/* ═══════════════════════════════════════════
   Kana Master — Modern Stylesheet
   ═══════════════════════════════════════════ */

/* ── Reset & Base ── */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}

:root{
  --font-jp: "Noto Sans JP", "Hiragino Sans", "Yu Gothic", sans-serif;
  --font-ui: "Inter", "Noto Sans JP", system-ui, sans-serif;

  --bg:     #f8f9fc;
  --bg-card:#ffffff;
  --bg-hover:#f0f2f8;
  --bg-active:#eceefb;

  --text:   #1a1d2e;
  --text-2: #5c6070;
  --text-3: #9298a8;

  --primary:   #5b6ff0;
  --primary-hover:#4a5de0;
  --primary-light:#eceefb;

  --accent:  #ef6c6c;
  --success: #34c77b;
  --warning: #f0a944;

  --border:  #e2e5ef;
  --shadow:  0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,.08);
  --shadow-lg: 0 8px 30px rgba(0,0,0,.12);

  --radius:  8px;
  --radius-lg:12px;
  --radius-xl:16px;

  --topbar-h: 56px;
  --toolbar-h:48px;
  --transition: .2s ease;
}

[hidden]{display:none!important}
html{font-size:16px;-webkit-font-smoothing:antialiased}
body{
  font-family:var(--font-ui);
  background:var(--bg);
  color:var(--text);
  line-height:1.5;
  min-height:100vh;
  overflow-x:hidden;
}
button{cursor:pointer;font-family:inherit;border:none;background:none;color:inherit}
a{color:var(--primary);text-decoration:none}
input,select,textarea{font-family:inherit}

/* ── Topbar ── */
.topbar{
  position:sticky;top:0;z-index:100;
  background:var(--bg-card);
  border-bottom:1px solid var(--border);
  height:var(--topbar-h);
}
.topbar__inner{
  max-width:1400px;margin:0 auto;
  display:flex;align-items:center;justify-content:space-between;
  height:100%;padding:0 20px;
}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--text)}
.brand__icon{
  width:38px;height:38px;
  display:block;
}
.brand__text{font-weight:600;font-size:15px;line-height:1.2}
.brand__text small{display:block;font-weight:400;font-size:11px;color:var(--text-3);letter-spacing:.02em}

.topnav{display:flex;gap:4px}
.topnav__btn{
  display:flex;align-items:center;gap:6px;
  padding:8px 16px;border-radius:var(--radius);
  font-size:14px;font-weight:500;color:var(--text-2);
  transition:all var(--transition);
}
.topnav__btn:hover{background:var(--bg-hover);color:var(--text)}
.topnav__btn.is-active{background:var(--primary-light);color:var(--primary)}
.topnav__btn{position:relative}
.wrongbook-badge{
  position:absolute;top:2px;right:2px;
  min-width:16px;height:16px;
  display:inline-flex;align-items:center;justify-content:center;
  background:var(--accent);color:#fff;
  border-radius:10px;padding:0 4px;
  font-size:10px;font-weight:700;line-height:1;
}

/* ── Language Switcher ── */
.lang-switcher{
  display:flex;gap:2px;
  background:var(--bg);border-radius:var(--radius);padding:2px;
  border:1px solid var(--border);
  margin-left:auto;
}
.lang-btn{
  padding:5px 10px;border-radius:6px;
  font-size:12px;font-weight:500;color:var(--text-3);
  transition:all var(--transition);
  white-space:nowrap;
}
.lang-btn:hover{color:var(--text);background:var(--bg-hover)}
.lang-btn.is-active{background:var(--bg-card);color:var(--text);box-shadow:var(--shadow)}

/* ── Pages ── */
.page{display:none}
.page.is-active{display:block}

/* ── First-visit resource cache ── */
.resource-gate{
  position:fixed;inset:0;z-index:1000;
  display:grid;place-items:center;padding:24px;
  background:rgba(248,249,252,.94);backdrop-filter:blur(10px);
  transition:opacity .28s ease,visibility .28s ease;
}
.resource-gate.is-ready{opacity:0;visibility:hidden;pointer-events:none}
.resource-gate__card{
  width:min(100%,360px);padding:32px;
  text-align:center;background:var(--bg-card);border:1px solid var(--border);
  border-radius:var(--radius-xl);box-shadow:var(--shadow-lg);
}
.resource-gate__icon{width:64px;height:64px;margin-bottom:16px}
.resource-gate h1{font-size:20px;letter-spacing:-.02em}
.resource-gate p{min-height:24px;margin:8px 0 16px;color:var(--text-2);font-size:14px}
.resource-gate__track{height:7px;overflow:hidden;border-radius:999px;background:var(--primary-light)}
.resource-gate__track i{display:block;width:0;height:100%;border-radius:inherit;background:var(--primary);transition:width .16s ease}
.resource-gate__retry{margin-top:18px}

/* ── Toolbar ── */
.toolbar{
  display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:8px;
  padding:10px 20px;
  flex-shrink:0;
}
.toolbar__tabs{display:flex;gap:4px}
.tab{
  padding:7px 18px;border-radius:20px;
  font-size:13px;font-weight:500;color:var(--text-2);
  border:1px solid var(--border);
  transition:all var(--transition);
}
.tab:hover{border-color:var(--primary);color:var(--primary)}
.tab.is-active{background:var(--primary);color:#fff;border-color:var(--primary)}

.toolbar__actions{display:flex;align-items:center;gap:8px}
.script-toggle{display:flex;gap:2px;background:var(--bg);border-radius:var(--radius);padding:2px;border:1px solid var(--border)}
.script-toggle__btn{
  padding:5px 12px;border-radius:6px;
  font-size:12px;font-weight:500;color:var(--text-3);
  transition:all var(--transition);
}
.script-toggle__btn:hover{color:var(--text)}
.script-toggle__btn.is-active{background:var(--bg-card);color:var(--text);box-shadow:var(--shadow)}

/* ── Split Layout ── */
.page--chart{
  display:flex;flex-direction:column;
  max-width:1400px;margin:0 auto;
  height:calc(100vh - var(--topbar-h));
}
.split{
  display:flex;gap:0;
  flex:1;min-height:0;
  padding:0 20px 20px;
}
.split__left{
  flex:0 0 420px;
  overflow-y:auto;overflow-x:hidden;
  padding-right:16px;
  scrollbar-width:thin;
}
.split__left::-webkit-scrollbar{width:4px}
.split__left::-webkit-scrollbar-thumb{background:var(--border);border-radius:2px}

.split__right{
  flex:1;min-width:0;
  background:var(--bg-card);
  border-radius:var(--radius-xl);
  box-shadow:var(--shadow);
  overflow-y:auto;
  padding:24px;
  position:relative;
}

/* ── Kana Grid ── */
.kana-grid{
  display:grid;
  gap:4px;
}
.kana-grid--5col{grid-template-columns:repeat(5,1fr)}
.kana-grid--3col{grid-template-columns:repeat(3,1fr)}

.kana-cell{
  position:relative;
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  padding:8px 4px;
  border-radius:var(--radius);
  cursor:pointer;
  transition:all var(--transition);
  background:var(--bg-card);
  border:2px solid transparent;
  min-height:72px;
}
.kana-cell:hover{
  background:var(--bg-hover);
  border-color:var(--primary-light);
  transform:translateY(-1px);
  box-shadow:var(--shadow);
}
.kana-cell.is-active{
  border-color:var(--primary);
  background:var(--primary-light);
}
.kana-cell__main{
  font-family:var(--font-jp);
  font-size:28px;font-weight:400;
  line-height:1.2;
  color:var(--text);
}
.kana-cell__sub{
  font-family:var(--font-jp);
  font-size:13px;
  color:var(--text-3);
  margin-top:1px;
}
.kana-cell__romaji{
  font-size:11px;font-weight:500;
  color:var(--text-3);
  margin-top:2px;
}

/* Empty cell */
.kana-cell--empty{
  background:transparent;cursor:default;
  border:2px solid transparent;
}
.kana-cell--empty:hover{background:transparent;transform:none;box-shadow:none;border-color:transparent}

/* Row header */
.kana-row-label{
  grid-column:1/-1;
  font-size:12px;font-weight:600;color:var(--text-3);
  padding:12px 4px 4px;
  letter-spacing:.03em;
  text-transform:uppercase;
  border-bottom:1px solid var(--border);
}

/* ── Detail Panel ── */
.detail-empty{
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  height:100%;text-align:center;opacity:.7;
}
.detail-empty__icon{color:var(--text-3);margin-bottom:16px}
.detail-empty__text{font-size:15px;color:var(--text-2)}

.detail__head{
  display:flex;align-items:center;gap:16px;
  padding-bottom:20px;
  border-bottom:1px solid var(--border);
}
.detail__kana-pair{display:flex;gap:12px}
.detail__kana-box{
  display:flex;flex-direction:column;align-items:center;
  padding:12px 20px;
  border-radius:var(--radius-lg);
  border:1px solid transparent;
  background:var(--bg);
  min-width:90px;
  transition:all var(--transition);
}
.detail__kana-box:hover{background:var(--primary-light);border-color:#cfd5fb}
.detail__kana-box.is-active{background:var(--primary-light);border-color:var(--primary);box-shadow:0 0 0 2px rgba(91,111,240,.12)}
.detail__kana-box:focus-visible{outline:3px solid rgba(91,111,240,.35);outline-offset:2px}
.detail__label{font-size:11px;font-weight:500;color:var(--text-3);margin-bottom:4px}
.detail__char{font-family:var(--font-jp);font-size:48px;font-weight:400;line-height:1.15}
.detail__romaji{font-size:28px;font-weight:600;color:var(--primary);margin-left:8px}

.btn-icon{
  width:40px;height:40px;
  display:flex;align-items:center;justify-content:center;
  border-radius:50%;transition:all var(--transition);
}
.btn-play{background:var(--primary);color:#fff}
.btn-play:hover{background:var(--primary-hover);transform:scale(1.05)}
.btn-play:active{transform:scale(.95)}

/* ── Detail Tabs ── */
.detail__tabs{
  display:flex;gap:4px;
  margin-top:16px;
  border-bottom:2px solid var(--border);
  padding-bottom:0;
}
.dtab{
  padding:8px 16px;
  font-size:13px;font-weight:500;
  color:var(--text-3);
  border-bottom:2px solid transparent;
  margin-bottom:-2px;
  transition:all var(--transition);
}
.dtab:hover{color:var(--text)}
.dtab.is-active{color:var(--primary);border-bottom-color:var(--primary)}

.detail__panel{margin-top:16px}

/* ── Stroke Order ── */
.stroke-area{display:flex;flex-direction:column;align-items:center;gap:12px}
.stroke-svg{
  width:min(280px,100%);height:auto;
  aspect-ratio:1;
  background:var(--bg);
  border:1px solid var(--border);
  border-radius:var(--radius-lg);
}
.stroke-guide{stroke:var(--border);stroke-width:.5;stroke-dasharray:4,4}
.stroke-path{
  fill:none;stroke:#555;stroke-width:3;
  stroke-linecap:round;stroke-linejoin:round;
}
.stroke-path--animated{
  stroke:var(--primary);stroke-width:4;
}
.stroke-path--ghost{
  fill:none;stroke:#ddd;stroke-width:3;
  stroke-linecap:round;stroke-linejoin:round;
}
.stroke-number{
  font-size:8px;fill:var(--primary);font-weight:700;
  font-family:var(--font-ui);
}

.stroke-controls{display:flex;align-items:center;gap:8px;flex-wrap:wrap;justify-content:center}
.stroke-counter{font-size:12px;color:var(--text-3);font-weight:500;margin-left:4px}

/* ── Handwriting Canvas ── */
.write-area{display:flex;flex-direction:column;align-items:center;gap:12px}
.write-canvas-wrap{
  position:relative;
  width:min(280px,100%);
  aspect-ratio:1;
  border:2px solid var(--border);
  border-radius:var(--radius-lg);
  overflow:hidden;
  background:#fff;
  touch-action:none;
}
.write-guide-svg{position:absolute;inset:0;width:100%;height:100%;pointer-events:none}
.write-ghost{
  position:absolute;inset:0;
  pointer-events:none;
  user-select:none;
  /* font fallback when no SVG stroke data */
  display:flex;align-items:center;justify-content:center;
  font-family:var(--font-jp);
  font-size:160px;
  color:rgba(0,0,0,.06);
}
.write-ghost.is-hidden{display:none}
/* Write script toggle */
.write-script-toggle{
  display:flex;gap:4px;
  background:var(--surface-2);
  border-radius:var(--radius);
  padding:3px;
}
.write-script-btn{
  padding:4px 14px;
  border:none;border-radius:calc(var(--radius) - 2px);
  font-size:13px;font-weight:500;cursor:pointer;
  background:transparent;color:var(--text-2);
  transition:background .15s,color .15s;
}
.write-script-btn.is-active{
  background:var(--surface-1);color:var(--text-1);
  box-shadow:0 1px 3px rgba(0,0,0,.12);
}
.write-canvas{position:absolute;inset:0;width:100%;height:100%;cursor:crosshair}
.write-controls{display:flex;align-items:center;gap:12px}
.write-hint-toggle{
  display:flex;align-items:center;gap:6px;
  font-size:13px;color:var(--text-2);cursor:pointer;
}
.write-hint-toggle input{accent-color:var(--primary)}

/* ── Origin ── */
.origin-flow{
  display:flex;align-items:center;justify-content:center;
  gap:16px;flex-wrap:wrap;
  padding:24px 0;
}
.origin-step{display:flex;flex-direction:column;align-items:center;gap:4px}
.origin-kanji{font-family:var(--font-jp);font-size:42px;font-weight:400;color:var(--text)}
.origin-result{font-family:var(--font-jp);font-size:42px;font-weight:400;color:var(--primary)}
.origin-label{font-size:11px;color:var(--text-3);font-weight:500}
.origin-arrow{font-size:24px;color:var(--text-3);font-weight:300}

/* ── Detail Nav ── */
.detail__nav{
  display:flex;justify-content:space-between;
  margin-top:20px;
  padding-top:16px;
  border-top:1px solid var(--border);
}

/* ── Buttons ── */
.btn{
  display:inline-flex;align-items:center;gap:6px;
  padding:8px 16px;border-radius:var(--radius);
  font-size:13px;font-weight:500;
  transition:all var(--transition);
  border:1px solid var(--border);
  background:var(--bg-card);color:var(--text);
}
.btn:hover{background:var(--bg-hover);border-color:var(--primary-light)}
.btn:active{transform:scale(.97)}
.btn--sm{padding:6px 12px;font-size:12px}
.btn--lg{padding:12px 32px;font-size:15px}
.btn--primary{background:var(--primary);color:#fff;border-color:var(--primary)}
.btn--primary:hover{background:var(--primary-hover);border-color:var(--primary-hover)}
.btn--ghost{background:none;border-color:transparent;color:var(--text-2)}
.btn--ghost:hover{background:var(--bg-hover);color:var(--text)}

/* ── Practice ── */
.page--practice{padding:40px 20px}
.practice-container{max-width:640px;margin:0 auto}
.practice-title{font-size:22px;font-weight:600;margin-bottom:24px;text-align:center}
.practice-form{display:flex;flex-direction:column;gap:20px}
.practice-field{border:none;padding:0}
.practice-field legend{font-size:14px;font-weight:600;color:var(--text-2);margin-bottom:8px;width:100%;flex-basis:100%}
.practice-field{display:flex;flex-wrap:wrap;gap:8px}

.chip-label{cursor:pointer}
.chip-label input{display:none}
.chip{
  display:inline-block;
  padding:8px 16px;border-radius:20px;
  font-size:13px;font-weight:500;
  border:1px solid var(--border);
  color:var(--text-2);
  transition:all var(--transition);
}
.chip:hover{border-color:var(--primary)}
.chip-label input:checked+.chip{background:var(--primary);color:#fff;border-color:var(--primary)}

/* ── Slider ── */
.practice-field--slider{flex-direction:column}
.slider-wrap{
  display:flex;align-items:center;gap:12px;width:100%;
}
.slider-wrap input[type=range]{
  flex:1;height:6px;
  -webkit-appearance:none;appearance:none;
  background:var(--border);border-radius:3px;outline:none;
  cursor:pointer;
}
.slider-wrap input[type=range]::-webkit-slider-thumb{
  -webkit-appearance:none;width:20px;height:20px;
  background:var(--primary);border-radius:50%;cursor:pointer;
  border:2px solid #fff;box-shadow:var(--shadow);
}
.slider-wrap input[type=range]::-moz-range-thumb{
  width:20px;height:20px;border:2px solid #fff;
  background:var(--primary);border-radius:50%;cursor:pointer;
  box-shadow:var(--shadow);
}
.slider-value{
  min-width:36px;text-align:center;
  font-size:16px;font-weight:600;color:var(--primary);
}

.quiz{text-align:center;padding:20px 0}
.quiz__progress{height:4px;background:var(--bg);border-radius:2px;margin-bottom:20px;overflow:hidden}
.quiz__progress-bar{height:100%;background:var(--primary);border-radius:2px;width:0;transition:width .3s ease}
.quiz__score{font-size:14px;color:var(--text-3);margin-bottom:16px;font-weight:500}
.quiz__prompt{
  font-family:var(--font-jp);
  font-size:72px;line-height:1.2;
  margin:16px 0;
  min-height:90px;
  display:flex;align-items:center;justify-content:center;
}
.quiz__speak{margin:0 auto 16px}
.quiz__choices{
  display:grid;grid-template-columns:1fr 1fr;gap:8px;
  max-width:400px;margin:0 auto 20px;
}
.choice{
  padding:14px 16px;border-radius:var(--radius);
  font-size:18px;font-weight:500;
  border:2px solid var(--border);
  background:var(--bg-card);
  transition:all var(--transition);
  cursor:pointer;
  font-family:var(--font-jp);
  line-height:1.3;
}
.choice:hover{border-color:var(--primary);background:var(--primary-light)}
.choice--correct{border-color:var(--success)!important;background:#e8f9ef!important;color:#1a7a42}
.choice--wrong{border-color:var(--accent)!important;background:#fdecea!important;color:#a33}
.choice:disabled{cursor:default;opacity:.7}

.quiz__feedback{
  font-size:15px;font-weight:500;
  min-height:24px;margin-bottom:16px;
}
.quiz__actions{display:flex;gap:8px;justify-content:center}

/* ── Wrong Answer Book ── */
.page--wrongbook{padding:40px 20px}
.wrongbook-header{text-align:center;margin-bottom:24px}
.wrongbook-desc{font-size:14px;color:var(--text-2);margin-top:8px}
.wrongbook-empty{
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  gap:12px;padding:60px 20px;color:var(--text-3);text-align:center;
}
.wrongbook-empty svg{opacity:.5}
.wrongbook-empty p{font-size:15px}
.wrongbook-list{
  display:grid;grid-template-columns:repeat(auto-fill,minmax(80px,1fr));gap:8px;
  margin-bottom:24px;
}
.wrongbook-item{
  display:flex;flex-direction:column;align-items:center;
  padding:10px 6px;border-radius:var(--radius);
  background:var(--bg-card);border:1px solid var(--border);
  position:relative;
}
.wrongbook-item__kana{font-family:var(--font-jp);font-size:28px;line-height:1.2}
.wrongbook-item__romaji{font-size:11px;color:var(--text-3);font-weight:500;margin-top:2px}
.wrongbook-item__count{
  position:absolute;top:4px;right:6px;
  font-size:10px;color:var(--accent);font-weight:600;
}
.wrongbook-item__remove{
  position:absolute;top:2px;left:4px;
  width:18px;height:18px;border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  font-size:14px;color:var(--text-3);opacity:0;
  transition:opacity var(--transition);cursor:pointer;
}
.wrongbook-item:hover .wrongbook-item__remove{opacity:1}
.wrongbook-item__remove:hover{color:var(--accent);background:var(--bg-hover)}
.wrongbook-actions{display:flex;gap:12px;justify-content:center;margin-top:20px}

/* ── Responsive ── */
@media(max-width:900px){
  .page--chart{height:auto;min-height:calc(100vh - var(--topbar-h))}
  .split{flex-direction:column;height:auto;padding:0 12px 12px}
  .split__left{flex:none;overflow:visible;padding-right:0;max-height:40vh;overflow-y:auto;margin-bottom:12px;
    border-bottom:1px solid var(--border);padding-bottom:12px}
  .split__right{min-height:55vh;border-radius:var(--radius-lg)}
  .toolbar{padding:10px 12px}
  .toolbar__tabs{overflow-x:auto;flex-wrap:nowrap;-webkit-overflow-scrolling:touch}
  .detail__head{flex-wrap:wrap}
  .detail__kana-box{min-width:70px;padding:8px 14px}
  .detail__char{font-size:38px}
  .detail__romaji{font-size:22px}
}

@media(max-width:600px){
  .topbar__inner{padding:0 12px}
  .brand__text{display:none}
  .topnav__btn span{display:none}
  .topnav__btn{padding:8px 12px}
  .lang-btn{padding:4px 6px;font-size:11px}
  .split__left{max-height:35vh}
  .kana-cell{min-height:56px;padding:4px 2px}
  .kana-cell__main{font-size:22px}
  .kana-cell__sub{font-size:11px}
  .kana-cell__romaji{font-size:10px}
  .script-toggle__btn{padding:4px 8px;font-size:11px}
  .tab{font-size:12px;padding:6px 12px}
  .stroke-svg,.write-canvas-wrap{width:min(220px,80vw)}
  .quiz__prompt{font-size:52px}
}

/* ── Animations ── */
@keyframes fadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}
.detail__head,.detail__panel,.origin-flow{animation:fadeIn .25s ease-out}

/* Cell hover glow */
.kana-cell:not(.kana-cell--empty):active{transform:scale(.95)}

/* Smooth detail panel transitions */
#detailContent{animation:fadeIn .2s ease-out}

@keyframes strokeDraw{
  to{stroke-dashoffset:0}
}
.stroke-path--drawing{
  animation:strokeDraw var(--draw-duration,.6s) ease forwards;
}

/* ── Scrollbar for WebKit ── */
::-webkit-scrollbar{width:6px;height:6px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:#d0d3de;border-radius:3px}
::-webkit-scrollbar-thumb:hover{background:#b0b4c4}

/* ── Attribution ── */
.attribution{
  text-align:center;padding:12px;font-size:11px;color:var(--text-3);
  border-top:1px solid var(--border);margin-top:auto;
}
.attribution a{color:var(--text-3);text-decoration:underline}