:root {
  color-scheme: dark;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: #eef2ff;
  background: #070b18;
  line-height: 1.7;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

/*
 * `display` を指定した要素にも `hidden` を効かせる。エラー・空状態の出し分けは
 * すべて `hidden` で行うため、ここで一度だけ勝たせておく。
 */
[hidden] {
  display: none !important;
}

body {
  min-width: 320px;
  margin: 0;
  background:
    radial-gradient(circle at 50% -10%, #1a2850 0, transparent 38rem),
    #070b18;
}

a {
  color: #a9c7ff;
  text-underline-offset: 0.2em;
}

a:hover {
  color: #d7e4ff;
}

a:focus-visible {
  outline: 3px solid #f7c969;
  outline-offset: 3px;
  border-radius: 0.2rem;
}

.site-header,
.site-footer,
.page-main {
  width: min(100% - 2rem, 64rem);
  margin-inline: auto;
}

.site-header {
  padding-block: 1.25rem;
}

.site-title {
  color: #ffffff;
  font-size: 1rem;
  font-weight: 700;
  text-decoration: none;
}

.site-nav ul,
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  margin: 0.75rem 0 0;
  padding: 0;
  list-style: none;
}

.page-main {
  min-height: 62vh;
  padding-block: clamp(2.5rem, 10vw, 6rem);
}

.eyebrow {
  margin: 0 0 0.5rem;
  color: #9fb5df;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.12em;
}

h1,
h2 {
  line-height: 1.25;
  text-wrap: balance;
}

h1 {
  margin: 0;
  font-size: clamp(2rem, 9vw, 4rem);
}

h2 {
  margin: 2rem 0 0.5rem;
  font-size: 1.3rem;
}

p {
  max-width: 44rem;
}

.lead {
  color: #cbd6ed;
  font-size: 1.05rem;
}

.panel {
  margin-top: 2rem;
  padding: clamp(1.25rem, 5vw, 2rem);
  border: 1px solid #2a3858;
  border-radius: 1rem;
  background: rgb(13 20 40 / 78%);
  box-shadow: 0 1.25rem 4rem rgb(0 0 0 / 25%);
}

.panel > :first-child {
  margin-top: 0;
}

.panel > :last-child {
  margin-bottom: 0;
}

.notice {
  color: #b8c5df;
}

/*
 * 補助画面（SC-03 / SC-04）の項目一覧。375px では縦に積み、広い画面では
 * 項目名と内容を2カラムにする。表組みにすると狭い画面で横スクロールが出る。
 */
.definition-grid {
  display: grid;
  gap: 0.15rem 1rem;
  margin: 0.75rem 0 0;
}

.definition-grid dt {
  color: #9fb5df;
  font-size: 0.85rem;
}

.definition-grid dd {
  margin: 0 0 0.75rem;
}

.definition-grid dd:last-of-type {
  margin-bottom: 0;
}

code {
  padding: 0.1em 0.35em;
  border-radius: 0.3rem;
  background: #111a31;
  font-size: 0.9em;
  overflow-wrap: anywhere;
}

/* ページ末尾の導線。タップ領域は44px以上（`ui_spec.md` 4章）。 */
.page-links {
  display: grid;
  gap: 0.5rem;
  margin-top: 1.5rem;
}

.page-links a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0.5rem 0.85rem;
  border: 1px solid #43577e;
  border-radius: 0.65rem;
  color: #eef2ff;
  background: #15213d;
  text-decoration: none;
}

.page-links a::after {
  margin-left: auto;
  content: "›";
  color: #9fb5df;
}

.page-links a:hover,
.page-links a:focus-visible {
  border-color: #8fb8ff;
  text-decoration: underline;
}

button,
input {
  font: inherit;
}

button {
  min-height: 44px;
  padding: 0.55rem 0.85rem;
  border: 1px solid #43577e;
  border-radius: 0.65rem;
  color: #eef2ff;
  background: #15213d;
  cursor: pointer;
}

button:hover {
  background: #203158;
}

button:focus-visible,
input:focus-visible + span {
  outline: 3px solid #f7c969;
  outline-offset: 3px;
}

.observation-panel {
  margin-bottom: 1rem;
}

.observation-summary {
  margin-block: 0.5rem 1rem;
  color: #eef2ff;
}

.observation-fieldset,
.environment-fieldset {
  margin: 0;
  padding: 0;
  border: 0;
}

.observation-fieldset {
  margin-bottom: 1.5rem;
}

.observation-fieldset legend,
.environment-fieldset legend {
  margin-bottom: 0.5rem;
  font-weight: 700;
}

.observation-fieldset .notice {
  margin-block: 0.5rem;
  font-size: 0.9rem;
}

.field {
  display: grid;
  gap: 0.35rem;
  margin-block: 0.75rem;
  min-width: 0;
}

.field label {
  color: #cbd6ed;
  font-size: 0.9rem;
}

.field-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(8.5rem, 1fr));
  gap: 0 0.75rem;
}

select,
input[type="text"],
input[type="date"],
input[type="time"],
input[type="number"] {
  width: 100%;
  min-height: 44px;
  padding: 0.5rem 0.65rem;
  border: 1px solid #43577e;
  border-radius: 0.65rem;
  color: #eef2ff;
  background: #111a31;
  font: inherit;
}

select:focus-visible,
input:focus-visible {
  outline: 3px solid #f7c969;
  outline-offset: 2px;
}

.error-text {
  margin-block: 0.5rem;
  color: #ffb4a8;
  font-size: 0.9rem;
}

.error-text:empty {
  margin: 0;
}

.consent-block {
  margin-top: 0.75rem;
  padding: 0.85rem;
  border: 1px solid #43577e;
  border-radius: 0.65rem;
  background: #111a31;
}

.consent-block p {
  margin-top: 0;
  font-size: 0.9rem;
}

.consent-actions {
  display: grid;
  gap: 0.5rem;
}

.checkbox-field {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  min-height: 44px;
  margin-top: 0.75rem;
  color: #cbd6ed;
  font-size: 0.9rem;
  cursor: pointer;
}

.checkbox-field input {
  width: 1.35rem;
  height: 1.35rem;
  flex: 0 0 auto;
  accent-color: #8fb8ff;
}

.environment-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
}

.environment-option {
  position: relative;
  min-width: 0;
}

.environment-option input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.environment-option span {
  display: grid;
  min-height: 48px;
  padding: 0.6rem;
  place-items: center;
  border: 1px solid #43577e;
  border-radius: 0.65rem;
  color: #cbd6ed;
  background: #111a31;
  text-align: center;
  cursor: pointer;
}

.environment-option input:checked + span {
  border-color: #8fb8ff;
  color: #fff;
  background: #263d6c;
  box-shadow: inset 0 0 0 1px #8fb8ff;
}

.sky-layout {
  display: grid;
  gap: 1rem;
}

.sky-panel,
.sky-sidebar .panel {
  margin-top: 0;
}

.chart-heading-row {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 1rem;
}

.chart-heading-row h2,
.selected-star h2,
.accessible-stars h2 {
  margin-top: 0;
}

.chart-heading-row p {
  margin-bottom: 0;
}

.chart-metrics {
  display: grid;
  flex: 0 0 auto;
  gap: 0.2rem;
  margin: 0;
  color: #9fb5df;
  font-size: 0.75rem;
}

.chart-metrics div {
  display: flex;
  justify-content: space-between;
  gap: 0.75rem;
}

.chart-metrics dd {
  margin: 0;
  color: #eef2ff;
  font-variant-numeric: tabular-nums;
}

.chart-frame {
  position: relative;
  width: 100%;
  margin-top: 1rem;
  aspect-ratio: 1;
  overflow: hidden;
  border: 1px solid #2f426a;
  border-radius: 1rem;
  background: #01030a;
}

/*
 * 読み込み中・失敗中は星図の上に説明を重ねる。星図領域を空白のまま残さない
 * （`logic_specifications.md` 7章、`screen_design.md` 2章「読込中」）。
 */
.chart-skeleton {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  margin: 0;
  padding: 1.25rem;
  color: #cbd6ed;
  font-size: 0.95rem;
  text-align: center;
  background: #070d1d;
}

/* 読み込み中だけ、進んでいることが分かる程度にゆっくり明滅させる。 */
.chart-frame[data-state="loading"] .chart-skeleton {
  animation: chart-skeleton-pulse 1.8s ease-in-out infinite;
}

@keyframes chart-skeleton-pulse {
  0%, 100% { background: #070d1d; }
  50% { background: #0d1730; }
}

.chart-skeleton[hidden] {
  display: none;
}

.chart-frame[data-state="error"] .chart-skeleton {
  color: #ffb4a8;
}

#sky-chart {
  display: block;
  width: 100%;
  height: 100%;
  touch-action: none;
  user-select: none;
}

.chart-controls {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
  margin-top: 0.75rem;
}

.chart-controls button:last-child {
  grid-column: 1 / -1;
}

.retry-button {
  width: 100%;
  margin-top: 0.75rem;
}

.overlay-fieldset {
  margin: 0.75rem 0 0;
  padding: 0.5rem 0.85rem 0.85rem;
  border: 1px solid #2f426a;
  border-radius: 0.75rem;
}

.overlay-fieldset legend {
  padding-inline: 0.35rem;
  color: #cbd6ed;
  font-size: 0.85rem;
}

.overlay-fieldset .checkbox-field {
  margin-top: 0;
}

.overlay-fieldset .notice {
  margin-bottom: 0;
  font-size: 0.85rem;
}

/* 星座詳細への導線。タップ領域を44px以上にする（`ui_spec.md` 4章）。 */
.constellation-link {
  display: flex;
  align-items: center;
  min-height: 44px;
  margin-top: 0.75rem;
  padding: 0.5rem 0.85rem;
  border: 1px solid #43577e;
  border-radius: 0.65rem;
  color: #eef2ff;
  background: #15213d;
  text-decoration: none;
}

.constellation-link::after {
  margin-left: auto;
  content: "›";
  color: #9fb5df;
}

.constellation-link:hover,
.constellation-link:focus-visible {
  border-color: #8fb8ff;
  text-decoration: underline;
}

.sky-sidebar {
  display: grid;
  align-content: start;
  gap: 1rem;
}

.selected-star-name {
  margin-block: 0.5rem 0;
  color: #fff;
  font-size: 1.35rem;
  font-weight: 700;
}

.recommendation-card h2 {
  margin-top: 0;
}

.recommendation-card .field {
  margin-top: 0;
}

.recommendation-headline {
  margin-block: 1rem 0.35rem;
  color: #fff;
  font-size: 1.25rem;
  font-weight: 700;
  /* 「22:10〜翌1:30」の桁をそろえる。 */
  font-variant-numeric: tabular-nums;
  line-height: 1.5;
}

.recommendation-card .notice {
  margin-block: 0.35rem;
  font-size: 0.9rem;
}

.recommendation-reasons {
  display: grid;
  gap: 0.35rem;
  margin-block: 0.75rem;
  padding: 0;
  list-style: none;
}

.recommendation-reasons li {
  padding: 0.35rem 0.65rem;
  border: 1px solid #2f426a;
  border-radius: 0.5rem;
  background: #111a31;
  color: #dce6fa;
  font-size: 0.9rem;
}

.recommendation-reasons[hidden] {
  display: none;
}

.recommendation-disclaimer {
  margin-bottom: 0;
  padding-top: 0.75rem;
  border-top: 1px solid #25304a;
  font-size: 0.85rem;
}

.accessible-stars ul {
  display: grid;
  max-height: 22rem;
  margin: 1rem 0 0;
  padding: 0;
  overflow: auto;
  list-style: none;
}

.accessible-stars button {
  width: 100%;
  border-width: 0 0 1px;
  border-radius: 0;
  color: #dce6fa;
  background: transparent;
  text-align: left;
}

.accessible-stars button:hover,
.accessible-stars button:focus-visible {
  background: #172440;
}

.site-footer {
  padding-block: 1.5rem 2.5rem;
  border-top: 1px solid #25304a;
  color: #9eaaca;
  font-size: 0.9rem;
}

@media (min-width: 48rem) {
  .site-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
  }

  .site-nav ul {
    margin-top: 0;
  }

  .environment-options {
    grid-template-columns: repeat(4, 1fr);
  }

  .consent-actions {
    grid-auto-flow: column;
    justify-content: start;
  }

  .chart-controls {
    display: flex;
  }

  .definition-grid {
    grid-template-columns: minmax(7rem, max-content) minmax(0, 1fr);
  }

  .definition-grid dt,
  .definition-grid dd {
    margin-bottom: 0.35rem;
  }

  .page-links {
    grid-auto-flow: column;
    justify-content: start;
  }
}

@media (min-width: 64rem) {
  .sky-layout {
    grid-template-columns: minmax(0, 2fr) minmax(17rem, 1fr);
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}