/* ==========================================================================
   ESTUDIO (/study/): carta 3D que gira (y se desliza en el móvil), contadores,
   la sesión como un viaje en tren, botones de nota, pantalla final con Mikan
   dormido sobre el mazo y el billete del día, y pantalla vacía.
   ========================================================================== */

.study { padding: clamp(14px, 3vw, 30px) 0 40px; overflow-x: clip; }
.study-wrap { max-width: 720px; }
.study-top { display: flex; align-items: flex-end; justify-content: space-between; gap: 12px; margin-bottom: 12px; }
.study-title { font-size: clamp(34px, 6vw, 52px); margin: 6px 0 0; }
.study-gear { background: var(--white); flex: none; }
.study-gear svg { transition: transform .5s cubic-bezier(.3, 1.4, .5, 1); }
.study-gear:hover svg { transform: rotate(90deg); }
.study-loading { padding: 80px 0; text-align: center; font: 700 18px/1 var(--f-display); color: var(--ink-soft); }
.study-loading .jp { display: inline-block; font-size: 28px; animation: wobble .8s ease-in-out infinite; margin-right: 6px; }
/* atajos: nunca por debajo de 11 px y con aire a los lados */
kbd { display: inline-block; min-width: 1.7em; padding: 2px 7px 1px; border: 2px solid currentColor; border-bottom-width: 3px; border-radius: 6px; font: 800 max(11px, .76em)/1.3 var(--f-display); text-align: center; opacity: .75; }

/* cartel de numeración de estación (.st-sign, --sm, --lg): en components.css */

/* ---------- selector de niveles (estaciones) ---------- */
.study-levels { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 12px; }
.lv-toggle {
  --lc: var(--rank-e);
  display: inline-flex; align-items: center; gap: 7px; min-height: 36px; padding: 5px 6px 5px 10px;
  border: 2px solid var(--ink); border-radius: 999px; background: var(--paper-2);
  font: 800 13px/1 var(--f-display); letter-spacing: .06em; cursor: pointer; opacity: .62;
  transition: transform .12s, background-color .2s, opacity .2s;
}
.lv-dot { width: 12px; height: 12px; border-radius: 50%; background: var(--white); border: 3px solid var(--lc); box-shadow: 0 0 0 1.5px var(--ink); }
.lv-left { min-width: 22px; padding: 4px 6px; border-radius: 999px; background: var(--lc); color: var(--li, var(--white)); font-size: 11px; text-align: center; font-variant-numeric: tabular-nums; }
.lv-left.is-zero { background: transparent; color: inherit; opacity: .5; }
.lv-toggle[aria-pressed="true"] { background: var(--ink); color: var(--paper); opacity: 1; box-shadow: var(--shadow-sm); }
.lv-toggle[aria-pressed="true"] .lv-dot { box-shadow: 0 0 0 1.5px var(--paper); }
.lv-toggle[aria-pressed="true"] .lv-left:not(.is-zero) { background: var(--paper); color: var(--ink); }
.lv-toggle:hover { transform: translateY(-2px); opacity: 1; }
.lv-toggle.is-nope { animation: shake .4s; }

/* ---------- HUD de la sesión: contadores + el tren que avanza ---------- */
.study-hud { display: grid; grid-template-columns: auto 1fr; gap: 14px; align-items: center; margin-bottom: 16px; }
.sh-counts { display: flex; gap: 6px; }
.sh-c {
  display: grid; justify-items: center; min-width: 58px; padding: 6px 8px 5px; border: 2px solid var(--ink); border-radius: 12px; background: var(--white);
  transition: transform .2s, box-shadow .2s, background-color .2s;
}
.sh-c b { display: block; font: 900 20px/1 var(--f-display); font-variant-numeric: tabular-nums; }
.sh-c small { margin-top: 2px; font: 800 11px/1.2 var(--f-display); letter-spacing: .1em; text-transform: uppercase; color: var(--ink-soft); }
.sh-c--new b { color: var(--teal); }
.sh-c--learn b { color: var(--seal); }
.sh-c--rev b { color: var(--choc-2); }
.sh-c.is-cur { transform: translateY(-3px); box-shadow: var(--shadow-sm); }
.sh-c.is-cur.sh-c--new { background: #e3f6f3; }
.sh-c.is-cur.sh-c--learn { background: #fde4e1; }
.sh-c.is-cur.sh-c--rev { background: var(--cream); }
.sh-c--drill { display: none; }
.sh-c--drill b { color: var(--seal); }
.study-hud.is-drill .sh-c { display: none; }
.study-hud.is-drill .sh-c--drill { display: grid; }
.is-bump { animation: bump .4s cubic-bezier(.3, 1.6, .5, 1); }
@keyframes bump { 40% { transform: scale(1.35); } }

.sh-ride { --v: 0; --n: 10; --lc: var(--rank-e); display: grid; grid-template-columns: 1fr auto; gap: 12px; align-items: center; }
.ride-track { position: relative; height: 36px; }
.ride-track::before { /* la vía: contorno de tinta y color de la línea apagado */
  content: ""; position: absolute; left: 4px; right: 4px; top: 24px; height: 9px; border-radius: 99px;
  background: color-mix(in srgb, var(--lc) 18%, var(--paper)); box-shadow: 0 0 0 3px var(--ink);
}
.ride-fill {
  position: absolute; left: 4px; top: 24px; height: 9px; border-radius: 99px; background: var(--lc);
  width: calc(19px + (100% - 46px) * var(--v) / 100); transition: width .6s cubic-bezier(.3, 1.2, .5, 1);
}
.ride-dots { /* una estación por tarjeta */
  position: absolute; left: 23px; right: 23px; top: 25.5px; height: 6px; z-index: 1;
  background: radial-gradient(circle, var(--white) 0 2.2px, transparent 2.6px) left center / calc(100% / var(--n)) 6px repeat-x;
  opacity: .9;
}
.ride-train {
  position: absolute; top: 0; z-index: 2; width: 46px; height: 25px;
  left: calc(23px + (100% - 46px) * var(--v) / 100); transform: translateX(-50%);
  transition: left .6s cubic-bezier(.3, 1.2, .5, 1);
}
.ride-train svg { width: 100%; height: auto; animation: chug .9s ease-in-out infinite; }
@keyframes chug { 50% { transform: translateY(-1.5px); } }
.sh-done { font: 700 13px/1 var(--f-display); letter-spacing: .04em; color: var(--ink-soft); white-space: nowrap; font-variant-numeric: tabular-nums; }
.sh-done b { display: inline-block; color: var(--ink); font-size: 18px; }
.sh-done i { font-style: normal; }

/* ---------- carta ---------- */
.sc-scene { perspective: 1600px; width: min(100%, 460px); margin: 0 auto; touch-action: pan-y; transition: transform .3s cubic-bezier(.3, 1.3, .5, 1); }
.sc-scene.is-dragging { transition: none; cursor: grabbing; user-select: none; -webkit-user-select: none; }
.sc-card {
  position: relative; height: clamp(300px, calc(100vh - 470px), 470px); height: clamp(300px, calc(100svh - 470px), 470px);
  transform-style: preserve-3d;
  transition: transform .62s cubic-bezier(.2, .85, .25, 1.15);
}
.sc-card:not(.is-flipped) { cursor: pointer; }
.sc-card.is-flipped { transform: rotateY(180deg); }
.sc-card.is-dealing { animation: deal .5s cubic-bezier(.2, .9, .3, 1.2) both; }
.sc-card.is-shake { animation: shake .45s; }
.sc-card.is-rated { transition: transform .45s cubic-bezier(.5, 0, .75, 0), opacity .45s; opacity: 0; }
.sc-card.is-out-right { transform: rotateY(180deg) translateX(-130%) rotate(-14deg); }
.sc-card.is-out-left { transform: rotateY(180deg) translateX(130%) rotate(14deg); }
@keyframes deal { 0% { transform: translate(60%, 30px) rotate(12deg); opacity: 0; } 100% { transform: none; opacity: 1; } }

.sc-face {
  position: absolute; inset: 0; backface-visibility: hidden; -webkit-backface-visibility: hidden;
  display: flex; flex-direction: column; overflow: hidden;
  background: var(--white); border: var(--line-thick) solid var(--ink); border-radius: 26px; box-shadow: 7px 8px 0 var(--ink);
}
.sc-face::before { /* papel */
  content: ""; position: absolute; inset: 0; background-image: var(--paper-noise); opacity: .8; pointer-events: none; mix-blend-mode: multiply;
}
.sc-back { transform: rotateY(180deg); background: var(--paper); }
/* la cara que no se ve queda oculta de verdad (no solo de espaldas): no se pinta ni la leen los lectores ni las
   pruebas de solapes; la de delante se oculta a mitad del giro, cuando ya no mira al usuario */
.sc-card:not(.is-flipped) .sc-back { visibility: hidden; }
.sc-card.is-flipped .sc-front { visibility: hidden; transition: visibility 0s .3s; }
.sc-strip {
  position: relative; z-index: 1; display: flex; align-items: center; justify-content: space-between; gap: 8px;
  padding: 8px 12px 8px 14px; border-bottom: var(--line) solid var(--ink); background: var(--teal); color: var(--white);
  font: 800 11.5px/1 var(--f-display); letter-spacing: .14em; text-transform: uppercase;
}
.sc--jp-en .sc-strip { background: var(--orange); color: var(--ink); }
.sc--en-jp .sc-strip { background: var(--pink); color: var(--ink); }
.sc-back .sc-strip { background: var(--ink); color: var(--paper); }
.sc-type-l { display: inline-flex; align-items: center; gap: 8px; min-width: 0; }
.sc-new {
  display: inline-block; padding: 4px 8px 3px; border: 2px solid var(--ink); border-radius: 6px; background: var(--gold-2); color: var(--ink);
  font: 900 11px/1 var(--f-display); font-style: normal; letter-spacing: .1em; transform: rotate(-4deg); box-shadow: 2px 2px 0 var(--ink);
}
.sc-new--again { background: var(--pink-2); }
.sc-new--drill { background: var(--white); }
.sc-body {
  position: relative; z-index: 1; flex: 1; min-height: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 10px;
  padding: 18px 20px 22px; text-align: center;
}
.sc-front .sc-body::before { /* sol de tramas detrás del kana */
  content: ""; position: absolute; width: 74%; aspect-ratio: 1; left: 13%; top: 50%; transform: translateY(-58%); border-radius: 50%; z-index: -1;
  background-image: var(--halftone-orange); background-size: 8px 8px;
  -webkit-mask: radial-gradient(circle, #000 35%, transparent 70%); mask: radial-gradient(circle, #000 35%, transparent 70%);
}
.sc-glyph { font: 900 clamp(120px, 30vw, 176px)/1 var(--f-round); color: var(--ink); text-shadow: 5px 5px 0 var(--orange-2); }
.sc-glyph--sm { font-size: 92px; text-shadow: 4px 4px 0 var(--teal-2); padding: 0; border: 0; background: none; cursor: pointer; transition: transform .15s; }
.sc-glyph--sm:hover { transform: rotate(-4deg) scale(1.04); }
.sc-word { font: 900 clamp(58px, 15vw, 88px)/1.05 var(--f-jp); text-shadow: 4px 4px 0 var(--orange-2); letter-spacing: .02em; }
.sc-word.is-long { font-size: clamp(44px, 11vw, 66px); }
.sc-kanji { font: 700 22px/1 var(--f-jp); color: var(--ink-soft); padding: 4px 12px; border: 2px dashed rgba(22,20,24,.3); border-radius: 999px; }
.sc-romaji { font: 600 18px/1 var(--f-body); color: var(--ink-soft); letter-spacing: .08em; }
.sc-en { font: 800 clamp(30px, 7vw, 44px)/1.1 var(--f-display); text-transform: uppercase; }
.sc-ask { margin: 4px 0 0; font: 700 13px/1 var(--f-display); letter-spacing: .14em; text-transform: uppercase; color: var(--seal); }
.sc-tap { margin: 0; font-size: 14px; line-height: 1.35; color: var(--ink-soft); }
.sc-say {
  display: inline-flex; align-items: center; gap: 6px; padding: 7px 14px; border: 2px solid var(--ink); border-radius: 999px; background: var(--gold-2);
  font: 800 13px/1 var(--f-display); letter-spacing: .08em; text-transform: uppercase; cursor: pointer; box-shadow: var(--shadow-sm);
  transition: transform .12s;
}
.sc-say:hover { transform: translateY(-2px) rotate(-2deg); }
.sc-say:active { transform: translateY(1px); }
.sc-say--sm { padding: 0; width: 34px; height: 34px; justify-content: center; font-size: 15px; flex: none; }
.is-ping { animation: ping .45s cubic-bezier(.3, 1.4, .5, 1); }
@keyframes ping { 40% { transform: scale(1.14) rotate(-4deg); } }

/* escribir el rōmaji */
.sc-type { display: flex; gap: 8px; width: min(100%, 290px); margin-top: 8px; }
.sc-type .input { min-height: 46px; padding: 8px 14px; font-size: 18px; text-align: center; }
.sc-type .btn { flex: none; min-height: 46px; }
.sc-typed { font: 700 14px/1.2 var(--f-display); padding: 6px 12px; border-radius: 999px; border: 2px solid var(--ink); }
.sc-typed.is-ok { background: #d8f2ee; }
.sc-typed.is-bad { background: #fbd9d6; }

/* reverso */
.sc-body--back {
  justify-content: flex-start; gap: 12px; overflow-y: auto; padding-top: 22px; overscroll-behavior: contain;
  touch-action: pan-y; /* el reverso se desplaza: sin esto, su scroll se quedaba el gesto horizontal y deslizar la carta no puntuaba */
  -webkit-mask: linear-gradient(#000 calc(100% - 22px), transparent); mask: linear-gradient(#000 calc(100% - 22px), transparent);
}
.sc-pair { display: flex; align-items: center; gap: 18px; }
.sc-big-romaji { font: 900 72px/1 var(--f-display); color: var(--seal); }
.sc-meaning { font: 900 clamp(30px, 7vw, 42px)/1.05 var(--f-display); text-transform: uppercase; color: var(--seal); }
.sc-meaning--sm { font-size: 20px; color: var(--ink-2); }
.sc-meaning.is-long { font-size: clamp(24px, 5.6vw, 32px); line-height: 1.1; } /* «matcha, powdered green tea»: tres líneas enormes en el móvil */
.sc-reading { display: flex; align-items: center; flex-wrap: wrap; justify-content: center; gap: 10px; font: 900 34px/1.1 var(--f-jp); }
.sc-reading-kanji { font-size: 26px; color: var(--choc); }
.sc-reading-r { font: 600 18px/1 var(--f-body); color: var(--ink-soft); }
.sc-mnemo { margin: 0; max-width: 34ch; font-size: 16px; line-height: 1.4; }
.sc-mnemo b, .sc-fact::before { display: block; font: 800 11px/1 var(--f-display); letter-spacing: .16em; text-transform: uppercase; color: var(--teal); margin-bottom: 6px; }
.sc-ex { display: flex; align-items: center; gap: 10px; padding: 8px 14px 8px 8px; border: 2px solid var(--ink); border-radius: 16px; background: var(--white); font-size: 16px; }
.sc-ex .jp { font-weight: 900; font-size: 20px; }
.sc-ex--block { text-align: left; align-items: flex-start; width: 100%; }
.sc-ex--block > div { display: grid; gap: 2px; }
/* las frases vienen con espacios entre bloques (つくえの うえに…): se parten por ahí, no dejando «す。» sola */
.sc-ex--block .jp { word-break: keep-all; overflow-wrap: anywhere; }
.sc-ex--block small { color: var(--ink-soft); font-size: 14px; line-height: 1.35; }
.sc-ex--block em { font-style: normal; color: var(--ink-2); font-size: 15px; line-height: 1.35; }
.sc-fact { margin: 0; font-size: 14.5px; line-height: 1.45; color: var(--ink-2); text-align: left; width: 100%; }
.sc-fact::before { content: "Did you know?"; color: var(--orange); }
/* reverso corto (palabra sin ejemplo): el contenido se centra en vez de quedarse arriba con un hueco debajo;
   con márgenes automáticos, si no cabe se desplaza igual que antes (no se corta por arriba) */
.sc-body--back > :first-child { margin-top: auto; }
.sc-body--back > :last-child { margin-bottom: auto; }
/* pulsos de la palabra: una casilla por pulso (っ, ー y ん resaltados: también cuentan) */
.sc-beats { display: flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 6px 10px; }
.sc-beats-n { font: 800 11px/1 var(--f-display); letter-spacing: .14em; text-transform: uppercase; color: var(--ink-soft); }
.sc-beats-n b { font-size: 14px; color: var(--ink); }
.sc-beats-row { display: inline-flex; gap: 4px; }
.sc-beats-row i {
  display: grid; place-items: center; min-width: 34px; height: 34px; padding: 0 4px; border: 2px solid var(--ink); border-radius: 8px;
  background: var(--white); box-shadow: 2px 2px 0 var(--ink); font: 900 18px/1 var(--f-jp); font-style: normal;
}
.sc-beats-row i.is-odd { background: var(--orange-2); }
.sc-beats-row i.is-pair { background: #d8f2ee; letter-spacing: -.06em; }

/* sellos que asoman al deslizar la carta */
.sc-sw {
  position: absolute; z-index: 3; top: 62px; padding: 5px 12px; border: 4px solid currentColor; border-radius: 10px;
  background: color-mix(in srgb, var(--white) 82%, transparent); font: 900 24px/1 var(--f-display); letter-spacing: .08em; text-transform: uppercase;
  pointer-events: none; opacity: 0; transition: opacity .12s;
}
.sc-sw--r { left: 16px; color: var(--teal); transform: rotate(-12deg); opacity: clamp(0, calc(var(--sw, 0) * 1.6), 1); }
.sc-sw--l { right: 16px; color: var(--seal); transform: rotate(12deg); opacity: clamp(0, calc(var(--sw, 0) * -1.6), 1); }
.sc-scene[data-swipe="r"] .sc-sw--r { transform: rotate(-12deg) scale(1.12); }
.sc-scene[data-swipe="l"] .sc-sw--l { transform: rotate(12deg) scale(1.12); }

/* sello del veredicto al puntuar */
.sc-verdict {
  position: absolute; z-index: 5; top: 34%; left: 50%; transform: translate(-50%, -50%) rotateY(180deg) rotate(-12deg) scale(2); opacity: 0;
  padding: 6px 18px; border: 5px solid currentColor; border-radius: 12px; font: 900 42px/1 var(--f-display); letter-spacing: .08em; text-transform: uppercase;
  color: var(--teal); pointer-events: none; mix-blend-mode: multiply; backface-visibility: hidden; white-space: nowrap;
}
.sc-verdict[data-g="1"] { color: var(--seal); }
.sc-verdict[data-g="2"] { color: var(--choc-2); }
.sc-verdict[data-g="4"] { color: var(--gold); }
.is-rated .sc-verdict { animation: verdict .3s cubic-bezier(.3, 1.4, .5, 1) forwards; }
@keyframes verdict { to { opacity: .9; transform: translate(-50%, -50%) rotateY(180deg) rotate(-12deg) scale(1); } }

/* ---------- botones ---------- */
.sc-actions { width: min(100%, 460px); margin: 22px auto 0; min-height: 72px; display: grid; }
.sc-flip { width: 100%; }
.sc-flip kbd { margin-left: 6px; }
.sc-rate { display: grid; gap: 10px; animation: popin .3s ease both; }
.sc-rate.is-2 { grid-template-columns: 1fr 1fr; }
.sc-rate.is-4 { grid-template-columns: repeat(4, 1fr); gap: 8px; }
.rate {
  --bg: var(--white);
  position: relative; display: grid; justify-items: center; gap: 3px; padding: 10px 6px 12px; min-height: 72px;
  border: var(--line) solid var(--ink); border-radius: 18px; background: var(--bg); box-shadow: var(--shadow); cursor: pointer;
  transition: transform .12s, box-shadow .12s;
}
.rate:hover { transform: translate(-2px, -2px); box-shadow: 6px 6px 0 var(--ink); }
.rate:active { transform: translate(3px, 3px); box-shadow: 1px 1px 0 var(--ink); }
.rate-lbl { display: inline-flex; align-items: center; gap: 6px; font: 900 18px/1 var(--f-display); letter-spacing: .06em; text-transform: uppercase; }
.rate-ivl { font: 700 12px/1 var(--f-display); letter-spacing: .06em; opacity: .75; }
.rate-arr { display: none; font-style: normal; font-size: 1.25em; opacity: .55; }
.rate kbd { position: absolute; top: 6px; right: 8px; font-size: 11px; opacity: .5; }
.rate--1 { --bg: #fbd9d6; }
.rate--2 { --bg: var(--cream); }
.rate--3 { --bg: #d8f2ee; }
.rate--4 { --bg: var(--gold-2); }
.rate.is-suggested { animation: nudge 1s ease-in-out 2; outline: 3px dashed var(--ink); outline-offset: 4px; }
@keyframes nudge { 0%, 100% { transform: none; } 50% { transform: translateY(-4px) rotate(-1deg); } }
.sc-rate.is-4 .rate-lbl { font-size: 15px; }

/* atajos y deshacer */
.sc-foot { display: flex; justify-content: center; align-items: center; gap: 6px 16px; flex-wrap: wrap; min-height: 30px; margin-top: 14px; }
.sc-keys { margin: 0; text-align: center; font-size: 13.5px; line-height: 1.9; }
.sc-keys kbd { margin: 0 3px; }
.sc-undo {
  display: inline-flex; align-items: center; gap: 6px; padding: 6px 12px; border: 2px solid transparent; border-radius: 999px; background: none;
  font: 800 12.5px/1 var(--f-display); letter-spacing: .1em; text-transform: uppercase; color: var(--ink-2); cursor: pointer;
}
.sc-undo:hover { border-color: var(--ink); background: var(--white); }
.sc-undo kbd { font-size: 11px; }
.sc-undo svg { flex: none; }
@media (hover: none) {
  .sc-keys, .rate kbd, .sc-flip kbd, .sc-undo kbd { display: none; }
  .rate-arr { display: inline; }
}

/* ---------- final: Mikan dormido sobre el mazo ---------- */
.done { text-align: center; padding: 6px 0 30px; }
.done-art { position: relative; width: 260px; height: 220px; margin: 6px auto 16px; } /* el título no toca el mazo */
.pile { position: absolute; left: 50%; bottom: 6px; width: 190px; height: 110px; transform: translateX(-50%); }
.pile i {
  position: absolute; left: 0; right: 0; bottom: calc(var(--i) * 9px); height: 96px;
  background: var(--white); border: var(--line) solid var(--ink); border-radius: 14px; box-shadow: 4px 4px 0 var(--ink);
  transform: rotate(calc((var(--i) - 1.5) * 4deg));
  background-image: radial-gradient(circle at 50% 50%, var(--seal) 0 14px, transparent 15px), var(--halftone); background-size: auto, 6px 6px;
}
.pile i:nth-child(2) { background-color: var(--cream); }
.pile i:nth-child(3) { background-color: #e3f6f3; }
.done-mikan { position: absolute; width: 170px; height: 170px; left: 50%; top: 0; transform: translateX(-50%); animation: breathe 3.2s ease-in-out infinite; transform-origin: 50% 90%; }
@keyframes breathe { 0%, 100% { transform: translateX(-50%) scale(1, 1); } 50% { transform: translateX(-50%) scale(1.03, .97); } }
.zzz { position: absolute; right: 30px; top: 18px; font: 900 26px/1 var(--f-display); color: var(--teal); -webkit-text-stroke: 1px var(--ink); }
.zzz b { position: absolute; opacity: 0; animation: zz 3s ease-in infinite; }
.zzz b:nth-child(2) { animation-delay: 1s; font-size: 20px; }
.zzz b:nth-child(3) { animation-delay: 2s; font-size: 15px; }
@keyframes zz { 0% { transform: translate(0, 10px) rotate(-10deg); opacity: 0; } 20% { opacity: 1; } 100% { transform: translate(26px, -50px) rotate(15deg); opacity: 0; } }
.done-title { display: grid; gap: 12px; text-transform: none; }
.done-title .jp { font: 900 clamp(38px, 8vw, 58px)/1 var(--f-jp); }
.done-title small { font: 700 15px/1.25 var(--f-display); letter-spacing: .14em; text-transform: uppercase; color: var(--seal); }
.done-lead { font-size: 18px; color: var(--ink-2); max-width: 46ch; margin-inline: auto; line-height: 1.5; }

/* billete del día (乗車券) */
.dticket {
  position: relative; display: grid; grid-template-columns: 1fr auto; max-width: 560px; margin: 20px auto 0; text-align: left;
  background: var(--cream); border: var(--line) solid var(--ink); border-radius: 18px; box-shadow: var(--shadow-lg);
  background-image: var(--halftone); background-size: 7px 7px;
}
.tk-main { padding: 14px 18px 16px; min-width: 0; }
.tk-top { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; padding-bottom: 10px; border-bottom: 2px dashed rgba(22,20,24,.28); }
.tk-k { font: 900 14px/1 var(--f-jp); padding: 5px 8px 4px; border: 2px solid var(--ink); border-radius: 6px; background: var(--white); letter-spacing: .1em; }
.tk-t { font: 800 13px/1 var(--f-display); letter-spacing: .14em; text-transform: uppercase; }
.tk-route { margin-left: auto; display: inline-flex; flex-wrap: wrap; align-items: center; gap: 6px; min-width: 0; }
.tk-more { padding: 3px 7px; border: 2px dashed var(--ink-soft); border-radius: 7px; font: 900 12px/1 var(--f-display); font-style: normal; color: var(--ink-2); }
.tk-route > i { font: 900 14px/1 var(--f-display); font-style: normal; color: var(--ink-soft); }
.tk-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; margin: 12px 0 0; }
.tk-stats div { min-width: 0; }
.tk-stats dt { font: 800 11px/1.2 var(--f-display); letter-spacing: .08em; text-transform: uppercase; color: var(--ink-soft); white-space: nowrap; }
.tk-stats dd { margin: 6px 0 0; font: 900 26px/1 var(--f-display); font-variant-numeric: tabular-nums; white-space: nowrap; }
.tk-stats dd .i { display: inline-block; } /* la llama de la racha, en línea con el número (el reset pone los svg en bloque) */
.tk-stub { position: relative; display: grid; place-items: center; align-content: center; gap: 10px; padding: 12px 20px; border-left: 3px dashed var(--ink); background: var(--white); border-radius: 0 15px 15px 0; }
.tk-stub::before, .tk-stub::after { /* muescas del billete */
  content: ""; position: absolute; left: -13px; width: 22px; height: 22px; border-radius: 50%; background: var(--paper); border: var(--line) solid var(--ink);
}
.tk-stub::before { top: -13px; clip-path: inset(50% 0 0 0); }
.tk-stub::after { bottom: -13px; clip-path: inset(0 0 50% 0); }
.tk-stub small { font: 800 11px/1 var(--f-display); letter-spacing: .12em; text-transform: uppercase; color: var(--ink-soft); }
.tk-stub .hanko { font-family: var(--f-jp); font-size: 28px; filter: none; mix-blend-mode: multiply; }
.hanko.is-slam { animation: slam .55s cubic-bezier(.3, 1.4, .5, 1) .35s both; }

/* próximos días y fallos */
.done-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; max-width: 560px; margin: 16px auto 0; text-align: left; }
.done-grid.is-one { grid-template-columns: 1fr; }
.done-box { padding: 14px 16px 12px; background: var(--white); border: var(--line) solid var(--ink); border-radius: 18px; box-shadow: var(--shadow); }
.done-box h3 { margin: 0 0 12px; font: 800 12.5px/1.35 var(--f-display); letter-spacing: .12em; text-transform: uppercase; }
.done-box h3 .muted { font-weight: 600; letter-spacing: .04em; text-transform: none; white-space: nowrap; } /* la nota baja entera, no partida */
.fc-bars { display: grid; grid-template-columns: minmax(40px, 1.25fr) repeat(6, minmax(0, 1fr)); gap: 6px; height: 112px; } /* «Tmrw» es más ancho: se montaba sobre «Thu» */
.fc-day { display: grid; grid-template-rows: auto 1fr auto; justify-items: center; gap: 4px; height: 100%; min-width: 0; }
.fc-day b { font: 800 12px/1 var(--f-display); font-variant-numeric: tabular-nums; }
.fc-day i { /* días futuros: rayado (aún por venir); mañana, color pleno de la línea */
  align-self: end; width: 72%; height: max(4px, var(--h)); border: 2px solid var(--ink); border-radius: 6px 6px 2px 2px;
  background: var(--white) repeating-linear-gradient(135deg, var(--lc) 0 2.5px, transparent 2.5px 7px);
}
.fc-day.is-tmrw i { background: var(--lc); box-shadow: 2px 2px 0 var(--ink); }
.fc-day.is-zero i { height: 4px; border-width: 1.5px; background: var(--paper-2); }
.fc-day.is-zero b { opacity: .35; }
.fc-day small { margin-top: 2px; font: 800 11px/1 var(--f-display); letter-spacing: .04em; text-transform: uppercase; color: var(--ink-soft); }
.fc-day.is-tmrw small { color: var(--seal); }
.tk-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.tk-chip {
  position: relative; display: inline-grid; justify-items: center; gap: 2px; padding: 6px 10px 5px; min-width: 52px;
  border: 2px solid var(--ink); border-radius: 12px; background: var(--paper); box-shadow: var(--shadow-sm); cursor: pointer; transition: transform .12s;
}
.tk-chip:hover { transform: translateY(-2px) rotate(-2deg); }
.tk-chip .jp { font: 900 22px/1.1 var(--f-jp); }
.tk-chip small { max-width: 16ch; font-size: 12px; line-height: 1.25; color: var(--ink-soft); text-align: center; } /* el significado entero, aunque ocupe dos líneas */
.tk-chip em { position: absolute; top: -9px; right: -9px; border: 2px solid var(--ink); border-radius: 999px; background: var(--seal); color: var(--white); font: 800 11px/1 var(--f-display); font-style: normal; padding: 3px 6px 2px; }
.done--drill .done-tricky { width: fit-content; min-width: min(100%, 280px); max-width: 560px; margin: 16px auto 0; text-align: left; }

.done-cta { margin-top: 22px; display: grid; gap: 14px; justify-items: center; }
.done-ok { display: inline-flex; align-items: center; gap: 12px; font: 800 18px/1.2 var(--f-display); margin: 0; }
.done-ok .hanko { font-family: var(--f-jp); font-size: 22px; }
.done-hint { max-width: 40ch; margin: 0 auto; color: var(--ink-2); }
.done-next .st-sign { box-shadow: 0 0 0 2px var(--ink); }
.done-more { margin: 20px 0 0; color: var(--ink-2); font-weight: 600; }
.done-more .btn { margin-left: 6px; }
.done-undo { margin: 14px 0 0; }

/* ---------- móvil ---------- */
@media (max-width: 560px) {
  /* móvil: todo cabe sobre la barra inferior */
  .study { padding-top: 10px; }
  .study-top { margin-bottom: 8px; align-items: center; }
  .study-top .eyebrow { display: none; }
  .study-title { font-size: 30px; margin: 0; }
  .study-gear { width: 40px; height: 40px; }
  .study-levels { margin-bottom: 8px; flex-wrap: nowrap; overflow-x: auto; scrollbar-width: none; padding: 2px 2px 4px; margin-inline: -2px; }
  .study-levels::-webkit-scrollbar { display: none; }
  .lv-toggle { flex: none; min-height: 32px; padding: 4px 5px 4px 9px; font-size: 12px; }
  .study-hud { gap: 10px; margin-bottom: 12px; }
  .sh-c { min-width: 44px; padding: 4px 7px 4px; border-radius: 10px; }
  .sh-c b { font-size: 16px; }
  .sh-c small { font-size: 11px; letter-spacing: .03em; }
  .sh-ride { gap: 8px; }
  .sh-done { font-size: 12px; }
  .sh-done b { font-size: 15px; }
  .sc-actions { margin-top: 16px; min-height: 64px; }
  .sc-flip { min-height: 60px; }
  .rate { min-height: 64px; padding: 8px 4px 10px; }
  .sc-rate.is-4 .rate kbd { display: none; } /* con 4 botones el número tapaba el intervalo */
  .sc-rate.is-4 { gap: 6px; }
  .sc-rate.is-4 .rate-lbl { font-size: 14px; letter-spacing: .02em; }
  .sc-rate.is-4 .rate-arr { display: none; } /* con cuatro, las flechas de deslizar apretaban «Again» contra el borde */
  .sc-glyph { font-size: 120px; }
  .sc-body--back { gap: 8px; padding: 12px 14px 22px; }
  /* la franja con el cartel de estación roba alto: más fina y un reverso más compacto para que quepa el ejemplo */
  .sc-strip { padding: 5px 10px 5px 12px; }
  .sc-strip .st-sign { width: 32px; height: 34px; gap: 3px; border-width: 2.5px; border-radius: 7px; box-shadow: 0 0 0 1.5px var(--ink); }
  .sc-strip .st-sign b { font-size: 11px; }
  .sc-strip .st-sign i { font-size: 13px; }
  .sc-pair { gap: 14px; }
  .sc-glyph--sm { font-size: 70px; text-shadow: 3px 3px 0 var(--teal-2); }
  .sc-big-romaji { font-size: 54px; }
  .sc-typed { font-size: 13px; padding: 5px 12px; }
  .sc-mnemo { font-size: 15px; line-height: 1.35; }
  .sc-mnemo b { margin-bottom: 6px; }
  .sc-ex { padding: 6px 12px 6px 6px; font-size: 15px; }
  .sc-meaning { font-size: 30px; }
  .sc-meaning.is-long { font-size: 24px; }
  .sc-reading { font-size: 28px; gap: 8px; }
  .sc-ex .jp { font-size: 18px; }
  /* deja sitio a Mikan, que vive encima de la barra inferior */
  .sc-card { height: clamp(290px, calc(100vh - 480px), 440px); height: clamp(290px, calc(100svh - 480px), 440px); }
  .sc-foot { justify-content: flex-start; }
  .tk-stats { grid-template-columns: repeat(2, 1fr); row-gap: 12px; }
  .tk-stub { padding: 12px 12px; }
  .tk-route { margin-left: 0; }
  .done-grid { grid-template-columns: 1fr; }
}

/* ---------- vacío ---------- */
.empty { text-align: center; padding: 10px 0 30px; }
.empty h2 { margin-top: 12px; }
.empty-art { position: relative; height: 210px; max-width: 420px; margin: 0 auto; }
.empty-art .sticker { position: absolute; bottom: 0; height: 190px; width: auto; }
.e-rin { left: 0; animation: floaty 4s ease-in-out infinite; }
.e-tad { right: 0; height: 170px !important; animation: floaty 4.6s ease-in-out .6s infinite; }
.e-deck { position: absolute; left: 50%; bottom: 14px; width: 104px; height: 140px; transform: translateX(-50%); }
.e-deck i { position: absolute; inset: 0; border: var(--line) solid var(--ink); border-radius: 14px; background: var(--white); box-shadow: 4px 4px 0 var(--ink); }
.e-deck i:nth-child(1) { transform: rotate(-9deg); background: var(--cream); }
.e-deck i:nth-child(2) { transform: rotate(6deg); background: #e3f6f3; }
.e-deck span { position: absolute; inset: 0; display: grid; place-items: center; font: 900 52px/1 var(--f-jp); color: var(--seal); transform: rotate(-3deg); }
.empty-levels { display: grid; gap: 12px; max-width: 560px; margin: 26px auto 0; text-align: left; }
.el-card {
  display: grid; grid-template-columns: auto 1fr auto; gap: 14px; align-items: center; padding: 12px 16px 12px 14px;
  background: var(--white); border: var(--line) solid var(--ink); border-radius: 18px; box-shadow: var(--shadow); text-decoration: none;
  transition: transform .15s, box-shadow .15s;
}
.el-card:hover { transform: translate(-2px, -2px) rotate(-.4deg); box-shadow: 6px 6px 0 var(--ink); }
.el-txt b { display: block; font: 800 17px/1.15 var(--f-display); }
.el-txt small { display: block; color: var(--ink-soft); font-size: 14px; line-height: 1.35; margin-top: 3px; }
.el-go { font: 900 24px/1 var(--f-display); color: var(--seal); transition: transform .15s; }
.el-card:hover .el-go { transform: translateX(4px); }
.empty-kana { margin-top: 22px; font-size: 15px; }
.empty-kana a { color: var(--seal); font-weight: 700; }

/* ---------- ajustes ---------- */
.study-settings { position: relative; }
.study-settings h3 { margin-bottom: 14px; padding-right: 44px; }
.ss-x { position: absolute; top: 14px; right: 14px; width: 38px; height: 38px; border: 2px solid var(--ink); border-radius: 50%; background: var(--white); font: 800 22px/1 var(--f-display); cursor: pointer; }
.ss-field { border: 0; padding: 0; margin: 0 0 16px; }
.ss-field legend { font: 800 13px/1 var(--f-display); letter-spacing: .12em; text-transform: uppercase; margin-bottom: 10px; }
.seg { display: grid; grid-template-columns: repeat(4, 1fr); border: var(--line) solid var(--ink); border-radius: 14px; overflow: hidden; margin-bottom: 6px; }
.seg label { position: relative; }
.seg input { position: absolute; opacity: 0; inset: 0; cursor: pointer; }
.seg span { display: block; padding: 11px 0; text-align: center; font: 900 18px/1 var(--f-display); border-left: 2px solid var(--ink); background: var(--white); }
.seg label:first-child span { border-left: 0; }
.seg input:checked + span { background: var(--ink); color: var(--paper); }
.seg input:focus-visible + span { outline: 3px solid var(--teal); outline-offset: -5px; }
.ss-toggle { display: grid; grid-template-columns: auto 1fr; gap: 12px; align-items: center; padding: 10px 0; border-top: 2px dashed rgba(22,20,24,.15); cursor: pointer; }
.ss-toggle input { position: absolute; opacity: 0; width: 1px; height: 1px; }
.ss-toggle b { display: block; font: 800 16px/1.2 var(--f-display); }
.ss-toggle small { display: block; margin-top: 2px; color: var(--ink-soft); font-size: 14px; line-height: 1.35; }
.sw { width: 50px; height: 28px; border: 2px solid var(--ink); border-radius: 999px; background: var(--paper-2); position: relative; transition: background-color .2s; }
.sw::after { content: ""; position: absolute; top: 2px; left: 2px; width: 20px; height: 20px; border-radius: 50%; background: var(--white); border: 2px solid var(--ink); transition: transform .2s cubic-bezier(.3, 1.4, .5, 1); }
.ss-toggle input:checked + .sw { background: var(--teal); }
.ss-toggle input:checked + .sw::after { transform: translateX(22px); }
.ss-toggle input:focus-visible + .sw { outline: 3px solid var(--teal); outline-offset: 3px; }
.ss-keys { margin-top: 6px; padding-top: 10px; border-top: 2px dashed rgba(22,20,24,.15); }
.ss-keys summary { cursor: pointer; font: 800 13px/1.4 var(--f-display); letter-spacing: .12em; text-transform: uppercase; }
.ss-keys dl { display: grid; gap: 8px; margin: 12px 0 8px; }
.ss-keys dl div { display: grid; grid-template-columns: 136px 1fr; gap: 10px; align-items: baseline; }
.ss-keys dt { white-space: nowrap; }
.ss-keys dd { margin: 0; font-size: 14px; line-height: 1.35; color: var(--ink-2); }
.ss-touch { display: none; margin: 10px 0 0; padding: 10px 8px 0; border-top: 2px dashed rgba(22,20,24,.15); font-size: 14px; }
/* en pantallas táctiles no hay teclado: solo el consejo de tocar y deslizar */
@media (hover: none) { .ss-keys { display: none; } .ss-touch { display: block; } }

/* dibujo de la mnemotecnia en el reverso de las tarjetas de kana */
.sc-art { width: min(170px, 46vw); height: auto; aspect-ratio: 1; object-fit: contain; margin: 2px auto 0; display: block; }

/* «+ Add E-0N»: añade al mazo el siguiente nivel con cartas */
.lv-toggle.lv-add { border-style: dashed; background: transparent; text-decoration: none; color: var(--ink); }
.lv-toggle.lv-add, .study-levels .lv-toggle.lv-add { padding-inline: 10px; } /* el chip no tiene contador a la derecha: aire simétrico */
.lv-toggle.lv-add:hover { background: var(--white); }

/* línea que explica los 4 botones (Raúl, 20/10: siempre Again/Hard/Good/Easy; que se entiendan) */
.sc-rate-ask { margin: 0 0 8px; text-align: center; font: 700 14px/1.35 var(--f-body); color: var(--ink); }
.sc-rate-ask span { display: block; font-weight: 400; font-size: 13px; color: var(--ink-soft); }
.sc-rate.is-4 .rate-ivl { white-space: nowrap; }
/* mazo vacío: el resto de niveles listos, como enlaces pequeños bajo la recomendación */
.empty-more { margin: 14px auto 0; font-size: 15px; }
.empty-more a { color: var(--seal); font-weight: 700; white-space: nowrap; }