/* =========================================================
   6次の隔たりシミュレーター — スタイル
   配色トークンは :root に定義し、ダークモードで上書きする
   ========================================================= */

:root {
  color-scheme: light;

  /* 面・インク */
  --bg: #f9f9f7;
  --surface: #fcfcfb;
  --surface-2: #f1f0eb;
  --text: #0b0b0b;
  --text-2: #52514e;
  --muted: #716f6a;
  --grid: #e1e0d9;
  --axis: #c3c2b7;
  --border: rgba(11, 11, 11, 0.10);
  --shadow: 0 1px 2px rgba(11, 11, 11, 0.04), 0 8px 24px -16px rgba(11, 11, 11, 0.18);

  /* 系列色（カテゴリ） */
  --series-1: #2a78d6;   /* 青: 最短経路・出発点・理論分布 */
  --series-2: #eb6834;   /* 橙: 宛先・実験結果 */
  --accent: var(--series-1);
  --accent-ink: #ffffff;

  /* 状態色 */
  --critical: #d03b3b;
  --good-text: #006300;

  /* ネットワーク描画 */
  --node: #c3c2b7;
  --edge-local: rgba(11, 11, 11, 0.06);
  --edge-shortcut: rgba(42, 120, 214, 0.16);
  --edge-tree: rgba(42, 120, 214, 0.28);

  /* 到達ホップ数の濃淡（青の単色ランプ） */
  --ramp-1: #9ec5f4;
  --ramp-2: #6da7ec;
  --ramp-3: #3987e5;
  --ramp-4: #256abf;
  --ramp-5: #1c5cab;
  --ramp-6: #104281;
  --ramp-7: #0d366b;

  --radius: 14px;
  --radius-sm: 8px;
  --font: system-ui, -apple-system, "Segoe UI", "Hiragino Sans", "Hiragino Kaku Gothic ProN",
          "Noto Sans JP", "Yu Gothic UI", "Meiryo", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg: #0d0d0d;
    --surface: #1a1a19;
    --surface-2: #242423;
    --text: #f0efec;
    --text-2: #c3c2b7;
    --muted: #898781;
    --grid: #2c2c2a;
    --axis: #383835;
    --border: rgba(255, 255, 255, 0.10);
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 8px 24px -16px rgba(0, 0, 0, 0.6);
    --series-1: #3987e5;
    --series-2: #d95926;
    --good-text: #0ca30c;
    --node: #4e4e4a;
    --edge-local: rgba(255, 255, 255, 0.05);
    --edge-shortcut: rgba(57, 135, 229, 0.18);
    --edge-tree: rgba(57, 135, 229, 0.32);
    --ramp-1: #1c5cab;
    --ramp-2: #256abf;
    --ramp-3: #3987e5;
    --ramp-4: #5598e7;
    --ramp-5: #86b6ef;
    --ramp-6: #b7d3f6;
    --ramp-7: #cde2fb;
  }
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0d0d0d;
  --surface: #1a1a19;
  --surface-2: #242423;
  --text: #f0efec;
  --text-2: #c3c2b7;
  --muted: #898781;
  --grid: #2c2c2a;
  --axis: #383835;
  --border: rgba(255, 255, 255, 0.10);
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 8px 24px -16px rgba(0, 0, 0, 0.6);
  --series-1: #3987e5;
  --series-2: #d95926;
  --good-text: #0ca30c;
  --node: #4e4e4a;
  --edge-local: rgba(255, 255, 255, 0.05);
  --edge-shortcut: rgba(57, 135, 229, 0.18);
  --edge-tree: rgba(57, 135, 229, 0.32);
  --ramp-1: #1c5cab;
  --ramp-2: #256abf;
  --ramp-3: #3987e5;
  --ramp-4: #5598e7;
  --ramp-5: #86b6ef;
  --ramp-6: #b7d3f6;
  --ramp-7: #cde2fb;
}

/* ---------- ベース ---------- */

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; animation: none !important; }
}

a { color: var(--series-1); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }

h1, h2, h3 { line-height: 1.3; letter-spacing: 0.01em; margin: 0; }
h2 { font-size: 1.5rem; font-weight: 700; }
h3 { font-size: 1.1rem; font-weight: 700; }
p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.9em;
  background: var(--surface-2);
  padding: 0.1em 0.4em;
  border-radius: 4px;
}

.container {
  width: min(1120px, 100% - 32px);
  margin-inline: auto;
}

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0);
  white-space: nowrap; border: 0;
}

/* ---------- ヘッダー ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: saturate(1.2) blur(10px);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  border-bottom: 1px solid var(--border);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 56px;
}
.brand {
  font-weight: 700;
  font-size: 1rem;
  color: var(--text);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.brand-mark {
  width: 22px; height: 22px;
  display: inline-block;
}
.site-nav {
  display: flex;
  gap: 4px;
  align-items: center;
}
.site-nav a {
  color: var(--text-2);
  text-decoration: none;
  font-size: 0.92rem;
  padding: 6px 10px;
  border-radius: 8px;
}
.site-nav a:hover { background: var(--surface-2); color: var(--text); }
@media (max-width: 720px) {
  .site-nav a:not(.theme-toggle) { display: none; }
}

.theme-toggle {
  appearance: none;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-2);
  width: 36px; height: 36px;
  border-radius: 10px;
  display: inline-grid;
  place-items: center;
  cursor: pointer;
}
.theme-toggle:hover { color: var(--text); background: var(--surface-2); }
.theme-toggle svg { width: 18px; height: 18px; }
.theme-toggle .icon-moon { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-sun { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-moon { display: block; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .icon-sun { display: none; }
  :root:not([data-theme="light"]) .theme-toggle .icon-moon { display: block; }
}

/* ---------- ヒーロー ---------- */

.hero {
  padding: 64px 0 40px;
}
.hero .eyebrow {
  color: var(--series-1);
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 12px;
}
.hero h1 {
  font-size: clamp(2.2rem, 5.5vw, 3.6rem);
  font-weight: 800;
  letter-spacing: -0.01em;
}
.hero h1 .sub {
  display: block;
  font-size: 0.42em;
  font-weight: 600;
  color: var(--text-2);
  margin-top: 10px;
  letter-spacing: 0.02em;
}
.hero .lead {
  max-width: 44em;
  font-size: 1.08rem;
  color: var(--text-2);
  margin-top: 24px;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

/* ---------- セクション・カード ---------- */

.section {
  padding: 40px 0;
}
.section + .section { border-top: 1px solid var(--border); }
.section-head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 18px;
}
.section-head .num {
  color: var(--muted);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}
.section-intro {
  max-width: 48em;
  color: var(--text-2);
  margin-bottom: 24px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
}
.card h3 { margin-bottom: 6px; }
.card .card-sub {
  color: var(--muted);
  font-size: 0.88rem;
  margin-bottom: 14px;
}

/* ---------- ボタン・フォーム ---------- */

.btn {
  appearance: none;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  padding: 9px 16px;
  border-radius: 10px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  transition: background 0.15s, transform 0.05s, border-color 0.15s;
}
.btn:hover { background: var(--surface-2); }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; transform: none; }
.btn-primary {
  background: var(--accent);
  border-color: transparent;
  color: var(--accent-ink);
}
.btn-primary:hover { background: color-mix(in srgb, var(--accent) 88%, black); }
.btn-sm { font-size: 0.86rem; padding: 6px 12px; border-radius: 8px; }
.btn.is-active {
  border-color: var(--accent);
  box-shadow: inset 0 0 0 1px var(--accent);
}
.btn:focus-visible, input:focus-visible, select:focus-visible, summary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.field { margin-bottom: 16px; }
.field-label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-size: 0.9rem;
  color: var(--text-2);
  margin-bottom: 4px;
}
.field-label output {
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  color: var(--text);
}
.field-help {
  font-size: 0.8rem;
  color: var(--muted);
  margin-top: 2px;
}
input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
  margin: 6px 0;
}

.radio-group { display: grid; gap: 6px; }
.radio-group label {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.9rem;
  line-height: 1.45;
}
.radio-group label:has(input:checked) {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 7%, var(--surface));
}
.radio-group input { margin-top: 4px; accent-color: var(--accent); }
.radio-group .radio-title { font-weight: 600; display: block; }
.radio-group .radio-desc { color: var(--muted); font-size: 0.8rem; display: block; }

.preset-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 18px;
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 8px;
}

/* ---------- シミュレーション レイアウト ---------- */

.sim-grid {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: 20px;
  align-items: start;
}
@media (max-width: 900px) {
  .sim-grid { grid-template-columns: 1fr; }
}

/* 画面が十分に高いときだけ操作パネルを追従させる（低い画面では下のボタンが隠れるため） */
@media (min-height: 900px) and (min-width: 901px) {
  .sim-controls { position: sticky; top: 72px; }
}

.canvas-card { padding: 16px; }
.canvas-wrap {
  position: relative;
  width: min(100%, 660px);
  margin: 0 auto;
  aspect-ratio: 1 / 1;
}
.canvas-wrap canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  border-radius: 10px;
}
.canvas-hud {
  position: absolute;
  left: 12px;
  top: 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  pointer-events: none;
}
.hud-chip {
  background: color-mix(in srgb, var(--surface) 85%, transparent);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 3px 10px;
  font-size: 0.8rem;
  color: var(--text-2);
  backdrop-filter: blur(6px);
  font-variant-numeric: tabular-nums;
}
.hud-chip strong { color: var(--text); }

.canvas-status {
  margin-top: 12px;
  min-height: 2.4em;
  font-size: 0.95rem;
  color: var(--text-2);
}
.canvas-status strong { color: var(--text); }
.canvas-status .ok { color: var(--good-text); font-weight: 700; }
.canvas-status .ng { color: var(--critical); font-weight: 700; }

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  font-size: 0.82rem;
  color: var(--text-2);
  margin-top: 10px;
}
.legend-item { display: inline-flex; align-items: center; gap: 7px; }
.legend-dot {
  width: 10px; height: 10px;
  border-radius: 50%;
  display: inline-block;
  box-shadow: 0 0 0 2px var(--surface);
}
.legend-line {
  width: 18px; height: 0;
  border-top: 2px solid;
  display: inline-block;
  border-radius: 2px;
}
.legend-ramp {
  width: 56px; height: 10px;
  border-radius: 3px;
  display: inline-block;
  background: linear-gradient(90deg, var(--ramp-1), var(--ramp-4), var(--ramp-7));
}

/* ---------- 統計タイル ---------- */

.tiles {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(128px, 1fr));
  gap: 12px;
  margin-top: 20px;
}
.tile {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
}
.tile-label {
  font-size: 0.8rem;
  color: var(--text-2);
  line-height: 1.3;
}
.tile-value {
  font-size: 1.6rem;
  font-weight: 650;
  margin-top: 4px;
  line-height: 1.2;
  letter-spacing: -0.01em;
}
.tile-value small {
  font-size: 0.55em;
  font-weight: 600;
  color: var(--muted);
  margin-left: 2px;
}
.tile-note {
  font-size: 0.75rem;
  color: var(--muted);
  margin-top: 4px;
}
.tile.is-accent { border-color: color-mix(in srgb, var(--series-2) 45%, var(--border)); }
.tile.is-accent .tile-label { color: var(--text-2); }

.tiles-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-top: 24px;
  margin-bottom: 4px;
}
.tiles-head h3 { font-size: 1rem; }
.tiles-head .note { font-size: 0.82rem; color: var(--muted); }

/* ミルグラムの数値タイル */
.fact-tiles {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
  margin: 20px 0;
}
.fact-tiles .tile-value { font-size: 2.2rem; }

/* ---------- チャート ---------- */

.chart-card { margin-top: 20px; }
.chart-head {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 16px;
  align-items: flex-start;
  margin-bottom: 8px;
}
.chart-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  font-size: 0.82rem;
  color: var(--text-2);
}
.chart-legend .swatch {
  width: 12px; height: 12px;
  border-radius: 3px;
  display: inline-block;
  vertical-align: -1px;
  margin-right: 6px;
}
.chart-legend .swatch.line {
  height: 0; width: 18px;
  border-top: 2px solid;
  border-radius: 2px;
  vertical-align: 3px;
}
.chart {
  position: relative;
  width: 100%;
}
.chart svg {
  display: block;
  width: 100%;
  height: auto;
  overflow: visible;
}
.chart text {
  font-family: var(--font);
  fill: var(--muted);
  font-size: 12px;
}
.chart .axis-label { fill: var(--text-2); }
.chart .grid line { stroke: var(--grid); stroke-width: 1; }
.chart .axis line { stroke: var(--axis); stroke-width: 1; }
.chart .marker-line { stroke: var(--axis); stroke-width: 1; }
.chart .marker-text { fill: var(--text-2); font-weight: 600; }
.chart .direct-label { fill: var(--text-2); font-weight: 600; font-size: 12px; }
.chart .empty-text { fill: var(--muted); font-size: 13px; }
.chart .hit { fill: transparent; }
.chart .hit:hover ~ .bar-group rect, .chart .bar.is-hover { filter: brightness(1.12); }

.chart-tooltip {
  position: absolute;
  pointer-events: none;
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: var(--shadow);
  padding: 8px 10px;
  font-size: 0.82rem;
  line-height: 1.4;
  min-width: 140px;
  opacity: 0;
  transform: translate(-50%, -100%);
  transition: opacity 0.1s;
  z-index: 2;
}
.chart-tooltip.is-visible { opacity: 1; }
.chart-tooltip .tt-title { color: var(--text-2); margin-bottom: 4px; font-weight: 600; }
.chart-tooltip .tt-row { display: flex; align-items: center; gap: 8px; justify-content: space-between; }
.chart-tooltip .tt-key {
  display: inline-block;
  width: 14px; height: 0;
  border-top: 2px solid;
  border-radius: 2px;
}
.chart-tooltip .tt-name { color: var(--text-2); flex: 1; }
.chart-tooltip .tt-val { font-weight: 700; font-variant-numeric: tabular-nums; }

.table-view { margin-top: 10px; }
.table-view summary {
  cursor: pointer;
  color: var(--text-2);
  font-size: 0.86rem;
  user-select: none;
}
.table-view table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.86rem;
  margin-top: 10px;
  font-variant-numeric: tabular-nums;
}
.table-view th, .table-view td {
  text-align: right;
  padding: 5px 8px;
  border-bottom: 1px solid var(--grid);
}
.table-view th:first-child, .table-view td:first-child { text-align: left; }
.table-view th { color: var(--text-2); font-weight: 600; }

.progress {
  height: 4px;
  background: var(--surface-2);
  border-radius: 2px;
  overflow: hidden;
  margin-top: 10px;
}
.progress > span {
  display: block;
  height: 100%;
  width: 0;
  background: var(--accent);
  transition: width 0.1s linear;
}

/* ---------- 解説 ---------- */

.prose { max-width: 48em; }
.prose h3 { margin-top: 28px; margin-bottom: 8px; }
.prose h3:first-child { margin-top: 0; }
.prose ul, .prose ol { padding-left: 1.4em; }
.prose li { margin-bottom: 0.35em; }
.prose dl { margin: 0; }
.prose dt { font-weight: 700; margin-top: 12px; }
.prose dd { margin: 2px 0 0 0; color: var(--text-2); }

.two-col {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
}

.callout {
  border-left: 3px solid var(--series-1);
  background: color-mix(in srgb, var(--series-1) 6%, var(--surface));
  padding: 14px 18px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text-2);
}
.callout strong { color: var(--text); }

.refs { font-size: 0.9rem; color: var(--text-2); }
.refs li { margin-bottom: 0.5em; }

/* ---------- フッター ---------- */

.site-footer {
  border-top: 1px solid var(--border);
  padding: 28px 0 48px;
  color: var(--muted);
  font-size: 0.86rem;
}
.site-footer .container {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 24px;
}