:root{--bg:#fff;--card:#fff;--fg:#22344a;--muted:#5b6f86;--line:#d6e4f5;--accent:#1d6fd8;--accent-fg:#fff;--blank:#dbe9fb;--answer:#d9480f;--tip-bg:#fff8e1;--tip-line:#ffd87a;--hl:#ffe9a8;
--s5:#d92d20;--s4:#e8590c;--s3:#d99100;--s2:#2f8fd8;--s1:#8aa0b8;
--font-display:"BIZ UDPGothic","Hiragino Sans","Yu Gothic","Meiryo",sans-serif;--font-body:"BIZ UDPGothic","Hiragino Sans","Yu Gothic","Meiryo",sans-serif}
@media (prefers-color-scheme:dark){:root{--bg:#16202b;--card:#1f2c3a;--fg:#eef3f9;--muted:#a9b9cb;--line:#33465a;--accent:#8ec3ff;--accent-fg:#0d1a26;--blank:#2f4257;--answer:#ffa97d;--tip-bg:#33291d;--tip-line:#6b5530;--hl:#5a4710;--s5:#ff7b72;--s4:#ff9a6b;--s3:#e0b04f;--s2:#7fb2e0;--s1:#9aa7b4;color-scheme:dark}}
*{box-sizing:border-box}
[hidden]{display:none!important}
body{margin:0;background:var(--bg);color:var(--fg);font-family:var(--font-body);font-size:18px;line-height:1.85;padding:0 16px 40px}
a{color:var(--accent)}
.wrap{max-width:40rem;margin:0 auto;display:flex;flex-direction:column;gap:16px}
header.site{max-width:40rem;margin:0 auto;padding:18px 0 6px;display:flex;align-items:baseline;justify-content:space-between;gap:12px;flex-wrap:wrap}
header.site .name{font-family:var(--font-display);font-weight:700;font-size:1.1rem;letter-spacing:.04em;color:var(--fg);text-decoration:none}
header.site nav{display:flex;gap:14px;font-size:.9rem}
header.site nav a{color:var(--muted);text-decoration:none}
header.site nav a:hover{color:var(--accent);text-decoration:underline}
.crumb{font-size:.82rem;color:var(--muted)}
.crumb a{color:var(--muted)}
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;box-shadow:0 2px 10px rgba(29,111,216,.08);padding:22px 20px 20px;display:flex;flex-direction:column;gap:16px}
.cat{font-size:.8rem;letter-spacing:.12em;color:var(--muted)}
h1{font-family:var(--font-display);font-weight:700;font-size:1.45rem;line-height:1.45;margin:0;text-wrap:balance;word-break:auto-phrase}
h2{font-family:var(--font-display);font-weight:700;font-size:1.15rem;margin:0 0 4px;text-wrap:balance}
p{margin:0}
p,ul.lines li,.tip{word-break:auto-phrase}
ul.lines{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:12px}
ul.lines li{padding-left:1.1em;position:relative;min-width:0;overflow-wrap:anywhere}
ul.lines li::before{content:"";position:absolute;left:0;top:.82em;width:.5em;height:2px;background:var(--muted)}
/* 空欄 */
.blank{padding:.05em .3em;margin:0 .1em;border-radius:4px;border-bottom:2px solid var(--s3);background:var(--blank);color:transparent;user-select:none;cursor:pointer;font-variant-numeric:tabular-nums;-webkit-box-decoration-break:clone;box-decoration-break:clone}
.blank[data-s="5"]{border-bottom-color:var(--s5)}.blank[data-s="4"]{border-bottom-color:var(--s4)}.blank[data-s="3"]{border-bottom-color:var(--s3)}.blank[data-s="2"]{border-bottom-color:var(--s2)}.blank[data-s="1"]{border-bottom-color:var(--s1)}
.revealed .blank:not(.off),.blank.peek:not(.off){background:var(--hl);color:var(--answer);font-weight:700;font-size:1.06em;border-bottom-style:solid;user-select:auto}
.revealed .blank:not(.off)::after,.blank.peek:not(.off)::after{content:"★" attr(data-s);font-size:.62em;font-weight:500;color:var(--muted);margin-left:.15em;vertical-align:.25em}
.blank.off{background:none;color:inherit;border-bottom:0;cursor:default;font-weight:700;user-select:auto;padding:0;margin:0}
.tip{background:var(--tip-bg);border:1px solid var(--tip-line);border-radius:8px;padding:10px 14px;font-size:.95rem}
.tip b{font-weight:700;margin-right:.4em}
.tip.big{font-size:1.3rem;line-height:1.75;font-weight:700;padding:18px 18px 20px;border:3px solid var(--accent);border-radius:14px;margin-bottom:18px;background:var(--tip-bg)}
.tip.big .tipk{display:table;font-size:.9rem;font-weight:700;color:var(--accent-fg);background:var(--accent);padding:2px 14px;border-radius:999px;letter-spacing:.1em;margin-bottom:8px}
.marks{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:4px}
.mark{font:inherit;font-weight:700;min-height:48px;border-radius:999px;border:2px solid var(--line);background:var(--card);color:var(--muted);cursor:pointer}
.mark[aria-pressed="true"]{background:#e6f6ec;border-color:#1f9d55;color:#13703b}
.mark.weak[aria-pressed="true"]{background:#fdecea;border-color:#d92d20;color:#b42318}
#memo textarea{width:100%;font:inherit;font-size:1rem;line-height:1.7;border:1px solid var(--line);border-radius:10px;padding:10px 12px;background:var(--card);color:var(--fg);resize:vertical}
.bar{height:10px;border-radius:999px;background:var(--blank);overflow:hidden}.bar span{display:block;height:100%;width:0;background:#1f9d55}
ul.toc .mk{color:#1f9d55;font-weight:700;margin-left:auto;padding-left:.4em;white-space:nowrap}
li.isweak .mk{color:#d92d20}
.qr{max-width:280px;margin:0 auto;background:#fff;border-radius:12px;padding:6px}.qr svg{display:block;width:100%;height:auto}
#transfer textarea{width:100%;font:inherit;font-size:.85rem;border:1px solid var(--line);border-radius:10px;padding:10px;background:var(--card);color:var(--fg);word-break:break-all}
.vh{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
label.btn{cursor:pointer}
.howto{font-size:.95rem;line-height:1.7;color:var(--fg);margin:0}
.notice{background:var(--blank);border-radius:8px;padding:10px 14px;font-size:.9rem;color:var(--muted)}
/* ページ見出し・範囲 */
.pgbar{display:flex;justify-content:space-between;align-items:baseline;gap:12px;flex-wrap:wrap}
.pgno{font-size:.95rem;color:var(--muted)}
.pgno b{font-family:var(--font-display);font-size:1.5rem;color:var(--fg);margin:0 .1em}
.starsum{font-size:.82rem;color:var(--s4);letter-spacing:.04em}
.range{display:flex;flex-wrap:wrap;align-items:center;gap:8px 10px}
.range .lab{font-size:.82rem;color:var(--muted)}
.chip{font:inherit;font-size:.85rem;line-height:1;min-height:36px;padding:0 12px;border-radius:999px;border:1px solid var(--line);background:var(--card);color:var(--muted);cursor:pointer}
.chip[aria-pressed="true"]{background:var(--accent);color:var(--accent-fg);border-color:var(--accent);font-weight:700}
.chip:focus-visible,.btn:focus-visible,input:focus-visible,summary:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
form.jump{display:flex;align-items:center;gap:6px;margin-left:auto;font-size:.85rem;color:var(--muted)}
form.jump input{font:inherit;width:5.6em;min-height:36px;border:1px solid var(--line);border-radius:8px;background:var(--card);color:var(--fg);padding:0 8px;text-align:center}
/* ボタン */
.btn{font:inherit;font-weight:700;min-height:52px;border-radius:10px;border:1px solid var(--line);background:var(--card);color:var(--fg);cursor:pointer;display:flex;align-items:center;justify-content:center;text-decoration:none;padding:0 12px;text-align:center}
.btn.primary{background:var(--accent);color:var(--accent-fg);border-color:var(--accent);font-size:1.05rem}
.btn.off,.btn:disabled{opacity:.4;pointer-events:none}
.act{display:grid;grid-template-columns:1fr}
.nav2{display:grid;grid-template-columns:1fr 2fr;gap:10px}
.navtitle{display:flex;justify-content:space-between;gap:12px;font-size:.8rem;color:var(--muted)}
.hint{color:var(--muted);font-size:.8rem;text-align:center}
/* 広告枠(導入時のみ出力。全面広告は使わない) */
.ad-wrap{margin:44px 0;min-height:110px;text-align:center}
.ad-label{font-size:.7rem;letter-spacing:.2em;color:var(--muted);margin-bottom:6px}
/* パネル */
.panel{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:20px;display:flex;flex-direction:column;gap:12px}
details.panel{padding:0;display:block}
details.panel>summary{cursor:pointer;padding:16px 20px;font-weight:700;font-size:1.1rem;color:var(--accent);list-style:none}
details.panel>summary::-webkit-details-marker{display:none}
details.panel>summary::after{content:"＋";float:right;color:var(--accent);font-size:1.3em;line-height:1}
details.panel[open]>summary::after{content:"－"}
details.panel>div{padding:0 20px 18px;display:flex;flex-direction:column;gap:10px}
details.panel:not([open])>summary{padding-bottom:14px}
.sum li strong{color:var(--answer)}
.src{color:var(--muted);font-size:.82rem;line-height:1.6}
.group h2{margin-bottom:8px}
ul.toc{list-style:none;margin:0;padding:0;display:flex;flex-direction:column}
ul.toc li{border-top:1px solid var(--line)}
ul.toc li:first-child{border-top:0}
ul.toc a{display:flex;align-items:baseline;gap:12px;padding:10px 4px;text-decoration:none;color:var(--fg)}
ul.toc a:hover span.t{color:var(--accent);text-decoration:underline}
ul.toc .no{font-family:var(--font-display);font-weight:700;min-width:2.2em;text-align:right;color:var(--muted)}
ul.toc .t{flex:1;min-width:0}
ul.toc li.dim{opacity:.45}
.imp{color:var(--s4);white-space:nowrap;font-size:.8rem;letter-spacing:.03em}
.note{color:var(--muted);font-size:.82rem;line-height:1.7}
.presets{display:flex;flex-wrap:wrap;gap:8px}
.prose{display:flex;flex-direction:column;gap:12px}
.prose h2{margin-top:10px}
.prose ul{margin:0;padding-left:1.3em}
.btns{display:grid;grid-template-columns:1fr;gap:10px}
.btns.two{grid-template-columns:1fr 1fr}
footer.site{max-width:40rem;margin:28px auto 0;border-top:1px solid var(--line);padding-top:16px;color:var(--muted);font-size:.82rem;line-height:1.7;display:flex;flex-direction:column;gap:8px}
footer.site nav{display:flex;gap:14px;flex-wrap:wrap}
footer.site a{color:var(--muted)}
@media (max-width:420px){h1{font-size:1.3rem}body{font-size:16px}form.jump{margin-left:0}}
@media (prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important}}