/* Cuaderno de estudio: papel, tinta y un solo acento (bermellón). Sin sombras ni cajas decorativas. */
:root{
  --bg:#f4efe6;--surface:#fbf8f2;--text:#1d1b18;--muted:#6f685d;--line:#d9d1c3;
  --accent:#b4351f;--accent-ink:#fff;--ok:#2f6f4e;--bad:#a3262a;
  --sans:"Hiragino Sans","Yu Gothic UI","Noto Sans JP","Segoe UI",system-ui,sans-serif;
  --serif:"Iowan Old Style","Palatino Linotype","Hiragino Mincho ProN","Yu Mincho",Georgia,serif;
}
:root[data-theme=dark]{
  --bg:#171513;--surface:#201d1a;--text:#ece6da;--muted:#9a9183;--line:#3a352e;
  --accent:#e0684f;--accent-ink:#171513;--ok:#6fbf94;--bad:#ee7b72;
}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--text);font:16px/1.6 var(--sans)}
h2,h3{font-family:var(--serif);font-weight:600;line-height:1.3}
h2{font-size:1.6rem;margin:0 0 4px}
h3{font-size:1.05rem;margin:28px 0 6px}
a{color:var(--text);text-decoration-color:var(--accent);text-underline-offset:3px}
a:hover{color:var(--accent)}
p{margin:.6em 0}
.muted,.read{color:var(--muted)}
.read{font-size:.85rem}
code{font-size:.85rem;color:var(--muted)}

/* barra superior */
.top{position:sticky;top:0;z-index:5;display:flex;align-items:center;gap:8px;padding:10px 20px;background:var(--bg);border-bottom:1px solid var(--line)}
.top h1{flex:1;margin:0;font:600 1rem var(--serif);letter-spacing:.02em}
.top button{background:none;border:0;color:var(--muted);padding:4px 8px;font-size:1rem;cursor:pointer}
.top button:hover{color:var(--text)}
#menuBtn{display:none}

/* estructura */
.layout{display:grid;grid-template-columns:250px minmax(0,1fr);max-width:1360px;margin:0 auto}
nav{padding:24px 12px 24px 20px;position:sticky;top:49px;align-self:start;height:calc(100vh - 49px);overflow:auto}
nav a{display:block;padding:5px 10px;border-left:2px solid transparent;color:var(--muted);text-decoration:none;font-size:.92rem}
nav a:hover{color:var(--text)}
nav a.on{border-left-color:var(--accent);color:var(--text)}
nav small{display:block;font-size:.78rem;line-height:1.35;opacity:.85}
nav h3{font:600 .7rem var(--sans);text-transform:uppercase;letter-spacing:.1em;color:var(--muted);margin:22px 10px 6px}
main{padding:32px 44px 100px;max-width:880px;min-width:0}

/* secciones en vez de tarjetas */
.card{background:none;border:0;border-top:1px solid var(--line);border-radius:0;padding:16px 0;margin:0}
.card:first-of-type{border-top:0}
a.card{display:block}
.badge{font-size:.68rem;text-transform:uppercase;letter-spacing:.08em;color:var(--accent);margin-left:8px;font-weight:600}

/* pestañas */
.tabs{display:flex;gap:22px;flex-wrap:wrap;margin:18px 0 14px;border-bottom:1px solid var(--line);position:sticky;top:49px;background:var(--bg);z-index:3}
.tabs button{background:none;border:0;border-bottom:2px solid transparent;color:var(--muted);padding:6px 0;margin-bottom:-1px;font:inherit;cursor:pointer}
.tabs button:hover{color:var(--text)}
.tabs button.on{color:var(--text);border-bottom-color:var(--accent)}

/* botones */
.btn{background:none;border:1px solid var(--line);color:var(--text);border-radius:3px;padding:6px 14px;font:inherit;font-size:.92rem;cursor:pointer}
.btn:hover{border-color:var(--text)}
.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:default}
.mini{padding:0 8px;font-size:.75rem;color:var(--muted);margin-left:6px;vertical-align:middle}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}

/* tablas */
table{width:100%;border-collapse:collapse}
td,th{padding:9px 8px 9px 0;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}
tr:last-child td{border-bottom:0}

/* japonés */
.ja{line-height:2;font-size:1.2rem}
ruby rt{font-size:.5em;color:var(--muted);font-weight:400}
body.nofuri rt{display:none}
body:not(.nofuri) .rd{display:none}
.face rt{display:none}
.big{font-size:1.5rem;margin:8px 0}
.huge{font-family:var(--serif);font-size:3.6rem;line-height:1.15}
.story{border-left:2px solid var(--accent);padding:2px 0 2px 12px;margin:10px 0;color:var(--text)}
.story:before{content:"Imagen · ";color:var(--muted);font-size:.8rem;text-transform:uppercase;letter-spacing:.06em}

/* cifras de inicio */
.figs{color:var(--muted);margin:10px 0 16px}
.figs b{color:var(--text);font-weight:600}

/* estudio */
.bar{height:2px;background:var(--line);margin-bottom:18px}
.bar i{display:block;height:100%;background:var(--accent)}
.flash{background:var(--surface);border:1px solid var(--line)!important;border-radius:4px;padding:32px 24px;text-align:center}
.flash hr{border:0;border-top:1px solid var(--line);margin:20px 0}
.flash input{max-width:340px;text-align:center}
input[type=text]{width:100%;padding:9px 12px;border-radius:3px;border:1px solid var(--line);background:var(--bg);color:var(--text);font:inherit}
.grades{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-top:6px}
.grades .btn{padding:10px 4px}
.grades small{display:block;color:var(--muted);font-size:.72rem}
.okc{color:var(--ok)}.badc{color:var(--bad)}
.fb{margin-top:10px;font-size:.92rem}

/* quiz */
.opt{display:block;width:100%;text-align:left;margin:6px 0;padding:10px 14px}
.opt.ok{border-color:var(--ok);color:var(--ok);font-weight:600}
.opt.bad{border-color:var(--bad);color:var(--bad)}
.qlist{border-top:1px solid var(--line)}
.qbtn{display:block;width:100%;text-align:left;background:none;border:0;border-bottom:1px solid var(--line);padding:12px 0;font:inherit;color:inherit;cursor:pointer}
.qbtn:hover b{color:var(--accent)}
.qbtn:disabled{opacity:.4;cursor:default}
.qbtn b{display:block;font-weight:600}
.qbtn span{font-size:.88rem}

/* kanji */
.kcard{display:flex;gap:20px;align-items:flex-start;padding:18px 0}
.kcard .huge{min-width:1.2em;text-align:center}

@media(max-width:760px){
  .layout{grid-template-columns:1fr}
  nav{position:static;height:auto}
  main{padding:18px 20px 60px}
  .tabs{top:49px}
  #menuBtn{display:inline-block}
  nav{display:none;min-height:0;border-bottom:1px solid var(--line);padding:8px 20px}
  nav.open{display:block}
  main{padding:18px 20px 60px}
}
@media(max-width:480px){.grades{grid-template-columns:repeat(2,1fr)}.huge{font-size:3rem}.kcard{gap:14px}}

/* entrevistas */
.hid{display:none;margin-top:8px;padding-left:12px;border-left:2px solid var(--line)}
.hid.on{display:block}
.lec{border-top:1px solid var(--line);padding:6px 0 18px}
.q{margin:14px 0}
.q input{margin:8px 0;display:block}
.dlg p{margin:2px 0}
.who{display:inline-block;min-width:7.5em;color:var(--muted);font-weight:600;font-size:.9rem}
.form{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:12px}
.form label{display:block;font-size:.85rem;color:var(--muted)}
.form input{margin-top:4px}

/* escritorio */
#rail{display:none}
@media(min-width:1100px){
  body{font-size:17px}
  h2{font-size:2rem}
  .grid2{display:grid;grid-template-columns:1fr 1fr;column-gap:40px}
}
@media(min-width:1180px){
  .layout{grid-template-columns:250px minmax(0,1fr) 290px}
  #rail{display:block;position:sticky;top:49px;align-self:start;height:calc(100vh - 49px);overflow:auto;padding:32px 24px;border-left:1px solid var(--line)}
}
.rail-hi{font-family:var(--serif);font-size:1.1rem;margin:0 0 4px}
#rail h3{font:600 .7rem var(--sans);text-transform:uppercase;letter-spacing:.1em;color:var(--muted);margin:22px 0 6px}
.rail-num{font-family:var(--serif);font-size:3.4rem;line-height:1;margin:4px 0 6px}
.keys{display:grid;grid-template-columns:auto 1fr;gap:6px 12px;margin:0;font-size:.88rem}
.keys dt{font-family:ui-monospace,Consolas,monospace;color:var(--text)}
.keys dd{margin:0;color:var(--muted)}
.rows{border-top:1px solid var(--line)}
.rowlink{display:flex;justify-content:space-between;gap:24px;align-items:baseline;padding:14px 4px;border-bottom:1px solid var(--line);color:var(--text);text-decoration:none}
.rowlink:hover{background:var(--surface)}
.rowlink:hover b{color:var(--accent)}
.rowmeta{text-align:right;font-size:.82rem;white-space:nowrap}
.top .user{color:var(--muted);font-size:.85rem}

/* login */
body.locked .top,body.locked .layout{display:none}
#login{display:none;position:fixed;inset:0;z-index:50;grid-template-columns:1.15fr 1fr;background:var(--bg);transition:opacity .35s,transform .35s}
body.ask #login{display:grid}
#login.leaving{opacity:0;transform:scale(1.015);pointer-events:none}
.lg-art{position:relative;overflow:hidden;background:#1d1b18;color:#f4efe6;display:flex;flex-direction:column;justify-content:center;align-items:center;gap:28px;padding:40px}
.lg-art:before{content:"";position:absolute;inset:0;background:repeating-linear-gradient(0deg,transparent 0 39px,rgba(244,239,230,.05) 39px 40px)}
.lg-mark{position:absolute;left:-.1em;bottom:-.22em;font-family:var(--serif);font-size:min(30vw,26rem);line-height:1;color:rgba(244,239,230,.05);white-space:nowrap;user-select:none}
.lg-seal{position:relative;width:84px;height:84px;display:grid;place-items:center;background:#b4351f;color:#f4efe6;font-family:var(--serif);font-size:3.2rem;border-radius:6px;transform:rotate(-4deg);box-shadow:inset 0 0 0 3px #b4351f,inset 0 0 0 5px rgba(244,239,230,.55);animation:sealIn .7s .1s both cubic-bezier(.2,.9,.3,1.2)}
.lg-vert{position:relative;writing-mode:vertical-rl;font-family:var(--serif);font-size:clamp(2.2rem,5vw,3.6rem);line-height:2.2;letter-spacing:.18em;margin:0;animation:fadeUp .8s .25s both}
.lg-vert rt{color:rgba(244,239,230,.6)}
.lg-es{position:relative;margin:0;color:rgba(244,239,230,.65);font-size:.95rem;letter-spacing:.04em;animation:fadeUp .8s .45s both}
.lg-form{align-self:center;justify-self:center;width:min(380px,calc(100% - 48px));display:flex;flex-direction:column;gap:16px;animation:fadeUp .6s .15s both}
.lg-form h1{font:600 1.7rem var(--serif);margin:0}
.lg-sub{margin:-8px 0 8px;color:var(--muted)}
.lg-form label{display:flex;flex-direction:column;gap:6px;font-size:.85rem;color:var(--muted)}
.lg-form input[type=text],.lg-form input[type=password]{padding:11px 12px;font-size:1rem}
.lg-form input:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px color-mix(in srgb,var(--accent) 20%,transparent)}
.pw{position:relative;display:block}
.pw input{padding-right:84px!important;width:100%}
.pw button{position:absolute;right:6px;top:50%;transform:translateY(-50%);background:none;border:0;color:var(--muted);font:inherit;font-size:.8rem;cursor:pointer;padding:6px 8px}
.pw button:hover{color:var(--text)}
.lg-form .chk{flex-direction:row;align-items:center;gap:8px}
.lg-btn{padding:12px;font-size:1rem}
.lg-err{min-height:1.4em;margin:0;color:var(--bad);font-size:.9rem}
.lg-form.shake{animation:shake .4s}
@keyframes fadeUp{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}
@keyframes sealIn{from{opacity:0;transform:rotate(-14deg) scale(1.5)}to{opacity:1;transform:rotate(-4deg) scale(1)}}
@keyframes shake{20%,60%{transform:translateX(-7px)}40%,80%{transform:translateX(7px)}}
@media(max-width:820px){
  #login{grid-template-columns:1fr;grid-template-rows:auto 1fr}
  .lg-art{flex-direction:row;padding:22px 24px;gap:18px;justify-content:flex-start}
  .lg-vert{writing-mode:horizontal-tb;font-size:1.4rem;line-height:1.8;letter-spacing:.06em}
  .lg-es,.lg-mark{display:none}
  .lg-seal{width:52px;height:52px;font-size:2rem}
}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}

/* racha y repaso libre */
.streak{margin:14px 0 8px}
.streak-top{display:flex;align-items:baseline;gap:10px}
.streak-num{font-family:var(--serif);font-size:3rem;line-height:1}
.cal{display:grid;grid-template-rows:repeat(7,14px);grid-auto-flow:column;grid-auto-columns:14px;gap:4px;margin:10px 0 6px;width:max-content}
.cal .d{display:block;border-radius:3px;background:var(--line)}
.cal .d.off{background:none}
.cal .d.l1{background:color-mix(in srgb,var(--accent) 35%,var(--line))}
.cal .d.l2{background:color-mix(in srgb,var(--accent) 65%,var(--line))}
.cal .d.l3{background:var(--accent)}
.cal .d.hoy{outline:1px solid var(--text);outline-offset:1px}
.streak-foot{font-size:.82rem}
.freehead{display:flex;justify-content:space-between;align-items:center;margin-bottom:8px;font-size:.9rem}
.grades.two{grid-template-columns:repeat(2,1fr)}
select{padding:8px 10px;border-radius:3px;border:1px solid var(--line);background:var(--bg);color:var(--text);font:inherit;max-width:100%}
.chk{display:flex;align-items:center;gap:8px;font-size:.92rem;cursor:pointer}