/* ============================================================
   夜のコンサートグランド
   黒檀ラッカーの舞台にフェルト赤の再生線。機能色(青=次に押す、
   琥珀=押鍵中、4段カラー)は既存の学習を壊さず色相維持で調律。
   ============================================================ */

/* 書体はindex.htmlの<link>で読み込む(@importは直列読み込みで表示が遅れるため)。
   和文書体は日本語表示のときだけi18n.jsが後から差し込む。 */

:root {
  /* 素材: 黒檀・象牙・フェルト・真鍮 */
  --ebony-deep: #120e0b;
  --ebony: #1c1613;
  --ebony-raised: #272019;
  --lacquer-line: #3b3128;
  --ivory: #f2ead9;
  --ivory-dim: #a89a85;
  --felt: #c2483f;
  --felt-deep: #96352e;
  --brass: #c9a96a;

  /* 機能色(信号) */
  --guide-color: #5b8def; /* 次に押すキー */
  --guide-glow: rgba(91, 141, 239, 0.65);
  --held-color: #e3a63c; /* 押鍵中 */
  --both-color: #58be8e; /* 次に押す+押鍵中 */

  --key-bg: var(--ebony-raised);
  --key-border: var(--lacquer-line);
  --key-text: #d8cdba;
  --accent: var(--ivory-dim);
  --white: var(--ivory);

  /* 表示書体はディドー系(Bodoni Moda)。19世紀の演奏会プログラムの書体であり、
     極端な太細のコントラストが黒鍵と白鍵・黒檀と象牙の対比とそのまま重なる。
     和文グリフは後続のZen系/OS内蔵書体が受け持つ(多言語スタック)。 */
  --font-display: "Bodoni Moda", "Zen Old Mincho", "Hiragino Mincho ProN", serif;
  --font-body: "IBM Plex Sans", "Zen Kaku Gothic New", "Hiragino Kaku Gothic ProN", sans-serif;
  --font-mono: "SF Mono", "Menlo", "Osaka-Mono", monospace;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 28px 24px 48px;
  background:
    radial-gradient(1200px 480px at 50% -160px, #241c15 0%, rgba(36, 28, 21, 0) 70%),
    var(--ebony-deep);
  color: var(--ivory);
  font-family: var(--font-body);
  font-size: 14px;
  line-height: 1.6;
  min-height: 100vh;
}

main,
.page {
  max-width: 1180px;
  margin: 0 auto;
}

/* --- 演奏会プログラム風ヘッダ ------------------------------------------- */

.masthead {
  max-width: 1180px;
  margin: 0 auto 26px;
}

.masthead-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 6px;
}

.masthead .eyebrow {
  font-size: 11px;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--brass);
}

/* 言語切替(SPEC_I18N_ONBOARDING §2.4)。選択中は非活性表示 */
.lang-switch {
  display: flex;
  gap: 4px;
  flex-shrink: 0;
}

.lang-button {
  font-family: var(--font-body);
  font-size: 12px;
  letter-spacing: 0.06em;
  padding: 4px 12px;
  min-height: 28px;
  border: 1px solid var(--lacquer-line);
  border-radius: 6px;
  background: var(--ebony-raised);
  color: var(--ivory);
  cursor: pointer;
}

.lang-button:hover:not(:disabled) {
  border-color: var(--brass);
}

.lang-button:disabled,
.lang-button.is-current {
  background: rgba(201, 169, 106, 0.16);
  border-color: var(--brass);
  color: var(--brass);
  cursor: default;
}

.lang-button:focus-visible {
  outline: 2px solid var(--felt);
  outline-offset: 2px;
}

h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 30px;
  letter-spacing: 0.08em;
  line-height: 1.25;
  margin: 0 0 10px 0;
}

.masthead .rule {
  height: 1px;
  background: linear-gradient(to right, var(--brass) 0%, rgba(201, 169, 106, 0.15) 60%, transparent 100%);
  margin: 0 0 10px;
}

.subtitle {
  color: var(--ivory-dim);
  font-size: 13px;
  margin-bottom: 0;
}

/* --- パネル -------------------------------------------------------------- */

.panel {
  max-width: 1180px;
  margin: 0 auto 18px;
  background: var(--ebony);
  border: 1px solid rgba(59, 49, 40, 0.8);
  border-radius: 12px;
  padding: 18px 22px;
}

.panel-title {
  /* 15pxではディドー系の細線が消えるため、小さなラベルは本文書体で組む
     (表示書体の見せ場はh1とオーバーレイに集約する) */
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 15px;
  letter-spacing: 0.14em;
  color: var(--ivory);
  margin: 0 0 12px;
}

.status-row {
  display: flex;
  flex-wrap: wrap;
  gap: 28px;
  align-items: baseline;
}

.status-item .label {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--ivory-dim);
  display: block;
  margin-bottom: 2px;
}

.status-item .value {
  font-size: 16px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

#progress-bar-outer {
  height: 5px;
  background: var(--lacquer-line);
  border-radius: 3px;
  margin-top: 14px;
  overflow: hidden;
}

#progress-bar-inner {
  height: 100%;
  background: linear-gradient(to right, var(--felt-deep), var(--felt));
  width: 0%;
  transition: width 0.15s ease-out;
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  font-size: 12px;
  color: var(--ivory-dim);
  margin-top: 14px;
}

.legend-swatch {
  display: inline-block;
  width: 12px;
  height: 12px;
  border-radius: 3px;
  margin-right: 6px;
  vertical-align: middle;
}

/* SPEC §18.2 曲選択 */
#song-select {
  background: var(--ebony-raised);
  color: var(--ivory);
  border: 1px solid var(--lacquer-line);
  border-radius: 6px;
  padding: 6px 10px;
  font-size: 14px;
  font-family: var(--font-body);
  cursor: pointer;
}

#song-select:focus-visible {
  outline: 2px solid var(--felt);
  outline-offset: 1px;
}

/* SPEC §16 補助レベル選択(選択肢はカード状に。checked行だけ象牙側に照らす) */
.assist-select {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-top: 16px;
  font-size: 13px;
}

.assist-select .assist-title {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--brass);
  margin-bottom: 2px;
}

.assist-select label {
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--key-text);
  padding: 6px 10px;
  border: 1px solid transparent;
  border-radius: 8px;
  transition: background 0.15s, border-color 0.15s;
}

.assist-select label:hover {
  background: rgba(242, 234, 217, 0.04);
}

.assist-select label:has(input:checked) {
  background: rgba(242, 234, 217, 0.06);
  border-color: var(--lacquer-line);
  color: var(--ivory);
}

.assist-select input[type="radio"] {
  accent-color: var(--felt);
  margin: 0;
  flex-shrink: 0;
}

.assist-select input[type="radio"]:focus-visible {
  outline: 2px solid var(--felt);
  outline-offset: 2px;
}

/* --- 段階開示(SPEC_I18N_ONBOARDING §4) ---------------------------------- */

details.fold {
  margin-top: 14px;
  border: 1px solid var(--lacquer-line);
  border-radius: 8px;
  background: rgba(242, 234, 217, 0.02);
}

details.fold > summary {
  cursor: pointer;
  list-style: none;
  padding: 9px 12px;
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--brass);
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 34px;
}

details.fold > summary::-webkit-details-marker {
  display: none;
}

/* 開閉の向きを示すシェブロン(テキスト装飾のみ・絵文字は使わない) */
details.fold > summary::before {
  content: "";
  width: 7px;
  height: 7px;
  border-right: 1.5px solid var(--brass);
  border-bottom: 1.5px solid var(--brass);
  transform: rotate(-45deg);
  transition: transform 0.15s;
  flex-shrink: 0;
}

details.fold[open] > summary::before {
  transform: rotate(45deg);
}

details.fold > summary:focus-visible {
  outline: 2px solid var(--felt);
  outline-offset: -2px;
  border-radius: 8px;
}

details.fold .fold-body {
  padding: 0 12px 14px;
}

details.fold .fold-body p {
  margin: 0 0 8px;
}

details.fold .fold-body p:last-child {
  margin-bottom: 0;
}

details.fold .assist-select:first-child {
  margin-top: 4px;
}

@media (prefers-reduced-motion: reduce) {
  details.fold > summary::before {
    transition: none;
  }
}

.page-footer {
  max-width: 1180px;
  margin: 0 auto;
  padding-top: 4px;
}

/* --- オンボーディング(SPEC_I18N_ONBOARDING §3) --------------------------- */

/* イントロ中は設定・凡例・説明・曲選択・譜面帯を伏せ、鍵盤と最小限の合図だけ見せる。
   音源クレジットはフッタに置いてあるため、イントロ中も出たままになる。 */
body.intro-mode #main-panel,
body.intro-mode #guide-panel {
  display: none;
}

.intro-cue {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 14px;
  font-size: 14px;
  color: var(--ivory);
}

.intro-cue[hidden] {
  display: none;
}

.intro-cue .intro-count {
  font-variant-numeric: tabular-nums;
  color: var(--brass);
  font-family: var(--font-mono);
}

#intro-confirm {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(10, 7, 5, 0.82);
  z-index: 11;
  text-align: center;
  padding: 24px;
  font-family: var(--font-display);
  font-size: 28px;
  letter-spacing: 0.08em;
  color: var(--ivory);
}

#intro-confirm[hidden] {
  display: none;
}

.intro-confirm-piece {
  margin-top: 14px;
  font-family: var(--font-body);
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--brass);
}

.intro-confirm-piece:empty {
  display: none;
}

/* --- 鍵盤 ---------------------------------------------------------------- */

.keyboard {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.key-row {
  display: flex;
  gap: 6px;
}

.key {
  position: relative;
  overflow: hidden;
  width: 62px;
  height: 70px;
  background: linear-gradient(to bottom, #2c251d 0%, var(--ebony-raised) 100%);
  border: 1px solid var(--lacquer-line);
  border-radius: 7px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  color: var(--key-text);
  transition: background 0.05s, border-color 0.05s, transform 0.05s;
  user-select: none;
  box-shadow: 0 2px 0 rgba(0, 0, 0, 0.45);
}

/* SPEC §14.2 段カラーをキー上辺の細い帯で示し、譜面帯の色と直接ひも付ける */
.key::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--row-color, transparent);
  opacity: 0.85;
  z-index: 1;
  pointer-events: none;
}

/* SPEC §14.1 接近表示: 次に押すキーの内部を下から満たす青い光。満ちきり=押す瞬間 */
.key .key-approach {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 0%;
  background: rgba(91, 141, 239, 0.4);
  z-index: 1;
  pointer-events: none;
}

/* 押鍵中は保持スイープが主役なので接近表示は隠す */
.key.held .key-approach {
  display: none;
}

/* SPEC §14.1 保持ガイド: キー内部を横切る充填スイープ。塗り切り=離す瞬間 */
.key .key-fill {
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 0%;
  background: rgba(0, 0, 0, 0.35);
  transition: width linear;
  z-index: 1;
  pointer-events: none;
}

.key .key-label {
  position: relative;
  z-index: 2;
  font-size: 17px;
  font-weight: 700;
  font-family: var(--font-mono);
}

.key .note-label {
  position: relative;
  z-index: 2;
  font-size: 11px;
  color: var(--ivory-dim);
  margin-top: 2px;
}

.key.held {
  background: var(--held-color);
  border-color: var(--held-color);
  color: #221708;
  transform: translateY(2px);
  box-shadow: none;
}

.key.held .note-label {
  color: #5c4413;
}

.key.guide {
  border-color: var(--guide-color);
  box-shadow: 0 0 0 2px var(--guide-color) inset, 0 2px 0 rgba(0, 0, 0, 0.45);
}

.key.guide .note-label {
  color: var(--guide-color);
}

.key.guide.held {
  background: var(--both-color);
  border-color: var(--both-color);
}

/* SPEC §14.1: 推定テンポ上「押すべき瞬間」が来たキーの脈動 */
.key.guide.ready:not(.held) {
  animation: key-ready-pulse 0.6s ease-in-out infinite;
}

@keyframes key-ready-pulse {
  0%, 100% {
    box-shadow: 0 0 0 2px var(--guide-color) inset, 0 0 0 0 rgba(91, 141, 239, 0);
  }
  50% {
    box-shadow: 0 0 0 2px var(--guide-color) inset, 0 0 12px 2px var(--guide-glow);
  }
}

.row-hint {
  font-size: 11px;
  font-variant-numeric: tabular-nums;
  color: var(--ivory-dim);
  width: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.notice {
  font-size: 12px;
  color: var(--ivory-dim);
  line-height: 1.7;
}

.notice strong {
  color: var(--ivory);
}

.notice a {
  color: var(--brass);
}

/* --- 開始オーバーレイ(プログラム表紙) ----------------------------------- */

#start-overlay {
  position: fixed;
  inset: 0;
  background: rgba(10, 7, 5, 0.88);
  display: flex;
  flex-direction: column;
  gap: 22px;
  align-items: center;
  justify-content: center;
  z-index: 10;
  text-align: center;
}

#start-overlay .overlay-eyebrow {
  font-size: 11px;
  letter-spacing: 0.42em;
  color: var(--brass);
}

#start-overlay .overlay-eyebrow {
  text-transform: uppercase;
}

#start-overlay .overlay-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 34px;
  letter-spacing: 0.12em;
  color: var(--ivory);
}

#start-overlay .overlay-tagline {
  max-width: 28em;
  padding: 0 24px;
  font-size: 15px;
  color: var(--ivory-dim);
  margin-top: -8px;
}

#start-overlay .overlay-skip {
  background: none;
  border: none;
  padding: 4px 10px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--ivory-dim);
  text-decoration: underline;
  text-underline-offset: 3px;
  margin-top: -8px;
}

#start-overlay .overlay-skip:hover {
  color: var(--ivory);
  filter: none;
}

#start-overlay .overlay-skip[hidden] {
  display: none;
}

#start-overlay button {
  font-size: 15px;
  font-family: var(--font-body);
  font-weight: 500;
  letter-spacing: 0.06em;
  padding: 14px 34px;
  border-radius: 8px;
  border: 1px solid var(--felt);
  background: linear-gradient(to bottom, var(--felt), var(--felt-deep));
  color: var(--ivory);
  cursor: pointer;
  transition: filter 0.15s;
}

#start-overlay button:hover {
  filter: brightness(1.12);
}

#start-overlay button:focus-visible {
  outline: 2px solid var(--ivory);
  outline-offset: 2px;
}

#start-overlay.hidden {
  display: none;
}

#error-box {
  max-width: 1180px;
  margin: 0 auto 16px;
  background: #401a17;
  border: 1px solid var(--felt-deep);
  color: #f0b8ae;
  padding: 12px 16px;
  border-radius: 8px;
  display: none;
  white-space: pre-wrap;
  font-size: 13px;
}

#error-box.visible {
  display: block;
}

/* --- ピアノロール型ガイド帯=舞台(SPEC.md §13.2) ------------------------- */

.guide-strip-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  font-size: 12px;
  color: var(--ivory-dim);
  margin-bottom: 10px;
}

.tempo-estimate {
  font-variant-numeric: tabular-nums;
  color: var(--brass);
  white-space: nowrap;
}

/* 黒檀の舞台面に五線譜風のヘアライン。フェルト赤の再生線が「今」を照らす */
.guide-strip {
  position: relative;
  height: 210px;
  background:
    repeating-linear-gradient(
      to bottom,
      transparent 0px,
      transparent 40px,
      rgba(242, 234, 217, 0.05) 40px,
      rgba(242, 234, 217, 0.05) 41px
    ),
    linear-gradient(to bottom, #171310, #100d0a);
  border: 1px solid var(--lacquer-line);
  border-radius: 10px;
  overflow: hidden;
}

.guide-playline {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 3px;
  background: var(--felt);
  box-shadow: 0 0 10px 1px rgba(194, 72, 63, 0.55);
  z-index: 2;
}

.guide-track {
  position: absolute;
  top: 0;
  left: 2px;
  right: 0;
  bottom: 0;
  /* SPEC §14.2: 帯はJS(requestAnimationFrame)がtranslateXで動かすため、
     CSS側のtransitionは付けない */
  will-change: transform;
}

.guide-block {
  position: absolute;
  top: 6px;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.guide-note-row {
  position: relative;
  height: 32px;
  min-width: 26px;
  background: var(--ebony-raised);
  border: 1px solid var(--lacquer-line);
  border-radius: 5px;
  overflow: hidden;
  display: flex;
  align-items: center;
  padding-left: 7px;
  font-size: 16px;
  color: var(--key-text);
  white-space: nowrap;
}

.guide-block.is-current .guide-note-row {
  border-color: var(--guide-color);
}

/* 再生線に到達した(=押すべき瞬間の)ブロック */
.guide-block.arrived .guide-note-row {
  border-color: var(--guide-color);
  box-shadow: 0 0 8px 1px var(--guide-glow);
}

.guide-note-row .guide-note-key-label {
  position: relative;
  z-index: 1;
  font-weight: 700;
  font-size: 17px;
  font-family: var(--font-mono);
}

/* SPEC §21.2: 紛らわしい記号刻印(,や.等)は拡大して読み間違いを防ぐ */
.guide-note-row .guide-note-key-label.punct {
  font-size: 24px;
  line-height: 1;
}

/* 凡例の脈動サンプル */
.legend-pulse {
  animation: key-ready-pulse-legend 0.6s ease-in-out infinite;
}

@keyframes key-ready-pulse-legend {
  0%, 100% { box-shadow: 0 0 0 0 rgba(91, 141, 239, 0); }
  50% { box-shadow: 0 0 6px 2px var(--guide-glow); }
}

/* 装飾アニメーションは動きの抑制設定に従う(ゲーム進行のスクロールはJS駆動で対象外) */
@media (prefers-reduced-motion: reduce) {
  .key.guide.ready:not(.held) {
    animation: none;
    box-shadow: 0 0 12px 2px var(--guide-glow), 0 0 0 2px var(--guide-color) inset;
  }
  .legend-pulse {
    animation: none;
    box-shadow: 0 0 6px 2px var(--guide-glow);
  }
}

/* 狭幅では鍵盤だけを内部スクロールさせ、ページ本体は横スクロールさせない */
@media (max-width: 620px) {
  body {
    overflow-x: hidden;
  }
  .keyboard {
    overflow-x: auto;
    padding-bottom: 6px;
  }
  .key-row {
    width: max-content;
  }
  .masthead-top {
    flex-wrap: wrap;
  }
  #intro-confirm {
    font-size: 22px;
  }
}

@media (max-width: 900px) {
  body {
    padding: 20px 12px 40px;
  }
  h1 {
    font-size: 24px;
  }
  .key {
    width: 46px;
    height: 58px;
  }
  .key .key-label {
    font-size: 14px;
  }
  .key .note-label {
    display: none;
  }
  .row-hint {
    width: 44px;
    font-size: 10px;
  }
}