:root {
    --background: hsl(222, 84%, 5%);
    --foreground: hsl(210, 40%, 98%);
    --card: hsl(217, 33%, 17%);
    --card-foreground: hsl(210, 40%, 98%);
    --primary: hsl(214, 100%, 27%);
    --primary-foreground: hsl(210, 40%, 98%);
    --secondary: hsl(215, 28%, 17%);
    --muted: hsl(215, 28%, 17%);
    --muted-foreground: hsl(217, 11%, 65%);
    --accent: hsl(214, 100%, 59%);
    --accent-foreground: hsl(210, 40%, 98%);
    --border: hsl(217, 33%, 17%);
    --radius: 0.75rem;
}

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

/* Fullscreen overlay */
#problem-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.95);
  display: none;
  flex-direction: column;
  justify-content: flex-start;
  align-items: center;
  padding: 40px 20px;
  z-index: 2000;
  overflow-y: auto;
  max-height: 100vh;
}

#problem-cards-container {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: center;
  max-width: 1200px;
  width: 100%;
}

#problem-overlay::-webkit-scrollbar {
  width: 8px;
}
#problem-overlay::-webkit-scrollbar-thumb {
  background: #555;
  border-radius: 4px;
}

#close-overlay {
  position: sticky;
  top: 0;
  z-index: 2100;
  margin-bottom: 20px;
}

#problem-overlay.active {
  display: flex;
}

#overlay-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 16px;
  padding: 10px;
  width: 100%;
  max-width: 1000px;
}

.quotation-bar {
    background: linear-gradient(90deg, #111, #222);
    color: #fff;
    font-size: 1rem;
    font-weight: 600;
    padding: 8px 0;
    border-top: 1px solid #333;
    border-bottom: 1px solid #333;
    letter-spacing: 1px;
}

.problem-box {
  background: #1558b0;
  color: white;
  border-radius: 12px;
  padding: 16px;
  border: 1px solid #444;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.5);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.problem-box:hover {
  transform: translateY(-4px);
  box-shadow: 0 6px 14px rgba(0, 0, 0, 0.6);
}

.problem-box h3 {
  font-size: 20px;
  font-weight: bold;
  color: var(--accent-foreground);
  margin-bottom: 10px;
}

.problem-box p {
  font-size: 15px;
  line-height: 1.6;
  color: #f0f0f0;
}

.overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.85);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 999;
}

.overlay-content {
  background: #1a1a1a;
  padding: 20px;
  border-radius: 12px;
  width: 80%;
  max-height: 80%;
  overflow-y: auto;
  position: relative;
  max-height: calc(100vh - 100px);
  -webkit-overflow-scrolling: touch;
}

body {
    font-family: 'Inter', system-ui, sans-serif;
    background-color: var(--background);
    color: var(--foreground);
    line-height: 1.5;
    scroll-behavior: smooth;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.header {
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    position: relative;
    z-index: 1000;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-icon {
    width: 2rem;
    height: 2rem;
    color: var(--accent);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: bold;
}

.logo .accent {
    color: var(--accent);
}

.nav-links {
    display: flex;
    gap: 1rem;
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-links button,
.nav-links a {
    background: none;
    border: none;
    color: var(--muted-foreground);
    cursor: pointer;
    transition: color 0.3s;
    font-family: inherit;
    text-decoration: none;
    font-size: 1rem;
}

.nav-links button:hover,
.nav-links a:hover {
    color: var(--foreground);
}

.home-button {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: linear-gradient(135deg, var(--accent), var(--primary));
    color: var(--accent-foreground) !important;
    text-decoration: none;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius);
    transition: all 0.3s ease;
    box-shadow: 0 0 8px rgba(59, 130, 246, 0.5);
}

.home-button:hover {
    transform: scale(1.05);
    box-shadow: 0 0 15px rgba(59, 130, 246, 0.8);
}

.btn-glow {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    font-weight: 600;
    border-radius: var(--radius);
    background: linear-gradient(135deg, var(--accent), var(--primary));
    color: var(--accent-foreground);
    border: none;
    text-decoration: none;
    font-family: inherit;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.btn-glow:hover {
    transform: scale(1.05);
    box-shadow: 0 0 20px rgba(59, 130, 246, 0.8);
    background: linear-gradient(135deg, hsl(214, 100%, 65%), hsl(214, 100%, 35%));
}

.btn-glow::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.4s ease, height 0.4s ease;
}

.btn-glow:hover::before {
    width: 200%;
    height: 200%;
}

.hero {
    position: relative;
    width: 100%;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem 1rem;
    box-sizing: border-box;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--background) 0%, var(--card) 100%);
}

.hero-bg::before,
.hero-bg::after {
    content: '';
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
}

.hero-bg::before {
    top: 25%;
    left: 25%;
    width: 16rem;
    height: 16rem;
    background: hsl(214, 100%, 59%, 0.1);
}

.hero-bg::after {
    bottom: 25%;
    right: 25%;
    width: 12rem;
    height: 12rem;
    background: hsl(214, 100%, 27%, 0.2);
}

.hero-content {
    position: relative;
    display: grid;
    gap: 3rem;
    align-items: center;
}

@media (min-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr 1fr;
    }
}

.hero-text {
    space-y: 2rem;
}

.date-badge {
    display: inline-flex;
    align-items: center;
    padding: 0.5rem 1rem;
    background: hsl(214, 100%, 59%, 0.2);
    color: var(--accent);
    border: 1px solid hsl(214, 100%, 59%, 0.3);
    border-radius: 9999px;
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.hero-title {
    font-size: 3rem;
    font-weight: bold;
    line-height: 1.1;
    margin-bottom: 1rem;
}

.hero-subtitle {
    font-size: 2rem;
    color: var(--muted-foreground);
    margin-top: 0.5rem;
}

.hero-description {
    font-size: 1.25rem;
    color: var(--muted-foreground);
    margin-bottom: 2rem;
}

@media (min-width: 1024px) {
    .hero-title {
        font-size: 4rem;
    }
}

.hero-buttons {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

@media (min-width: 640px) {
    .hero-buttons {
        flex-direction: row;
    }
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    font-weight: 600;
    border-radius: var(--radius);
    transition: all 0.3s;
    cursor: pointer;
    border: none;
    text-decoration: none;
    font-family: inherit;
}

.btn-primary {
    background: var(--accent);
    color: var(--accent-foreground);
    box-shadow: 0 0 20px rgba(59, 130, 246, 0.3);
}

.btn-primary:hover {
    background: hsl(214, 100%, 55%);
}

.btn-secondary {
    background: transparent;
    color: var(--foreground);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: var(--card);
}

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

.feature-card {
    background: var(--card);
    padding: 1.5rem;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    transition: all 0.3s;
}

.feature-card:hover {
    border-color: hsl(214, 100%, 59%, 0.5);
    transform: translateY(-5px);
}

.feature-card:last-child {
    grid-column: span 2;
}

.feature-icon {
    width: 3rem;
    height: 3rem;
    color: var(--accent);
    margin-bottom: 1rem;
}

.feature-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.feature-description {
    color: var(--muted-foreground);
    font-size: 0.875rem;
}

@media (max-width: 576px) {
    .hero {
        padding: 60px 15px;
        min-height: auto;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: 0.75rem;
    }

    .feature-card {
        padding: 1rem 1.5rem;
        width: 100%;
        max-width: 400px;
        margin: 0 auto;
        border-radius: 0.5rem;
    }

    .feature-card:last-child {
        grid-column: auto;
    }

    .feature-icon {
        width: 2.5rem;
        height: 2.5rem;
        margin-bottom: 0.75rem;
    }

    .feature-title {
        font-size: 1rem;
    }

    .feature-description {
        font-size: 0.8rem;
        line-height: 1.4;
    }
}

.sponsors-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
}

@media (min-width: 576px) {
    .sponsors-grid {
        gap: 0.75rem;
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    }
}

.sponsor-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    transition: transform 0.3s, box-shadow 0.3s;
    min-height: 140px;
    text-align: center;
    flex: 0 1 200px;
    max-width: 220px;
    text-align: center;
}

.sponsor-card img {
    max-width: 100%;
    max-height: 70px;
    object-fit: contain;
    margin-bottom: 0.8rem;
    transition: filter 0.3s;
}

.sponsor-name {
    font-size: 1rem;
    font-weight: 600;
    color: var(--foreground);
}

.sponsor-card:hover {
    transform: scale(1.05);
    box-shadow: 0 0 15px rgba(59, 130, 246, 0.4);
}

.sponsor-tier {
    margin-bottom: 3rem;
    text-align: center;
}

.sponsor-tier-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--foreground);
}

.sponsor-card.highlight {
    border: 2px solid var(--primary);
    box-shadow: 0 0 15px rgba(59, 130, 246, 0.4);
}

.sponsor-row {
    display: flex;
    justify-content: center;
    gap: 3rem;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

@media (min-width: 576px) {
    .sponsor-row {
        gap: 1.5rem;
    }
}

.sponsor-block {
    text-align: center;
}

.sponsor-block .sponsor-tier-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--foreground);
}

.sponsor-row .sponsor-card {
    flex: 0 1 220px;
}

.section {
    padding: 5rem 0;
}

.section-alt {
    background: hsl(217, 33%, 17%, 0.5);
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: bold;
    margin-bottom: 1rem;
}

.section-description {
    font-size: 1.125rem;
    color: var(--muted-foreground);
    max-width: 32rem;
    margin: 0 auto;
}

.timeline {
    max-width: 64rem;
    margin: 0 auto;
}

.day {
    margin-bottom: 3rem;
}

.day-header {
    display: flex;
    align-items: center;
    margin-bottom: 2rem;
}

.day-number {
    background: var(--accent);
    color: var(--accent-foreground);
    border-radius: 50%;
    width: 3rem;
    height: 3rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1.125rem;
    margin-right: 1rem;
}

.day-title {
    font-size: 1.5rem;
    font-weight: bold;
}

.timeline-cards {
    display: grid;
    gap: 1.5rem;
}

@media (min-width: 768px) {
    .timeline-cards {
        grid-template-columns: repeat(2, 1fr);
    }
}

.timeline-cards.three-cols {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.timeline-card {
    background: var(--card);
    padding: 1.5rem;
    border-radius: var(--radius);
    border: 1px solid var(--border);
}

.timeline-card-header {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
}

.timeline-icon {
    width: 1.25rem;
    height: 1.25rem;
    color: var(--accent);
    margin-right: 0.75rem;
}

.timeline-card-title {
    font-size: 1.25rem;
    font-weight: 600;
}

.timeline-details {
    color: var(--muted-foreground);
}

.timeline-detail {
    display: flex;
    align-items: center;
    margin-bottom: 0.5rem;
}

.timeline-detail i {
    width: 1rem;
    margin-right: 0.5rem;
}

.registration-container {
    max-width: 48rem;
    margin: 0 auto;
}

.event-selector {
    margin-bottom: 3rem;
}

.event-selector h3 {
    font-size: 1.5rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 2rem;
}

.event-options {
    display: grid;
    gap: 1rem;
    margin-bottom: 2rem;
}

@media (min-width: 768px) {
    .event-options {
        grid-template-columns: repeat(3, 1fr);
    }
}

.event-option {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
}

.event-option:hover {
    transform: scale(1.05);
    border-color: hsl(214, 100%, 59%, 0.5);
}

.event-option.selected {
    background: var(--accent);
    color: var(--accent-foreground);
    box-shadow: 0 0 15px rgba(59, 130, 246, 0.4);
}

.team-selector {
    margin-bottom: 3rem;
}

.team-selector h3 {
    font-size: 1.5rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 2rem;
}

.team-options {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}

@media (min-width: 768px) {
    .team-options {
        grid-template-columns: repeat(4, 1fr);
        gap: 0.75rem;
    }
}

.team-option {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
    min-width: 0;
}

.team-option:hover {
    transform: scale(1.05);
    border-color: hsl(214, 100%, 59%, 0.5);
}

.team-option.selected {
    background: var(--accent);
    color: var(--accent-foreground);
    box-shadow: 0 0 15px rgba(59, 130, 246, 0.4);
}

.team-option.disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.team-option.disabled:hover {
    transform: none;
}

.team-icon {
    width: 2rem;
    height: 2rem;
    color: var(--accent);
    margin: 0 auto 0.5rem;
}

.team-option.selected .team-icon {
    color: var(--accent-foreground);
}

.team-label {
    font-weight: 600;
    margin-bottom: 0.25rem;
    font-size: 0.9rem;
}

.team-subtitle {
    font-size: 0.75rem;
    color: var(--muted-foreground);
}

.team-option.selected .team-subtitle {
    color: var(--accent-foreground);
}

.pricing-display {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    text-align: center;
    margin-bottom: 2rem;
}

.pricing-amount {
    font-size: 3rem;
    font-weight: bold;
    color: var(--accent);
    margin-bottom: 1rem;
}

.pricing-details {
    color: var(--muted-foreground);
    margin-bottom: 2rem;
}

.venue-grid {
    display: grid;
    gap: 2rem;
    align-items: center;
}

@media (min-width: 1024px) {
    .venue-grid {
        grid-template-columns: 1fr 1fr;
    }
}

.venue-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.venue-detail {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1rem;
    background: var(--card);
    border-radius: var(--radius);
    border: 1px solid var(--border);
}

.venue-detail i {
    color: var(--accent);
    margin-top: 0.25rem;
    font-size: 1.25rem;
}

.venue-detail-content h4 {
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.venue-detail-content p {
    color: var(--muted-foreground);
    font-size: 0.875rem;
}

.venue-image {
    background: var(--card);
    border-radius: var(--radius);
    padding: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 20rem;
}

.venue-image img {
    width: 100%;
    height: auto;
    border-radius: var(--radius);
}

.themes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.theme-card {
    background: var(--card);
    border-radius: var(--radius);
    padding: 2rem;
    text-align: center;
    transition: transform 0.3s, background 0.3s;
    position: relative;
    cursor: pointer;
}

.theme-card:hover {
    transform: translateY(-8px);
    background: hsl(217, 33%, 25%);
}

.theme-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--accent);
}

.theme-title {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--foreground);
}

.theme-description {
    font-size: 1rem;
    color: var(--muted-foreground);
}

.theme-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    text-align: left;
    z-index: 10;
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.3s ease, transform 0.3s ease;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.3);
}

.theme-card:hover .theme-overlay {
    opacity: 1;
    transform: translateY(0);
}

.theme-overlay-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--foreground);
    margin-bottom: 1rem;
}

.theme-overlay-content p {
    font-size: 0.9rem;
    color: var(--muted-foreground);
    margin-bottom: 0.5rem;
}

.theme-problem-boxes {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    margin-top: 1rem;
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.theme-problem-boxes.active {
    opacity: 1;
    transform: translateY(0);
}

@media (min-width: 768px) {
    .theme-problem-boxes {
        grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    }
}

@media (max-width: 768px) {
    .theme-overlay {
        position: relative;
        width: 100%;
        margin-top: 1rem;
        opacity: 0;
        transform: translateY(0);
    }

    .theme-card:hover .theme-overlay {
        opacity: 1;
        transform: translateY(0);
    }

    .theme-problem-boxes {
        grid-template-columns: 1fr;
    }

    #overlay-content {
        display: flex;
        flex-direction: column;
        overflow: visible;
        gap: 16px;
        padding: 10px;
    }

    .problem-box {
        flex: none;
        max-width: 100%;
    }
}

.footer {
    border-top: 1px solid var(--border);
    padding: 3rem 0;
}

.footer-content {
    display: grid;
    gap: 2rem;
}

@media (min-width: 768px) {
    .footer-content {
        grid-template-columns: repeat(4, 1fr);
    }
}

.footer-section h4 {
    font-weight: 600;
    margin-bottom: 1rem;
}

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

.footer-section li {
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    color: var(--muted-foreground);
}

.footer-section button,
.footer-section a {
    background: none;
    border: none;
    color: var(--muted-foreground);
    cursor: pointer;
    transition: color 0.3s;
    font-family: inherit;
    text-align: left;
    text-decoration: none;
}

.footer-section button:hover,
.footer-section a:hover {
    color: var(--foreground);
}

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

.footer-brand .logo span {
    font-size: 1.25rem;
    font-weight: bold;
}

.footer-brand p {
    color: var(--muted-foreground);
}

.footer-copyright {
    border-top: 1px solid var(--border);
    margin-top: 2rem;
    padding-top: 2rem;
    text-align: center;
    color: var(--muted-foreground);
}

.hidden {
    display: none;
}

::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--background);
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent);
}

@media (max-width: 992px) {
    .hero-content {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .hero-text {
        max-width: 100%;
    }

    .hero-buttons {
        justify-content: center;
    }

    .features-grid {
        grid-template-columns: repeat(2, 1fr);
        width: 100%;
    }
}

@media (max-width: 576px) {
    .hero {
        padding: 60px 15px;
        min-height: auto;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .feature-card {
        padding: 1rem;
    }
}

.menu-toggle {
    display: none;
}

@media (max-width: 768px) {
    .menu-toggle {
        display: block;
        font-size: 1.5rem;
        color: var(--foreground);
        cursor: pointer;
        position: relative;
        z-index: 1002;
        margin-right: 1rem;
    }

    .nav-links {
        display: none;
        flex-direction: column;
        background: var(--card);
        position: absolute;
        top: 60px;
        left: 1rem;
        right: 1rem;
        width: auto;
        border-radius: var(--radius);
        padding: 1rem;
        box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
        z-index: 1001;
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links button,
    .nav-links a {
        font-size: 0.9rem;
        padding: 0.5rem;
        text-align: center;
        width: 100%;
    }

    .home-button {
        display: flex !important;
        justify-content: center;
        width: 100%;
        text-align: center;
        margin-top: 0.5rem;
        padding: 0.75rem 1rem;
        background: linear-gradient(135deg, var(--accent), var(--primary));
        color: var(--accent-foreground) !important;
        border-radius: var(--radius);
        text-decoration: none;
        font-size: 1rem;
        font-weight: 600;
    }

    .nav-links .home-button {
        order: 999;
        display: flex !important;
    }
}