.learning-topic__body .workbook-opening,.learning-topic__body .workbook-chain{padding-block:clamp(54px,8vw,94px)}.learning-topic__body .workbook-chapters{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));margin-top:38px;border-top:2px solid var(--topic-ink)}.learning-topic__body .workbook-chapters a{position:relative;display:grid;grid-template-columns:minmax(0,1fr) auto;gap:8px 20px;min-height:118px;padding:22px;border-bottom:1px solid var(--topic-rule);color:inherit;text-decoration:none}.learning-topic__body .workbook-chapters a:nth-child(odd){border-right:1px solid var(--topic-rule)}.learning-topic__body .workbook-chapters a:hover{background:#f4eee3}.learning-topic__body .workbook-chapters small{grid-column:1/-1;color:var(--topic-accent);font:800 .64rem var(--mono);letter-spacing:.07em}.learning-topic__body .workbook-chapters b{font-family:Songti SC,STSong,Georgia,serif;font-size:1.16rem}.learning-topic__body .workbook-chapters span{align-self:end;color:var(--topic-muted);font-size:.74rem;font-weight:800}.workbook-console{position:sticky;top:58px;z-index:20;border-block:1px solid #4e616a;background:#20343d;color:#f5efe5;box-shadow:0 12px 30px #1c2a301f}.workbook-console__inner{display:flex;align-items:center;justify-content:space-between;gap:24px;min-height:86px;padding-block:12px}.workbook-console__summary{display:grid;grid-template-columns:auto auto;gap:2px 12px;align-items:baseline}.workbook-console__summary>span{grid-column:1/-1;color:#f0a27d;font:850 .63rem var(--mono);letter-spacing:.11em}.workbook-console__summary b{font:800 1.25rem var(--mono)}.workbook-console__summary b i{color:#f0a27d;font-style:normal}.workbook-console__summary small{color:#b8c6ca;font-size:.72rem}.workbook-console .sr-only{position:absolute;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0,0,0,0);clip-path:inset(50%);white-space:nowrap;border:0}.workbook-console__query{display:flex;min-width:min(420px,38vw);gap:7px}.workbook-console__query label{display:flex;min-width:0;flex:1}.workbook-console__query input,.workbook-console__query select{width:100%;min-width:0;min-height:44px;padding:8px 10px;border:1px solid #60727a;border-radius:0;background:#20343d;color:#f5efe5;font:750 .72rem var(--mono)}.workbook-console__query input::placeholder{color:#b8c6ca}.workbook-console__query select{max-width:150px}.workbook-empty button{min-height:44px;padding:9px 13px;border:1px solid #60727a;background:transparent;color:#d5dfe0;font:800 .72rem var(--mono);cursor:pointer}.workbook-empty button:focus-visible{outline:3px solid var(--topic-accent);outline-offset:3px}.workbook-empty{margin-block:40px;padding:26px;border-block:2px solid var(--topic-ink);text-align:center}.workbook-empty b{font-family:Songti SC,STSong,Georgia,serif;font-size:1.35rem}.workbook-empty p{margin:8px auto 18px;max-width:52ch;color:var(--topic-muted);line-height:1.7}.workbook-empty button{border-color:var(--topic-ink);color:var(--topic-ink)}.workbook-questions{background:var(--topic-paper)}.learning-topic__body .workbook-section{padding-block:clamp(64px,9vw,112px)}.workbook-section__header{display:grid;grid-template-columns:150px minmax(0,1fr);gap:8px 34px;align-items:start;padding-bottom:32px;border-bottom:2px solid var(--topic-ink)}.workbook-section__header>div{grid-row:1/3;display:flex;flex-direction:column;gap:9px;color:var(--topic-accent);font:850 .65rem var(--mono);letter-spacing:.08em}.workbook-section__header>div small{color:var(--topic-muted)}.learning-topic__body .workbook-section__header h2{max-width:19ch}.workbook-section__header>p{max-width:68ch;color:var(--topic-muted);line-height:1.8}.workbook-question-list{display:grid}.workbook-question{scroll-margin-top:164px;padding-block:clamp(42px,6vw,72px);border-bottom:1px solid var(--topic-rule)}.workbook-question[hidden]{display:none}.workbook-question__head{display:grid;grid-template-columns:120px minmax(0,1fr) auto;gap:24px;align-items:start}.workbook-question__number{display:grid;gap:8px}.workbook-question__number span{color:var(--topic-accent);font:900 1.35rem var(--mono)}.workbook-question__number small{color:var(--topic-muted);font:750 .61rem/1.5 var(--mono)}.workbook-question__title h3{max-width:29ch;font-family:Songti SC,STSong,"Noto Serif SC",Georgia,serif;font-size:clamp(1.55rem,2.8vw,2.35rem);font-weight:720;line-height:1.28;letter-spacing:-.025em}.workbook-question__title h3 a{display:inline-flex;align-items:center;justify-content:center;min-width:44px;min-height:44px;margin-left:5px;color:var(--topic-accent);font:800 .72rem var(--mono);text-decoration:none;vertical-align:middle}.workbook-question__title>div{display:flex;flex-wrap:wrap;gap:6px;margin-top:12px}.workbook-question__title>div span{padding:4px 8px;background:#eee7db;color:var(--topic-muted);font:800 .62rem var(--mono)}.workbook-plain{display:grid;grid-template-columns:120px minmax(0,1fr);gap:24px;margin-top:34px;padding:28px 0;border-top:1px solid var(--topic-rule)}.workbook-plain>span{color:var(--topic-accent);font:850 .64rem var(--mono);letter-spacing:.08em}.workbook-plain h4{font-family:Songti SC,STSong,Georgia,serif;font-size:1.3rem}.workbook-plain p{max-width:75ch;margin-top:12px;color:var(--topic-muted);font-size:.94rem;line-height:1.88}.workbook-opening-answer{display:grid;grid-template-columns:120px minmax(0,1fr);gap:24px;padding:25px 0;border-block:2px solid var(--topic-ink)}.workbook-opening-answer>span{color:var(--topic-accent);font:850 .66rem var(--mono)}.workbook-opening-answer>span b{display:block;margin-bottom:5px;font-size:1.35rem}.workbook-opening-answer p{max-width:72ch;font-size:1rem;font-weight:700;line-height:1.82}.workbook-deep{border-bottom:1px solid var(--topic-rule)}.workbook-deep summary{display:flex;align-items:center;justify-content:space-between;gap:18px;min-height:58px;padding:10px 0;cursor:pointer;list-style:none}.workbook-deep summary::-webkit-details-marker{display:none}.workbook-deep summary span{font-weight:850}.workbook-deep summary small{color:var(--topic-accent);font:800 .61rem var(--mono);letter-spacing:.06em}.workbook-deep summary:after{content:"＋";color:var(--topic-accent);font-size:1.15rem}.workbook-deep[open] summary:after{content:"－"}.workbook-deep__body{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));border-top:1px solid var(--topic-rule)}.workbook-deep__body section{min-width:0;padding:24px 22px 24px 0;border-bottom:1px solid var(--topic-rule)}.workbook-deep__body section:nth-child(odd){border-right:1px solid var(--topic-rule)}.workbook-deep__body section:nth-child(2n){padding-left:22px}.workbook-deep__body h4{color:var(--topic-accent);font:850 .66rem var(--mono);letter-spacing:.08em}.workbook-deep__body p{margin-top:9px;color:var(--topic-muted);font-size:.87rem;line-height:1.8;overflow-wrap:anywhere}.workbook-deep__body code{display:block;max-width:100%;margin-top:14px;padding:12px 14px;overflow-x:auto;background:#20343d;color:#f5efe5;font:650 .76rem/1.6 var(--mono);white-space:nowrap}.workbook-deep__body .is-tradeoff{background:#f4eee3}.workbook-deep__body .is-pitfall h4{color:#a24a38}.workbook-deep__body .is-followup h4{color:#6c5290}.workbook-sources{display:grid;margin-top:26px;border-top:1px solid var(--topic-rule)}.workbook-sources>span{padding:13px 0 8px;color:var(--topic-accent);font:850 .63rem var(--mono);letter-spacing:.08em}.workbook-sources a{display:grid;grid-template-columns:64px minmax(0,1fr) auto;gap:12px;align-items:center;min-height:48px;padding:8px 4px;border-top:1px solid var(--topic-rule);color:var(--topic-ink);text-decoration:none}.workbook-sources a:hover b{text-decoration:underline}.workbook-sources small{color:var(--topic-accent);font:800 .62rem var(--mono)}.workbook-sources b{font-size:.78rem;line-height:1.5}.workbook-sources i{color:var(--topic-accent);font-style:normal}.workbook-related{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin-top:18px}.workbook-related>span{margin-right:4px;color:var(--topic-muted);font:800 .62rem var(--mono);letter-spacing:.07em}.workbook-related a{display:inline-flex;align-items:center;gap:8px;min-height:44px;padding:6px 10px;border-bottom:1px solid var(--topic-rule);color:var(--topic-accent);font-size:.74rem;font-weight:800;text-decoration:none}.workbook-related i{font-style:normal}@media(max-width:900px){.workbook-question__head,.workbook-plain,.workbook-opening-answer{grid-template-columns:90px minmax(0,1fr)}}@media(max-width:980px){.workbook-console__inner{flex-wrap:wrap}.workbook-console__query{order:3;min-width:100%}}@media(max-width:680px){.workbook-console{top:54px}.workbook-console__inner{display:grid;gap:10px;padding-block:10px}.workbook-console__query{display:grid;grid-template-columns:minmax(0,1fr) 132px;order:auto}.workbook-console__query select{max-width:none}.learning-topic__body .workbook-chapters{grid-template-columns:1fr}.learning-topic__body .workbook-chapters a:nth-child(odd){border-right:0}.workbook-section__header{grid-template-columns:1fr}.workbook-section__header>div{grid-row:auto;flex-direction:row;justify-content:space-between}.workbook-question{scroll-margin-top:250px}.workbook-question__head{grid-template-columns:1fr;gap:14px}.workbook-question__number{display:flex;align-items:center;justify-content:space-between}.workbook-plain,.workbook-opening-answer{grid-template-columns:1fr;gap:10px}.workbook-deep__body{grid-template-columns:1fr}.workbook-deep__body section,.workbook-deep__body section:nth-child(2n){padding:20px 0;border-right:0}.workbook-deep summary small{display:none}.workbook-sources a{grid-template-columns:54px minmax(0,1fr) auto}.workbook-question__title h3 a{min-width:44px}}