:root {
    --primary: #0047FF;
    --secondary: #FF3366;
    --accent: #6B4EFF;
    --text: #1a1a1a;
    --text-light: #666666;
    --bg: #ffffff;
    --bg-light: #f8f8f8;
    --border: #e0e0e0;
}

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

body {
    font-family: 'Inter', sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
}

/* Navigation */
nav {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.98);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(10px);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 1.5rem 3rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-family: 'Space Mono', monospace;
    font-size: 1.3rem;
    font-weight: 700;
    letter-spacing: -0.5px;
    color: var(--text);
    text-decoration: none;
}

.logo span {
    color: var(--primary);
}

.nav-links {
    display: flex;
    gap: 2.5rem;
    list-style: none;
}

.nav-links a {
    color: var(--text);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    letter-spacing: 0.3px;
    transition: color 0.3s ease;
}

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

/* Hero */
.participation-hero {
    padding: 12rem 3rem 6rem;
    text-align: center;
    background: linear-gradient(180deg, var(--bg-light) 0%, var(--bg) 100%);
}

.hero-container {
    max-width: 1000px;
    margin: 0 auto;
}

.hero-badge {
    font-family: 'Space Mono', monospace;
    font-size: 0.75rem;
    color: var(--primary);
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-bottom: 2rem;
}

.hero-title {
    font-size: clamp(4rem, 8vw, 7rem);
    line-height: 1;
    font-weight: 700;
    letter-spacing: -3px;
    margin-bottom: 1.5rem;
}

.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.2rem);
    color: var(--text-light);
    line-height: 1.7;
    font-weight: 400;
}

/* Filter Section */
.filter-section {
    position: sticky;
    top: 73px;
    z-index: 999;
    background: var(--bg);
    border-bottom: 2px solid var(--border);
    padding: 1.5rem 3rem;
}

.filter-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.filter-label {
    font-family: 'Space Mono', monospace;
    font-size: 0.85rem;
    color: var(--text-light);
    letter-spacing: 1px;
    text-transform: uppercase;
}

.filter-buttons {
    display: flex;
    gap: 0.8rem;
    flex-wrap: wrap;
    flex: 1;
}

.filter-btn {
    font-family: 'Space Mono', monospace;
    font-size: 0.85rem;
    padding: 0.6rem 1.2rem;
    background: white;
    border: 1px solid var(--border);
    color: var(--text);
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.filter-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.filter-btn.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

/* Stats Bar */
.stats-bar {
    padding: 4rem 3rem;
    background: var(--bg-light);
}

.stats-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 3rem;
}

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

.stat-number {
    font-size: clamp(2.5rem, 4vw, 3.5rem);
    font-weight: 700;
    color: var(--primary);
    line-height: 1;
    margin-bottom: 0.8rem;
}

.stat-label {
    font-family: 'Space Mono', monospace;
    font-size: 0.85rem;
    color: var(--text-light);
    letter-spacing: 0.5px;
}

/* Events Section */
.events-section {
    padding: 6rem 3rem;
}

.events-container {
    max-width: 1200px;
    margin: 0 auto;
}

/* Year Section */
.year-section {
    margin-bottom: 6rem;
}

.year-header {
    position: sticky;
    top: 140px;
    z-index: 99;
    background: var(--bg);
    padding: 2rem 0;
    margin-bottom: 3rem;
    border-bottom: 3px solid var(--primary);
}

.year-header h2 {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    letter-spacing: -1.5px;
    color: var(--primary);
}

/* Event Card */
.event-card {
    display: grid;
    grid-template-columns: 180px 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
    padding: 2.5rem;
    background: white;
    border: 1px solid var(--border);
    border-left: 4px solid var(--primary);
    transition: all 0.3s ease;
}

.event-card:hover {
    transform: translateX(5px);
    box-shadow: -5px 5px 20px rgba(0, 0, 0, 0.08);
}

.event-card.hidden {
    display: none;
}

.event-date {
    font-family: 'Space Mono', monospace;
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--primary);
    padding-top: 0.2rem;
}

.event-content {
    flex: 1;
}

.event-type {
    font-family: 'Space Mono', monospace;
    font-size: 0.75rem;
    color: var(--accent);
    letter-spacing: 1.5px;
    text-transform: uppercase;
    margin-bottom: 0.8rem;
}

.event-content h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    line-height: 1.3;
}

.event-content > p {
    font-size: 1.05rem;
    line-height: 1.7;
    color: var(--text-light);
    margin-bottom: 1.5rem;
}

/* Event Details */
.event-details {
    background: var(--bg-light);
    padding: 1.5rem;
    margin: 1.5rem 0;
    border-left: 3px solid var(--accent);
}

.detail-item {
    font-size: 0.95rem;
    line-height: 1.7;
    color: var(--text-light);
    margin-bottom: 1rem;
}

.detail-item:last-child {
    margin-bottom: 0;
}

.detail-item strong {
    color: var(--text);
    font-weight: 600;
}

/* Workshop List */
.workshop-list {
    background: var(--bg-light);
    padding: 1.5rem;
    margin: 1.5rem 0;
}

.workshop-item {
    font-size: 0.95rem;
    line-height: 1.7;
    color: var(--text-light);
    margin-bottom: 1rem;
    padding-left: 1.5rem;
    position: relative;
}

.workshop-item:last-child {
    margin-bottom: 0;
}

.workshop-item::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 700;
}

.workshop-item strong {
    color: var(--primary);
    font-weight: 600;
}

/* Event Tags */
.event-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
    margin-top: 1.5rem;
}

.tag {
    font-family: 'Space Mono', monospace;
    font-size: 0.75rem;
    padding: 0.4rem 0.8rem;
    background: var(--bg-light);
    border: 1px solid var(--border);
    color: var(--text);
    letter-spacing: 0.3px;
}

/* Event Links */
.event-link {
    display: inline-block;
    font-family: 'Space Mono', monospace;
    font-size: 0.85rem;
    color: var(--primary);
    text-decoration: none;
    margin-top: 1rem;
    margin-right: 1.5rem;
    transition: color 0.3s ease;
}

.event-link:hover {
    color: var(--secondary);
}

/* CTA */
.cta-section {
    padding: 8rem 3rem;
    background: var(--primary);
    color: white;
    text-align: center;
}

.cta-content {
    max-width: 800px;
    margin: 0 auto;
}

.cta-content h2 {
    font-size: clamp(2rem, 4vw, 3.5rem);
    line-height: 1.2;
    font-weight: 700;
    letter-spacing: -1.5px;
    margin-bottom: 2rem;
}

.cta-content p {
    font-size: 1.2rem;
    line-height: 1.8;
    margin-bottom: 3rem;
    opacity: 0.9;
}

.btn {
    display: inline-block;
    padding: 1rem 2rem;
    font-family: 'Space Mono', monospace;
    font-size: 0.9rem;
    font-weight: 700;
    letter-spacing: 0.5px;
    text-decoration: none;
    border: 2px solid white;
    background: white;
    color: var(--primary);
    transition: all 0.3s ease;
}

.btn:hover {
    background: transparent;
    color: white;
}

/* Footer */
footer {
    padding: 4rem 3rem 2rem;
    background: var(--bg-light);
    border-top: 1px solid var(--border);
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 4rem;
    margin-bottom: 3rem;
}

.footer-section h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    letter-spacing: -0.3px;
}

.footer-section p {
    color: var(--text-light);
    line-height: 1.7;
    font-size: 0.95rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: 0.8rem;
}

.footer-section a {
    color: var(--text-light);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--primary);
}

.footer-bottom {
    max-width: 1400px;
    margin: 0 auto;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--text-light);
}

/* Large Screen Optimizations */
@media (min-width: 1920px) {
    .participation-hero {
        padding: 14rem 4rem 8rem;
    }

    .hero-title {
        font-size: 8rem;
    }

    .events-section {
        padding: 8rem 4rem;
    }

    .event-card {
        padding: 3rem;
    }

    .stat-number {
        font-size: 4rem;
    }
}

@media (min-width: 2560px) {
    body {
        font-size: 18px;
    }

    .participation-hero {
        padding: 16rem 5rem 10rem;
    }

    .hero-title {
        font-size: 10rem;
    }

    .events-section {
        padding: 10rem 5rem;
    }

    .event-card {
        padding: 4rem;
        gap: 4rem;
    }

    .stat-number {
        font-size: 5rem;
    }
}

@media (min-width: 3840px) {
    body {
        font-size: 22px;
    }

    .participation-hero {
        padding: 20rem 8rem 12rem;
    }

    .hero-title {
        font-size: 12rem;
    }

    .events-section {
        padding: 14rem 8rem;
    }

    .event-card {
        padding: 5rem;
        gap: 5rem;
    }

    .stat-number {
        font-size: 6rem;
    }
}

/* Responsive */
@media (max-width: 1024px) {
    .event-card {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .event-date {
        padding-bottom: 0.5rem;
        border-bottom: 1px solid var(--border);
    }

    .filter-container {
        flex-direction: column;
        align-items: flex-start;
    }

    .filter-buttons {
        width: 100%;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .participation-hero {
        padding: 8rem 2rem 4rem;
    }

    .filter-section {
        padding: 1rem 2rem;
    }

    .filter-btn {
        font-size: 0.75rem;
        padding: 0.5rem 0.9rem;
    }

    .stats-bar {
        padding: 3rem 2rem;
    }

    .stats-container {
        grid-template-columns: repeat(2, 1fr);
        gap: 2rem;
    }

    .events-section {
        padding: 3rem 2rem;
    }

    .event-card {
        padding: 1.5rem;
        margin-bottom: 2rem;
    }

    .year-header {
        top: 115px;
        padding: 1.5rem 0;
    }

    .cta-section {
        padding: 4rem 2rem;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .footer-bottom {
        flex-direction: column;
        gap: 1rem;
    }
}