:root {
  --ink: #000000;
  --muted: #000000;
  --paper: #f5f7fb;
  --mist: #e7edf4;
  --accent: #2f6f6b;
  --accent-dark: #245855;
  --card: #ffffff;
  --line: rgba(31, 42, 51, 0.12);
  --shadow: 0 6px 18px rgba(31, 42, 51, 0.06);
  --radius: 16px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Work Sans", "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  background: #eef2f7;
  position: relative;
}

html {
  scroll-padding-top: 84px;
}

h1, h2, h3 {
  font-family: "IBM Plex Sans", "Work Sans", "Helvetica Neue", Arial, sans-serif;
  margin: 0 0 0.6rem;
  color: #001a7f;
}

h1 {
  font-size: clamp(2.4rem, 4vw, 3.6rem);
  line-height: 1.08;
}

h2 {
  font-size: clamp(1.8rem, 3vw, 2.4rem);
}

h3 {
  font-size: 1.25rem;
}

p {
  margin: 0 0 1rem;
}

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

.container {
  width: min(1120px, 90vw);
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  background: #eef2f7;
  border-bottom: 1px solid var(--line);
  z-index: 10;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
  gap: 1.5rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.8rem;
}

.brand-link {
  cursor: pointer;
}

.brand-mark {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-family: "IBM Plex Sans", "Work Sans", "Helvetica Neue", Arial, sans-serif;
  font-weight: 700;
  background: var(--accent);
  color: white;
}

.brand-title {
  font-weight: 600;
}

.brand-subtitle {
  color: var(--muted);
  font-size: 0.85rem;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.9rem;
}

.site-nav a {
  padding-bottom: 0.2rem;
  border-bottom: 2px solid transparent;
}

.site-nav a:hover {
  border-color: var(--accent);
}

.hero {
  padding: 8rem 0 12rem;
  background:
    linear-gradient(180deg, rgba(248, 249, 251, 0.35) 0%, rgba(248, 249, 251, 0.55) 60%, rgba(238, 242, 247, 1) 100%),
    url("../images/denver_green.png");
  background-size: cover;
  background-position: center 45%;
  background-repeat: no-repeat;
  position: relative;
}

.hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 48px;
  background: linear-gradient(180deg, rgba(238, 242, 247, 0) 0%, rgba(238, 242, 247, 1) 100%);
  pointer-events: none;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.hero-intro {
  transform: translateY(-100px);
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.75rem;
  color: var(--ink);
  margin-bottom: 1rem;
}

.lead {
  font-size: 1.1rem;
  color: var(--ink);
}

.hero-lead {
  display: block;
  background: none;
  padding: 0;
  border-radius: 0;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  margin-top: 1.5rem;
  flex-wrap: wrap;
}

.btn {
  padding: 0.75rem 1.6rem;
  border-radius: 999px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--accent);
  color: white;
}

.btn-primary:hover {
  background: var(--accent-dark);
}

.btn-outline {
  border-color: var(--accent);
  color: var(--accent-dark);
  background: transparent;
}

.card-label {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ink);
}

.hero-details {
  margin-top: 2rem;
  border-top: none;
  padding-top: 1.5rem;
  display: grid;
  gap: 0.8rem;
}

.hero-card {
  display: block;
  background: rgba(255, 255, 255, 0.6);
  padding: 1rem 1.2rem;
  border-radius: 12px;
  transform: translateY(120px);
  width: 100%;
  max-width: 420px;
}

.detail-list {
  display: grid;
  gap: 0.4rem;
  color: var(--ink);
}

.detail-list span {
  font-weight: 600;
  color: var(--ink);
}

.section {
  padding: 4rem 0;
  content-visibility: auto;
  contain-intrinsic-size: 800px;
}

.section-alt {
  background: transparent;
  border: none;
}

.simple-list {
  margin: 1rem 0 0;
  padding-left: 1.2rem;
  color: var(--muted);
}

.timeline {
  display: grid;
  gap: 0.8rem;
  margin-top: 2rem;
}

.timeline-item {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 1.2rem;
  padding: 0.6rem 0;
  border-bottom: 1px solid var(--line);
}

.timeline-date {
  font-weight: 600;
  color: var(--ink);
}

.timeline-text {
  color: var(--ink);
}

.timeline-item:last-child {
  border-bottom: none;
}

.grid {
  display: grid;
  gap: 1.5rem;
}

.cards {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 1.6rem;
  border: 1px solid var(--line);
  min-height: 140px;
}

.card-title {
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.person-card {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.person-avatar {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  background: #ffffff;
  flex-shrink: 0;
}

.speaker-list {
  display: grid;
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.speaker-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 1.6rem;
  border: 1px solid var(--line);
}

.speaker-header {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 1.4rem;
  align-items: center;
  margin-bottom: 0.8rem;
}

.speaker-avatar {
  width: 130px;
  height: 130px;
  border-radius: 50%;
  object-fit: cover;
  background: #ffffff;
}

.speaker-link {
  color: inherit;
}

.speaker-name {
  font-weight: 700;
  font-size: 1.1rem;
}

.speaker-org {
  color: var(--muted);
}

.schedule {
  display: grid;
  gap: 0.6rem;
  margin-top: 1.5rem;
}

.schedule-row {
  display: grid;
  grid-template-columns: 90px 1fr;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--line);
}

.schedule-row:last-child {
  border-bottom: none;
}

.schedule-keynote {
  font-weight: 700;
}

.organizers {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.organizer {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 0.6rem;
  background: var(--card);
  border-radius: 14px;
  padding: 1rem 0.8rem 1.2rem;
  border: 1px solid var(--line);
}

.person-name {
  font-weight: 600;
}

.person-org {
  color: var(--muted);
  font-size: 0.9rem;
}

.organizer-note {
  margin-top: 1.5rem;
}

.contact-list {
  margin: 0.4rem 0 0;
  padding-left: 1.2rem;
  color: var(--muted);
}

.contact-list li {
  margin: 0.2rem 0;
}

.teletyped {
  font-family: "Courier New", Courier, monospace;
  font-size: 0.95em;
  letter-spacing: 0.02em;
}

@media (max-width: 1100px) {
  .organizers {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  .speaker-header {
    grid-template-columns: 1fr;
    justify-items: center;
    text-align: center;
  }

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

.sponsor-row {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 1.5rem;
}

.sponsor-logo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.8rem 1.6rem;
  border-radius: 999px;
  background: var(--card);
  border: 1px solid var(--line);
  min-height: 64px;
}

.sponsor-logo img {
  max-height: 36px;
  max-width: 180px;
}

.site-footer {
  padding: 2rem 0 1.5rem;
  border-top: 1px solid rgba(18, 20, 26, 0.08);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.2rem;
  margin-bottom: 1rem;
}

.footer-title {
  font-weight: 600;
  margin-bottom: 0.4rem;
}

.footer-links {
  display: grid;
  gap: 0.3rem;
}

.footer-note {
  font-size: 0.85rem;
  color: var(--muted);
}

.muted {
  color: var(--muted);
}

@media (max-width: 860px) {
  .site-header .container {
    flex-direction: column;
    align-items: flex-start;
  }

  .site-nav {
    gap: 0.6rem 1rem;
  }

  .timeline-item {
    grid-template-columns: 1fr;
  }

  .schedule-row {
    grid-template-columns: 1fr;
    gap: 0.3rem;
  }
}