@charset "UTF-8";
/* ==========================================================
   シンポジウム「くらしを変える数理モデリング」
   ========================================================== */
.print-only { display: none; }
:root {
  --c-primary: #6b2f93;
  --c-primary-dark: #56237a;
  --c-primary-deep: #4d1f6d;
  --c-heading: #5a2482;
  --c-accent: #a0417f;
  --c-text: #2b2233;
  --c-text-strong: #3d2f4a;
  --c-text-sub: #5b4c68;
  --c-text-mute: #6a5b76;
  --c-bg: #fbf8fd;
  --c-surface: #ffffff;
  --c-tint: #f4eaf9;
  --c-border: #e6d8f0;
  --c-border-soft: #ece2f3;
  --c-footer: #3a1f4f;
  /* チラシと同じヒラギノを優先し、無い環境では近い Web フォントで表示 */
  --font-body: "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Noto Sans JP", Meiryo, sans-serif;
  --font-display: var(--font-body);
  --font-serif: "Hiragino Mincho ProN", "Shippori Mincho", "Yu Mincho", "YuMincho", serif;
  --container: 1120px;
  --gutter: 40px;
}

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

html { scroll-behavior: smooth; scroll-padding-top: 80px; }

body {
  margin: 0;
  background: var(--c-bg);
  color: var(--c-text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  -webkit-text-size-adjust: 100%;
}

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

a { color: var(--c-primary); }
a:hover { color: var(--c-primary-deep); }

h1, h2, h3, p { margin: 0; }

.mf { font-family: var(--font-display); }

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--c-primary); color: #fff; padding: 8px 16px; z-index: 100;
}
.skip-link:focus { left: 8px; top: 8px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  min-height: 48px; padding: 0 28px; border-radius: 999px;
  font-weight: 700; font-size: 16px; text-decoration: none;
  transition: background-color .15s, border-color .15s, color .15s;
}
.btn svg { width: 18px; height: 18px; flex-shrink: 0; }
.btn--primary { background: var(--c-primary); color: #fff; }
.btn--primary:hover { background: var(--c-primary-dark); color: #fff; }
.btn--ghost { background: #fff; color: var(--c-primary); border: 2px solid #d9c3ea; }
.btn--ghost:hover { border-color: var(--c-primary); color: var(--c-primary-dark); }
.btn--sm { min-height: 44px; padding: 0 20px; font-size: 14px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 10;
  background: rgba(251, 248, 253, 0.94);
  border-bottom: 1px solid var(--c-border-soft);
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
}
.site-header__inner {
  display: flex; align-items: center; gap: 24px;
  padding-top: 12px; padding-bottom: 12px;
}
.site-header__logo {
  flex-grow: 1;
  color: var(--c-primary-deep); font-weight: 900; font-size: 18px; text-decoration: none;
}
.site-nav { display: flex; gap: 20px; align-items: center; }
.site-nav a {
  color: var(--c-text-strong); text-decoration: none; font-weight: 500; font-size: 15px; padding: 10px 4px;
}
.site-nav a:hover { color: var(--c-primary); }

/* ---------- Hero ---------- */
.hero { background: linear-gradient(160deg, #f3e6f7 0%, #fbf8fd 55%, #eef0fb 100%); }
.hero__inner {
  display: flex; flex-wrap: wrap; gap: 48px; align-items: center;
  padding-top: 72px; padding-bottom: 80px;
}
.hero__text { flex: 1 1 520px; display: flex; flex-direction: column; gap: 22px; }
.hero__label {
  align-self: flex-start;
  background: var(--c-primary); color: #fff;
  font-weight: 700; font-size: 15px; letter-spacing: .12em;
  padding: 8px 18px; border-radius: 999px;
}
.hero__title {
  align-self: flex-start;
  font-family: var(--font-serif);
  font-size: 70px; line-height: 1.2; font-weight: 800; letter-spacing: .04em;
  color: var(--c-heading);
  background: linear-gradient(120deg, #c24a8e 0%, #9a3d9e 45%, #5e2a8c 100%);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero__catch { font-family: var(--font-serif); font-size: 24px; font-weight: 500; letter-spacing: .04em; color: var(--c-text-strong); }
.hero__catch span { padding: 0 4px; background: linear-gradient(transparent 82%, #ecc96a 82%, #ecc96a 92%, transparent 92%); }
.hero__date { display: flex; flex-wrap: wrap; gap: 12px 28px; align-items: baseline; margin-top: 8px; }
.hero__day { color: var(--c-heading); font-weight: 900; font-size: 40px; line-height: 1; }
.hero__day small { font-size: 22px; margin-left: 6px; }
.hero__time { font-size: 18px; font-weight: 700; color: var(--c-text-strong); }
.hero__time small { font-weight: 500; color: var(--c-text-mute); font-size: 15px; margin-left: 10px; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; list-style: none; margin: 0; padding: 0; }
.chips li {
  background: #fff; border: 1px solid #e2d3ee; border-radius: 999px;
  padding: 6px 14px; font-size: 14px; font-weight: 500;
}
.hero__actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 8px; }
.hero__visual { flex: 1 1 340px; display: flex; justify-content: center; }
.hero__visual img { width: 100%; max-width: 460px; border-radius: 32px; mix-blend-mode: multiply; }

/* ---------- Info strip ---------- */
.info-strip { background: #fff; border-top: 1px solid var(--c-border-soft); border-bottom: 1px solid var(--c-border-soft); }
.info-strip__grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 20px;
  padding-top: 28px; padding-bottom: 28px; margin: 0 auto;
}
.info-item { display: flex; gap: 14px; align-items: flex-start; }
.info-item svg { width: 28px; height: 28px; flex-shrink: 0; stroke: var(--c-primary); }
.info-item dt { font-size: 13px; color: var(--c-text-mute); font-weight: 700; }
.info-item dd { margin: 0; font-size: 14px; }
.info-item dd strong { display: block; font-size: 16px; }

/* ---------- Sections ---------- */
.section { padding-top: 80px; padding-bottom: 80px; }
.section--white { background: #fff; border-top: 1px solid var(--c-border-soft); }
.section--bordered { border-top: 1px solid var(--c-border-soft); }
.section-head { display: flex; flex-direction: column; gap: 8px; margin-bottom: 28px; }
.section-head__en { font-size: 14px; letter-spacing: .2em; color: var(--c-accent); font-weight: 700; }
.section-head__title { font-size: 34px; font-weight: 900; color: var(--c-text-strong); line-height: 1.4; }

/* About */
.about { max-width: var(--container); margin: 0 auto; padding: 88px var(--gutter) 64px; }
.about p { max-width: 820px; font-size: 17px; line-height: 2; text-align: justify; }
.about p + p { margin-top: 20px; }
/* Why（3大学で開催する理由） */
.why {
  background: #fff;
  border-top: 1px solid var(--c-border-soft);
  border-bottom: 1px solid var(--c-border-soft);
  padding-top: 80px; padding-bottom: 80px;
}
.why__lead { max-width: 820px; margin: 0 0 36px; }
.why__lead p { font-size: 17px; line-height: 2; text-align: justify; }
.why__lead p + p { margin-top: 20px; }
.why__grid {
  list-style: none; margin: 0; padding: 0;
  display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px;
}
.why__card {
  background: var(--c-bg); border: 1px solid var(--c-border); border-radius: 20px;
  padding: 28px 24px; display: flex; flex-direction: column; gap: 10px;
}
.why__num {
  align-self: flex-start;
  background: var(--c-primary); color: #fff; font-weight: 900;
  padding: 4px 14px; border-radius: 8px; font-size: 18px; line-height: 1.5;
}
.why__card h3 { font-size: 19px; font-weight: 900; color: var(--c-heading); line-height: 1.5; }
.why__card p { font-size: 15px; line-height: 1.8; color: var(--c-text); }
/* ---------- Program ---------- */
.program { padding-top: 56px; padding-bottom: 88px; }
.program__list { display: flex; flex-direction: column; gap: 28px; }
.session { background: #fff; border: 1px solid var(--c-border); border-radius: 20px; overflow: hidden; }
.session__head {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px 20px;
  padding: 16px 28px; background: var(--c-tint);
}
.session__part { background: var(--c-primary); color: #fff; font-weight: 900; padding: 4px 16px; border-radius: 8px; font-size: 18px; }
.session__time { font-weight: 700; color: var(--c-heading); font-size: 17px; }
.session__title { font-weight: 900; font-size: 20px; }
.session__body { padding: 28px; }

.keynote { display: flex; flex-wrap: wrap; gap: 28px; align-items: center; }
.keynote img { width: 200px; height: 160px; object-fit: cover; border-radius: 14px; }
.keynote__text { flex: 1 1 380px; display: flex; flex-direction: column; gap: 14px; }
.keynote__theme { font-size: 26px; line-height: 1.45; font-weight: 900; color: var(--c-heading); }
.speaker-line { display: flex; flex-wrap: wrap; gap: 6px 16px; align-items: baseline; }
.speaker-line__name { font-size: 22px; font-weight: 700; }
.speaker-line__name small, .speaker__name small { font-size: 15px; }
.speaker-line__aff { font-size: 15px; color: var(--c-text-sub); }

.speakers { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; }
.speaker { display: flex; gap: 16px; align-items: flex-start; }
.speaker img { width: 96px; height: 128px; object-fit: cover; border-radius: 12px; flex-shrink: 0; }
.speaker__body { display: flex; flex-direction: column; gap: 6px; }
.speaker__univ { font-size: 14px; font-weight: 700; color: var(--c-accent); }
.speaker__theme { font-size: 18px; font-weight: 900; color: var(--c-heading); line-height: 1.4; }
.speaker__name { font-size: 17px; font-weight: 700; margin-top: 4px; }
.speaker__name small { font-size: 14px; }
.speaker__aff { font-size: 14px; color: var(--c-text-sub); }

.company { display: flex; flex-wrap: wrap; gap: 16px 36px; align-items: center; }
.company .company__name { flex: 0 0 auto; font-size: 22px; font-weight: 900; line-height: 1.5; }
.company p:not(.company__name) { flex: 1 1 420px; font-size: 16px; line-height: 1.9; }

/* ---------- Entry ---------- */
.entry { display: flex; flex-wrap: wrap; gap: 40px; }
.entry__text { flex: 1 1 420px; display: flex; flex-direction: column; gap: 16px; }
.entry__text .section-head { margin-bottom: 0; }
.entry__venue { font-size: 26px; font-weight: 700; color: var(--c-heading); }
.entry__text p { font-size: 16px; line-height: 1.9; }
.entry__box {
  flex: 1 1 380px; background: var(--c-tint); border-radius: 24px; padding: 36px;
  display: flex; flex-direction: column; gap: 18px; justify-content: center;
}
.entry__box h3 { font-size: 26px; font-weight: 900; color: var(--c-primary-deep); }
.entry__box p { font-size: 15px; line-height: 1.8; }
.entry__box .entry__deadline {
  align-self: flex-start;
  background: #fff; border: 1px solid var(--c-border); border-radius: 8px;
  padding: 6px 14px; font-size: 15px; color: var(--c-text-strong);
}
.entry__deadline strong { color: var(--c-primary-deep); font-size: 17px; }
.entry__box .btn { align-self: flex-start; }

/* ---------- Access ---------- */
.venue-badge {
  align-self: flex-start; margin-top: 8px;
  background: var(--c-primary); color: #fff; font-weight: 700; padding: 6px 18px; border-radius: 8px;
}
.access { display: flex; flex-wrap: wrap; gap: 28px; align-items: flex-start; }
.routes { flex: 1 1 400px; display: flex; flex-direction: column; gap: 14px; list-style: none; margin: 0; padding: 0; }
.route {
  background: #fff; border: 1px solid var(--c-border); border-radius: 16px;
  padding: 18px 22px; display: flex; gap: 14px;
}
.route__num {
  flex-shrink: 0; width: 32px; height: 32px; border-radius: 50%; color: #fff;
  display: flex; align-items: center; justify-content: center; font-weight: 900;
}
.route__num--1 { background: #5a2482; }
.route__num--2 { background: #b0306f; }
.route__num--3 { background: #5d5d66; }
.route__num--4 { background: #1f4f8a; }
.route h4 { margin: 0 0 4px; font-size: 18px; font-weight: 900; color: var(--c-text-strong); }
.route p { font-size: 15px; line-height: 1.8; }
.route .note { font-size: 14px; line-height: 1.7; color: var(--c-text-sub); margin-top: 4px; }
.access__map { flex: 1 1 440px; }
.access__map img { width: 100%; border-radius: 16px; border: 1px solid var(--c-border); background: #fff; }

.guide-title { margin: 48px 0 24px; font-size: 26px; font-weight: 900; color: var(--c-text-strong); }
.guide { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 24px; }
.guide__card {
  background: #fff; border: 1px solid var(--c-border); border-radius: 20px; padding: 24px;
  display: flex; flex-direction: column; gap: 16px;
}
.guide__head { display: flex; align-items: center; gap: 12px; }
.guide__num { background: var(--c-primary); color: #fff; font-weight: 900; padding: 4px 14px; border-radius: 8px; font-size: 18px; }
.guide__head h4 { margin: 0; font-size: 20px; font-weight: 900; }
.guide__card img { width: 100%; border-radius: 12px; }
.guide__card img.floor { max-width: 420px; align-self: center; }
.guide__card p { font-size: 15px; line-height: 1.8; }

.notice {
  margin: 32px 0 0; padding: 20px 24px; list-style: none;
  background: var(--c-tint); border-radius: 16px; font-size: 15px; line-height: 1.8;
}
.notice li::before { content: "・"; }
.notice li.strong { font-weight: 700; color: var(--c-primary-deep); }

/* ---------- Contact ---------- */
.contact { display: flex; flex-wrap: wrap; gap: 24px 48px; align-items: center; padding-top: 72px; padding-bottom: 72px; }
.contact__label { display: flex; align-items: center; gap: 16px; flex: 0 0 auto; }
.contact__icon {
  width: 56px; height: 56px; border-radius: 50%; background: var(--c-primary);
  display: flex; align-items: center; justify-content: center;
}
.contact__icon svg { width: 26px; height: 26px; }
.contact__label small { display: block; font-size: 14px; color: var(--c-text-mute); font-weight: 700; }
.contact__label strong { display: block; font-size: 22px; font-weight: 900; }
.contact__label span { display: block; font-size: 14px; color: var(--c-text-sub); }
.contact__detail { margin: 0; font-size: 16px; display: grid; grid-template-columns: auto 1fr; gap: 6px 4px; }
.contact__detail dd { margin: 0; }

/* ---------- Footer ---------- */
.site-footer { background: var(--c-footer); color: #efe6f5; }
.site-footer__inner { padding-top: 40px; padding-bottom: 40px; font-size: 15px; line-height: 1.8; }
.site-footer p + p { margin-top: 8px; }
.site-footer .copy { font-size: 13px; color: #c9b6d8; margin-top: 20px; }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .site-nav { display: none; }
}
@media (max-width: 760px) {
  :root { --gutter: 20px; }
  .hero__inner { padding-top: 48px; padding-bottom: 56px; gap: 32px; }
  .hero__title { font-size: 44px; }
  .hero__catch { font-size: 18px; }
  .hero__day { font-size: 34px; }
  .section { padding-top: 56px; padding-bottom: 56px; }
  .about { padding-top: 56px; }
  .why { padding-top: 56px; padding-bottom: 56px; }
  .why__lead p { font-size: 16px; }
  .section-head__title { font-size: 28px; }
  .session__head, .session__body { padding-left: 20px; padding-right: 20px; }
  .keynote img { width: 140px; height: 112px; }
  .keynote__theme { font-size: 22px; }
  .entry__box { padding: 28px 22px; }
  .site-header__logo { font-size: 15px; }
  .guide { grid-template-columns: 1fr; }
}