:root {
  --bg: #f8fafc;
  --surface: #fff;
  --ink: #0f172a;
  --muted: #64748b;
  --line: #e2e8f0;
  --accent: #0d9488;
  --accent-dark: #0f766e;
  --accent-soft: #ccfbf1;
  --reg-bg: #fff7ed;
  --reg-border: #fdba74;
  --reg-ink: #9a3412;
  --hero-gradient: linear-gradient(165deg, #ecfeff 0%, #f8fafc 45%, #fff 100%);
  --max: 68rem;
  --radius: 0.75rem;
  --shadow: 0 1px 3px rgb(15 23 42 / 0.06), 0 8px 24px rgb(15 23 42 / 0.04);
}
@font-face {
  font-family: "Noto Sans JP";
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  unicode-range: U+FA4F;
  src: url("https://fonts.gstatic.com/l/font?kit=-F6jfjtqLzI2JPCgQBnw7HFyzSD-AsregP8VFBEj75vA0FOaKC8-7g&skey=72472b0eb8793570&v=v56") format("truetype");
}

@font-face {
  font-family: "Noto Sans JP";
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  unicode-range: U+FA4F;
  src: url("https://fonts.gstatic.com/l/font?kit=-F6jfjtqLzI2JPCgQBnw7HFyzSD-AsregP8VFCMj75vA0FOaKC8-7g&skey=72472b0eb8793570&v=v56") format("truetype");
}

@font-face {
  font-family: "Noto Sans JP";
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  unicode-range: U+FA4F;
  src: url("https://fonts.gstatic.com/l/font?kit=-F6jfjtqLzI2JPCgQBnw7HFyzSD-AsregP8VFPYk75vA0FOaKC8-7g&skey=72472b0eb8793570&v=v56") format("truetype");
}


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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: "Noto Sans JP", "Hiragino Sans", "Yu Gothic UI", "Meiryo", sans-serif;
  font-weight: 400;
  line-height: 1.7;
}

a {
  color: var(--accent-dark);
  text-underline-offset: 0.15em;
}

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

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  z-index: 100;
  padding: 0.6rem 1rem;
  background: var(--accent);
  color: #fff;
  font-weight: 500;
  text-decoration: none;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
}

.wrap {
  width: min(calc(100% - 2rem), var(--max));
  margin-inline: auto;
}

.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding-block: 1rem 0.75rem;
  font-size: 0.92rem;
  font-weight: 500;
}

.site-header a {
  color: var(--ink);
  text-decoration: none;
}

.site-header a:hover {
  color: var(--accent-dark);
}

.brand {
  font-weight: 700;
  letter-spacing: -0.02em;
}

.site-nav {
  display: flex;
  gap: 1.25rem;
}

.site-nav a[aria-current="page"] {
  color: var(--accent-dark);
  font-weight: 700;
}

.hero {
  padding: 1.5rem 0 3.5rem;
  background: var(--hero-gradient);
  border-bottom: 1px solid var(--line);
}

.hero h1 {
  margin: 0;
  font-size: clamp(2.25rem, 6.5vw, 3.75rem);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.04em;
}

.hero-lede {
  margin: 0.85rem 0 0;
  max-width: 38em;
  color: var(--muted);
  font-size: 1.05rem;
}

.reg-banner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1.25rem;
  margin-top: 1.75rem;
  padding: 1.1rem 1.35rem;
  background: var(--reg-bg);
  border: 2px solid var(--reg-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.reg-banner-label {
  display: inline-block;
  padding: 0.2rem 0.65rem;
  background: var(--reg-ink);
  border-radius: 999px;
  color: #fff;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.reg-banner-main {
  margin: 0;
  color: var(--reg-ink);
  font-size: clamp(1.15rem, 3vw, 1.45rem);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.02em;
}

.reg-banner-sub {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.event-facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 16rem), 1fr));
  gap: 1rem;
  margin: 1.5rem 0 0;
  padding: 0;
  list-style: none;
}

.event-facts li {
  margin: 0;
  padding: 1rem 1.15rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.fact-label {
  display: block;
  margin-bottom: 0.25rem;
  color: var(--accent-dark);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.fact-value {
  margin: 0;
  font-size: 1rem;
  font-weight: 500;
  line-height: 1.5;
}

.fact-value small {
  display: block;
  margin-top: 0.15rem;
  color: var(--muted);
  font-size: 0.88rem;
  font-weight: 400;
}

main {
  padding: 3rem 0 5rem;
}

main > section + section {
  margin-top: 3.5rem;
}

section > h2 {
  margin: 0 0 1rem;
  font-size: clamp(1.35rem, 3vw, 1.65rem);
  font-weight: 700;
  letter-spacing: -0.03em;
}

.fact-value small + small {
  margin-top: 0.25rem;
}

.fact-value small a {
  color: var(--accent-dark);
}

.overview {
  margin: 1.75rem 0 0;
  font-size: 1.05rem;
  line-height: 1.85;
}

.track-section + .track-section,
.track-section + .content-block {
  margin-top: 3.5rem;
}

.track-header {
  margin-bottom: 0.75rem;
  padding-bottom: 0.65rem;
  border-bottom: 2px solid var(--accent-soft);
}

.track-header h2 {
  margin: 0;
  font-size: clamp(1.35rem, 3vw, 1.65rem);
  font-weight: 700;
  letter-spacing: -0.03em;
}

.track-meta {
  margin: 0.2rem 0 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.talk-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.talk-list > li + li {
  margin-top: 0.65rem;
}

.talk {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.talk[open] {
  border-color: #99f6e4;
  box-shadow: var(--shadow);
}

.talk-summary {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 0.75rem 1.5rem;
  align-items: baseline;
  padding: 1.1rem 1.25rem;
  cursor: pointer;
  list-style: none;
}

.talk-summary::-webkit-details-marker {
  display: none;
}

.talk-summary::after {
  content: "";
  grid-column: 1 / -1;
  width: 0.55rem;
  height: 0.55rem;
  margin-top: 0.15rem;
  border-right: 2px solid var(--accent);
  border-bottom: 2px solid var(--accent);
  transform: rotate(45deg);
  justify-self: start;
  transition: transform 0.2s;
}

.talk[open] .talk-summary::after {
  transform: rotate(-135deg);
  margin-top: 0.35rem;
}

.talk-summary:focus {
  outline: none;
}

.talk-summary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: -2px;
}

.talk-title {
  margin: 0;
  font-size: clamp(1.05rem, 2.5vw, 1.25rem);
  font-weight: 700;
  line-height: 1.45;
  letter-spacing: -0.02em;
}

.talk-speaker {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
  white-space: nowrap;
}

.talk-abstract {
  padding: 0 1.25rem 1.15rem;
  border-top: 1px solid var(--line);
}

.talk-abstract p {
  margin: 0.85rem 0 0;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.75;
}

.talk-abstract p:first-child {
  margin-top: 0.85rem;
}

.talk-abstract ul,
.talk-abstract ol {
  margin: 0.85rem 0 0;
  padding-left: 1.35rem;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.75;
}

.talk-abstract li + li {
  margin-top: 0.35rem;
}

.talk-abstract code {
  font-family: ui-monospace, "Cascadia Code", "Source Code Pro", monospace;
  font-size: 0.9em;
}

.talk-materials {
  margin: 1rem 0 0;
  padding-top: 0.85rem;
  border-top: 1px dashed var(--line);
  font-size: 0.95rem;
  font-weight: 500;
}

.talk-materials a {
  text-decoration-thickness: 2px;
}

.prices {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.4rem 2rem;
  width: min(100%, 24rem);
  margin: 1rem 0 1.25rem;
}

.prices div {
  display: contents;
}

.prices dt,
.prices dd {
  margin: 0;
  padding-block: 0.5rem;
  border-bottom: 1px solid var(--line);
}

.prices dd {
  text-align: right;
  font-weight: 600;
}

.content-block p {
  margin: 0;
}

.content-block p + p {
  margin-top: 0.75rem;
}

.intro p,
.overview,
.content-block p,
.talk-abstract p {
  text-align: justify;
  text-justify: inter-ideograph;
  text-align-last: left;
}

.intro {
  margin-top: 1.25rem;
}

.intro p {
  margin: 0;
  font-size: 1.05rem;
  line-height: 1.85;
}

.intro p + p {
  margin-top: 1.15rem;
}

.featured-event {
  display: block;
  margin-top: 2.25rem;
  padding: 1.75rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 0.15rem);
  box-shadow: var(--shadow);
  color: inherit;
  text-decoration: none;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.featured-event:hover {
  border-color: #99f6e4;
  box-shadow: 0 4px 20px rgb(13 148 136 / 0.1);
}

.featured-event:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.featured-event h2 {
  margin: 0 0 1rem;
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 700;
  letter-spacing: -0.03em;
}

.featured-event .reg-banner {
  margin-top: 0;
}

.featured-event .event-facts {
  margin-top: 1.25rem;
}

.featured-event .talk-preview {
  margin: 1.5rem 0 0;
  padding: 0;
  list-style: none;
}

.featured-event .talk-preview li {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 0.5rem 1.5rem;
  align-items: baseline;
  padding: 0.75rem 0;
  border-top: 1px solid var(--line);
}

.featured-event .talk-preview li:last-child {
  border-bottom: 1px solid var(--line);
}

.featured-event .talk-preview .talk-title {
  font-size: 1rem;
  font-weight: 600;
}

.featured-event .more {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-top: 1.25rem;
  color: var(--accent-dark);
  font-weight: 600;
}

.featured-event .more::after {
  content: "→";
}

.archive {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  margin: 0.5rem 0 0;
  padding: 0;
  list-style: none;
}

.archive a {
  color: var(--ink);
  font-weight: 500;
  text-decoration: none;
}

.archive a:hover {
  color: var(--accent-dark);
  text-decoration: underline;
}

.site-footer {
  margin-top: 0;
  padding-block: 2rem 2.5rem;
  border-top: 1px solid var(--line);
  background: var(--surface);
  color: var(--muted);
  font-size: 0.88rem;
}

.site-footer-inner {
  display: grid;
  gap: 0.35rem;
}

.site-footer p {
  margin: 0;
}

.site-footer a {
  color: inherit;
}

.site-footer a:hover {
  color: var(--accent-dark);
}

@media (max-width: 40rem) {
  .talk-summary {
    grid-template-columns: 1fr;
    gap: 0.25rem;
  }

  .talk-speaker {
    white-space: normal;
  }

  .featured-event .talk-preview li {
    grid-template-columns: 1fr;
    gap: 0.15rem;
  }
}

@media print {
  .hero {
    background: #fff;
  }

  .reg-banner {
    border: 1px solid #ccc;
  }

  .talk {
    break-inside: avoid;
  }

  .talk[open] summary ~ * {
    display: block;
  }

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