/* ─── VARIABLES ─── */
:root {
    --ink: #1a1a2e;
    --body: #2d2d44;
    --muted: #6b6b8d;
    --accent: #0f5e97;
    --accent-light: #1a8fd1;
    --accent-glow: #e8f4fd;
    --teal: #0d7377;
    --teal-light: #14a3a8;
    --rose: #c2185b;
    --surface: #ffffff;
    --bg: #f6f7fb;
    --bg-alt: #eef0f6;
    --border: #dde0ea;
    --hero-gradient: linear-gradient(135deg, #0c2340 0%, #1a3a5c 30%, #0f5e97 60%, #0d7377 100%);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 72px;
}

body {
    font-family: 'DM Sans', sans-serif;
    color: var(--body);
    background: var(--bg);
    line-height: 1.7;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

/* NAV */
nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255,255,255,0.92);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    transition: box-shadow 0.3s;
}
nav.scrolled { box-shadow: 0 2px 24px rgba(0,0,0,0.08); }
.nav-inner {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}
.nav-logo {
    font-family: 'Source Serif 4', serif;
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--ink);
    text-decoration: none;
}
.nav-logo span { color: var(--accent); }
.nav-links { display: flex; gap: 6px; }
.nav-links a {
    color: var(--body);
    text-decoration: none;
    font-size: 0.82rem;
    font-weight: 500;
    padding: 6px 12px;
    border-radius: 6px;
    transition: all 0.2s;
    letter-spacing: 0.01em;
}
.nav-links a:hover { background: var(--accent-glow); color: var(--accent); }

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 8px;
    background: none;
    border: none;
}
.hamburger span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--ink);
    border-radius: 2px;
    transition: all 0.3s;
}

/* HERO */
/* .hero {
    background: var(--hero-gradient);
    padding: 140px 24px 80px;
    position: relative;
    overflow: hidden;
} */
.hero {
    background:
        linear-gradient(rgba(8, 20, 40, 0.98), rgba(8, 20, 40, 0.69)),
        url("images/hero_banner.png") center/cover no-repeat,
        var(--hero-gradient);
    padding: 140px 24px 80px;
    position: relative;
    overflow: hidden;
}
.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 600px 400px at 20% 50%, rgba(13,115,119,0.25), transparent),
        radial-gradient(ellipse 500px 500px at 80% 30%, rgba(15,94,151,0.3), transparent);
    pointer-events: none;
}
.hero::after {
    display: none;
    content: '';
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    pointer-events: none;
}
.hero-inner {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
    text-align: center;
}
.hero-badge {
    display: inline-block;
    background: rgba(255,255,255,0.12);
    border: 1px solid rgba(255,255,255,0.2);
    color: rgba(255,255,255,0.9);
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    padding: 6px 18px;
    border-radius: 100px;
    margin-bottom: 28px;
    backdrop-filter: blur(8px);
}
.hero h1 {
    font-family: 'Source Serif 4', serif;
    font-weight: 700;
    font-size: clamp(2rem, 4.5vw, 3.2rem);
    color: #fff;
    line-height: 1.2;
    margin-bottom: 16px;
}
.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.2rem);
    color: rgba(255,255,255,0.8);
    font-weight: 400;
    line-height: 1.6;
    max-width: 700px;
    margin: 0 auto 36px;
}
.hero-meta {
    display: flex;
    gap: 32px;
    justify-content: center;
    flex-wrap: wrap;
}
.hero-meta-item {
    display: flex;
    align-items: center;
    gap: 8px;
    color: rgba(255,255,255,0.85);
    font-size: 0.92rem;
    font-weight: 500;
}
.hero-meta-item svg {
    width: 18px;
    height: 18px;
    opacity: 0.7;
}

/* SECTIONS */
.section {
    max-width: 900px;
    margin: 0 auto;
    padding: 72px 24px;
}
.section-wide {
    max-width: 1120px;
}
.section-title {
    font-family: 'Source Serif 4', serif;
    font-weight: 700;
    font-size: 1.8rem;
    color: var(--ink);
    margin-bottom: 8px;
    position: relative;
    display: inline-block;
}
.section-title::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 48px;
    height: 3px;
    background: var(--accent);
    border-radius: 3px;
}
.section-lead {
    color: var(--muted);
    font-size: 1.02rem;
    margin-top: 16px;
    margin-bottom: 40px;
    max-width: 680px;
}

/* THEMES / CARDS */
.theme-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 32px;
}
.theme-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 28px;
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
}
.theme-card:hover {
    border-color: var(--accent);
    box-shadow: 0 8px 32px rgba(15,94,151,0.1);
    transform: translateY(-2px);
}
.theme-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
}
.theme-card:nth-child(1)::before { background: var(--accent); }
.theme-card:nth-child(2)::before { background: var(--teal); }
.theme-card:nth-child(3)::before { background: var(--rose); }
.theme-number {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.72rem;
    font-weight: 500;
    color: var(--muted);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin-bottom: 10px;
}
.theme-card h3 {
    font-family: 'Source Serif 4', serif;
    font-weight: 600;
    font-size: 1.12rem;
    color: var(--ink);
    margin-bottom: 12px;
    line-height: 1.35;
}
.theme-card p {
    font-size: 0.9rem;
    color: var(--body);
    line-height: 1.65;
}

/* ABOUT / OVERVIEW TEXT */
.prose {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--body);
}
.prose p + p { margin-top: 16px; }

/* SPEAKERS */
.speaker-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 20px;
    margin-top: 32px;
}
.speaker-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 24px;
    text-align: center;
    transition: all 0.3s;
}
.speaker-card:hover {
    border-color: var(--accent);
    box-shadow: 0 4px 20px rgba(15,94,151,0.08);
}
.speaker-avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-glow), var(--bg-alt));
    margin: 0 auto 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'Source Serif 4', serif;
    font-weight: 600;
    font-size: 1.4rem;
    color: var(--accent);
}
.speaker-name {
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--ink);
    margin-bottom: 4px;
}
.speaker-affil {
    font-size: 0.82rem;
    color: var(--muted);
}
.speaker-theme {
    display: inline-block;
    font-size: 0.7rem;
    font-weight: 600;
    padding: 3px 10px;
    border-radius: 100px;
    letter-spacing: 0.02em;
    margin-top: 10px;
}
.speaker-theme.theme-1 { background: #e8f4fd; color: var(--accent); }
.speaker-theme.theme-2 { background: #e0f2f1; color: var(--teal); }
.speaker-theme.theme-3 { background: #fce4ec; color: var(--rose); }

/* SCHEDULE */
.schedule-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 32px;
    background: var(--surface);
    border-radius: 14px;
    overflow: hidden;
    border: 1px solid var(--border);
}
.schedule-table th {
    background: var(--bg-alt);
    font-size: 0.78rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--muted);
    padding: 14px 20px;
    text-align: left;
}
.schedule-table td {
    padding: 14px 20px;
    font-size: 0.92rem;
    border-top: 1px solid var(--border);
}
.schedule-table tr:hover td { background: var(--accent-glow); }
.time-cell {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.84rem;
    color: var(--accent);
    font-weight: 500;
    white-space: nowrap;
}
.event-type {
    display: inline-block;
    font-size: 0.7rem;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 4px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}
.type-talk { background: #e8f4fd; color: var(--accent); }
.type-panel { background: #fce4ec; color: var(--rose); }
.type-break { background: #f1f1f1; color: var(--muted); }
.type-contrib { background: #e0f2f1; color: var(--teal); }

/* CFP SUBMIT */
.submit-cta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    flex-wrap: wrap;
    background: linear-gradient(135deg, #0c2340 0%, #0f5e97 60%, #0d7377 100%);
    border-radius: 14px;
    padding: 32px 40px;
    margin-top: 20px;
}
.submit-cta-text h3 {
    font-family: 'Source Serif 4', serif;
    font-weight: 700;
    font-size: 1.15rem;
    color: #fff;
    margin-bottom: 6px;
}
.submit-cta-text p {
    font-size: 0.88rem;
    color: rgba(255,255,255,0.75);
    max-width: 480px;
}
.btn-submit {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: #fff;
    color: var(--accent);
    font-weight: 700;
    font-size: 0.92rem;
    padding: 13px 28px;
    border-radius: 8px;
    text-decoration: none;
    white-space: nowrap;
    transition: all 0.2s;
    border: 2px solid transparent;
    cursor: pointer;
    letter-spacing: 0.01em;
}
.btn-submit:hover {
    background: var(--accent-glow);
    color: var(--accent);
    border-color: rgba(255,255,255,0.4);
}
.btn-submit.disabled {
    background: rgba(255,255,255,0.15);
    color: rgba(255,255,255,0.6);
    cursor: not-allowed;
    border: 2px solid rgba(255,255,255,0.2);
}
.btn-submit.disabled:hover {
    background: rgba(255,255,255,0.2);
    color: rgba(255,255,255,0.75);
    border-color: rgba(255,255,255,0.3);
}
.submit-badge {
    display: inline-block;
    background: rgba(255,255,255,0.15);
    border: 1px solid rgba(255,255,255,0.25);
    color: rgba(255,255,255,0.85);
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    padding: 3px 10px;
    border-radius: 100px;
    margin-bottom: 10px;
    display: block;
    width: fit-content;
}

/* CFP */
.cfp-box {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 40px;
    margin-top: 32px;
}
.cfp-box h3 {
    font-family: 'Source Serif 4', serif;
    font-weight: 600;
    font-size: 1.15rem;
    color: var(--ink);
    margin-bottom: 16px;
}
.cfp-box ul {
    list-style: none;
    padding: 0;
}
.cfp-box li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 8px;
    font-size: 0.92rem;
}
.cfp-box li::before {
    content: '›';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 700;
    font-size: 1.1rem;
    line-height: 1.5;
}

.dates-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
    margin-top: 28px;
}
.date-item {
    background: var(--bg);
    border-radius: 10px;
    padding: 18px 20px;
    border-left: 3px solid var(--accent);
}
.date-label {
    font-size: 0.78rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--muted);
    margin-bottom: 4px;
}
.date-value {
    font-weight: 600;
    color: var(--ink);
    font-size: 0.95rem;
}

/* ORGANIZERS */
.org-subheading {
    font-family: 'Source Serif 4', serif;
    font-weight: 600;
    font-size: 1.2rem;
    color: var(--ink);
    margin-bottom: 8px;
    margin-top: 40px;
}
.org-subheading:first-of-type { margin-top: 0; }
.org-sublead {
    font-size: 0.88rem;
    color: var(--muted);
    margin-bottom: 20px;
}
.org-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(190px, 1fr));
    gap: 20px;
    margin-bottom: 48px;
}
.org-grid-5 {
    grid-template-columns: repeat(auto-fill, minmax(170px, 1fr));
}
.org-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 24px 16px 20px;
    text-align: center;
    transition: all 0.3s;
}
.org-card:hover {
    border-color: var(--accent);
    box-shadow: 0 4px 20px rgba(15,94,151,0.08);
    transform: translateY(-2px);
}
.org-photo {
    width: 88px;
    height: 88px;
    border-radius: 50%;
    object-fit: cover;
    margin: 0 auto 14px;
    display: block;
    border: 3px solid var(--bg-alt);
    transition: border-color 0.3s;
}
.org-card:hover .org-photo { border-color: var(--accent-glow); }
.org-photo-placeholder {
    width: 88px;
    height: 88px;
    border-radius: 50%;
    margin: 0 auto 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'Source Serif 4', serif;
    font-weight: 600;
    font-size: 1.3rem;
    border: 3px solid var(--bg-alt);
    transition: border-color 0.3s;
}
.org-photo-placeholder.tc {
    background: linear-gradient(135deg, #e8f4fd, #d0ebfa);
    color: var(--accent);
}
.org-photo-placeholder.so {
    background: linear-gradient(135deg, #e0f2f1, #c8ede9);
    color: var(--teal);
}
.org-card:hover .org-photo-placeholder { border-color: var(--accent-glow); }
.org-name {
    font-weight: 600;
    font-size: 0.92rem;
    color: var(--ink);
    margin-bottom: 2px;
}
.org-role {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--accent);
    margin-bottom: 4px;
}
.org-grid-5 .org-role {
    color: var(--teal);
}
.org-affil {
    font-size: 0.8rem;
    color: var(--muted);
    line-height: 1.4;
}
.org-link {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 0.78rem;
    font-weight: 500;
    color: var(--accent);
    text-decoration: none;
    margin-top: 8px;
    padding: 3px 10px;
    border-radius: 5px;
    border: 1px solid var(--border);
    transition: all 0.2s;
}
.org-link:hover {
    background: var(--accent-glow);
    border-color: var(--accent);
}
.org-link svg {
    width: 12px;
    height: 12px;
}

/* FOOTER */
footer {
    background: var(--ink);
    color: rgba(255,255,255,0.6);
    padding: 48px 24px;
    text-align: center;
    font-size: 0.88rem;
}
footer a { color: rgba(255,255,255,0.8); text-decoration: none; }
footer a:hover { color: #fff; }
.footer-inner {
    max-width: 900px;
    margin: 0 auto;
}
.footer-title {
    font-family: 'Source Serif 4', serif;
    font-weight: 600;
    color: rgba(255,255,255,0.85);
    font-size: 1.05rem;
    margin-bottom: 8px;
}

/* DIVIDER */
.divider {
    border: none;
    border-top: 1px solid var(--border);
    margin: 0;
}

/* RESPONSIVE */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(16px);
        flex-direction: column;
        padding: 16px;
        border-bottom: 1px solid var(--border);
        box-shadow: 0 8px 32px rgba(0,0,0,0.08);
    }
    .nav-links.open { display: flex; }
    .hamburger { display: flex; }
    .hero { padding: 120px 20px 60px; }
    .hero-meta { gap: 16px; }
    .section { padding: 48px 20px; }
    .cfp-box { padding: 24px; }
    .schedule-table { font-size: 0.85rem; }
    .schedule-table td, .schedule-table th { padding: 10px 12px; }
}

/* ANIMATIONS */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}