:root {
  --navy-950: #071d31;
  --navy-900: #0e2e4d;
  --navy-800: #123b60;
  --navy-700: #1c4f78;
  --green-700: #287063;
  --green-600: #397f72;
  --blue-300: #b7d7e5;
  --blue-100: #e8f2f6;
  --ink: #173d56;
  --ink-soft: #294b5e;
  --muted: #365d70;
  --line: rgba(14, 46, 77, .18);
  --paper: #f3f6f5;
  --white: #ffffff;
  --header-height: 98px;
  --radius-lg: 24px;
  --shadow: 0 22px 56px rgba(7, 29, 49, .16);
  --shadow-soft: 0 14px 36px rgba(7, 29, 49, .09);
  --font-sans: "Hiragino Maru Gothic ProN", "BIZ UDPGothic", "Yu Gothic", "Hiragino Sans", Meiryo, sans-serif;
  --font-serif: "Yu Mincho", "Hiragino Mincho ProN", serif;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 24px);
}

body {
  margin: 0;
  overflow-x: hidden;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 500;
  line-height: 1.85;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body.menu-open { overflow: hidden; }

img {
  display: block;
  max-width: 100%;
}

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

button,
a { -webkit-tap-highlight-color: transparent; }

button,
input,
textarea,
select { font: inherit; }

:focus-visible {
  outline: 3px solid rgba(40, 112, 99, .38);
  outline-offset: 4px;
}

.container {
  width: min(1180px, calc(100% - 48px));
  margin-inline: auto;
}

.container-wide {
  width: min(1440px, calc(100% - 48px));
  margin-inline: auto;
}

.skip-link {
  position: fixed;
  z-index: 9999;
  top: 10px;
  left: 10px;
  padding: 10px 16px;
  color: var(--white);
  background: var(--navy-950);
  border-radius: 8px;
  transform: translateY(-160%);
  transition: transform .2s ease;
}

.skip-link:focus { transform: none; }

.eyebrow {
  margin: 0 0 10px;
  color: var(--green-700);
  font-size: .82rem;
  font-weight: 800;
  letter-spacing: .12em;
  text-transform: uppercase;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 54px;
  padding: 13px 27px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: .025em;
  transition: transform .2s ease, box-shadow .2s ease, color .2s ease, background-color .2s ease;
}

.button:hover { transform: translateY(-2px); }

.button-primary {
  color: var(--white);
  background: var(--navy-900);
  box-shadow: 0 10px 24px rgba(14, 46, 77, .2);
}

.button-primary:hover {
  background: var(--navy-700);
  box-shadow: 0 14px 28px rgba(14, 46, 77, .25);
}

.button-outline {
  color: var(--navy-900);
  background: var(--white);
  border-color: rgba(14, 46, 77, .3);
}

.button-outline:hover { background: var(--blue-100); }

.site-header {
  position: sticky;
  z-index: 1000;
  top: 0;
  min-height: var(--header-height);
  background: rgba(255, 255, 255, .96);
  border-bottom: 1px solid rgba(14, 46, 77, .1);
  backdrop-filter: blur(18px);
  transition: box-shadow .2s ease, background-color .2s ease;
}

.site-header.is-scrolled {
  background: rgba(255, 255, 255, .99);
  box-shadow: 0 8px 24px rgba(7, 29, 49, .09);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-height);
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  flex: 0 1 auto;
  gap: 14px;
  min-width: 300px;
}

.brand-mark {
  flex: 0 0 auto;
  width: 68px;
  height: 68px;
  object-fit: contain;
}

.brand-copy {
  display: grid;
  min-width: 0;
  line-height: 1.2;
}

.brand-kicker {
  color: var(--ink-soft);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: .02em;
  white-space: nowrap;
}

.brand-title {
  margin-top: 6px;
  color: var(--navy-900);
  font-size: clamp(1.28rem, 1.4vw, 1.48rem);
  font-weight: 800;
  letter-spacing: .035em;
  line-height: 1.2;
  white-space: nowrap;
}

.brand-title small {
  font-size: .78em;
  font-weight: 700;
}

.global-nav {
  display: flex;
  align-items: stretch;
  align-self: stretch;
}

.global-nav a {
  display: grid;
  place-items: center;
  margin: 16px 2px;
  padding: 0 15px;
  color: var(--ink);
  font-size: 1rem;
  font-weight: 700;
  white-space: nowrap;
  border-radius: 10px;
  transition: color .2s ease, background-color .2s ease;
}

.global-nav a:hover,
.global-nav a:focus-visible {
  color: var(--white);
  background: var(--navy-900);
  outline: none;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  color: var(--navy-900);
  background: transparent;
  border: 0;
  cursor: pointer;
}

.nav-toggle-label {
  font-size: .95rem;
  font-weight: 800;
}

.nav-toggle-lines {
  display: grid;
  gap: 5px;
  width: 27px;
}

.nav-toggle-lines i {
  display: block;
  width: 100%;
  height: 2px;
  background: currentColor;
  transition: transform .2s ease, opacity .2s ease;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-lines i:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-lines i:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-lines i:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.program-hero,
.abstracts-hero,
.registration-hero,
.pre-event-hero {
  padding: clamp(46px, 6vw, 72px) 0 clamp(40px, 5vw, 58px);
  background: var(--white);
  border-bottom: 1px solid var(--line);
}

.program-hero h1,
.abstracts-hero h1,
.registration-hero h1,
.pre-event-hero h1 {
  margin: 0;
  color: var(--navy-900);
  font-family: var(--font-sans);
  font-size: clamp(2.35rem, 4.5vw, 3.8rem);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: .025em;
}

.section {
  margin-bottom: 52px;
  padding: clamp(32px, 5vw, 58px);
  background: rgba(255, 255, 255, .94);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
}

.section-heading { margin-bottom: 30px; }

.section-heading h2 {
  margin: 0;
  color: var(--navy-900);
  font-family: var(--font-serif);
  font-size: clamp(2rem, 4vw, 3.2rem);
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: .04em;
}

.site-footer {
  position: relative;
  overflow: hidden;
  padding: 80px 0 24px;
  color: var(--white);
  background: var(--navy-950);
}

.footer-orbit {
  position: absolute;
  border: 1px solid rgba(183, 215, 229, .16);
  border-radius: 50%;
}

.footer-orbit-one {
  width: 470px;
  height: 470px;
  right: -180px;
  top: -250px;
}

.footer-orbit-two {
  width: 250px;
  height: 250px;
  right: 40px;
  top: -140px;
}

.footer-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1.18fr .82fr .82fr;
  gap: clamp(42px, 6vw, 78px);
}

.footer-logo-row {
  display: flex;
  align-items: center;
  gap: 20px;
}

.footer-logo-row img {
  flex: 0 0 auto;
  width: 92px;
  height: 92px;
  object-fit: contain;
  background: radial-gradient(circle at center, var(--white) 0 45%, transparent 50%);
}

.footer-brand h2,
.footer-links h2,
.footer-office h2 {
  margin: 0 0 18px;
  color: var(--white);
  font-size: 1.25rem;
  font-weight: 800;
  line-height: 1.45;
}

.footer-logo-row h2 { margin-bottom: 7px; }

.footer-brand p,
.footer-office p,
.footer-meta dd,
.footer-links a {
  color: var(--white);
  font-size: .98rem;
  font-weight: 500;
  line-height: 1.75;
}

.footer-brand p,
.footer-office p { margin: 0; }

.footer-meta { margin: 28px 0 0; }

.footer-meta div {
  display: grid;
  grid-template-columns: 58px 1fr;
  gap: 15px;
  margin-top: 12px;
}

.footer-meta dt {
  color: var(--blue-300);
  font-size: .92rem;
  font-weight: 800;
}

.footer-meta dd { margin: 0; }

.footer-link-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px 26px;
}

.footer-link-column {
  display: grid;
  align-content: start;
  gap: 12px;
}

.footer-links a {
  display: block;
  font-weight: 650;
}

.footer-links a:hover,
.footer-office a:hover {
  color: var(--blue-300);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.footer-contact { margin-top: 15px !important; }
.footer-contact a { color: var(--blue-300); }

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-top: 58px;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, .18);
  color: var(--white);
  font-size: .86rem;
}

.footer-bottom p { margin: 0; }
.footer-bottom a { color: var(--blue-300); }

.page-top {
  position: fixed;
  z-index: 800;
  right: 24px;
  bottom: 24px;
  display: grid;
  width: 50px;
  height: 50px;
  place-items: center;
  color: var(--white);
  background: var(--navy-800);
  border: 0;
  border-radius: 50%;
  box-shadow: 0 10px 22px rgba(7, 29, 49, .24);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  cursor: pointer;
  transition: opacity .2s ease, transform .2s ease, visibility .2s ease;
}

.page-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: none;
}

[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .6s ease, transform .6s ease;
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

@media (max-width: 1220px) {
  .nav-toggle {
    display: flex;
    z-index: 1002;
  }

  .global-nav {
    position: fixed;
    z-index: 1001;
    inset: var(--header-height) 0 auto;
    display: grid;
    max-height: calc(100vh - var(--header-height));
    padding: 14px 24px 24px;
    overflow-y: auto;
    background: rgba(255, 255, 255, .99);
    border-top: 1px solid var(--line);
    box-shadow: 0 24px 40px rgba(7, 29, 49, .14);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-12px);
    transition: opacity .2s ease, visibility .2s ease, transform .2s ease;
  }

  .global-nav.is-open {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .global-nav a {
    justify-content: start;
    min-height: 54px;
    margin: 0;
    padding: 0 12px;
    border-bottom: 1px solid var(--line);
    border-radius: 0;
  }
}

@media (max-width: 900px) {
  :root { --header-height: 86px; }

  .container,
  .container-wide { width: min(100% - 32px, 1180px); }

  .brand {
    min-width: 0;
    gap: 11px;
  }

  .brand-mark {
    width: 56px;
    height: 56px;
  }

  .brand-kicker { font-size: .84rem; }
  .brand-title { font-size: 1.1rem; }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 44px;
  }

  .footer-logo-row img {
    width: 76px;
    height: 76px;
  }

  .footer-bottom {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 620px) {
  :root { --header-height: 78px; }

  .container,
  .container-wide { width: min(100% - 24px, 1180px); }

  .brand-mark {
    width: 49px;
    height: 49px;
  }

  .brand-kicker {
    max-width: min(62vw, 290px);
    overflow: hidden;
    font-size: .72rem;
    text-overflow: ellipsis;
  }

  .brand-title {
    max-width: min(62vw, 290px);
    overflow: hidden;
    font-size: .98rem;
    text-overflow: ellipsis;
  }

  .brand-title small { display: none; }
  .nav-toggle-label { display: none; }
  .button { width: 100%; }

  .program-hero,
  .abstracts-hero,
  .registration-hero,
  .pre-event-hero { padding-block: 40px 36px; }

  .program-hero h1,
  .abstracts-hero h1,
  .registration-hero h1,
  .pre-event-hero h1 { font-size: clamp(2rem, 10vw, 2.65rem); }

  .footer-link-columns {
    grid-template-columns: 1fr 1fr;
    gap: 12px 22px;
  }

  .page-top {
    right: 16px;
    bottom: 16px;
    width: 46px;
    height: 46px;
  }
}

@media (max-width: 420px) {
  .footer-link-columns { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }

  [data-reveal] {
    opacity: 1;
    transform: none;
  }
}