/* 参加者サイト全体の見た目。Anthropic のトップ（anthropic.com）に倣う（2026-09-27 本人指示）。
   値は計算済みスタイルから取った: 地 #faf9f5／文字 #141413、見出しは太いゴシック、導入文は明朝、
   目玉は墨色の角丸24のカード、一覧は細い区切り線の行、足元は墨色。ボタンは角丸8。
   日本語の読みやすさを優先して、本文はゴシック（Anthropic は本文も明朝系）。
   お題ページ（body.uc）は、この上に odai.css（Claude Academy に倣う）を重ねる。 */

:root {
  --bg: #faf9f5;
  --ink: #141413;
  --body: #3d3d3a;
  --muted: #5f5e59;
  --line: rgba(20, 20, 19, 0.12);
  --line-strong: rgba(20, 20, 19, 0.2);
  --panel: #f0eee6;
  --card: #fcfcfb;
  --dark: #141413;
  --dark-text: #faf9f5;
  --dark-muted: #b0aea5;
  --brand: #0b7da3;
  --sans: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", "YuGothic", Meiryo, sans-serif;
  --serif: ui-serif, "Hiragino Mincho ProN", "Yu Mincho", "YuMincho", "Noto Serif JP", Georgia, serif;
  --pad: clamp(20px, 5.4vw, 78px);
  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
}

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

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

body {
  margin: 0;
  overflow-x: clip;
  background: var(--bg);
  color: var(--body);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.85;
  word-break: auto-phrase;
  text-wrap: pretty;
}

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

a {
  color: var(--ink);
  text-decoration-color: rgba(20, 20, 19, 0.35);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.22em;
}

a:hover {
  text-decoration-color: var(--ink);
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 2px;
  border-radius: 4px;
}

h1,
h2,
h3 {
  color: var(--ink);
  font-family: var(--sans);
  letter-spacing: 0;
  text-wrap: balance;
}

.wrap {
  max-width: 1284px;
  margin: 0 auto;
  padding-inline: var(--pad);
  box-sizing: content-box;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

/* ---------- ボタン ---------- */

.btn {
  display: inline-flex;
  gap: 8px;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 0 18px;
  border: 0;
  border-radius: 8px;
  font-family: var(--sans);
  font-size: 0.9375rem;
  font-weight: 500;
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  transition: background-color 160ms ease, color 160ms ease, transform 120ms var(--ease);
}

.btn:active {
  transform: scale(0.98);
}

.btn svg,
.site-header__cta svg,
.rows svg {
  width: 16px;
  height: 16px;
  flex: 0 0 auto;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.btn--dark {
  background: var(--ink);
  color: var(--dark-text);
}

.btn--dark:hover {
  background: #2e2e2b;
}

.btn--light {
  background: var(--dark-text);
  color: var(--ink);
}

.btn--light:hover {
  background: #fff;
}

.btn--ghost-light {
  background: transparent;
  box-shadow: inset 0 0 0 1px rgba(250, 249, 245, 0.45);
  color: var(--dark-text);
}

.btn--ghost-light:hover {
  background: rgba(250, 249, 245, 0.08);
}

.btn--ghost {
  background: transparent;
  box-shadow: inset 0 0 0 1px var(--line-strong);
  color: var(--ink);
}

.btn--ghost:hover {
  background: rgba(20, 20, 19, 0.04);
}

/* ---------- ヘッダー ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--line);
  background: rgba(250, 249, 245, 0.94);
  backdrop-filter: saturate(1.2) blur(10px);
}

.site-header__inner {
  display: flex;
  gap: 12px 28px;
  align-items: center;
  max-width: 1284px;
  min-height: 64px;
  margin: 0 auto;
  padding-inline: var(--pad);
  box-sizing: content-box;
}

.brand {
  display: inline-flex;
  gap: 12px;
  align-items: center;
  margin-right: auto;
  color: var(--ink);
  text-decoration: none;
}

.brand__mark {
  width: 34px;
  height: 8px;
  flex: 0 0 auto;
  background: radial-gradient(circle, var(--brand) 3.6px, transparent 4.1px) 0 0 / 13px 8px repeat-x;
}

.brand__text {
  display: grid;
  font-size: 0.9375rem;
  font-weight: 600;
  line-height: 1.35;
}

.brand__text small {
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 400;
}

.site-nav {
  display: flex;
  gap: 2px;
  font-size: 0.9375rem;
}

.site-nav a {
  padding: 8px 12px;
  border-radius: 8px;
  color: var(--ink);
  line-height: 1.3;
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 160ms ease;
}

.site-nav a:hover {
  background: rgba(20, 20, 19, 0.05);
}

.site-nav a[aria-current="page"] {
  background: rgba(20, 20, 19, 0.07);
  font-weight: 600;
}

.site-header__cta {
  display: inline-flex;
  gap: 6px;
  align-items: center;
  min-height: 34px;
  padding: 0 14px;
  border-radius: 8px;
  background: var(--ink);
  color: var(--dark-text);
  font-size: 0.9375rem;
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
}

.site-header__cta:hover {
  background: #2e2e2b;
}

.site-header__cta svg {
  width: 14px;
  height: 14px;
}

/* ---------- 足元 ---------- */

.site-footer {
  margin-top: clamp(72px, 9vw, 120px);
  background: var(--dark);
  color: var(--dark-muted);
  font-size: 0.875rem;
  line-height: 1.8;
}

.site-footer__inner {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) repeat(3, minmax(0, 1fr));
  gap: 40px 32px;
  max-width: 1284px;
  margin: 0 auto;
  padding: 64px var(--pad) 48px;
  box-sizing: content-box;
}

.site-footer p {
  margin: 0 0 12px;
}

.site-footer__title {
  color: var(--dark-text);
  font-size: 1.0625rem;
  font-weight: 600;
  line-height: 1.5;
}

.site-footer h2 {
  margin: 0 0 12px;
  color: var(--dark-text);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.02em;
}

.site-footer ul {
  display: grid;
  gap: 6px;
  margin: 0 0 16px;
  padding: 0;
  list-style: none;
}

.site-footer a {
  color: var(--dark-muted);
  text-decoration: none;
}

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

.site-footer a:focus-visible {
  outline-color: var(--dark-text);
}

.site-footer__bottom {
  max-width: 1284px;
  margin: 0 auto;
  padding: 20px var(--pad) 28px;
  border-top: 1px solid rgba(250, 249, 245, 0.12);
  box-sizing: content-box;
  font-size: 0.8125rem;
}

.site-footer__bottom p {
  margin: 0;
}

/* ---------- 下書きの但し書き ---------- */

.draft-note {
  margin-top: 16px;
}

.draft-note p {
  margin: 0;
  padding: 10px 14px;
  border-radius: 10px;
  background: #fbf3e2;
  box-shadow: inset 0 0 0 1px rgba(138, 90, 0, 0.35);
  color: var(--muted);
  font-size: 0.875rem;
  line-height: 1.6;
}

.draft-note b {
  color: #7a5200;
}

/* ---------- トップ ---------- */

.home-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
  gap: 24px clamp(40px, 6vw, 96px);
  align-items: start;
  padding-top: clamp(28px, 3.6vw, 52px);
  padding-bottom: 0;
}

.home-hero h1 {
  margin: 0;
  font-size: clamp(2.25rem, 3.9vw, 3.6rem);
  font-weight: 700;
  line-height: 1.18;
}

.home-hero__lead {
  max-width: 24em;
  margin: 0 0 20px;
  color: var(--ink);
  font-family: var(--serif);
  font-size: clamp(1.125rem, 1.55vw, 1.375rem);
  line-height: 1.7;
}

.home-hero__meta {
  margin: 0;
  color: var(--muted);
  font-size: 0.9375rem;
  line-height: 1.6;
}

.media-band {
  margin-top: 0;
  margin-bottom: 0;
}

/* トップの一番上に置く写真（見出しは重ねず、直下に置く） */
.media-band--top {
  padding-top: clamp(16px, 2vw, 28px);
}

.media-band--top img {
  height: clamp(300px, 62vh, 680px);
  aspect-ratio: auto;
  object-position: 50% 40%;
}

.media-band img {
  display: block;
  width: 100%;
  aspect-ratio: 21 / 9;
  object-fit: cover;
  border-radius: 24px;
}

.section {
  padding-top: clamp(56px, 7vw, 96px);
}

.section__head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 2fr);
  gap: 16px 64px;
  align-items: end;
  margin-bottom: 28px;
}

.section__head h2,
.split__head h2 {
  margin: 0;
  font-size: 1.5rem;
  font-weight: 600;
  line-height: 1.4;
}

.section__head p,
.split__head p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9375rem;
  line-height: 1.8;
}

/* 左に見出し、右に中身（Anthropic の「使命」の節の組み） */
.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 2fr);
  gap: 24px 64px;
  padding-top: clamp(56px, 7vw, 96px);
}

.split__head {
  display: grid;
  align-content: start;
  gap: 12px;
}

.split__head .btn {
  justify-self: start;
  margin-top: 8px;
}

.prose-lead {
  margin: 0 0 20px;
  color: var(--ink);
  font-family: var(--serif);
  font-size: clamp(1.25rem, 1.9vw, 1.625rem);
  line-height: 1.6;
}

.prose p {
  margin: 0 0 16px;
}

.prose p:last-child {
  margin-bottom: 0;
}

/* 3つの問いのカード */
.card-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.q-card {
  display: flex;
  flex-direction: column;
  padding: 16px 16px 24px;
  border-radius: 16px;
  background: var(--panel);
}

.q-card img {
  display: block;
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: 10px;
}

.q-card__label {
  margin: 18px 8px 4px;
  color: var(--muted);
  font-size: 0.875rem;
}

.q-card h3 {
  margin: 0 8px 10px;
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.45;
}

.q-card p:last-child {
  margin: 0 8px;
  color: var(--body);
  font-size: 0.9375rem;
  line-height: 1.8;
}

/* 区切り線の行 */
.rows {
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line-strong);
  list-style: none;
}

.rows > li {
  border-bottom: 1px solid var(--line-strong);
}

.rows a {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 4px 24px;
  align-items: center;
  padding: 20px 4px;
  color: inherit;
  text-decoration: none;
}

.rows__text {
  display: grid;
  gap: 4px;
}

.rows__title {
  color: var(--ink);
  font-size: 1.0625rem;
  font-weight: 600;
  line-height: 1.5;
}

.rows__desc {
  color: var(--muted);
  font-size: 0.9375rem;
  line-height: 1.7;
}

.rows__tag {
  color: var(--muted);
  font-size: 0.8125rem;
}

.rows a svg {
  width: 20px;
  height: 20px;
  color: var(--ink);
  transition: transform 200ms var(--ease);
}

.rows a:hover .rows__title {
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.22em;
}

.rows a:hover svg {
  transform: translateX(4px);
}

.rows--steps > li {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 4px 20px;
  padding: 22px 4px;
}

.rows__num {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 999px;
  box-shadow: inset 0 0 0 1px var(--line-strong);
  color: var(--ink);
  font-size: 0.9375rem;
  font-weight: 600;
  line-height: 1;
}

/* 墨色の目玉カード */
.feature-card {
  display: grid;
  justify-items: center;
  gap: 16px;
  margin-top: clamp(64px, 8vw, 112px);
  padding: clamp(48px, 8vw, 112px) clamp(24px, 5vw, 72px);
  border-radius: 24px;
  background: var(--dark);
  color: var(--dark-text);
  text-align: center;
}

.feature-card__eyebrow {
  margin: 0;
  color: var(--dark-muted);
  font-size: 0.9375rem;
}

.feature-card h2 {
  margin: 0;
  color: var(--dark-text);
  font-size: clamp(1.75rem, 3.2vw, 2.75rem);
  font-weight: 700;
  line-height: 1.3;
}

.feature-card p:not(.feature-card__eyebrow) {
  max-width: 30em;
  margin: 0;
  color: #e8e6dc;
  font-family: var(--serif);
  font-size: clamp(1.0625rem, 1.5vw, 1.3125rem);
  line-height: 1.7;
}

.feature-card__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  margin-top: 12px;
}

/* ---------- 下層ページ ---------- */

.page-head {
  padding-top: clamp(48px, 6vw, 88px);
}

.page-head__kicker {
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 0.9375rem;
}

.page-head h1 {
  margin: 0 0 16px;
  font-size: clamp(2rem, 3.8vw, 3.25rem);
  font-weight: 700;
  line-height: 1.25;
}

.page-head__lead {
  max-width: 34em;
  margin: 0;
  color: var(--ink);
  font-family: var(--serif);
  font-size: clamp(1.125rem, 1.6vw, 1.375rem);
  line-height: 1.75;
}

.num-list {
  margin: 0 0 20px;
  padding: 0;
  counter-reset: n;
  list-style: none;
}

.num-list li {
  position: relative;
  margin-bottom: 12px;
  padding-left: 44px;
  counter-increment: n;
}

.num-list li::before {
  content: counter(n);
  position: absolute;
  top: 0.1em;
  left: 0;
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border-radius: 999px;
  box-shadow: inset 0 0 0 1px var(--line-strong);
  color: var(--ink);
  font-size: 0.875rem;
  font-weight: 600;
  line-height: 1;
}

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

.dot-list li {
  position: relative;
  margin-bottom: 10px;
  padding-left: 22px;
}

.dot-list li::before {
  content: "";
  position: absolute;
  top: 0.8em;
  left: 4px;
  width: 6px;
  height: 6px;
  border-radius: 999px;
  background: var(--ink);
}

.note {
  margin: 20px 0;
  padding: 18px 20px;
  border-radius: 12px;
  background: var(--panel);
}

.note strong {
  display: block;
  margin-bottom: 4px;
  color: var(--ink);
  font-weight: 600;
}

.note p {
  margin: 0;
}

.note--wide {
  padding: clamp(20px, 3vw, 32px);
}

.note--wide p {
  font-family: var(--serif);
  font-size: clamp(1.0625rem, 1.4vw, 1.25rem);
  line-height: 1.75;
  color: var(--ink);
}

.shot {
  margin: 20px 0;
}

.shot img {
  display: block;
  width: 100%;
  border-radius: 12px;
  box-shadow: 0 0 0 1px var(--line), 0 6px 20px rgba(20, 20, 19, 0.08);
}

.shot figcaption {
  margin-top: 10px;
  color: var(--muted);
  font-size: 0.875rem;
}

.rule-list {
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line-strong);
  list-style: none;
}

.rule-list > li {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: 4px 20px;
  padding: 26px 0;
  border-bottom: 1px solid var(--line-strong);
}

.rule-list h3 {
  margin: 0 0 8px;
  font-size: 1.1875rem;
  font-weight: 600;
  line-height: 1.5;
}

.rule-list p {
  margin: 0 0 8px;
}

.rule-list p:last-child {
  margin-bottom: 0;
}

.rule-list .rows__num {
  width: 36px;
  height: 36px;
  font-size: 1rem;
}

/* 講師 */
.profile {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(220px, 0.6fr);
  gap: 32px clamp(40px, 6vw, 96px);
  align-items: end;
  padding-top: clamp(48px, 6vw, 88px);
}

.profile__name {
  margin: 0 0 8px;
  font-size: clamp(2rem, 3.8vw, 3.25rem);
  font-weight: 700;
  line-height: 1.25;
}

.profile__role {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 0.9375rem;
}

.profile__portrait {
  margin: 0;
}

.profile__portrait img {
  display: block;
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  border-radius: 16px;
}

.link-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.link-grid--3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.link-card {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border-radius: 16px;
  background: var(--card);
  box-shadow: 0 0 0 1px var(--line), 0 1px 2px rgba(20, 20, 19, 0.06);
  color: inherit;
  text-decoration: none;
  transition: box-shadow 200ms ease;
}

.link-card:hover {
  box-shadow: 0 0 0 1px var(--line-strong), 0 6px 20px rgba(20, 20, 19, 0.08);
}

.link-card img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  background: var(--panel);
}

.link-card__body {
  display: grid;
  gap: 4px;
  padding: 16px 18px 20px;
}

.link-card__label {
  color: var(--muted);
  font-size: 0.8125rem;
}

.link-card__title {
  color: var(--ink);
  font-size: 1.0625rem;
  font-weight: 600;
  line-height: 1.45;
}

.link-card__desc {
  color: var(--muted);
  font-size: 0.875rem;
  line-height: 1.7;
}

/* ---------- 狭い画面 ---------- */

@media (max-width: 960px) {
  .home-hero,
  .split,
  .section__head,
  .profile {
    grid-template-columns: minmax(0, 1fr);
  }

  .home-hero {
    align-items: start;
  }

  /* 見出しの2行目（11文字）が1行に収まる大きさ */
  .home-hero h1 {
    font-size: clamp(1.5rem, 7.6vw, 3.25rem);
  }

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

  .q-card {
    display: grid;
    grid-template-columns: minmax(0, 200px) minmax(0, 1fr);
    gap: 0 20px;
    align-items: center;
  }

  .q-card img {
    grid-row: span 3;
  }

  .q-card__label {
    margin-top: 0;
  }

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

  .site-footer__inner {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .site-footer__brand {
    grid-column: 1 / -1;
  }

  .profile__portrait {
    max-width: 280px;
  }
}

@media (max-width: 760px) {
  /* スマホではヘッダーを貼り付けない（2段で画面を圧迫するため） */
  .site-header {
    position: relative;
  }

  .site-header__inner {
    flex-wrap: wrap;
    gap: 6px 12px;
    min-height: 0;
    padding-top: 10px;
    padding-bottom: 8px;
  }

  .site-nav {
    order: 3;
    width: 100%;
    margin-inline: -8px;
    overflow-x: auto;
    scrollbar-width: none;
    font-size: 0.875rem;
  }

  .site-nav::-webkit-scrollbar {
    display: none;
  }

  .site-nav a {
    padding: 6px 8px;
  }

  .site-header__cta {
    min-height: 32px;
    padding: 0 12px;
    font-size: 0.875rem;
  }

  .media-band img {
    aspect-ratio: 4 / 3;
    border-radius: 16px;
  }

  .media-band--top img {
    height: auto;
    aspect-ratio: 4 / 3;
  }

  .q-card {
    display: flex;
  }

  .link-grid,
  .link-grid--3 {
    grid-template-columns: minmax(0, 1fr);
  }

  .site-footer__inner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  }

  .feature-card {
    border-radius: 18px;
  }
}

@media (max-width: 420px) {
  body {
    font-size: 16px;
  }

  .brand__text small {
    display: none;
  }
}

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

  .btn,
  .rows a svg,
  .link-card,
  .site-nav a {
    transition: none;
  }
}

@media print {
  .site-header,
  .site-footer,
  .draft-note {
    display: none;
  }
}