/* base reset */
html{color-scheme:light}
body{margin:0;font-size:14px}
img{max-width:100%}
[hidden]{display:none!important}
/* Layout: an onboarding questionnaire first (one question per screen, big tiles), then a small app with tabs:
   recommendations (route drawn as a line of stations), full shelf, beginner's guide, settings. Four UI languages. */
:root{
  --bg:#F2F4F7; --surface:#FFFFFF; --ink:#141C26; --muted:#5A6676; --line:#D9DFE7;
  --accent:#2443C4; --accent-ink:#FFFFFF; --accent-soft:#E6EBFB;
  --mark:#FFD24D; --mark-soft:#FFF4CC; --warn:#A5520B; --warn-soft:#FCEFD9; --ok:#1C7A4A; --ok-soft:#E1F3E8;
  --f-display:"Noto Serif SC","Songti SC","STSong",Georgia,serif;
  --f-body:system-ui,-apple-system,"Segoe UI","PingFang SC","Hiragino Sans GB","Hiragino Sans","Microsoft YaHei","Yu Gothic","Noto Sans SC",sans-serif;
  --f-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --r:10px;
}
:root:lang(ja){--f-display:"Noto Serif JP","Hiragino Mincho ProN","Yu Mincho",Georgia,serif;
  --f-body:system-ui,-apple-system,"Segoe UI","Hiragino Sans","Hiragino Kaku Gothic ProN","Yu Gothic","Meiryo",sans-serif}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){
  --bg:#0E131A; --surface:#161D26; --ink:#E7ECF2; --muted:#95A2B2; --line:#2A3441;
  --accent:#8FA3FF; --accent-ink:#0E131A; --accent-soft:#1E2848;
  --mark:#D9B23A; --mark-soft:#332B12; --warn:#F0B067; --warn-soft:#3A2A16; --ok:#6FD39E; --ok-soft:#173326; color-scheme:dark}}
:root[data-theme="dark"]{
  --bg:#0E131A; --surface:#161D26; --ink:#E7ECF2; --muted:#95A2B2; --line:#2A3441;
  --accent:#8FA3FF; --accent-ink:#0E131A; --accent-soft:#1E2848;
  --mark:#D9B23A; --mark-soft:#332B12; --warn:#F0B067; --warn-soft:#3A2A16; --ok:#6FD39E; --ok-soft:#173326; color-scheme:dark}

*{box-sizing:border-box}
body{background:var(--bg);color:var(--ink);font-family:var(--f-body);font-size:15px;line-height:1.65}
a{color:var(--accent)}
button{font:inherit}
.wrap{max-width:1180px;margin:0 auto;padding-inline:20px;padding-block:14px 64px}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
h2.sec{font-family:var(--f-display);font-weight:900;font-size:26px;margin:0;text-wrap:balance}
.hl{background:linear-gradient(transparent 58%,var(--mark) 58%,var(--mark) 92%,transparent 92%)}
.intro{color:var(--muted);margin:6px 0 16px;max-width:46em}

/* top bar */
.topbar{display:flex;flex-wrap:wrap;align-items:center;gap:10px 18px;padding-bottom:12px;border-bottom:2px solid var(--ink)}
.brand-mini{font-family:var(--f-display);font-weight:900;font-size:20px;background:none;border:0;padding:0;color:var(--ink);cursor:pointer;white-space:nowrap}
.tabs{display:flex;flex-wrap:wrap;gap:2px;flex:1 1 auto}
.tabs button{font-size:14px;padding:6px 12px;border:0;border-radius:7px;background:transparent;color:var(--muted);cursor:pointer}
.tabs button:hover{color:var(--ink)}
.tabs button[aria-current="page"]{background:var(--accent-soft);color:var(--accent);font-weight:600}
.langs{display:flex;flex-wrap:wrap;gap:2px;padding:3px;border:1px solid var(--line);border-radius:9px;background:var(--surface);margin-left:auto}
.langs button{font-size:13px;padding:3px 10px;border:0;border-radius:6px;background:transparent;color:var(--muted);cursor:pointer}
.langs button[aria-pressed="true"]{background:var(--ink);color:var(--bg)}
.view{padding-top:28px}

/* onboarding */
.hero{max-width:760px;margin:0 auto 22px}
.hero h1{font-family:var(--f-display);font-weight:900;font-size:clamp(30px,5vw,44px);line-height:1.15;margin:0}
.hero p{color:var(--muted);margin:10px 0 0}
.meta{font-family:var(--f-mono);font-size:12px;color:var(--muted);display:flex;gap:6px 18px;flex-wrap:wrap;margin-top:10px}
.meta b{color:var(--ink);font-weight:600}
.wizard{max-width:760px;margin:0 auto;background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:26px 24px 20px}
.wz-step{font-family:var(--f-mono);font-size:12px;letter-spacing:.08em;color:var(--accent);font-weight:600}
.wz-welcome{margin:4px 0 0;font-size:13px;color:var(--muted)}
.wizard h2{font-family:var(--f-display);font-weight:900;font-size:clamp(22px,3.4vw,28px);line-height:1.3;margin:6px 0 4px;text-wrap:balance}
.wz-sub{margin:0 0 18px;color:var(--muted);font-size:14px}
.tiles{display:grid;grid-template-columns:repeat(auto-fill,minmax(210px,1fr));gap:10px}
.tiles.compact{grid-template-columns:repeat(auto-fill,minmax(170px,1fr))}
.tile{display:flex;flex-direction:column;align-items:flex-start;gap:3px;text-align:left;padding:14px 16px;border:1.5px solid var(--line);border-radius:10px;background:var(--bg);color:var(--ink);cursor:pointer;line-height:1.35;min-width:0}
.tile b{font-size:15px}
.tile small{font-size:12.5px;color:var(--muted)}
.tile:hover{border-color:var(--accent)}
.tile[aria-pressed="true"]{border-color:var(--accent);background:var(--accent-soft)}
.tile.skip{background:transparent;border-style:dashed;color:var(--muted)}
.tile.skip:hover{color:var(--ink)}
.tile.other{background:transparent}
.chips-pick{display:flex;flex-wrap:wrap;gap:8px}
.pick{padding:8px 14px;border:1.5px solid var(--line);border-radius:99px;background:var(--bg);color:var(--ink);cursor:pointer;font-size:14px}
.pick:hover{border-color:var(--accent)}
.pick[aria-pressed="true"]{border-color:var(--accent);background:var(--accent);color:var(--accent-ink)}
.major-in{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:6px}
.major-in .text-in{flex:1 1 240px}
.detect-msg{font-size:13px;color:var(--muted);min-height:1.6em;margin:0 0 14px}
.wz-foot{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px;margin-top:22px;padding-top:14px;border-top:1px solid var(--line)}
.wz-foot .right{display:flex;flex-wrap:wrap;gap:8px;margin-left:auto}
.linkbtn{background:none;border:0;padding:4px 0;color:var(--muted);text-decoration:underline;text-underline-offset:3px;cursor:pointer;font-size:13.5px}
.linkbtn:hover{color:var(--ink)}
.btn{font-size:14px;padding:8px 16px;border-radius:8px;border:1.5px solid var(--ink);background:transparent;color:var(--ink);cursor:pointer;white-space:nowrap}
.btn:hover{background:var(--ink);color:var(--bg)}
.btn.primary{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}
.btn.primary:hover{filter:brightness(1.08)}
.btn:disabled{opacity:.45;cursor:not-allowed;filter:none}
.text-in{width:100%;font:inherit;padding:10px 12px;border:1.5px solid var(--line);border-radius:8px;background:var(--bg);color:var(--ink)}
.text-in:focus{border-color:var(--accent);outline:none}

/* recommendations */
.route-head{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:flex-start;gap:10px 20px}
.summary{color:var(--muted);margin:6px 0 0;display:flex;flex-wrap:wrap;align-items:baseline;gap:4px 10px}
.summary b{color:var(--ink)}
.ideas{margin-top:18px;padding:14px 18px;background:var(--surface);border:1px dashed var(--line);border-radius:var(--r);max-width:820px}
.ideas h3{margin:0 0 6px;font-size:14px}
.ideas ul{margin:0;padding-left:1.2em;color:var(--muted)}
.ideas li{margin:2px 0}
.stages{margin-top:26px;display:grid}
.stage{display:grid;grid-template-columns:44px minmax(0,1fr);gap:0 16px}
.rail{position:relative;display:flex;justify-content:center}
.rail::before{content:"";position:absolute;top:0;bottom:0;left:50%;width:3px;transform:translateX(-50%);background:repeating-linear-gradient(var(--line) 0 6px,transparent 6px 11px)}
.stage:first-child .rail::before{top:18px}
.stage:last-child .rail::before{bottom:auto;height:18px}
.dot{position:relative;z-index:1;width:36px;height:36px;border-radius:50%;background:var(--ink);color:var(--bg);font-family:var(--f-mono);font-weight:600;display:grid;place-items:center;font-size:15px}
.stage-body{padding-bottom:28px;min-width:0}
.stage-body h3{margin:4px 0 2px;font-size:18px;font-family:var(--f-display);font-weight:600}
.stage-body .sub{margin:0 0 12px;color:var(--muted);font-size:13px}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(270px,1fr));gap:12px}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:14px 16px;display:flex;flex-direction:column;gap:9px;min-width:0}
.card.prereq{border-style:dashed}
.card-top{display:flex;justify-content:space-between;align-items:flex-start;gap:10px}
.card h4{margin:0;font-size:16px;line-height:1.35;min-width:0;overflow-wrap:anywhere}
.src{flex:none;font-size:11px;font-weight:600;padding:1px 7px;border-radius:4px;white-space:nowrap}
.src.web{background:var(--ok-soft);color:var(--ok)}
.src.gh{background:var(--accent-soft);color:var(--accent)}
.card p{margin:0;font-size:14px;color:var(--muted)}
.howto{font-size:13.5px;line-height:1.55;padding:8px 10px;border-left:3px solid var(--mark);background:var(--bg);border-radius:0 6px 6px 0}
.howto b{font-size:12px;letter-spacing:.04em;margin-right:6px}
.chips{display:flex;flex-wrap:wrap;gap:5px}
.chip{font-size:11.5px;padding:1px 8px;border-radius:99px;border:1px solid var(--line);color:var(--muted)}
.chip.why{border-color:transparent;background:var(--accent-soft);color:var(--accent)}
.chip.warn{border-color:transparent;background:var(--warn-soft);color:var(--warn)}
.actions{margin-top:auto;display:flex;flex-wrap:wrap;align-items:center;gap:6px 14px;padding-top:2px}
a.go{display:inline-block;font-size:13.5px;font-weight:600;text-decoration:none;padding:6px 12px;border-radius:7px;background:var(--accent);color:var(--accent-ink)}
a.go:hover{filter:brightness(1.08)}
a.repo-link{font-size:12px;color:var(--muted)}
.term{background:none;border:0;padding:0;color:inherit;border-bottom:1.5px dotted var(--accent);cursor:help}
.term:hover{color:var(--accent)}
.pop{position:absolute;z-index:20;max-width:min(300px,calc(100vw - 32px));background:var(--ink);color:var(--bg);font-size:13px;line-height:1.5;padding:10px 12px;border-radius:8px;box-shadow:0 6px 20px rgba(0,0,0,.18)}
.pop b{display:block;margin-bottom:2px}

/* guide */
.guide{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:28px 40px}
@media (max-width:880px){.guide{grid-template-columns:1fr}}
.steps{list-style:none;margin:0;padding:0;display:grid;gap:12px;counter-reset:s}
.steps li{display:grid;grid-template-columns:28px minmax(0,1fr);gap:10px;counter-increment:s}
.steps li::before{content:counter(s);font-family:var(--f-mono);font-weight:600;width:26px;height:26px;border-radius:50%;border:1.5px solid var(--ink);display:grid;place-items:center;font-size:13px}
.steps b{display:block}
.steps span{color:var(--muted);font-size:14px}
.gloss{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:2px 20px;margin:0}
.gloss div{padding:8px 0;border-bottom:1px solid var(--line)}
.gloss dt{font-weight:600;font-size:14px}
.gloss dd{margin:0;color:var(--muted);font-size:13.5px}

/* library */
.filters{display:flex;flex-wrap:wrap;gap:10px 16px;align-items:center}
.filters .text-in{max-width:240px;padding:7px 10px;font-size:14px}
.fgroup{display:flex;flex-wrap:wrap;gap:4px}
.fgroup button{font-size:13px;padding:4px 10px;border-radius:6px;border:1px solid var(--line);background:var(--surface);color:var(--ink);cursor:pointer}
.fgroup button[aria-pressed="true"]{background:var(--ink);color:var(--bg);border-color:var(--ink)}
.count{font-family:var(--f-mono);font-size:12px;color:var(--muted);margin:14px 0 4px}
.rows{display:grid}
.row{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,2.1fr) 210px;gap:6px 20px;padding:14px 0;border-bottom:1px solid var(--line);align-items:start}
.row .nm{display:grid;gap:4px;justify-items:start;min-width:0}
.row .nm b{font-size:15px;line-height:1.35;overflow-wrap:anywhere}
.row .body{display:grid;gap:6px;min-width:0}
.row p{margin:0;font-size:14px;color:var(--muted)}
.row .howto{font-size:13px}
.row .chips{justify-content:flex-end}
.row .links{display:flex;flex-wrap:wrap;gap:4px 12px;font-size:13px}
.row .links a.muted{color:var(--muted)}
@media (max-width:760px){.row{grid-template-columns:1fr}.row .chips{justify-content:flex-start}}
.empty{padding:24px 0;color:var(--muted)}

/* settings */
.sets{display:grid;gap:4px;max-width:860px}
.sgroup{padding:16px 0;border-bottom:1px solid var(--line);display:grid;grid-template-columns:180px minmax(0,1fr);gap:8px 20px;align-items:start}
@media (max-width:700px){.sgroup{grid-template-columns:1fr}}
.sgroup h3{margin:4px 0 0;font-size:14px}
.pills{display:flex;flex-wrap:wrap;gap:6px}
.pill{font-size:13.5px;padding:5px 12px;border-radius:99px;border:1.5px solid var(--line);background:var(--surface);color:var(--ink);cursor:pointer}
.pill:hover{border-color:var(--accent)}
.pill[aria-pressed="true"]{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}
.pill.unsure{border-style:dashed;color:var(--muted)}
.pill.unsure[aria-pressed="true"]{background:var(--ink);border-color:var(--ink);color:var(--bg);border-style:solid}
.sgroup .text-in{max-width:320px;padding:7px 10px;font-size:14px;margin-bottom:8px}
.zero{display:flex;gap:10px;align-items:flex-start;cursor:pointer}
.zero input{margin-top:4px;width:16px;height:16px;accent-color:var(--accent);flex:none}
.zero b{display:block;font-size:14px}
.zero span span{font-size:13px;color:var(--muted);display:block}
.set-actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:22px}

footer{margin-top:48px;font-size:12.5px;color:var(--muted)}
.toast{position:fixed;left:50%;bottom:calc(env(safe-area-inset-bottom,0px) + 20px);transform:translateX(-50%);background:var(--ink);color:var(--bg);padding:8px 16px;border-radius:8px;font-size:13px;z-index:30}
@media (prefers-reduced-motion:no-preference){
  .card{animation:rise .35s ease both}
  .wizard .wz-body{animation:fade .25s ease both}
  @keyframes rise{from{transform:translateY(6px)}to{transform:none}}
  @keyframes fade{from{transform:translateX(8px)}to{transform:none}}
}