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

:root {
    --color-bg: #ffffff;
    --color-bg-alt: #f7f8fa;
    --color-text: #1a1a2e;
    --color-text-muted: #555;
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-border: #e2e8f0;
    --color-hero-bg: #0f172a;
    --color-hero-text: #f1f5f9;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --max-width: 960px;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 70px;
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.6;
    font-size: 16px;
    text-align: justify;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--color-primary);
    text-decoration: none;
}
a:hover {
    text-decoration: underline;
}

img {
    max-width: 100%;
    display: block;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Navigation ===== */
#navbar {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--color-hero-bg);
    border-bottom: 1px solid rgba(255,255,255,0.08);
    backdrop-filter: blur(12px);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 56px;
}

.nav-logo {
    color: #fff;
    font-weight: 700;
    font-size: 1.05rem;
    letter-spacing: -0.02em;
}
.nav-logo:hover {
    text-decoration: none;
    opacity: 0.85;
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    color: #fff;
    font-size: 1.4rem;
    cursor: pointer;
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 28px;
}

.nav-links a {
    color: rgba(255,255,255,0.75);
    font-size: 0.875rem;
    font-weight: 500;
    transition: color 0.2s;
}
.nav-links a:hover {
    color: #fff;
    text-decoration: none;
}

/* ===== Hero ===== */
.hero {
    background: var(--color-hero-bg);
    color: var(--color-hero-text);
    padding: 64px 0 56px;
    text-align: center !important;
}

.hero-logo {
    width: 180px;
    height: 180px;
    margin: 0 auto 24px;
}

.hero-venue {
    font-size: 0.95rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: rgba(255,255,255,0.55);
    margin-bottom: 20px;
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.025em;
    max-width: 750px;
    margin: 0 auto 20px;
}

.hero-details {
    font-size: 1.1rem;
    color: rgba(255,255,255,0.6);
}

/* ===== Sections ===== */
.section {
    padding: 52px 0;
}

.section-alt {
    background: var(--color-bg-alt);
}

.section h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 18px;
    letter-spacing: -0.02em;
    text-align: left;
}

.section h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-top: 28px;
    margin-bottom: 12px;
    text-align: left;
}

.section p {
    color: var(--color-text-muted);
    margin-bottom: 12px;
}

.section-note {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin-bottom: 24px;
}

/* ===== Directions Grid ===== */
.directions-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
    margin-top: 24px;
}

.direction-card {
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: 10px;
    padding: 24px;
}

.direction-card h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--color-text);
}

.direction-card p {
    font-size: 0.9rem;
    margin-bottom: 0;
    line-height: 1.6;
}

.section-title-center {
    text-align: center !important;
}

/* ===== Simple List ===== */
.simple-list {
    list-style: disc;
    padding-left: 20px;
    color: var(--color-text-muted);
}

.simple-list li {
    margin-bottom: 8px;
    font-size: 0.95rem;
}

.simple-list li strong {
    color: var(--color-text);
}

/* ===== Speakers Grid ===== */
.speakers-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
    margin-top: 8px;
}

.speaker-card {
    text-align: center !important;
}

.speaker-photo {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    margin: 0 auto 16px;
    object-fit: cover;
    image-rendering: -webkit-optimize-contrast;
    image-rendering: smooth;
}

.placeholder-photo {
    background: linear-gradient(135deg, #cbd5e1, #94a3b8);
}

.speaker-card h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.speaker-card h4 a {
    color: var(--color-text);
}
.speaker-card h4 a:hover {
    color: var(--color-primary);
    text-decoration: none;
}

.speaker-affiliation {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-bottom: 0;
}

/* ===== Schedule Table ===== */
.schedule-table-wrapper {
    overflow-x: auto;
}

.schedule-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.92rem;
}

.schedule-table th {
    text-align: left;
    font-weight: 600;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--color-text-muted);
    padding: 12px 16px;
    border-bottom: 2px solid var(--color-border);
}

.schedule-table td {
    padding: 14px 16px;
    border-bottom: 1px solid var(--color-border);
    vertical-align: middle;
}

.schedule-table td:first-child {
    white-space: nowrap;
    font-variant-numeric: tabular-nums;
    color: var(--color-text-muted);
    width: 160px;
}

.schedule-break {
    background: var(--color-bg-alt);
}

/* Badges */
.badge {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 3px 10px;
    border-radius: 20px;
    white-space: nowrap;
}

.badge-invited {
    background: #dbeafe;
    color: #1e40af;
}

.badge-contributed {
    background: #dcfce7;
    color: #166534;
}

.badge-break {
    background: #f1f5f9;
    color: #64748b;
}

.badge-misc {
    background: #fef3c7;
    color: #92400e;
}

/* ===== Call for Papers ===== */
.topic-list {
    list-style: none;
    padding: 0;
    margin-top: 12px;
}

.topic-list li {
    position: relative;
    padding: 12px 0 12px 24px;
    color: var(--color-text-muted);
    border-bottom: 1px solid var(--color-border);
    font-size: 0.95rem;
}

.topic-list li:last-child {
    border-bottom: none;
}

.topic-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 20px;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--color-primary);
}

.topic-list li strong {
    color: var(--color-text);
}

/* Dates Grid */
.dates-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
    margin-top: 16px;
}

.date-item {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    padding: 16px 20px;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.date-label {
    font-size: 0.82rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--color-text-muted);
}

.date-value {
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text);
}

/* ===== Organizers Grid ===== */
.organizers-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
    margin-top: 8px;
}

.organizer-card {
    text-align: center !important;
}

.organizer-photo {
    width: 110px;
    height: 110px;
    border-radius: 50%;
    margin: 0 auto 14px;
    object-fit: cover;
}

.organizer-card h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 2px;
}

.organizer-card h4 a {
    color: var(--color-text);
}
.organizer-card h4 a:hover {
    color: var(--color-primary);
}

.organizer-affiliation {
    font-size: 0.85rem;
    color: var(--color-primary);
    font-weight: 500;
    margin-bottom: 8px;
}

.organizer-bio {
    font-size: 0.84rem;
    color: var(--color-text-muted);
    line-height: 1.55;
    max-width: 280px;
    margin: 0 auto;
}

/* ===== Footer ===== */
.footer {
    background: var(--color-hero-bg);
    color: rgba(255,255,255,0.5);
    text-align: center !important;
    padding: 32px 0;
    font-size: 0.85rem;
}

.footer p {
    color: rgba(255,255,255,0.5);
    max-width: none;
}

.footer-contact {
    margin-top: 8px;
}

.footer a {
    color: rgba(255,255,255,0.7);
}
.footer a:hover {
    color: #fff;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 1.75rem;
    }

    .hero {
        padding: 56px 0 48px;
    }

    .section {
        padding: 36px 0;
    }

    .directions-grid,
    .dates-grid {
        grid-template-columns: 1fr;
    }

    .speakers-grid,
    .organizers-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }

    .nav-toggle {
        display: block;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 56px;
        left: 0;
        right: 0;
        background: var(--color-hero-bg);
        flex-direction: column;
        padding: 16px 24px;
        gap: 16px;
        border-bottom: 1px solid rgba(255,255,255,0.08);
    }

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

@media (max-width: 480px) {
    .speakers-grid,
    .organizers-grid {
        grid-template-columns: 1fr;
    }
}