:root {
  --ink: #13241c;
  --ink-soft: #3d5248;
  --paper: #f3f6f1;
  --paper-deep: #e4ebe3;
  --line: #c5d1c6;
  --accent: #1f6b4a;
  --accent-soft: #d8efe4;
  --warn: #7a4a12;
  --radius: 18px;
  --font-display: "Newsreader", "Hiragino Mincho ProN", serif;
  --font-body: "IBM Plex Sans JP", "Hiragino Sans", sans-serif;
}

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

html,
body {
  margin: 0;
  min-height: 100%;
  /* LIFF: 親ページ側でスクロールさせる（iframe 内スクロールに頼らない） */
  overflow-x: hidden;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

body {
  color: var(--ink);
  font-family: var(--font-body);
  background:
    radial-gradient(1200px 600px at 10% -10%, #d9eee3 0%, transparent 55%),
    radial-gradient(900px 500px at 100% 0%, #e8efd8 0%, transparent 45%),
    var(--paper);
  line-height: 1.65;
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.92em;
  background: var(--paper-deep);
  padding: 0.1em 0.35em;
  border-radius: 6px;
}

.page {
  width: min(920px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 1.5rem 0 3rem;
}

.page-book {
  padding-bottom: 4rem;
}

.top {
  display: grid;
  gap: 0.25rem;
  margin-bottom: 2rem;
}

.page-book .top {
  margin-bottom: 0.85rem;
}

.brand {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 600;
  letter-spacing: 0.02em;
  line-height: 1.2;
}

.page-book .brand {
  font-size: 1.35rem;
}

.top-note,
.back,
.eyebrow,
.foot {
  color: var(--ink-soft);
  font-size: 0.92rem;
}

.back {
  text-decoration: none;
  width: fit-content;
}

.back:hover {
  color: var(--accent);
}

.intro h1,
.intro-compact h1 {
  margin: 0.2rem 0 0.6rem;
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 3.5vw, 2rem);
  font-weight: 600;
  line-height: 1.25;
}

.page-book .intro-compact h1 {
  font-size: 1.35rem;
  margin-bottom: 0.25rem;
}

.intro p,
.intro-compact p {
  margin: 0;
  color: var(--ink-soft);
  max-width: 36rem;
}

.intro-compact {
  margin-bottom: 0.85rem;
}

.eyebrow {
  margin: 0;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: none;
}

.courses {
  display: grid;
  gap: 0.9rem;
  margin-top: 1.75rem;
}

.course {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 1rem;
  align-items: center;
  padding: 1.15rem 1.2rem;
  text-decoration: none;
  color: inherit;
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  backdrop-filter: blur(8px);
  transition:
    transform 160ms ease,
    border-color 160ms ease,
    background 160ms ease;
}

.course:hover {
  transform: translateY(-2px);
  border-color: #9fb8a8;
  background: #fff;
}

.course-key {
  display: grid;
  place-items: center;
  width: 3rem;
  height: 3rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 600;
}

.course-body {
  display: grid;
  gap: 0.2rem;
}

.course-name {
  font-weight: 600;
  font-size: 1.05rem;
}

.course-meta {
  color: var(--accent);
  font-size: 0.88rem;
  font-weight: 500;
}

.course-desc {
  color: var(--ink-soft);
  font-size: 0.92rem;
}

.course-cta {
  color: var(--ink-soft);
  font-size: 0.88rem;
  white-space: nowrap;
}

.foot {
  margin-top: 2.5rem;
}

/*
  Cal.com inline embed は「親の高さ制限なし」が公式推奨。
  height / overflow:hidden を付けると LIFF で見切れて操作不能になる。
*/
.cal-shell {
  background: rgba(255, 255, 255, 0.8);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: visible;
}

.cal-inline,
.cal-inline.cal-inline-container {
  width: 100%;
  min-height: 480px;
  height: auto !important;
  overflow: visible !important;
}

.cal-inline > div {
  width: 100%;
  height: auto !important;
  min-height: 0;
  overflow: visible !important;
}

.cal-inline iframe {
  width: 100%;
  border: 0;
  display: block;
  /* 埋め込み側が高さを書き換えるので固定しない */
  min-height: 640px;
}

.cal-placeholder {
  padding: 1.5rem 1.35rem 1.75rem;
}

.cal-placeholder-title {
  margin: 0 0 0.5rem;
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--warn);
}

.cal-placeholder ol {
  margin: 1rem 0;
  padding-left: 1.2rem;
  color: var(--ink-soft);
}

.cal-placeholder-link {
  margin-top: 1rem;
  word-break: break-all;
}

.cal-fallback {
  margin: 0;
  padding: 0.75rem 1rem 0;
  font-size: 0.88rem;
  color: var(--ink-soft);
}

.cal-fallback a {
  color: var(--accent);
}

@media (max-width: 720px) {
  .page {
    width: calc(100% - 1.25rem);
    padding-top: 0.85rem;
  }

  .course {
    grid-template-columns: auto 1fr;
    grid-template-areas:
      "key body"
      "cta cta";
  }

  .course-key {
    grid-area: key;
  }

  .course-body {
    grid-area: body;
  }

  .course-cta {
    grid-area: cta;
    justify-self: start;
    padding-left: 4rem;
  }

  .cal-inline iframe {
    min-height: 720px;
  }
}