:root {
  color-scheme: light;
  --paper: #f7f1e6;
  --ink: #2b1f1a;
  --muted: #6f625a;
  --accent: #b84f2a;
  --accent-dark: #7a2f17;
  --line: #d5c5b1;
  --panel: #fffaf0;
  --shadow: 0 18px 45px rgba(48, 23, 10, 0.12);
  --font-title: "Hiragino Mincho ProN", "Yu Mincho", "Noto Serif JP", serif;
  --font-body: "Hiragino Sans", "Yu Gothic", "Noto Sans JP", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: radial-gradient(circle at 20% 10%, #fff4e2 0%, #f5e6d2 42%, #ead8c0 100%);
  color: var(--ink);
  font-family: var(--font-body);
  line-height: 1.85;
}

a {
  color: var(--accent-dark);
  text-underline-offset: 0.2em;
}

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

.hero {
  position: relative;
  overflow: hidden;
  padding: 52px max(6vw, 24px) 72px;
  border-bottom: 6px solid rgba(255, 255, 255, 0.25);
  background: linear-gradient(135deg, rgba(184, 79, 42, 0.97), rgba(122, 47, 23, 0.98));
  color: #fff;
}

.hero::after {
  position: absolute;
  right: -70px;
  bottom: -130px;
  width: 360px;
  height: 360px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 50%;
  box-shadow: 0 0 0 42px rgba(255, 255, 255, 0.04), 0 0 0 84px rgba(255, 255, 255, 0.03);
  content: "";
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 1040px;
  margin: 0 auto;
}

.eyebrow {
  margin: 0 0 10px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.22em;
  text-transform: uppercase;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-title);
  line-height: 1.45;
}

h1 {
  margin: 0 0 14px;
  font-size: clamp(30px, 5vw, 50px);
}

.lead {
  max-width: 760px;
  margin: 0;
  color: #fff4eb;
  font-size: 16px;
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 22px;
  font-size: 13px;
}

.breadcrumbs a {
  color: #fff;
}

.breadcrumbs span::before {
  margin-right: 8px;
  color: rgba(255, 255, 255, 0.6);
  content: "/";
}

.page-main {
  display: grid;
  max-width: 1120px;
  margin: -36px auto 80px;
  padding: 0 max(4vw, 20px);
  gap: 28px;
}

.panel,
.session-card {
  position: relative;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.panel {
  padding: clamp(22px, 4vw, 34px);
}

.panel h2 {
  margin: 0 0 18px;
  font-size: 23px;
}

.link-grid,
.campaign-grid,
.session-nav {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.link-grid {
  grid-template-columns: repeat(auto-fit, minmax(235px, 1fr));
}

.campaign-grid {
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.link-card,
.campaign-card,
.session-nav a {
  display: block;
  height: 100%;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fffdf8;
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
  transition: border-color 0.15s ease, box-shadow 0.15s ease, transform 0.15s ease;
}

.link-card:hover,
.campaign-card:hover,
.session-nav a:hover {
  border-color: var(--accent);
  color: var(--accent-dark);
  box-shadow: 0 10px 24px rgba(80, 38, 18, 0.11);
  transform: translateY(-2px);
}

.campaign-card small,
.session-nav small {
  display: block;
  margin-top: 5px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 500;
}

.home-link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  margin-top: 22px;
  color: #fff;
  font-weight: 700;
}

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

.session-card {
  padding: clamp(24px, 5vw, 46px);
  scroll-margin-top: 24px;
}

.session-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 30px;
  padding-bottom: 22px;
  border-bottom: 1px solid var(--line);
}

.session-number,
.session-date {
  margin: 0;
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.session-header h2 {
  margin: 4px 0 0;
  font-size: clamp(24px, 4vw, 34px);
}

.log-link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  padding: 9px 16px;
  border-radius: 999px;
  background: var(--accent-dark);
  color: #fff;
  font-size: 13px;
  font-weight: 700;
  text-decoration: none;
}

.log-link:hover {
  background: var(--accent);
  color: #fff;
}

.session-content {
  max-width: 820px;
  margin: 0 auto;
}

.session-content h3 {
  margin: 40px 0 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid #ead8c4;
  color: var(--accent-dark);
  font-size: 22px;
}

.session-content h3:first-child {
  margin-top: 0;
}

.session-content h4 {
  margin: 30px 0 10px;
  color: #56372a;
  font-size: 18px;
}

.session-content p {
  margin: 0 0 1.15em;
}

.session-content ul {
  margin: 0 0 22px;
  padding-left: 1.4em;
}

.session-content li {
  margin: 7px 0;
}

.session-footer {
  margin-top: 38px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  text-align: right;
}

.back-to-top {
  position: fixed;
  right: max(18px, 3vw);
  bottom: max(18px, 3vw);
  z-index: 20;
  display: grid;
  width: 58px;
  height: 58px;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.42);
  border-radius: 50%;
  background: rgba(122, 47, 23, 0.94);
  box-shadow: 0 12px 30px rgba(48, 23, 10, 0.28);
  color: #fff;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.08em;
  opacity: 0;
  pointer-events: none;
  text-decoration: none;
  transform: translateY(10px);
  transition: opacity 0.2s ease, transform 0.2s ease, background-color 0.15s ease;
}

.back-to-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--accent);
  color: #fff;
}

@media (max-width: 640px) {
  .hero {
    padding-bottom: 60px;
  }

  .page-main {
    margin-top: -28px;
  }

  .session-header {
    display: grid;
  }

  .log-link {
    justify-self: start;
  }

  .back-to-top {
    width: 52px;
    height: 52px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .link-card,
  .campaign-card,
  .session-nav a,
  .back-to-top {
    transition: none;
  }
}