:root{
  --bg:#0f1523;
  --bg2:#161f33;
  --card:#1b2537;
  --card2:#222e45;
  --line:#2c3a55;
  --tx:#eaf0fb;
  --tx2:#9fb0cc;
  --acc:#f2b705;
  --acc2:#ff7a45;
  --ok:#2fbf71;
  --bad:#ef4d5a;
  --r:16px;
  --safe: env(safe-area-inset-bottom, 0px);
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;padding:0}
body{
  background:radial-gradient(120% 80% at 50% 0%, #1b2740 0%, var(--bg) 60%);
  background-attachment:fixed;
  color:var(--tx);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",system-ui,"Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif;
  min-height:100dvh;
  overscroll-behavior-y:contain;
}
b{font-weight:700}

/* ---------- topbar ---------- */
#topbar{
  position:sticky;top:0;z-index:20;
  display:flex;align-items:center;gap:10px;
  padding:12px 14px;
  background:rgba(15,21,35,.82);
  backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line);
}
.brand{display:flex;flex-direction:column;line-height:1.1;margin-right:auto}
.brand-hz{font-size:19px;font-weight:800;letter-spacing:.5px}
.brand-sub{font-size:10px;color:var(--tx2);letter-spacing:2px}
.stats-mini{display:flex;gap:6px}
.chip{
  background:var(--card);border:1px solid var(--line);border-radius:999px;
  padding:5px 10px;font-size:12px;color:var(--tx2);white-space:nowrap;
}
.chip b{color:var(--tx)}
.icon-btn{
  background:var(--card);border:1px solid var(--line);color:var(--tx);
  width:34px;height:34px;border-radius:12px;font-size:22px;line-height:1;
  cursor:pointer;padding:0 0 3px 0;
}

/* ---------- layout ---------- */
#app{max-width:640px;margin:0 auto;padding:16px 14px calc(28px + var(--safe))}
.screen{display:flex;flex-direction:column;gap:14px;animation:in .22s ease}
@keyframes in{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}

/* ---------- selector nivel ---------- */
.level-switch{display:flex;gap:6px;background:var(--card);padding:5px;border-radius:14px;border:1px solid var(--line)}
.level-switch button{
  flex:1;background:transparent;border:0;color:var(--tx2);
  padding:10px 0;border-radius:10px;font-size:14px;font-weight:600;cursor:pointer;
}
.level-switch button.on{background:var(--acc);color:#20180a}

/* ---------- tarjeta progreso ---------- */
.progress-card{background:linear-gradient(160deg,var(--card2),var(--card));border:1px solid var(--line);border-radius:var(--r);padding:16px}
.pc-row{display:flex;justify-content:space-between;align-items:flex-end;margin-bottom:12px}
.pc-right{text-align:right}
.pc-label{font-size:11px;color:var(--tx2);text-transform:uppercase;letter-spacing:1px}
.pc-big{font-size:28px;font-weight:800;line-height:1.1}
.xpbar{height:8px;background:#0d1424;border-radius:99px;overflow:hidden}
.xpbar i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--acc),var(--acc2));transition:width .5s}
.pc-foot{display:flex;justify-content:space-between;font-size:11px;color:var(--tx2);margin-top:7px}

/* ---------- menú ---------- */
.menu{display:flex;flex-direction:column;gap:10px}
.mode-card{
  display:flex;align-items:center;gap:13px;text-align:left;
  background:var(--card);border:1px solid var(--line);border-radius:var(--r);
  padding:15px 14px;color:var(--tx);cursor:pointer;width:100%;
  transition:transform .12s, border-color .12s;
}
.mode-card:active{transform:scale(.985);border-color:var(--acc)}
.mode-card.ghost{background:transparent}
.mc-ico{font-size:26px;width:34px;text-align:center;flex:none}
.mc-txt{display:flex;flex-direction:column;gap:3px;flex:1;min-width:0}
.mc-txt b{font-size:16px}
.mc-txt small{font-size:12px;color:var(--tx2)}
.mc-badge{
  background:var(--acc2);color:#2a1105;font-size:11px;font-weight:800;
  border-radius:99px;padding:3px 8px;flex:none;
}
.mc-badge[hidden]{display:none}

/* ---------- quiz ---------- */
.quizbar{display:flex;flex-direction:column;gap:6px}
.qb-progress{height:6px;background:#0d1424;border-radius:99px;overflow:hidden}
.qb-progress i{display:block;height:100%;width:0;background:var(--acc);transition:width .3s}
.qb-meta{display:flex;justify-content:space-between;font-size:12px;color:var(--tx2)}
.qb-score{color:var(--acc);font-weight:700}
.qbody{display:flex;flex-direction:column;gap:14px}
.qfoot{display:flex;flex-direction:column;gap:9px;min-height:56px}

.prompt{font-size:13px;color:var(--tx2);text-align:center}
.card-panel{
  background:var(--card);border:1px solid var(--line);border-radius:var(--r);
  padding:20px 16px;
}

/* flashcard */
.flash{
  min-height:min(46dvh,300px);display:flex;flex-direction:column;
  align-items:center;justify-content:center;gap:12px;text-align:center;cursor:pointer;
}
.flash .hz{font-size:clamp(46px,15vw,76px);font-weight:700;line-height:1.15}
.flash .py{font-size:19px;color:var(--acc)}
.flash .es{font-size:17px}
.flash .ej{font-size:16px;line-height:1.8;border-top:1px dashed var(--line);padding-top:12px;width:100%}
.flash .ejes{font-size:13px;color:var(--tx2);margin-top:-4px}
.flash .tap{font-size:12px;color:var(--tx2)}
.flash .lvl-tag{font-size:10px;letter-spacing:1px;color:var(--tx2);border:1px solid var(--line);border-radius:99px;padding:2px 8px}

/* frase con hueco */
.sentence{font-size:clamp(20px,6vw,26px);line-height:2;text-align:center;word-break:break-word}
.sentence .gap{color:var(--acc);border-bottom:2px solid var(--acc);padding:0 14px}
.sentence .gap.filled{border-bottom-color:transparent}
.trans{font-size:13px;color:var(--tx2);text-align:center;font-style:italic}

/* botones */
.btn{
  background:var(--card2);border:1px solid var(--line);color:var(--tx);
  border-radius:14px;padding:14px 12px;font-size:16px;cursor:pointer;
  width:100%;font-family:inherit;transition:transform .1s,background .15s,border-color .15s;
}
.btn:active{transform:scale(.98)}
.btn.primary{background:var(--acc);color:#20180a;border-color:var(--acc);font-weight:700}
.btn.ok{background:rgba(47,191,113,.18);border-color:var(--ok);color:#b6f3d1}
.btn.bad{background:rgba(239,77,90,.18);border-color:var(--bad);color:#ffc4c9}
.btn:disabled{opacity:.55;cursor:default}
.opts{display:grid;grid-template-columns:1fr 1fr;gap:9px}
.opts .btn{font-size:18px}
@media(max-width:360px){.opts{grid-template-columns:1fr}}

/* valoración flashcard */
.rate{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}
.rate .btn{padding:13px 4px;font-size:14px;display:flex;flex-direction:column;gap:3px;align-items:center}
.rate .btn small{font-size:10px;color:var(--tx2)}

/* construir frases */
.build-slot{
  min-height:78px;background:#0d1424;border:1px dashed var(--line);border-radius:14px;
  padding:10px;display:flex;flex-wrap:wrap;gap:7px;align-content:flex-start;
}
.build-bank{display:flex;flex-wrap:wrap;gap:7px;justify-content:center}
.tok{
  background:var(--card2);border:1px solid var(--line);color:var(--tx);
  border-radius:11px;padding:10px 13px;font-size:19px;cursor:pointer;font-family:inherit;
  transition:transform .1s;
}
.tok:active{transform:scale(.94)}
.tok.used{opacity:.25;pointer-events:none}
.build-slot .tok{background:var(--acc);color:#20180a;border-color:var(--acc)}

/* feedback */
.feedback{border-radius:14px;padding:12px 14px;font-size:14px;line-height:1.55;animation:in .2s}
.feedback.ok{background:rgba(47,191,113,.13);border:1px solid rgba(47,191,113,.45)}
.feedback.bad{background:rgba(239,77,90,.13);border:1px solid rgba(239,77,90,.45)}
.feedback .fb-title{font-weight:700;margin-bottom:4px}
.feedback .fb-note{color:var(--tx2);font-size:13px}

/* lectura */
.reader{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:18px 16px}
.reader h3{margin:0 0 12px;font-size:20px}
.reader p{margin:0;font-size:18px;line-height:2.1;text-align:justify}
.reader.small p{font-size:16px;line-height:1.95}
.question{font-size:18px;line-height:1.7;text-align:center;padding:0 4px}
.opts.stack{grid-template-columns:1fr}
.opts.stack .btn{font-size:16px;text-align:left;line-height:1.5}
.textsize{display:flex;gap:6px;justify-content:flex-end}
.textsize button{background:var(--card2);border:1px solid var(--line);color:var(--tx2);border-radius:9px;padding:4px 10px;font-size:12px;cursor:pointer}

/* lista textos */
.list{display:flex;flex-direction:column;gap:10px}
.list-item{
  display:flex;align-items:center;gap:12px;background:var(--card);border:1px solid var(--line);
  border-radius:var(--r);padding:14px;color:var(--tx);cursor:pointer;text-align:left;
}
.list-item .li-t{flex:1;min-width:0}
.list-item .li-t b{display:block;font-size:16px}
.list-item .li-t small{color:var(--tx2);font-size:12px}
.li-done{color:var(--ok);font-size:13px;white-space:nowrap}

/* resultado */
.result{align-items:center;text-align:center;padding-top:14px}
.res-emoji{font-size:64px}
.result h2{margin:0;font-size:26px}
.res-sub{margin:0;color:var(--tx2);font-size:14px}
.res-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px;width:100%;margin:8px 0}
.res-box{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:14px}
.res-box .v{font-size:24px;font-weight:800}
.res-box .k{font-size:11px;color:var(--tx2);text-transform:uppercase;letter-spacing:1px}
.res-actions{display:flex;flex-direction:column;gap:9px;width:100%}

/* stats */
.stat-row{display:flex;justify-content:space-between;align-items:center;padding:13px 0;border-bottom:1px solid var(--line);font-size:15px}
.stat-row:last-child{border-bottom:0}
.stat-row span{color:var(--tx2);font-size:13px}
.danger{color:var(--bad);border-color:rgba(239,77,90,.5)}
.sec-title{font-size:12px;text-transform:uppercase;letter-spacing:1.5px;color:var(--tx2);margin:6px 0 -4px}
.wordlist{display:flex;flex-wrap:wrap;gap:7px}
.wordlist span{background:var(--card2);border:1px solid var(--line);border-radius:9px;padding:6px 10px;font-size:16px}

.toast{
  position:fixed;left:50%;bottom:calc(22px + var(--safe));transform:translateX(-50%);
  background:var(--acc);color:#20180a;font-weight:700;font-size:14px;
  padding:10px 18px;border-radius:99px;z-index:50;animation:pop .3s;
  box-shadow:0 8px 24px rgba(0,0,0,.4);
}
@keyframes pop{from{opacity:0;transform:translate(-50%,12px)}to{opacity:1;transform:translate(-50%,0)}}