:root{--blue:#004077;--red:#c10630;--ink:#1b2330;--muted:#556273;--line:#d7e0ea;--wash:#f4f7fa;--soft:#edf3f8;font:18px/1.72 Corbel,'Segoe UI',Arial,sans-serif;color:var(--ink);background:#fff}*{box-sizing:border-box}body{margin:0}a{color:var(--blue);text-underline-offset:3px}button,input,select{font:inherit}button,input,select,summary{touch-action:manipulation}a:focus-visible,button:focus-visible,input:focus-visible,summary:focus-visible,select:focus-visible{outline:3px solid var(--red);outline-offset:3px}.skip{position:absolute;top:-90px;left:18px;background:white;padding:10px;z-index:99}.skip:focus{top:5px}.book-header{background:var(--blue);border-bottom:4px solid var(--red);padding:18px 28px;display:flex;justify-content:space-between;gap:24px;color:#fff;align-items:center}.book-header a{color:inherit;text-decoration:none;font-weight:700;line-height:1.4}.book-header span{font-size:.79rem;white-space:nowrap}.book-layout{display:grid;grid-template-columns:290px minmax(0,1fr);max-width:1560px;margin:auto}.book-nav{padding:28px 22px;position:sticky;top:0;height:100vh;overflow:auto;border-right:1px solid var(--line)}.book-nav h2{font-size:1rem;line-height:1.4;margin:22px 0 12px}.book-nav h3{font-size:.84rem;margin-top:28px}.book-nav a{display:block;font-size:.86rem;padding:8px 0;text-decoration:none;line-height:1.5}.book-nav a.current{border-left:3px solid var(--red);padding-left:12px;font-weight:700;background:var(--wash)}.book-main{min-width:0;padding:36px 52px 80px;max-width:1190px}h1{font-size:2.18rem;line-height:1.22;max-width:950px;margin:8px 0 22px}h2{font-size:1.5rem;line-height:1.35;margin:52px 0 18px;scroll-margin-top:20px}h3{font-size:1.13rem;line-height:1.42;margin:28px 0 12px}p{margin:0 0 17px}.lead{font-size:1.12rem;line-height:1.62}.eyebrow{color:var(--red);font-size:.76rem;font-weight:700;letter-spacing:.06em}.lesson-meta,.source-note{font-size:.82rem;color:var(--muted)}ul,ol{padding-left:25px}li{margin:9px 0}li p:last-child{margin-bottom:0}.note,.result{border-left:3px solid var(--blue);background:var(--wash);padding:17px 22px;margin:22px 0}.result{border-color:var(--red);background:#faf5f6}.note p:last-child,.result p:last-child{margin-bottom:0}summary{cursor:pointer;font-weight:600}.question{border-top:1px solid var(--line);padding:17px 0}.question[open] summary{margin-bottom:15px}.formula{position:relative;margin:25px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:12px 0 18px}.math{overflow-x:auto;padding:8px 0;max-width:100%}.katex-display{margin:.45em 0;text-align:left}.katex{font-size:1.08em}.formula figcaption{font-size:.88rem;padding-right:42px;margin-top:10px;color:var(--muted)}.formula-number{font-weight:600;color:var(--blue)}.copy-tex{position:absolute;right:0;bottom:14px;border:1px solid var(--line);background:white;color:var(--blue);font-size:.65rem;padding:3px 6px;border-radius:4px;cursor:pointer}.table-wrap{overflow:auto;max-width:100%;margin:24px 0}table{width:100%;border-collapse:collapse;font-size:.88rem}th,td{border:1px solid var(--line);padding:11px 14px;vertical-align:top;text-align:left}th{background:var(--wash)}.worked-steps li,.practice-steps li{padding-left:5px;margin:18px 0}.widget{border:1px solid var(--line);padding:22px;border-radius:7px;background:#fff}.widget h3{margin:0 0 13px}.widget-layout{display:grid;grid-template-columns:235px minmax(0,1fr);gap:25px}.widget-controls label{display:block;font-size:.88rem;margin-bottom:19px}.widget-controls input[type=range]{width:100%;accent-color:var(--blue)}.widget-controls output{font-weight:600;color:var(--blue)}.widget-controls select{width:100%;border:1px solid #bdc9d6;padding:6px;background:white}.widget-stats{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin:17px 0}.widget-stat{border-top:1px solid var(--line);padding-top:7px;font-size:.83rem}.widget-stat strong{display:block;color:var(--blue);font-size:1.03rem}.widget-plot{width:100%;height:auto;display:block;background:white}.widget-explanation{font-size:.89rem;margin-top:15px}.widget button,.btn{border:1px solid #bac9d7;padding:8px 15px;background:#fff;color:var(--blue);border-radius:5px;cursor:pointer;font-size:.86rem}.btn.primary{background:var(--blue);color:#fff}.widget .warning{color:#943f08;font-weight:600}.download-links{display:flex;flex-wrap:wrap;gap:10px}.download-links a{padding:8px 13px;border:1px solid var(--line);border-radius:4px;text-decoration:none;font-size:.84rem}.femm-figure{margin:25px 0}.femm-figure img{width:100%;height:auto;display:block;border:1px solid var(--line)}.femm-figure figcaption{font-size:.81rem;color:var(--muted);margin:10px 0}.completion{display:block;font-weight:600;margin-top:25px}.completion input{width:19px;height:19px;accent-color:var(--blue);margin-right:10px}.references{margin:35px 0;font-size:.88rem}.lesson-footer{display:flex;gap:25px;justify-content:space-between;border-top:2px solid var(--line);padding-top:24px;margin-top:40px}.lesson-footer a{max-width:48%;font-size:.86rem}.book-foot{margin-top:45px;font-size:.76rem;color:var(--muted)}pre{background:var(--wash);padding:18px;overflow:auto;border:1px solid var(--line);font-size:.77rem;line-height:1.6}code{font-family:Consolas,'Cascadia Mono',monospace}.home-main{max-width:1140px;padding:38px 30px 90px;margin:auto}.home-main h1{max-width:900px}.home-summary{display:flex;gap:42px;flex-wrap:wrap;border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:20px 0;margin:26px 0}.home-summary strong{display:block;font-size:1.4rem;color:var(--blue)}.home-summary span{font-size:.81rem;color:var(--muted)}.home-tools{display:flex;gap:12px;flex-wrap:wrap;align-items:center;margin:27px 0}.home-tools input{padding:9px 12px;flex:1;min-width:250px;border:1px solid #b4c2d0;border-radius:4px}.home-tools .active{background:var(--blue);color:#fff}.book-module{border-top:1px solid var(--line);margin-top:20px;padding-top:5px}.book-module h3{font-size:1.12rem;margin:18px 0}.book-module ol{list-style:none;padding:0}.book-module li a{display:flex;gap:15px;padding:13px 16px;text-decoration:none;border:1px solid var(--line);border-radius:4px;line-height:1.5}.book-module li a:hover{background:var(--wash)}.lesson-tag{font-size:.92rem;color:var(--red);font-weight:700;min-width:3em;flex-shrink:0;white-space:nowrap;font-variant-numeric:tabular-nums}.completed-mark{margin-left:auto;color:#276343}.hidden{display:none!important}.toolbar-info{font-size:.82rem;color:var(--muted)}
@media(max-width:1100px){.book-layout{grid-template-columns:235px minmax(0,1fr)}.book-main{padding:30px}.widget-layout{grid-template-columns:200px minmax(0,1fr)}}
@media(max-width:780px){:root{font-size:17px}.book-header{padding:15px 20px}.book-header span{display:none}.book-layout{display:block}.book-nav{position:static;height:auto;padding:18px 20px;border-right:none;border-bottom:1px solid var(--line)}.book-nav nav{display:flex;gap:6px 17px;flex-wrap:wrap}.book-nav h2{margin-top:15px}.book-nav h3{margin-top:15px}.book-nav a{font-size:.79rem;padding:5px 0}.book-nav nav:first-of-type a{flex-basis:100%}.book-main{padding:28px 20px 65px}.home-main{padding:28px 20px 65px}h1{font-size:1.87rem}h2{margin-top:39px}.widget{padding:16px}.widget-layout{display:block}.widget-controls{display:grid;grid-template-columns:1fr 1fr;gap:10px 16px}.widget-controls label{margin-bottom:12px}.widget-controls input{max-width:100%}.widget-plot{margin-top:10px}.widget-stats{gap:10px}.table-wrap table{min-width:490px}.math::after{content:'Длинную формулу можно прокрутить по горизонтали';display:block;font:11px/1.5 'Segoe UI',Arial,sans-serif;color:var(--muted);margin:7px 0}.lesson-footer{display:block}.lesson-footer a{display:block;max-width:100%;margin:14px 0}.home-summary{gap:25px}.home-tools input{flex-basis:100%;min-width:0}.book-module li a{padding:11px 9px;gap:7px}.formula figcaption{padding-right:0}.copy-tex{position:static;display:block;margin-top:9px}}
@media print{.book-header,.book-nav,.skip,.copy-tex,.completion,.lesson-footer,.widget-controls,.home-tools{display:none}.book-layout{display:block}.book-main,.home-main{padding:0;max-width:none}.math{overflow:visible}.note,.result{background:none;border:1px solid #ccc}.formula{break-inside:avoid}h2,h3{break-after:avoid}.widget-layout{display:block}.question>p{display:block}.book-foot{margin-top:20px}.hidden{display:block!important}}

/* Пошаговые расчётные примеры */
.example-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:22px;margin:30px 0}.example-card{border:1px solid var(--line);border-radius:7px;padding:23px;min-width:0}.example-card h2{margin:0 0 15px;font-size:1.22rem}.example-card p{font-size:.9rem}.example-step{padding-top:28px;margin-top:45px;border-top:2px solid var(--line);scroll-margin-top:20px}.example-step>h2{margin-top:8px}.example-step>.eyebrow{margin-bottom:0}.example-main .table-wrap caption{text-align:left;font-weight:600;padding:0 0 12px}.example-main .table-wrap:focus-visible{outline:3px solid var(--red);outline-offset:3px}.step-files{padding:18px 21px;border:1px solid var(--line);background:var(--wash);margin:25px 0}.step-files h3{margin-top:0}.step-files .download-links{margin-bottom:12px}.step-files p:last-child{margin-bottom:0}.example-script{margin:20px 0}.capture-pending{border-left:3px solid #9caaba;background:var(--wash);padding:15px 20px;font-size:.88rem;color:var(--muted)}.step-next{text-align:right;margin-top:24px}.example-lesson-list{font-size:.94rem}.example-main .download-links a{overflow-wrap:anywhere}.example-main .table-wrap td{overflow-wrap:anywhere}
@media(max-width:780px){.example-grid{grid-template-columns:1fr}.example-card{padding:20px}.example-step{margin-top:32px;padding-top:23px}.step-files{padding:16px}.example-main .table-wrap table{min-width:490px}.step-next{text-align:left}}
@media print{.example-card,.step-files{break-inside:avoid}.capture-pending{background:none}.example-step{break-before:auto}.example-script{display:none}.step-next{display:none}}
.table-scroll-note{display:none}
@media(max-width:780px){.example-main .table-wrap table.compact-table{min-width:0;table-layout:fixed}.example-main table.compact-table th:first-child{width:55%}.table-scroll-note{display:block;margin-bottom:-12px;font-size:.82rem;color:var(--muted)}}