:root {
  --ink: #122235;
  --muted: #647284;
  --line: #d9e2ea;
  --paper: #ffffff;
  --soft: #f3f7f8;
  --brand: #137b7a;
  --brand-dark: #0d555b;
  --accent: #c83532;
  --accent-soft: #fbe9e6;
  --shadow: 0 22px 70px rgba(18, 34, 53, 0.12);
  --radius: 8px;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--soft);
  font-size: 16px;
  line-height: 1.65;
}

a {
  color: var(--brand-dark);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.2em;
}

a:hover {
  color: var(--accent);
}

img {
  max-width: 100%;
}

.site-header {
  color: #fff;
  background:
    linear-gradient(120deg, rgba(13, 85, 91, 0.96), rgba(18, 34, 53, 0.92)),
    radial-gradient(circle at 85% 18%, rgba(200, 53, 50, 0.22), transparent 34%);
}

.header-inner,
.content,
.footer-inner {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header > .header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex: 0 0 auto;
  gap: 24px;
  min-height: 92px;
}

.brand-link {
  display: inline-flex;
  align-items: center;
  gap: 16px;
  color: inherit;
  text-decoration: none;
}

.brand-logo {
  width: 104px;
  height: auto;
  padding: 10px 12px;
  border-radius: var(--radius);
  background: #fff;
}

.brand-title {
  display: block;
  font-size: 1.05rem;
  font-weight: 800;
  letter-spacing: 0;
}

.brand-date {
  display: block;
  color: rgba(255, 255, 255, 0.78);
  font-size: 0.92rem;
  font-weight: 600;
}

.mobile-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
  font: inherit;
  cursor: pointer;
}

.mobile-toggle span,
.mobile-toggle::before,
.mobile-toggle::after {
  display: block;
  width: 20px;
  height: 2px;
  margin: 5px auto;
  background: currentColor;
  content: "";
}

.main-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  flex: 1 1 auto;
  gap: 8px;
}

.nav-link,
.nav-button {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  padding: 0 14px;
  border: 0;
  border-radius: var(--radius);
  color: rgba(255, 255, 255, 0.9);
  background: transparent;
  font: inherit;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
}

.nav-link:hover,
.nav-button:hover,
.nav-link[aria-current="page"],
.nav-button[aria-expanded="true"] {
  color: #fff;
  background: rgba(255, 255, 255, 0.13);
}

.nav-item {
  position: relative;
}

.dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  z-index: 20;
  display: none;
  min-width: 190px;
  padding: 8px;
  border: 1px solid rgba(18, 34, 53, 0.08);
  border-radius: var(--radius);
  background: #fff;
  box-shadow: var(--shadow);
}

.dropdown[data-open="true"] {
  display: grid;
}

.dropdown a {
  padding: 9px 10px;
  border-radius: 6px;
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
}

.dropdown a:hover {
  background: var(--soft);
}

.hero {
  padding: 60px 0 70px;
}

.eyebrow {
  margin: 0 0 12px;
  color: rgba(255, 255, 255, 0.76);
  font-size: 0.82rem;
  font-weight: 800;
  text-transform: uppercase;
}

.hero h1 {
  max-width: 780px;
  margin: 0;
  font-size: clamp(2.4rem, 6vw, 5.4rem);
  line-height: 0.96;
  letter-spacing: 0;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 28px 0 0;
}

.pill {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 0 12px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 999px;
  color: rgba(255, 255, 255, 0.86);
  background: rgba(255, 255, 255, 0.08);
  font-weight: 700;
}

.contact-panel {
  display: none;
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  background: rgba(18, 34, 53, 0.32);
}

.contact-panel[data-open="true"] {
  display: block;
}

.contact-panel .header-inner {
  padding: 18px 0;
}

.contact-panel p {
  margin: 0;
  color: rgba(255, 255, 255, 0.9);
  font-weight: 700;
}

.contact-panel a {
  color: #fff;
}

main {
  background: linear-gradient(#fff 0, #fff 360px, var(--soft) 360px);
}

.intro {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 28px;
  padding: 46px 0 26px;
}

.intro h2 {
  margin: 0;
  font-size: clamp(1.8rem, 3vw, 3rem);
  line-height: 1.05;
  letter-spacing: 0;
}

.intro p {
  margin: 0;
  color: var(--muted);
}

.session-list {
  display: grid;
  gap: 24px;
  padding: 24px 0 72px;
}

.session-card {
  display: grid;
  grid-template-columns: minmax(280px, 0.95fr) minmax(0, 1.05fr);
  gap: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
  box-shadow: 0 16px 46px rgba(18, 34, 53, 0.08);
}

.video-frame {
  position: relative;
  min-height: 100%;
  background: #0b1722;
}

.video-frame::before {
  display: block;
  padding-top: 56.25%;
  content: "";
}

.video-frame iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.session-body {
  padding: clamp(22px, 3vw, 36px);
}

.session-body h3 {
  margin: 0 0 12px;
  color: var(--brand-dark);
  font-size: clamp(1.35rem, 2.5vw, 2.05rem);
  line-height: 1.12;
  letter-spacing: 0;
}

.session-body p {
  margin: 0 0 14px;
  color: #33465a;
}

.speakers {
  margin: 16px 0;
  padding: 0;
  list-style: none;
}

.speakers li {
  position: relative;
  padding: 7px 0 7px 22px;
  color: #33465a;
}

.speakers li::before {
  position: absolute;
  top: 1.05em;
  left: 0;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  content: "";
}

.downloads {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.download-link {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 13px;
  border: 1px solid rgba(19, 123, 122, 0.22);
  border-radius: var(--radius);
  color: var(--brand-dark);
  background: #eef8f7;
  font-size: 0.92rem;
  font-weight: 800;
  text-decoration: none;
}

.download-link:hover {
  border-color: rgba(200, 53, 50, 0.28);
  color: var(--accent);
  background: var(--accent-soft);
}

.site-footer {
  padding: 34px 0;
  color: rgba(255, 255, 255, 0.78);
  background: #122235;
  text-align: center;
}

.site-footer a {
  color: #fff;
}

@media (max-width: 860px) {
  .site-header > .header-inner {
    display: block;
  }

  .topbar {
    min-height: 82px;
  }

  .mobile-toggle {
    display: block;
  }

  .main-nav {
    display: none;
    align-items: stretch;
    padding: 0 0 18px;
  }

  .main-nav[data-open="true"] {
    display: grid;
  }

  .nav-link,
  .nav-button {
    justify-content: space-between;
    width: 100%;
  }

  .nav-item {
    width: 100%;
  }

  .dropdown {
    position: static;
    margin-top: 6px;
    box-shadow: none;
  }

  .hero {
    padding: 38px 0 48px;
  }

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

  .session-card {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .header-inner,
  .content,
  .footer-inner {
    width: min(100% - 28px, 1120px);
  }

  .brand-logo {
    width: 86px;
  }

  .brand-title {
    font-size: 0.96rem;
  }
}