:root {
  --paper: #fffaf0;
  --paper-deep: #f7e7c6;
  --panel: #fffdfa;
  --shelf: #fff4d9;
  --ink: #2b251d;
  --muted: #736651;
  --line: #dfc895;
  --green-deep: #13221d;
  --green: #2f6844;
  --green-bright: #4de1a4;
  --green-soft: #e6eee9;
  --yellow: #f2c75c;
  --red: #c65b4a;
  --blue: #2b83c6;
  --road: #51645f;
  --road-dark: #3c514d;
  --radius: 8px;
  --shadow: 0 10px 26px rgba(86, 60, 24, .09);
  color-scheme: light;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { min-width: 320px; background: var(--paper); }
body {
  min-width: 320px;
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Yu Gothic", "Hiragino Kaku Gothic ProN", Meiryo, system-ui, sans-serif;
  line-height: 1.6;
  overflow-x: clip;
}
a { color: inherit; }
button, input { font: inherit; }
button { cursor: pointer; }
button:disabled, input:disabled { cursor: not-allowed; }
:focus-visible { outline: 3px solid var(--yellow); outline-offset: 3px; }

.site-header {
  min-height: 56px;
  background: var(--green-deep);
  color: #f9fff8;
  border-bottom: 4px solid var(--green-bright);
}
.header-inner, .footer-inner {
  width: min(1100px, calc(100% - 36px));
  margin: 0 auto;
  padding: 9px 0;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}
.brand {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: baseline;
  gap: 9px;
  color: #fff;
  text-decoration: none;
  white-space: nowrap;
}
.brand strong { font-size: 1rem; letter-spacing: .04em; }
.brand span { color: #b9d9c9; font-size: .75rem; letter-spacing: .06em; }
.site-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 6px;
}
.site-nav a, .site-footer a {
  min-height: 34px;
  display: inline-flex;
  align-items: center;
  padding: 5px 9px;
  border-radius: 7px;
  color: #eef8f1;
  font-size: .82rem;
  text-decoration: none;
}
.site-nav a:hover, .site-nav a:focus-visible, .site-footer a:hover, .site-footer a:focus-visible {
  background: rgba(77, 225, 164, .16);
}

.app-shell {
  width: min(1100px, calc(100% - 36px));
  margin: 0 auto;
  padding: 20px 0 44px;
  display: grid;
  gap: 18px;
}
body.is-playing .app-intro,
body.is-playing .howto-panel,
body.is-playing .related-nav { display: none; }

.app-intro {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(290px, .8fr);
  gap: 18px;
  align-items: stretch;
}
.intro-copy, .rules-panel, .control-panel, .game-area, .result-panel, .howto-panel, .related-nav a {
  background: rgba(255, 253, 250, .94);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.intro-copy { padding: 22px 26px; }
.eyebrow, .panel-kicker {
  margin: 0 0 6px;
  color: var(--green);
  font-size: .72rem;
  font-weight: 800;
  letter-spacing: .12em;
  text-transform: uppercase;
}
h1, h2, h3, p { margin-top: 0; }
h1 {
  margin-bottom: 8px;
  color: var(--green-deep);
  font-size: clamp(30px, 4vw, 42px);
  line-height: 1.13;
  letter-spacing: -.02em;
}
h1 span {
  display: block;
  margin-top: 4px;
  color: var(--muted);
  font-size: .47em;
  font-weight: 700;
  letter-spacing: .07em;
}
.lead { margin-bottom: 0; color: var(--muted); font-size: 1.02rem; }
.rules-panel { padding: 20px 22px; }
.rules-panel h2, .board-heading h2, .result-panel h2, .howto-panel h2 {
  margin-bottom: 7px;
  color: var(--green-deep);
  font-size: clamp(22px, 3vw, 30px);
  line-height: 1.2;
}
.rules-panel p { margin-bottom: 8px; font-size: .9rem; }
.rules-panel ul { margin: 0; padding-left: 1.2em; color: var(--muted); font-size: .86rem; }

.control-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto auto;
  gap: 16px;
  align-items: center;
  padding: 15px 18px;
  background: var(--shelf);
}
.control-copy { min-width: 0; }
.game-status { margin: 0 0 3px; color: var(--green-deep); font-weight: 800; }
.input-status { margin: 0; color: var(--muted); font-size: .83rem; }
.input-status.is-warning { color: #8d4b31; }
.input-status.is-blocked { color: #9c4438; font-weight: 700; }
.metrics { display: grid; grid-template-columns: repeat(4, minmax(54px, 1fr)); gap: 6px; }
.metric {
  min-width: 64px;
  padding: 7px 8px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: rgba(255, 253, 250, .72);
  text-align: center;
}
.metric span { display: block; color: var(--muted); font-size: .64rem; letter-spacing: .08em; }
.metric strong { display: block; color: var(--green-deep); font-size: 1.04rem; line-height: 1.25; }
.control-actions { display: flex; gap: 7px; }
.button {
  min-height: 44px;
  padding: 8px 18px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-weight: 800;
  letter-spacing: .03em;
}
.button-primary { background: var(--green); color: #fff; border-color: var(--green-deep); }
.button-primary:hover:not(:disabled), .button-primary:focus-visible { background: var(--green-deep); }
.button-primary:disabled { opacity: .5; }

.game-area { padding: 17px 18px 18px; }
.board-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}
.board-heading h2 { margin-bottom: 0; }
.signal-status {
  margin: 0;
  padding: 5px 9px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--shelf);
  color: var(--muted);
  font-size: .78rem;
  font-weight: 800;
  letter-spacing: .04em;
}
.signal-status.is-wave { border-color: var(--green); background: #d6f6e5; color: var(--green-deep); }
.signal-status.is-gridlock { border-color: var(--red); background: #fae8e3; color: #8f342c; }

.intersection-board {
  position: relative;
  width: 100%;
  height: clamp(280px, calc(100vh - 420px), 390px);
  min-height: 280px;
  overflow: hidden;
  isolation: isolate;
  border: 1px solid #314b45;
  border-radius: 11px;
  background: #dce9dc;
  box-shadow: inset 0 0 0 7px rgba(255, 255, 255, .18);
}
.road { position: absolute; z-index: 0; background: var(--road); }
.road-vertical { top: 0; bottom: 0; left: 35%; width: 30%; }
.road-horizontal { top: 35%; right: 0; left: 0; height: 30%; }
.lane-markings { position: absolute; z-index: 1; opacity: .82; }
.lane-markings-vertical {
  top: 0; bottom: 0; left: calc(50% - 1px); width: 2px;
  background: repeating-linear-gradient(to bottom, #d8debd 0 17px, transparent 17px 31px);
}
.lane-markings-horizontal {
  top: calc(50% - 1px); right: 0; left: 0; height: 2px;
  background: repeating-linear-gradient(to right, #d8debd 0 17px, transparent 17px 31px);
}
.intersection-core {
  position: absolute;
  z-index: 2;
  top: 35%; left: 35%; width: 30%; height: 30%;
  display: grid; place-items: center;
  border: 1px dashed rgba(241, 227, 172, .8);
  background: var(--road-dark);
  color: rgba(255, 255, 255, .82);
  font-size: clamp(.64rem, 1.4vw, .83rem);
  letter-spacing: .1em;
}
.direction-label {
  position: absolute;
  z-index: 3;
  color: #35534b;
  font-size: .72rem;
  font-weight: 800;
  letter-spacing: .05em;
  text-shadow: 0 1px rgba(255,255,255,.65);
}
.direction-north { top: 7px; left: 50%; transform: translateX(-50%); }
.direction-east { top: 50%; right: 8px; transform: translateY(-50%); }
.direction-south { bottom: 7px; left: 50%; transform: translateX(-50%); }
.direction-west { top: 50%; left: 8px; transform: translateY(-50%); }
.vehicle-layer { position: absolute; z-index: 5; inset: 0; }
.vehicle {
  position: absolute;
  width: clamp(66px, 9vw, 88px);
  min-height: 47px;
  display: grid;
  grid-template-columns: 17px 1fr;
  grid-template-rows: 1fr auto;
  align-items: center;
  gap: 0 4px;
  padding: 5px 6px;
  transform: translate(-50%, -50%);
  border: 2px solid #fff;
  border-radius: 8px;
  background: #f5f0d1;
  color: var(--ink);
  box-shadow: 0 4px 10px rgba(16, 35, 38, .24);
  transition: left .08s linear, top .08s linear, background-color .16s ease, border-color .16s ease, opacity .16s ease;
  text-align: left;
}
.vehicle::after {
  content: "";
  position: absolute;
  right: -5px;
  bottom: -5px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--yellow);
  border: 2px solid #fff;
}
.vehicle-word { min-width: 0; overflow: hidden; font-size: clamp(.78rem, 1.6vw, 1rem); font-weight: 900; line-height: 1.2; text-overflow: ellipsis; white-space: nowrap; }
.vehicle-direction { align-self: start; color: var(--green-deep); font-size: 1rem; line-height: 1.05; }
.vehicle-route { grid-column: 1 / -1; color: var(--muted); font-size: .57rem; line-height: 1.1; white-space: nowrap; }
.vehicle.is-candidate { border-color: var(--yellow); box-shadow: 0 0 0 2px rgba(242, 199, 92, .34), 0 4px 10px rgba(16,35,38,.24); }
.vehicle.is-cleared { border-color: var(--green-bright); background: #d6f6e5; color: var(--green-deep); }
.vehicle.is-cleared::after { background: var(--green-bright); }
.vehicle.is-collision { border-color: #fff; background: #f7c9bd; color: #8f342c; opacity: .95; }
.vehicle.is-collision::after { background: var(--red); }
.priority-panel {
  position: absolute;
  z-index: 8;
  top: 9px;
  right: 9px;
  width: min(220px, calc(100% - 18px));
  padding: 7px 9px;
  border: 1px solid rgba(223, 200, 149, .92);
  border-radius: 7px;
  background: rgba(255, 250, 240, .92);
  box-shadow: 0 3px 10px rgba(16, 35, 38, .14);
}
.priority-title { margin: 0 0 2px; color: var(--green-deep); font-size: .66rem; font-weight: 900; letter-spacing: .1em; }
.priority-panel ol { margin: 0; padding-left: 1.3em; color: var(--muted); font-size: .68rem; line-height: 1.35; }
.priority-panel li::marker { color: var(--green); font-weight: 900; }
.priority-panel li strong { color: var(--ink); }
.wave-banner {
  position: absolute;
  z-index: 9;
  top: 50%; left: 50%;
  padding: 9px 15px;
  transform: translate(-50%, -50%);
  border: 2px solid var(--green-bright);
  border-radius: 999px;
  background: rgba(19, 34, 29, .9);
  color: #d9ffeb;
  font-size: clamp(1rem, 3vw, 1.6rem);
  font-weight: 900;
  letter-spacing: .1em;
  box-shadow: 0 0 0 7px rgba(77, 225, 164, .18);
  pointer-events: none;
}

.typing-form {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: center;
  gap: 8px 14px;
  margin-top: 13px;
}
.typing-form > label { color: var(--green-deep); font-weight: 800; }
.typing-row { display: flex; gap: 8px; min-width: 0; }
.typing-row input {
  min-width: 0;
  flex: 1 1 auto;
  min-height: 50px;
  padding: 9px 13px;
  border: 2px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  font-size: 1.1rem;
}
.typing-row input:focus { border-color: var(--green); outline: 3px solid rgba(77, 225, 164, .25); }
.typing-row input:disabled { background: #f0eee6; }
.typing-note { grid-column: 2; margin: -2px 0 0; color: var(--muted); font-size: .76rem; }

.result-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 16px;
  align-items: center;
  padding: 19px 22px;
  background: var(--green-soft);
}
.result-panel h2 { margin-bottom: 5px; }
.result-panel p { margin-bottom: 0; color: var(--muted); }
.result-stats { display: grid; grid-template-columns: repeat(3, minmax(80px, 1fr)); gap: 7px; margin: 0; }
.result-stats div { min-width: 80px; padding: 8px; border: 1px solid #b8cfc2; border-radius: 7px; background: rgba(255,255,255,.68); text-align: center; }
.result-stats dt { color: var(--muted); font-size: .66rem; }
.result-stats dd { margin: 0; color: var(--green-deep); font-size: 1.18rem; font-weight: 900; }

.howto-panel { padding: 17px 20px 19px; }
.howto-panel h2 { margin-bottom: 12px; font-size: 1.4rem; }
.howto-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.howto-grid > div { display: grid; grid-template-columns: auto 1fr; gap: 8px; align-items: start; padding: 10px 11px; border: 1px solid var(--line); border-radius: 7px; background: var(--shelf); }
.howto-grid span { color: var(--green); font-weight: 900; font-size: .8rem; }
.howto-grid p { margin: 0; color: var(--muted); font-size: .82rem; }
.related-nav { display: grid; grid-template-columns: repeat(4, 1fr); gap: 9px; }
.related-nav a { display: block; padding: 11px 12px; text-decoration: none; }
.related-nav a:hover, .related-nav a:focus-visible { border-color: var(--green); }
.related-nav span, .related-nav small { display: block; }
.related-nav span { color: var(--green-deep); font-weight: 900; }
.related-nav small { color: var(--muted); font-size: .76rem; }

.site-footer { background: var(--green-deep); color: #e9f7ed; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 15px; padding-top: 17px; padding-bottom: 17px; }
.footer-inner > div { display: flex; align-items: baseline; gap: 8px; }
.footer-inner strong { font-size: .86rem; }
.footer-inner span { color: #a6cdb8; font-size: .72rem; }
.footer-inner nav { display: flex; flex-wrap: wrap; gap: 3px; }
.footer-inner a { min-height: 28px; font-size: .74rem; }

@media (max-width: 900px) {
  .app-intro { grid-template-columns: 1fr; }
  .control-panel { grid-template-columns: minmax(0, 1fr) auto; }
  .control-actions { grid-column: 2; grid-row: 1; }
  .metrics { grid-column: 1 / -1; grid-row: 2; }
}
@media (max-width: 640px) {
  .header-inner, .footer-inner, .app-shell { width: calc(100% - 28px); }
  .header-inner, .footer-inner { align-items: flex-start; flex-direction: column; }
  .site-nav { width: 100%; justify-content: flex-start; }
  .site-nav a { flex: 1 1 auto; justify-content: center; min-width: 0; }
  .app-shell { padding-top: 14px; gap: 13px; }
  .intro-copy, .rules-panel { padding: 17px 15px; }
  h1 { font-size: 30px; }
  .lead { font-size: .92rem; }
  .control-panel { grid-template-columns: 1fr; gap: 9px; padding: 13px 14px; }
  .control-actions { grid-column: auto; grid-row: auto; }
  .control-actions .button { width: 100%; }
  .metrics { grid-column: auto; grid-row: auto; width: 100%; }
  .metric { min-width: 0; }
  .game-area { padding: 14px 12px 15px; }
  .board-heading { align-items: start; flex-direction: column; gap: 5px; }
  .intersection-board { height: clamp(240px, calc(100vh - 594px), 290px); min-height: 240px; }
  .direction-label { font-size: .65rem; }
  .priority-panel { width: min(125px, calc(100% - 18px)); }
  .priority-panel ol { font-size: .62rem; }
  .vehicle { width: 70px; min-height: 43px; padding: 4px 5px; }
  .vehicle-word { font-size: .75rem; }
  .vehicle-route { font-size: .52rem; }
  .typing-form { grid-template-columns: 1fr; gap: 5px; }
  .typing-row { width: 100%; }
  .typing-row input { min-height: 48px; font-size: 1rem; }
  .typing-row .button { padding-inline: 15px; }
  .typing-note { grid-column: auto; margin-top: 0; }
  .result-panel { grid-template-columns: 1fr; padding: 16px 15px; }
  .result-stats { width: 100%; }
  .howto-grid, .related-nav { grid-template-columns: 1fr; }
  .footer-inner nav { width: 100%; }
  .footer-inner a { flex: 1 1 auto; justify-content: center; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; }
}