:root {
    --color-background: #0b1020;
    --color-surface: #111a2f;
    --color-primary: #1e88e5;
    --color-accent: #ffb74d;
    --color-neutral: #f4f6fb;
    --font-sans: "IBM Plex Sans", system-ui, -apple-system, sans-serif;
    --font-mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, monospace;
    --max-width: 1160px;
    --radius-lg: 20px;
    --radius-md: 16px;
    --radius-sm: 10px;
    scroll-behavior: smooth;
    color-scheme: dark;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: var(--font-sans);
    background: var(--color-background);
    color: var(--color-neutral);
    line-height: 1.6;
}

a {
    color: inherit;
    text-decoration: none;
}

header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: rgba(11, 16, 32, 0.9);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(244, 246, 251, 0.08);
}

.nav {
    margin: 0 auto;
    max-width: var(--max-width);
    padding: 18px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.brand-left {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.brand-right {
    display: flex;
    align-items: center;
}

.brand-left img {
    height: 60px;
    width: auto;
    max-width: 100px;
}

.brand-right img {
    height: 50px;
    width: auto;
    max-width: 100px;
}

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

.nav-links a {
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    letter-spacing: 0.02em;
    transition: background 0.2s ease, color 0.2s ease;
}

.nav-links a:hover,
.nav-links a:focus-visible {
    background: rgba(30, 136, 229, 0.18);
    color: var(--color-neutral);
}

.nav-toggle {
    display: none;
    background: none;
    border: 1px solid rgba(244, 246, 251, 0.2);
    color: var(--color-neutral);
    padding: 0.35rem 0.55rem;
    border-radius: var(--radius-sm);
    font-size: 1.15rem;
}

.video-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    filter: blur(6px) brightness(0.7);
    -webkit-filter: blur(6px) brightness(0.7);
    overflow: hidden;
    background: rgba(11, 5, 75, 0.6);
}

.video-background iframe {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 120%;
    height: 120%;
    min-width: 120%;
    min-height: 120%;
    transform: translate(-50%, -50%) scale(1.1);
}

.header-section {
    position: relative;
    min-height: 85vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 80px;
    overflow: hidden;
}

.header-title {
    text-align: center;
    font-size: 64px;
    font-weight: 900;
    padding: 30px;
    animation: fadeIn 1.5s ease-in;
    text-shadow: 2px 2px 15px rgba(0, 0, 0, 0.5);
    background: linear-gradient(45deg, #ffffff, #589ED6);
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 20px;
}

.header-titles {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.header-title.date {
    margin-top: -90px;
    font-size: 40px;
}

.hero {
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at top,
            rgba(30, 136, 229, 0.25),
            transparent 55%);
    pointer-events: none;
}

.hero-inner {
    margin: 0 auto;
    max-width: var(--max-width);
    padding: 120px 24px 96px;
    display: grid;
    gap: 48px;
}

.hero-copy {
    max-width: 660px;
    display: grid;
    gap: 24px;
}

.hero-overline {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    letter-spacing: 0.24em;
    text-transform: uppercase;
    color: var(--color-accent);
    text-align: justify;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 3.6rem);
    line-height: 1.12;
    margin: 0;
    text-wrap: balance;
}

.hero-subtitle {
    margin: 0;
    color: rgba(244, 246, 251, 0.75);
    font-size: 1.1rem;
    text-align: justify;
}

.hero-cta {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    align-items: center;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.85rem 1.5rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.95rem;
    letter-spacing: 0.02em;
    transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.button-primary {
    background: var(--color-primary);
    color: var(--color-neutral);
    box-shadow: 0 10px 22px rgba(30, 136, 229, 0.25);
    padding: 0.7rem 1.2rem;
    max-width: 180px;
}

.button-primary:hover,
.button-primary:focus-visible {
    transform: translateY(-1px);
    box-shadow: 0 14px 28px rgba(30, 136, 229, 0.3);
}

.button-outline {
    border: 1px solid rgba(244, 246, 251, 0.28);
    color: var(--color-neutral);
    background: transparent;
}

.button-outline:hover,
.button-outline:focus-visible {
    border-color: rgba(244, 246, 251, 0.45);
}

.hero-highlights {
    display: grid;
    gap: 16px;
}

.highlight-card {
    padding: 1.1rem 1.25rem;
    border-radius: var(--radius-md);
    border: 1px solid rgba(244, 246, 251, 0.08);
    background: rgba(17, 26, 47, 0.9);
    display: grid;
    gap: 4px;
    text-align: justify;
}

.highlight-card strong {
    font-size: 1.75rem;
}

main {
    display: grid;
    gap: 96px;
    padding: 0 24px 104px;
}

section {
    margin: 0 auto;
    max-width: var(--max-width);
    width: 100%;
    display: grid;
    gap: 32px;
}

.section-heading {
    display: flex;
    flex-direction: column;
    gap: 12px;
    max-width: var(--max-width);
    width: 100%;
}

.section-heading h2 {
    font-size: clamp(2rem, 4vw, 2.6rem);
    margin: 0;
    text-wrap: balance;
}

.section-heading p {
    margin: 0;
    color: rgba(244, 246, 251, 0.72);
    text-align: justify;
}

.card-grid {
    display: grid;
    gap: 24px;
    width: 100%;
}

.card {
    padding: 28px;
    border-radius: var(--radius-md);
    background: rgba(17, 26, 47, 0.85);
    border: 1px solid rgba(244, 246, 251, 0.08);
    display: grid;
    gap: 18px;
}

.coming-soon-card {
    padding: 40px 24px;
    border-radius: var(--radius-md);
    background: rgba(17, 26, 47, 0.7);
    border: 1px dashed var(--color-primary);
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    width: 100%;
    margin-top: 8px;
}

.coming-soon-badge {
    display: inline-block;
    padding: 6px 18px;
    border-radius: 20px;
    background: rgba(30, 136, 229, 0.18);
    color: var(--color-primary);
    border: 1px solid var(--color-primary);
    font-family: var(--font-mono);
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.coming-soon-text {
    color: rgba(244, 246, 251, 0.8);
    font-size: 1.05rem;
    margin: 0;
}

.card h3 {
    margin: 0;
    font-size: 1.25rem;
}

.card p {
    margin: 0;
    color: rgba(244, 246, 251, 0.72);
    text-align: justify;
}

.countdown {
    display: grid;
    gap: 20px;
    width: 100%;
}

.countdown-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 16px;
    width: 100%;
}

.countdown-item {
    padding: 20px;
    border-radius: var(--radius-sm);
    background: rgba(17, 26, 47, 0.9);
    border: 1px solid var(--color-primary);
    text-align: center;
    display: grid;
    gap: 6px;
}

.countdown-item span:first-child {
    font-size: 2rem;
    font-weight: 600;
    color: var(--color-primary);
}

.split-layout {
    display: grid;
    gap: 24px;
    width: 100%;
}

.split-layout img {
    width: 100%;
    border-radius: var(--radius-md);
    object-fit: cover;
    height: clamp(260px, 38vw, 400px);
}

.split-content {
    display: grid;
    gap: 18px;
    width: 100%;
}

.list-grid {
    display: grid;
    gap: 18px;
    width: 100%;
}

.list-item {
    padding: 20px;
    border-radius: var(--radius-sm);
    border: 1px solid rgba(244, 246, 251, 0.08);
    background: rgba(17, 26, 47, 0.92);
    display: grid;
    gap: 6px;
}

.list-item span {
    text-align: justify;
}

.logolist {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 16px;
    width: 100%;
}

.logobox {
    padding: 18px;
    border-radius: var(--radius-sm);
    border: 1px dashed rgba(244, 246, 251, 0.12);
    background: rgba(17, 26, 47, 0.72);
    text-align: justify;
    font-size: 0.95rem;
    font-weight: 500;
    color: rgba(244, 246, 251, 0.74);
}

.agenda-days {
    display: grid;
    gap: 24px;
    width: 100%;
}

.agenda-day {
    display: grid;
    gap: 16px;
    width: 100%;
}

.agenda-day h3 {
    margin: 0;
    font-size: 1.15rem;
    color: var(--color-primary);
}

.agenda-list {
    display: grid;
    gap: 16px;
    width: 100%;
}

.agenda-item {
    border-radius: var(--radius-sm);
    border: 1px solid var(--color-primary);
    background: rgba(17, 26, 47, 0.88);
    padding: 18px 20px;
    display: grid;
    gap: 4px;
}

.agenda-time {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: rgba(244, 246, 251, 0.58);
    text-align: justify;
}

.agenda-title {
    margin: 0;
    font-size: 1.05rem;
    font-weight: 400;
}

.agenda-tabs {
    display: flex;
    gap: 16px;
    margin-bottom: 24px;
    width: 100%;
}

.agenda-tab {
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-sm);
    background: rgba(17, 26, 47, 0.9);
    border: 1px solid var(--color-primary);
    color: var(--color-neutral);
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.2s ease, border-color 0.2s ease;
}

.agenda-tab.active {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: var(--color-neutral);
}

.agenda-tab:hover,
.agenda-tab:focus-visible {
    background: rgba(30, 136, 229, 0.18);
    border-color: rgba(244, 246, 251, 0.45);
}

.agenda-day {
    display: none;
}

.agenda-day.active {
    display: grid;
}

.workshop-accordion {
    display: grid;
    gap: 18px;
    width: 100%;
}

details {
    border-radius: var(--radius-md);
    border: 1px solid var(--color-primary);
    background: rgba(17, 26, 47, 0.88);
    padding: 18px 22px;
}

summary {
    cursor: pointer;
    list-style: none;
    display: flex;
    justify-content: space-between;
    gap: 12px;
    align-items: center;
    font-weight: 500;
    font-size: 1.05rem;
}

summary::-webkit-details-marker {
    display: none;
}

summary span {
    font-family: var(--font-mono);
    font-size: 1.1rem;
    color: var(--color-primary);
    transition: transform 0.2s ease;
}

details[open] summary span {
    transform: rotate(45deg);
}

details[open] summary {
    margin-bottom: 12px;
}

.workshop-accordion p,
.workshop-accordion li {
    text-align: justify;
}

.award-grid {
    display: grid;
    gap: 20px;
    width: 100%;
}

.award-cta {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 1rem 1.3rem;
    border-radius: var(--radius-sm);
    border: 1px solid rgba(244, 246, 251, 0.15);
    background: rgba(17, 26, 47, 0.88);
    width: 100%;
}

.award-cta div {
    text-align: justify;
}

.sponsor-logos {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    padding: 24px;
}

.sponsor-logo {
    width: 100%;
    max-width: 100%;
    height: auto;
    object-fit: contain;
    filter: brightness(0.9);
    transition: transform 0.3s ease, filter 0.3s ease;
}

.sponsor-logo:hover {
    transform: scale(1.02);
    filter: brightness(1.1);
}

.footer-section {
    margin-top: 80px;
    border-top: 1px solid rgba(244, 246, 251, 0.08);
    background: rgba(11, 16, 32, 0.92);
    padding: 24px;
}

.footer-container {
    margin: 0 auto;
    max-width: var(--max-width);
    display: grid;
    gap: 24px;
    text-align: center;
    width: 100%;
}

.footer-heading {
    margin: 0;
}

.footer-text {
    margin: 0;
    color: rgba(244, 246, 251, 0.72);
    font-size: 0.9rem;
}

.message-button {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--color-primary);
    color: var(--color-neutral);
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: 0 10px 22px rgba(30, 136, 229, 0.25);
    transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.message-button:hover,
.message-button:focus-visible {
    transform: translateY(-2px);
    box-shadow: 0 14px 28px rgba(30, 136, 229, 0.3);
}

.contact-form-container {
    position: fixed;
    bottom: 80px;
    right: 20px;
    background: var(--color-surface);
    border: 1px solid rgba(244, 246, 251, 0.18);
    border-radius: var(--radius-md);
    padding: 20px;
    width: 320px;
    max-width: 90vw;
    box-shadow: 0 10px 22px rgba(0, 0, 0, 0.2);
    display: none;
    z-index: 1000;
}

.contact-form-container.active {
    display: block;
}

.contact-form-container h3,
.contact-form-container p {
    text-align: justify;
}

.form-control {
    width: 100%;
    border-radius: var(--radius-sm);
    border: 1px solid rgba(244, 246, 251, 0.18);
    background: rgba(11, 16, 32, 0.8);
    padding: 0.75rem;
    font-family: var(--font-sans);
    font-size: 0.95rem;
    color: var(--color-neutral);
    margin-bottom: 12px;
    transition: border 0.2s ease;
}

.form-control:focus {
    outline: none;
    border-color: var(--color-primary);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    padding: 0.85rem 1.5rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.95rem;
    letter-spacing: 0.02em;
    background: var(--color-primary);
    color: var(--color-neutral);
    border: none;
    cursor: pointer;
    transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.btn:hover,
.btn:focus-visible {
    transform: translateY(-1px);
    box-shadow: 0 14px 28px rgba(30, 136, 229, 0.3);
}

@media (min-width: 768px) {
    .hero-inner {
        grid-template-columns: 1fr 320px;
        align-items: center;
    }

    .hero-highlights {
        align-self: center;
    }

    .split-layout {
        grid-template-columns: 1fr 1fr;
        align-items: center;
    }

    .split-layout:nth-child(even) {
        direction: rtl;
    }

    .split-layout:nth-child(even)>* {
        direction: ltr;
    }

    .card-grid,
    .award-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .nav {
        padding: 18px 24px;
    }

    .brand-left img,
    .brand-right img {
        height: 50px;
        max-width: 100px;
    }

    .hero-inner {
        padding: 120px 24px 96px;
    }

    .hero-overline {
        text-align: justify;
    }

    .hero-title {
        text-align: left;
    }

    .hero-subtitle {
        text-align: justify;
    }

    .hero-cta {
        flex-direction: row;
        width: auto;
    }

    .button {
        width: auto;
    }

    .section-heading {
        text-align: left;
    }

    .section-heading p {
        text-align: justify;
    }

    .highlight-card,
    .card p,
    .list-item span,
    .agenda-time,
    .agenda-title,
    .workshop-accordion p,
    .workshop-accordion li,
    .award-cta div {
        text-align: justify;
    }
}

@media (max-width: 767px) {
    .nav {
        flex-wrap: wrap;
        padding: 12px 16px;
    }

    .nav-links {
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        background: rgba(11, 16, 32, 0.95);
        border: 1px solid rgba(244, 246, 251, 0.08);
        border-radius: 0 0 var(--radius-md) var(--radius-md);
        padding: 16px;
        display: none;
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
        z-index: 10;
    }

    .nav-links a {
        width: 100%;
        padding: 0.6rem;
        border-radius: var(--radius-sm);
        background: rgba(17, 26, 47, 0.8);
        font-size: 0.95rem;
        text-align: center;
    }

    .nav-links[data-open="true"] {
        display: flex;
    }

    .nav-toggle {
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }

    .header-section {
        min-height: 60vh;
        padding-top: 50px;
    }

    .hero-inner {
        padding: 60px 16px 48px;
    }

    main {
        gap: 48px;
        padding-bottom: 60px;
    }

    section {
        gap: 20px;
    }

    .split-layout img {
        height: clamp(160px, 25vw, 240px);
    }

    .countdown-grid {
        grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    }

    .countdown-item {
        padding: 12px;
    }

    .countdown-item span:first-child {
        font-size: 1.5rem;
    }

    .agenda-tabs {
        flex-direction: column;
        align-items: stretch;
    }

    .agenda-tab {
        width: 100%;
        text-align: center;
    }

    .contact-form-container {
        width: 95vw;
        max-width: 280px;
        bottom: 60px;
        right: 10px;
    }

    .message-button {
        bottom: 12px;
        right: 12px;
        width: 44px;
        height: 44px;
        font-size: 1.3rem;
    }
}

@media (max-width: 480px) {
    .header-title {
        font-size: clamp(1.6rem, 7vw, 2.8rem);
    }

    .header-title.date {
        font-size: clamp(1.2rem, 4vw, 1.6rem);
        margin-top: -60px;
    }

    .hero-title {
        font-size: clamp(1.5rem, 5vw, 2rem);
    }

    .hero-subtitle {
        font-size: 0.9rem;
    }

    .section-heading h2 {
        font-size: clamp(1.4rem, 4vw, 1.8rem);
    }

    .section-heading p {
        font-size: 0.85rem;
    }

    .button,
    .btn {
        font-size: 0.85rem;
        padding: 0.6rem 1rem;
    }

    .button-primary {
        padding: 0.6rem 1rem;
        max-width: 150px;
    }

    .highlight-card strong {
        font-size: 1.3rem;
    }

    .card h3 {
        font-size: 1rem;
    }

    .card p {
        font-size: 0.85rem;
    }

    .list-item span {
        font-size: 0.85rem;
    }

    .agenda-day h3 {
        font-size: 1rem;
    }

    .agenda-time {
        font-size: 0.75rem;
    }

    .agenda-title {
        font-size: 0.95rem;
    }

    .workshop-accordion p,
    .workshop-accordion li {
        font-size: 0.85rem;
    }

    .award-cta div {
        font-size: 0.85rem;
    }

    .footer-text {
        font-size: 0.8rem;
    }
}