/* ことばカード — 丸ゴシック、すみれ色とミント、ころんとしたカード。 */
:root{
  --bg:#F4F1FF; --surface:#FFFFFF; --ink:#2D2654; --sub:#6F6894; --line:#E3DDF7;
  --violet:#6C5CE7; --violet-ink:#FFFFFF; --mint:#2EC4A6; --peach:#FF9F7A; --sun:#FFC845; --rose:#F2668B;
  --round:"Hiragino Maru Gothic ProN","Zen Maru Gothic","BIZ UDPGothic","Hiragino Sans","Noto Sans JP",system-ui,sans-serif;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){:root{--bg:#171428;--surface:#221E3A;--ink:#EDEAFF;--sub:#ABA4D2;--line:#363057;--violet:#9C8FFF;--violet-ink:#16122E;color-scheme:dark}}
*{box-sizing:border-box}
html,body{margin:0}
body{background:var(--bg);color:var(--ink);font-family:var(--round);font-size:16px;line-height:1.7;
  background-image:radial-gradient(circle at 10% 0%,color-mix(in srgb,var(--violet) 14%,transparent),transparent 40%),radial-gradient(circle at 100% 30%,color-mix(in srgb,var(--mint) 12%,transparent),transparent 35%);
  background-attachment:fixed;min-height:100vh}
a{color:inherit}
:focus-visible{outline:3px solid var(--violet);outline-offset:3px;border-radius:14px}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}
.shell{max-width:560px;margin:0 auto;padding:calc(env(safe-area-inset-top,0px) + 8px) max(16px,env(safe-area-inset-right,0px)) calc(28px + env(safe-area-inset-bottom,0px)) max(16px,env(safe-area-inset-left,0px))}
.bar{display:flex;align-items:center;gap:10px;min-height:52px;position:sticky;top:0;z-index:5;background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:blur(8px);margin:0 -4px;padding:0 4px}
.back{font-size:12px;color:var(--sub);text-decoration:none}
.nav-back{font:inherit;font-size:15px;font-weight:700;color:var(--violet);background:none;border:0;min-height:44px;padding:0 6px;cursor:pointer}
.bar-t{margin:0 auto 0 0;font-weight:700;font-size:15px}
#labLink:not([hidden])+.bar-t{display:none}
.due-pill{margin-left:auto;font-size:13px;font-weight:700;background:var(--surface);border:2px solid var(--line);border-radius:999px;padding:2px 12px;color:var(--violet)}
.hero{background:var(--violet);color:var(--violet-ink);border-radius:28px;padding:24px 22px 22px;margin:8px 0 26px;position:relative;overflow:hidden}
.hero::after{content:"";position:absolute;right:-30px;top:-30px;width:130px;height:96px;border-radius:18px;background:var(--sun);transform:rotate(14deg);opacity:.9;box-shadow:-24px 30px 0 -6px var(--mint)}
.hero h1{margin:0;font-size:30px;line-height:1.3;position:relative;z-index:1}
.hero p{margin:8px 0 18px;font-size:14.5px;opacity:.92;max-width:22em;position:relative;z-index:1}
.hero .hero-note{margin:10px 0 0;font-size:13px;opacity:.9}
.btn{font:inherit;font-weight:700;font-size:15.5px;min-height:50px;padding:10px 22px;border-radius:999px;border:0;background:var(--violet);color:var(--violet-ink);cursor:pointer;
  box-shadow:0 4px 0 color-mix(in srgb,var(--violet) 60%,#000);transition:transform .1s,box-shadow .1s}
.btn:active{transform:translateY(3px);box-shadow:0 1px 0 color-mix(in srgb,var(--violet) 60%,#000)}
.btn:disabled{opacity:.5;cursor:default;transform:none}
.btn.big{background:var(--sun);color:#3A2A00;box-shadow:0 5px 0 #C9951C;width:100%;font-size:17px;min-height:56px;position:relative;z-index:1}
.btn.ghost{background:transparent;color:var(--violet);box-shadow:inset 0 0 0 2px var(--violet)}
.btn.danger{color:var(--rose);box-shadow:inset 0 0 0 2px var(--rose)}
.sec{font-size:15px;margin:0 0 10px;color:var(--sub);letter-spacing:.06em}
.decks{list-style:none;margin:0 0 14px;padding:0;display:grid;gap:12px}
.deck{font:inherit;color:var(--ink);width:100%;display:grid;grid-template-columns:1fr auto;grid-template-rows:auto auto;column-gap:12px;text-align:left;cursor:pointer;
  background:var(--surface);border:2px solid var(--line);border-radius:20px;padding:16px 18px;position:relative;box-shadow:0 6px 0 -2px var(--line);transition:transform .15s}
.deck:hover{transform:translateY(-2px)}
.deck::before{content:"";position:absolute;left:-2px;top:16px;bottom:16px;width:6px;border-radius:0 6px 6px 0;background:var(--k)}
.c0{--k:var(--violet)}.c1{--k:var(--mint)}.c2{--k:var(--peach)}.c3{--k:var(--sun)}.c4{--k:var(--rose)}
.d-name{font-weight:700;font-size:17px}
.d-meta{grid-row:2;font-size:13px;color:var(--sub)}
.d-due{grid-row:1/3;grid-column:2;align-self:center;min-width:46px;height:46px;border-radius:23px;display:grid;place-items:center;font-weight:700;background:var(--rose);color:#fff;padding:0 10px;font-size:17px}
.d-due.zero{background:color-mix(in srgb,var(--mint) 20%,transparent);color:var(--mint)}
.newdeck{display:flex;gap:10px}
input[type=text]{font:inherit;font-size:16px;color:var(--ink);background:var(--surface);border:2px solid var(--line);border-radius:16px;padding:10px 14px;min-height:50px;width:100%}
input[type=text]:focus{border-color:var(--violet);outline:none}
.newdeck .btn{flex:none}
.err{color:var(--rose);font-size:13px;margin:6px 0 0}
.err:empty{display:none}
.how{margin-top:22px;background:var(--surface);border-radius:16px;padding:12px 16px;border:2px dashed var(--line);font-size:14px}
.how summary{cursor:pointer;font-weight:700;color:var(--violet)}
.how p{margin:8px 0 0;color:var(--sub)}
.none{color:var(--sub);font-size:14px;list-style:none}
.deck-head{margin:8px 0 22px}
.deck-head h1{margin:0;font-size:26px;line-height:1.35;word-break:break-word}
.deck-head p{margin:2px 0 14px;color:var(--sub);font-size:14px}
.row{display:flex;gap:10px;flex-wrap:wrap}
.addcard{background:var(--surface);border-radius:22px;padding:18px;border:2px solid var(--line);display:grid;gap:10px;margin-bottom:24px}
.addcard label{display:grid;gap:2px;font-size:13px;color:var(--sub);font-weight:700}
.addcard .sec{margin:0}
.cards{list-style:none;margin:0;padding:0;display:grid;gap:8px}
.card-row{display:flex;align-items:center;gap:10px;background:var(--surface);border-radius:14px;padding:10px 8px 10px 14px;border:2px solid var(--line)}
.cr-t{flex:1;min-width:0;display:grid}
.cr-t b{font-size:15px;word-break:break-word}
.cr-t span{font-size:13px;color:var(--sub);word-break:break-word}
.cr-due{font-size:12px;color:var(--violet);font-weight:700;flex:none}
.cr-del{font:inherit;font-size:20px;width:44px;height:44px;border-radius:22px;border:0;background:none;color:var(--sub);cursor:pointer;flex:none}
.cr-del:hover{background:color-mix(in srgb,var(--rose) 14%,transparent);color:var(--rose)}
/* 復習 */
.prog{display:flex;align-items:center;gap:12px;margin:10px 0 18px;font-size:13px;color:var(--sub);font-weight:700}
.prog-bar{flex:1;height:10px;border-radius:5px;background:var(--line);overflow:hidden}
.prog-bar i{display:block;height:100%;width:0;background:var(--mint);border-radius:5px;transition:width .3s}
.stage{perspective:1400px;margin-bottom:18px}
.flip{display:block;width:100%;height:min(54vh,380px);min-height:280px;border:0;padding:0;background:none;cursor:pointer;position:relative;transform-style:preserve-3d;
  transition:transform .55s cubic-bezier(.3,1.3,.5,1);font:inherit;color:inherit}
.flip.is-flipped{transform:rotateY(180deg)}
.face{position:absolute;inset:0;border-radius:28px;backface-visibility:hidden;-webkit-backface-visibility:hidden;display:flex;flex-direction:column;align-items:center;justify-content:center;
  padding:28px 22px;text-align:center;border:3px solid var(--line)}
.f-front{background:var(--surface);box-shadow:0 10px 0 -2px var(--line),0 24px 40px -24px rgba(60,40,140,.45);
  background-image:radial-gradient(circle at 92% 10%,color-mix(in srgb,var(--sun) 40%,transparent) 0 26px,transparent 27px)}
.f-back{background:var(--violet);color:var(--violet-ink);border-color:var(--violet);transform:rotateY(180deg);box-shadow:0 10px 0 -2px color-mix(in srgb,var(--violet) 60%,#000)}
.lbl{position:absolute;top:16px;left:20px;font-size:12px;font-weight:700;opacity:.6;letter-spacing:.2em}
.txt{font-size:clamp(22px,6vw,30px);font-weight:700;line-height:1.5;word-break:break-word}
.tap{position:absolute;bottom:18px;font-size:12.5px;color:var(--sub)}
.ex{margin-top:14px;font-size:15px;opacity:.9;max-width:24em}
.ex:empty{display:none}
.grades{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.g{font:inherit;min-height:72px;border-radius:20px;border:0;cursor:pointer;display:grid;align-content:center;gap:0;color:#fff;transition:transform .1s;padding:6px}
.g b{font-size:15px}
.g small{font-size:11.5px;opacity:.9}
.g:active{transform:translateY(3px)}
.g-ng{background:var(--rose);box-shadow:0 5px 0 #B53E62}
.g-mid{background:var(--sun);color:#3A2A00;box-shadow:0 5px 0 #C9951C}
.g-ok{background:var(--mint);box-shadow:0 5px 0 #1B8F78}
.keys{font-size:12px;color:var(--sub);text-align:center;margin:16px 0 0}
.done{text-align:center;background:var(--surface);border-radius:28px;padding:30px 20px;border:3px solid var(--line)}
.done h1{font-size:22px;margin:0 0 6px}
.done p{color:var(--sub);margin:0 0 18px}
.done-mark{font-size:46px;color:var(--peach);margin:0!important;line-height:1.2}
.foot{margin-top:34px;font-size:12px;color:var(--sub);line-height:1.7;border-top:2px dotted var(--line);padding-top:12px}
.foot p{margin:0}
@media (hover:none){.keys{display:none}}
@media (prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important}.flip.is-flipped .f-front{visibility:hidden}}