:root {
  --paper: #fbf6ea;
  --ink-text: #3d3029;
  --muted: #75675b;
  --tomato: #d8433a;
  --tomato-deep: #b4332b;
  --rule: #e7dcc8;
  --accent: var(--tomato);
  --tint: #fdeeea;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink-text);
  font-family: "Zen Maru Gothic", "Hiragino Maru Gothic ProN", "Hiragino Sans", sans-serif;
  font-weight: 500;
  line-height: 1.8;
}

a {
  color: var(--tomato-deep);
}

h1,
h2,
h3 {
  font-weight: 900;
  line-height: 1.35;
  text-wrap: balance;
}

.site-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
  max-width: 1160px;
  margin: 0 auto;
  padding: 16px 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--ink-text);
  font-size: 1.25rem;
  font-weight: 900;
  text-decoration: none;
}

.logo .m {
  width: 34px;
  height: 34px;
}

.site-header nav {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 20px;
}

.site-header nav a {
  color: var(--ink-text);
  font-weight: 700;
  text-decoration: none;
}

.site-header nav a:hover {
  color: var(--tomato-deep);
  text-decoration: underline;
}

main {
  display: block;
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px 48px;
}

.btn {
  display: block;
  width: 100%;
  padding: 13px 22px;
  border: 2px solid var(--tomato-deep);
  border-radius: 999px;
  background: var(--tomato-deep);
  color: #fff;
  font: inherit;
  font-weight: 900;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
}

.btn:hover {
  background: #952820;
  border-color: #952820;
}

.btn-sub {
  background: #fff;
  color: var(--tomato-deep);
}

.btn-sub:hover {
  background: var(--tint);
  border-color: var(--tomato-deep);
}

:focus-visible {
  outline: 3px solid #2469ad;
  outline-offset: 2px;
}

/* トップ */
.hero {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
  align-items: center;
  gap: 48px;
  padding: 32px 0 48px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--tomato-deep);
  font-weight: 900;
}

.hero h1 {
  margin: 0 0 16px;
  font-size: clamp(1.9rem, 3.6vw, 2.8rem);
}

.lead {
  margin: 0 0 24px;
  font-size: 1.05rem;
}

.hero .btn {
  display: inline-block;
  width: auto;
}

.hero-sheet {
  position: relative;
  display: block;
  text-decoration: none;
  transform: rotate(1.2deg);
  transition: transform 0.2s ease;
}

.hero-sheet:hover {
  transform: rotate(0deg);
}

.hero-sheet .sheet-wrap {
  box-shadow: 0 2px 4px rgba(61, 48, 41, 0.14), 0 16px 32px rgba(61, 48, 41, 0.14);
}

.hero-sheet::before {
  content: "";
  position: absolute;
  z-index: 1;
  top: -14px;
  left: 50%;
  width: 110px;
  height: 28px;
  background: rgba(244, 199, 90, 0.8);
  transform: translateX(-50%) rotate(-2deg);
}

.features {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 32px;
  padding: 24px 0 32px;
  border-top: 2px dashed var(--rule);
  border-bottom: 2px dashed var(--rule);
}

.features h2 {
  margin: 0 0 4px;
  font-size: 1.15rem;
}

.features p {
  margin: 0;
  font-size: 0.95rem;
}

.months > h2 {
  margin: 40px 0 0;
  font-size: 1.7rem;
}

.year-title {
  margin: 24px 0 12px;
  color: var(--muted);
  font-size: 1.15rem;
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 24px 20px;
}

.card {
  display: block;
  color: inherit;
  text-decoration: none;
}

.card .sheet-wrap {
  overflow: hidden;
  border-radius: 6px;
  box-shadow: 0 1px 3px rgba(61, 48, 41, 0.2);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.card:hover .sheet-wrap {
  box-shadow: 0 8px 18px rgba(61, 48, 41, 0.2);
  transform: translateY(-3px);
}

.card-title {
  margin: 8px 0 0;
  font-weight: 900;
}

.now-badge {
  margin-left: 8px;
  padding: 2px 10px;
  border-radius: 999px;
  background: var(--tomato-deep);
  color: #fff;
  font-size: 0.8rem;
}

/* 月のページ */
.month-head h1 {
  margin: 8px 0 0;
  font-size: clamp(1.45rem, 3vw, 2rem);
}

.month-head p {
  margin: 0 0 16px;
  color: var(--muted);
}

.studio {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  align-items: start;
  gap: 28px;
}

.stage .sheet-wrap {
  overflow: hidden;
  border-radius: 6px;
  box-shadow: 0 2px 4px rgba(61, 48, 41, 0.14), 0 12px 24px rgba(61, 48, 41, 0.12);
}

.controls {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

fieldset {
  margin: 0;
  padding: 0;
  border: 0;
}

legend,
.field > span {
  display: block;
  margin-bottom: 4px;
  padding: 0;
  font-size: 0.9rem;
  font-weight: 700;
}

.segmented {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.segmented label {
  flex: 1 1 auto;
  cursor: pointer;
}

.segmented input {
  position: absolute;
  opacity: 0;
}

.segmented span {
  display: block;
  padding: 7px 10px;
  border: 2px solid var(--rule);
  border-radius: 10px;
  background: #fff;
  font-size: 0.9rem;
  font-weight: 700;
  text-align: center;
  white-space: nowrap;
}

.segmented input:checked + span {
  border-color: var(--tomato-deep);
  background: var(--tint);
  color: var(--tomato-deep);
}

.segmented input:focus-visible + span {
  outline: 3px solid #2469ad;
  outline-offset: 2px;
}

.field {
  display: block;
}

.field input {
  width: 100%;
  padding: 10px 12px;
  border: 2px solid var(--rule);
  border-radius: 10px;
  background: #fff;
  color: inherit;
  font: inherit;
}

.hint {
  margin: 0;
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.6;
}

.controls .btn + .btn {
  margin-top: -6px;
}

.month-article {
  max-width: 720px;
  margin: 40px auto 0;
}

.month-article h2 {
  margin: 28px 0 6px;
  font-size: 1.2rem;
}

.month-article ul {
  margin: 0;
  padding-left: 1.3em;
}

.month-article p {
  margin: 0;
}

.month-article .hint {
  margin-top: 6px;
}

blockquote {
  margin: 0;
  padding: 12px 16px;
  border-left: 4px solid var(--rule);
  background: #fff;
}

.month-nav {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  max-width: 720px;
  margin: 32px auto 0;
  font-weight: 700;
}

/* 広告 */
.ad {
  margin: 32px auto;
  max-width: 728px;
  text-align: center;
}

.ad-label {
  margin: 0 0 4px !important;
  color: var(--muted);
  font-size: 0.75rem;
}

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

.ad-placeholder {
  display: grid;
  place-items: center;
  min-height: 100px;
  border: 2px dashed #c9bba5;
  border-radius: 8px;
  color: var(--muted);
  font-size: 0.85rem;
}

/* 文章ページ */
.prose {
  max-width: 720px;
}

.prose h1 {
  margin: 16px 0 12px;
  font-size: 1.8rem;
}

.prose h2 {
  margin: 32px 0 6px;
  font-size: 1.2rem;
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.prose th,
.prose td {
  padding: 8px;
  border: 1px solid var(--rule);
  text-align: left;
  vertical-align: top;
}

.todo {
  padding: 8px 12px;
  border-radius: 8px;
  background: #fff3c4;
}

.site-footer {
  padding: 24px;
  border-top: 2px dashed var(--rule);
  color: var(--muted);
  font-size: 0.85rem;
  text-align: center;
}

.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 4px 16px;
}

.site-footer a {
  color: inherit;
}

.site-footer p {
  margin: 8px 0 0;
}

@media (max-width: 860px) {
  .hero,
  .studio {
    grid-template-columns: minmax(0, 1fr);
  }

  .hero {
    gap: 28px;
    padding-top: 12px;
  }

  .features {
    grid-template-columns: minmax(0, 1fr);
    gap: 16px;
  }

  .cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
  }
}