/* ──────────────────────────────────────────────────────────────────────────
   slides.adao.dev — shared design system
   Structure (nav, fonts, layout, components) is standard across all pages.
   COLORS are tokenized: a page themes itself by overriding the :root vars
   below in a small inline <style> (see any conference page for an example).
   ────────────────────────────────────────────────────────────────────────── */

:root {
    /* Default theme — the standard dark slides.adao.dev palette */
    --font: 'Inter', 'Segoe UI', system-ui, sans-serif;
    --bg-start: #0a0f1e;
    --bg-end: #0d2137;
    --bg-glow: rgba(96, 165, 250, 0.15);
    --accent: #60a5fa;
    --accent-warm: #f59e0b;
    --surface: rgba(255, 255, 255, 0.05);
    --surface-hover: rgba(255, 255, 255, 0.09);
    --border: rgba(255, 255, 255, 0.1);
    --text-primary: #f1f5f9;
    --text-secondary: rgba(241, 245, 249, 0.65);
    --radius: 14px;
    --shadow: 0 1px 4px rgba(0, 0, 0, 0.06);
}

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

body {
    font-family: var(--font);
    margin: 0;
    padding: 0;
    background: var(--bg-start);
    background-image:
        radial-gradient(ellipse 80% 60% at 50% -10%, var(--bg-glow) 0%, transparent 70%),
        linear-gradient(160deg, var(--bg-start) 0%, var(--bg-end) 100%);
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.6;
}

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

/* ── Nav (index) ── */
nav {
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 2rem;
    height: 60px;
    background: color-mix(in srgb, var(--bg-start) 80%, transparent);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
}
.nav-brand {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: -0.01em;
}
.nav-brand span { color: var(--accent); }
.nav-home {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--accent);
    text-decoration: none;
    padding: 0.4rem 1rem;
    border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent);
    border-radius: 999px;
    transition: background 0.2s, border-color 0.2s;
}
.nav-home:hover {
    background: color-mix(in srgb, var(--accent) 10%, transparent);
    border-color: color-mix(in srgb, var(--accent) 60%, transparent);
    text-decoration: none;
}
.nav-home svg { width: 14px; height: 14px; flex-shrink: 0; }

/* ── Back link (sub-pages) ── */
.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    background: transparent;
    color: var(--accent);
    border: 1px solid color-mix(in srgb, var(--accent) 45%, transparent);
    padding: 0.45rem 1rem;
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 600;
    transition: background 0.2s, border-color 0.2s;
}
.back-link:hover {
    background: color-mix(in srgb, var(--accent) 10%, transparent);
    border-color: var(--accent);
    text-decoration: none;
}

/* ── Layout ── */
.container { max-width: 1100px; margin: 0 auto; padding: 2rem; }

/* ── Hero (index) ── */
.hero { text-align: center; padding: 5rem 2rem 3rem; }
.hero-eyebrow {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--accent);
    background: color-mix(in srgb, var(--accent) 10%, transparent);
    border: 1px solid color-mix(in srgb, var(--accent) 25%, transparent);
    border-radius: 999px;
    padding: 0.3rem 0.9rem;
    margin-bottom: 1.25rem;
}
h1 {
    font-weight: 700;
    letter-spacing: -0.03em;
    margin: 0 0 0.75rem;
    line-height: 1.1;
    color: var(--text-primary);
}
.hero h1 { font-size: clamp(2rem, 5vw, 3.25rem); }
header h1 { font-size: 2rem; margin-bottom: 0.5rem; }
.hero-sub {
    font-size: 1.05rem;
    color: var(--text-secondary);
    margin: 0 auto;
    max-width: 420px;
}

/* ── Event grid (index) ── */
.events-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.25rem; }
.year-divider { grid-column: 1 / -1; display: flex; align-items: center; gap: 0.75rem; margin-top: 1rem; }
.year-divider::after { content: ""; flex: 1; height: 1px; background: var(--border); }
.year-label {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-secondary);
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 999px;
    padding: 0.2rem 0.7rem;
}
.event-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.75rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    transition: background 0.2s, border-color 0.2s, transform 0.2s;
}
.event-card:hover {
    background: var(--surface-hover);
    border-color: color-mix(in srgb, var(--accent) 25%, transparent);
    transform: translateY(-3px);
}
.event-title { font-size: 1.1rem; font-weight: 600; color: var(--text-primary); margin: 0; line-height: 1.3; }
.event-date { font-size: 0.82rem; color: var(--accent); font-weight: 500; margin: 0; }
.event-description { font-size: 0.9rem; color: var(--text-secondary); margin: 0.25rem 0 0; flex: 1; }
.event-link {
    align-self: flex-start;
    margin-top: 1rem;
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--accent-warm);
    text-decoration: none;
    border: 1px solid color-mix(in srgb, var(--accent-warm) 35%, transparent);
    border-radius: 999px;
    padding: 0.35rem 0.9rem;
    transition: background 0.2s, border-color 0.2s;
}
.event-link:hover {
    background: color-mix(in srgb, var(--accent-warm) 10%, transparent);
    border-color: color-mix(in srgb, var(--accent-warm) 60%, transparent);
    text-decoration: none;
}
.event-link svg { width: 12px; height: 12px; }

/* ── Event page header ── */
header { text-align: center; padding: 2rem 0; margin-bottom: 1.5rem; }
.conference-logo { display: block; max-width: 340px; width: 100%; height: auto; margin: 0 auto 1rem; }
.event-meta { margin-top: 0.5rem; color: var(--text-secondary); font-weight: 500; }
.event-summary {
    border: 1px solid var(--border);
    background: var(--surface);
    border-radius: 12px;
    padding: 1.25rem 1.35rem;
    color: var(--text-secondary);
    max-width: 900px;
}

/* ── Sessions (event page) ── */
.sessions-title { margin: 1.75rem 0 0.9rem; color: var(--text-primary); font-size: 1.6rem; letter-spacing: 0.01em; }
.session-list { display: grid; gap: 1rem; }
.session {
    border: 1px solid var(--border);
    background: var(--surface);
    border-left: 4px solid var(--accent);
    border-radius: 8px;
    padding: 1.25rem 1.5rem;
    box-shadow: var(--shadow);
}
.session-type {
    margin: 0 0 0.4rem;
    font-size: 0.82rem;
    color: var(--accent);
    letter-spacing: 0.09em;
    text-transform: uppercase;
    font-weight: 600;
}
.session h3 { margin: 0; color: var(--text-primary); font-size: 1.08rem; font-weight: 600; line-height: 1.4; }
.session-summary { margin: 0.75rem 0 0; color: var(--text-secondary); font-size: 0.97rem; }

/* ── Slides: download button + embedded PDF viewer ── */
.session-slides { margin-top: 0.9rem; }
.download-link {
    display: inline-block;
    color: var(--accent);
    border: 1px solid color-mix(in srgb, var(--accent) 50%, transparent);
    background: color-mix(in srgb, var(--accent) 8%, transparent);
    padding: 0.45rem 0.85rem;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 600;
    text-decoration: none;
    transition: background 0.2s, border-color 0.2s;
    margin-bottom: 0.75rem;
}
.download-link:hover {
    background: color-mix(in srgb, var(--accent) 18%, transparent);
    border-color: var(--accent);
    text-decoration: none;
}
.pdf-viewer {
    display: block;
    width: 100%;
    height: 520px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--surface);
}

/* ── Video embed + details card (video event pages) ── */
.video-wrapper {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    overflow: hidden;
    border-radius: 18px;
    margin-bottom: 1.1rem;
    background: #000;
    box-shadow: 0 0 0 1px var(--border);
}
.video-wrapper iframe { position: absolute; top: 0; left: 0; width: 100%; height: 100%; border: 0; }
.details {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 18px;
    padding: 1.35rem 1.4rem;
}
.details h1 { font-size: 1.55rem; line-height: 1.3; }
.meta { margin: 0.45rem 0 1rem; color: var(--text-secondary); font-size: 0.95rem; }
.summary { margin: 0 0 1.25rem; color: var(--text-primary); max-width: 880px; font-size: 0.97rem; }
.actions { display: flex; flex-wrap: wrap; gap: 0.75rem; }

/* ── Action / platform buttons (brand colors are intentionally fixed) ── */
.btn-youtube, .btn-twitch, .btn-webcast {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.7rem 1.15rem;
    border-radius: 999px;
    color: #fff;
    text-decoration: none;
    font-weight: 600;
    letter-spacing: 0.01em;
    transition: background 0.2s ease;
}
.btn-youtube:hover, .btn-twitch:hover, .btn-webcast:hover { text-decoration: none; }
.btn-youtube { background: #ff0000; } .btn-youtube:hover { background: #cc0000; }
.btn-twitch { background: #9147ff; } .btn-twitch:hover { background: #7b34e0; }
.btn-webcast { background: var(--accent); }
.btn-webcast svg { height: 1.1em; width: auto; flex-shrink: 0; }

/* ── Event photo gallery ── */
.photos-section { margin: 3rem 0; }
.photos-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}
.photo {
    width: 100%;
    height: 150px;
    object-fit: cover;
    border-radius: 10px;
    transition: transform 0.2s ease;
}
.photo:hover { transform: scale(1.04); }
.photo-card {
    border: 1px solid var(--border);
    background: var(--surface);
    border-radius: 8px;
    padding: 0.6rem;
    box-shadow: var(--shadow);
}
.photo-card .photo { height: auto; border-radius: 6px; }
.download-link.icon-link { display: inline-flex; align-items: center; gap: 0.45rem; }
.download-link.icon-link svg { width: 16px; height: 16px; flex: 0 0 16px; }

/* ── Footer ── */
footer {
    text-align: center;
    padding: 2rem 1rem;
    border-top: 1px solid var(--border);
    font-size: 0.85rem;
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.6rem;
}
footer a { color: var(--accent); font-weight: 500; }

/* ── Responsive ── */
@media (max-width: 700px) {
    nav { padding: 0 1rem; }
    .hero { padding: 3.5rem 1rem 2rem; }
    .container { padding: 1.5rem 1rem; }
    .events-grid { grid-template-columns: 1fr; }
}