 0.1), transparent);
    transition: left 0.6s ease;
}

.partner-logo:hover::before {
    left: 100%;
}

.partner-logo:hover {
    transform: scale(1.05) rotate(2deg);
}

.partner-logo img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-sm);
}

.foodmandu-placeholder {
    width: 180px;
    height: 60px;
    /* background: linear-gradient(135deg, var(--primary-red), #ff6b7a); */
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: var(--font-sm);
    margin: 0 auto;
}

.case-content h3 {
    font-size: var(--font-xl);
    font-weight: 700;
    margin-bottom: var(--space-md);
    color: var(--primary-black);
}

.case-content p {
    font-size: var(--font-base);
    color: var(--medium-grey);
    line-height: 1.7;
    margin-bottom: var(--space-lg);
}

.highlight {
    background: linear-gradient(135deg, var(--primary-red), var(--accent-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
}

/* Current Sprint */
.current-sprint-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.current-partner {
    background: var(--primary-white);
    padding: var(--space-xl);
    border-radius: var(--radius-xl);
    margin: var(--space-xl) 0;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.06);
    transition: all 0.3s ease;
}

.current-partner:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
}

.partner-placeholder {
    width: 180px;
    height: 80px;
    margin: 0 auto var(--space-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-xl);
    font-weight: 700;
    color: white;
    animation: pulse 2s infinite;
}

.current-partner p {
    font-size: var(--font-base);
    color: var(--medium-grey);
    line-height: 1.7;
}

/* Timeline */
.timeline-section {
    margin-top: var(--space-3xl);
    background: var(--primary-white);
    padding: var(--space-2xl);
    border-radius: var(--radius-xl);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
}

.timeline-title {
    text-align: center;
    font-size: var(--font-2xl);
    font-weight: 700;
    margin-bottom: var(--space-2xl);
    color: var(--primary-black);
}

.timeline-container {
    overflow-x: auto;
    padding: var(--space-md) 0;
}

.timeline {
    display: flex;
    gap: var(--space-lg);
    min-width: 800px;
    position: relative;
    padding: 0 var(--space-lg);
}

.timeline::before {
    content: '';
    position: absolute;
    top: 4rem;
    left: 10%;
    right: 10%;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-red), var(--accent-blue), var(--accent-purple));
    border-radius: 2px;
    z-index: 0;
}

.timeline-item {
    flex: 1;
    text-align: center;
    position: relative;
    z-index: 1;
}

.timeline-icon {
    font-size: var(--font-4xl);
    margin-bottom: var(--space-sm);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    display: block;
    background: var(--primary-white);
    width: 80px;
    height: 80px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-sm);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.timeline-icon:hover {
    transform: scale(1.3) rotateY(360deg);
    box-shadow: 0 8px 25px rgba(230, 57, 70, 0.2);
}

.timeline-item h4 {
    font-size: var(--font-sm);
    font-weight: 600;
    color: var(--primary-black);
    margin-bottom: var(--space-xs);
}

.timeline-date {
    font-size: var(--font-xs);
    color: var(--medium-grey);
    background: var(--light-grey);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    display: inline-block;
}

/* Why Join Section */
.why-join {
    background: var(--primary-black);
    color: var(--primary-white);
    position: relative;
    overflow: hidden;
}

.why-join::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><polygon points="50,10 90,90 10,90" fill="rgba(230,57,70,0.05)"/></svg>') repeat;
    animation: float 25s infinite linear reverse;
    pointer-events: none;
}

.why-join .section-title {
    color: var(--primary-white);
    position: relative;
    z-index: 1;
}

.split-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-2xl);
    margin-top: var(--space-2xl);
    position: relative;
    z-index: 1;
}

.split-card {
    background: rgba(255, 255, 255, 0.05);
    padding: var(--space-2xl);
    border-radius: var(--radius-xl);
    text-align: center;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid rgba(255, 255, 255, 0.1);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.split-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--primary-red), var(--accent-blue));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.split-card:hover::before {
    opacity: 0.1;
}

.split-card:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-8px) scale(1.02);
}

.split-card h3 {
    font-size: var(--font-2xl);
    font-weight: 700;
    margin-bottom: var(--space-md);
    color: var(--primary-red);
    position: relative;
    z-index: 1;
}

.split-card p {
    color: var(--light-grey);
    font-size: var(--font-base);
    position: relative;
    z-index: 1;
}

/* CTA Section */
.cta-section {
    background: linear-gradient(135deg, var(--soft-grey), var(--primary-white), rgba(77, 171, 247, 0.05));
    text-align: center;
    position: relative;
}

.cta-tagline {
    font-size: clamp(var(--font-2xl), 4vw, var(--font-3xl));
    font-weight: 700;
    margin-bottom: var(--space-xl);
    font-style: italic;
    color: var(--primary-black);
    animation: bounce 2s infinite;
}

.cta-buttons {
    display: flex;
    gap: var(--space-lg);
    justify-content: center;
    flex-wrap: wrap;
}

/* Footer */
footer {
    background: var(--primary-black);
    color: var(--primary-white);
    padding: var(--space-2xl) var(--space-xl) var(--space-xl);
    text-align: center;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-logo-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-xl);
}

.footer-logo-img {
    width: 180px;
    height: 24px;
    /* background: linear-gradient(135deg, var(--primary-red), var(--accent-purple)); */
    border-radius: var(--radius-sm);
}

.footer-logo {
    font-size: var(--font-lg);
    font-weight: 700;
    color: var(--primary-red);
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: var(--space-xl);
    margin-bottom: var(--space-xl);
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--light-grey);
    text-decoration: none;
    font-size: var(--font-sm);
    transition: all 0.3s ease;
}

.footer-links a:hover {
    color: var(--primary-red);
    transform: translateY(-2px);
}

.social-icons {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
    margin-bottom: var(--space-xl);
}

.social-icon {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    color: var(--primary-white);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    font-size: var(--font-lg);
}

.social-icon:hover {
    background: var(--primary-red);
    transform: translateY(-4px) rotate(360deg);
}

.footer-tagline {
    font-size: var(--font-sm);
    color: var(--medium-grey);
    font-style: italic;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUpFade {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes float {
    from { transform: translateX(-50px); }
    to { transform: translateX(50px); }
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(-10px); }
    60% { transform: translateY(-5px); }
}

.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.fade-in-up.visible {
    opacity: 1;
    transform: translateY(0);
}

.stagger-1 { transition-delay: 0.1s; }
.stagger-2 { transition-delay: 0.2s; }
.stagger-3 { transition-delay: 0.3s; }
.stagger-4 { transition-delay: 0.4s; }

/* Mobile Responsiveness */
@media (max-width: 768px) {
    nav {
        padding: var(--space-md);
    }

    .nav-links {
        display: none;
    }

    .hero {
        padding: var(--space-md);
        min-height: 90vh;
    }

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

    .sprint-case {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
        text-align: center;
    }

    .split-section {
        grid-template-columns: 1fr;
        gap: var(--space-lg);
    }

    .section {
        padding: var(--space-2xl) var(--space-md);
    }

    .timeline {
        min-width: 600px;
    }

    .footer-links {
        flex-direction: column;
        gap: var(--space-md);
    }

    .icon-cards {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .icon-cards {
        grid-template-columns: 1fr;
    }
}

/* Special hover effects */
.wiggle:hover {
    animation: wiggle 0.6s ease-in-out;
}

.launch:hover {
    animation: launch 0.8s ease-out;
}

@keyframes wiggle {
    0%, 100% { transform: rotate(0deg); }
    25% { transform: rotate(-8deg); }
    75% { transform: rotate(8deg); }
}

@keyframes launch {
    0% { transform: translateY(0) scale(1); }
    50% { transform: translateY(-25px) scale(1.1); }
    100% { transform: translateY(0) scale(1); }
}