/* Официальная дизайн-система Anthropic / Claude
   Цвета и типографика по бренд-гайду Anthropic. */
@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;500;600;700&family=Lora:ital,wght@0,400;0,500;0,600;1,400&display=swap');

:root{
  --dark:#141413; --light:#faf9f5; --mid:#b0aea5; --lightgray:#e8e6dc;
  --orange:#d97757; --blue:#6a9bcc; --green:#788c5d;
  --bg:var(--light); --card:#fffefb; --ink:var(--dark); --muted:#6e6c63; --line:var(--lightgray);
  --accent:var(--orange); --accent-ink:#fff; --ok:var(--green);
  --head:"Poppins",Arial,sans-serif;
  --body:"Lora",Georgia,"Times New Roman",serif;
}
[data-theme="dark"]{
  --bg:#1a1917; --card:#242320; --ink:#f0ede4; --muted:#9a9690; --line:#333230;
  --lightgray:#2e2c29; --light:#1a1917; --dark:#f0ede4;
}
/* Кнопка тёмной темы */
.theme-toggle{position:fixed;top:16px;right:16px;z-index:999;background:var(--card);border:1px solid var(--line);border-radius:999px;padding:6px 12px;cursor:pointer;font-family:var(--head);font-size:13px;color:var(--muted);transition:.2s;box-shadow:0 2px 8px rgba(0,0,0,.08)}
.theme-toggle:hover{color:var(--ink)}
*{box-sizing:border-box}
html,body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--body);font-size:18px;line-height:1.7}
h1,h2,h3,h4,.brand,.card-title,.btn,.mod-title,.crumbs,.card-sub,.meta,.nav-btn,.progress-label{font-family:var(--head)}
a{color:inherit;text-decoration:none}
.layout{display:flex;min-height:100vh;max-width:1320px;margin:0 auto}

/* Sidebar */
.sidebar{width:312px;flex:0 0 312px;border-right:1px solid var(--line);padding:30px 24px;position:sticky;top:0;height:100vh;overflow-y:auto}
.brand{font-weight:700;font-size:17px;letter-spacing:.01em;display:block;margin-bottom:28px;color:var(--dark)}
.mod{margin-bottom:22px}
.mod-title{font-size:11px;text-transform:uppercase;letter-spacing:.1em;color:var(--mid);margin-bottom:9px;font-weight:600}
.sidebar ul{list-style:none;margin:0;padding:0}
.sidebar li{margin:2px 0}
.lesson-link{display:flex;align-items:flex-start;gap:9px;padding:8px 10px;border-radius:10px;font-size:14px;font-family:var(--head);color:var(--muted);transition:.15s}
.lesson-link:hover{background:#f0eee6;color:var(--ink)}
.lesson-link.active{background:#efe7da;color:var(--ink);font-weight:500}
.check{width:16px;height:16px;flex:0 0 16px;border:1.5px solid var(--mid);border-radius:50%;margin-top:2px;display:inline-block}
.check.done{background:var(--green);border-color:var(--green);position:relative}
.check.done::after{content:"✓";color:#fff;font-size:11px;position:absolute;top:-2px;left:2.5px}

/* Content */
.content{flex:1;padding:52px 68px;max-width:880px}
.crumbs{color:var(--muted);font-size:13px;letter-spacing:.02em;margin-bottom:20px}
.display{font-size:30px;line-height:1.04;font-weight:600;letter-spacing:-.02em;margin:.1em 0 .3em}
.lede{font-size:21px;line-height:1.55;color:#3a3833;max-width:60ch}
.meta{color:var(--muted);font-size:14px;margin:20px 0 26px}
.btn{display:inline-block;background:var(--accent);color:var(--accent-ink);padding:13px 26px;border-radius:999px;font-weight:500;border:none;cursor:pointer;font-size:15px;transition:.15s}
.btn:hover{filter:brightness(.96)}

.cards{display:grid;gap:12px;margin:14px 0 36px}
.card{display:flex;gap:15px;align-items:center;background:var(--card);border:1px solid var(--line);border-radius:18px;padding:20px 24px;transition:.15s}
.card:hover{box-shadow:0 6px 22px rgba(20,20,19,.06);transform:translateY(-1px);border-color:#d9d5c5}
.card-title{font-size:18px;font-weight:600}
.card-sub{color:var(--muted);font-size:13px;margin-top:2px}
h2{font-size:28px;font-weight:600;letter-spacing:-.01em;margin:34px 0 8px}

/* Lesson body */
.lesson article h1{font-size:40px;font-weight:600;line-height:1.12;letter-spacing:-.02em;margin:.1em 0 .5em}
.lesson article h2{font-size:27px;margin-top:1.7em}
.lesson article h3{font-size:21px;margin-top:1.4em}
.lesson article p{margin:1em 0}
.lesson article ul,.lesson article ol{padding-left:1.3em}
.lesson article li{margin:.55em 0}
.lesson blockquote{border-left:3px solid var(--orange);background:#f6f0e7;margin:1.5em 0;padding:14px 20px;border-radius:0 12px 12px 0;color:#3a3833}
.lesson code{background:var(--lightgray);padding:2px 7px;border-radius:6px;font-size:.88em;font-family:"Poppins",monospace}
.lesson hr{border:none;border-top:1px solid var(--line);margin:2em 0}
.lesson table{width:100%;border-collapse:collapse;margin:1.5em 0;font-size:15px;font-family:var(--head)}
.lesson th{background:#efe7da;text-align:left;padding:11px 14px;border:1px solid var(--line);font-weight:600;font-size:13px}
.lesson td{padding:11px 14px;border:1px solid var(--line);vertical-align:top;line-height:1.55}
.lesson tbody tr:nth-child(even){background:#faf7f0}
.video{position:relative;padding-bottom:56.25%;height:0;margin:0 0 30px;border-radius:16px;overflow:hidden;background:#000;box-shadow:0 8px 28px rgba(20,20,19,.12)}
.video iframe,.video video{position:absolute;inset:0;width:100%;height:100%;border:0}
.dub-badge{display:inline-block;font-family:var(--head);font-size:12px;font-weight:500;color:var(--green);background:#eef0e7;border:1px solid #dfe3d2;padding:5px 12px;border-radius:999px;margin:-18px 0 26px}
.done-btn{margin:30px 0 8px}
.done-btn.done{background:var(--green)}
.lesson-nav{display:flex;justify-content:space-between;gap:12px;margin:32px 0;border-top:1px solid var(--line);padding-top:22px}
.nav-btn{color:var(--accent);font-weight:500;font-size:14px}
.todo{background:#f6f0e7;padding:22px;border-radius:14px;color:var(--muted)}

.progress-bar{height:8px;background:var(--lightgray);border-radius:999px;margin:28px 0 6px;overflow:hidden}
.progress-fill{height:100%;width:0;background:var(--green);transition:.4s}
.progress-label{color:var(--muted);font-size:13px}

.back-link{display:block;font-family:var(--head);font-size:13px;color:var(--muted);margin:-14px 0 22px}
.back-link:hover{color:var(--accent)}
.home{max-width:980px;margin:0 auto;padding-top:60px}
.course-cards .card{align-items:center}
.card-meta{font-family:var(--head);color:var(--mid);font-size:12px;margin-top:8px}
.lesson pre{background:#2b2a27;color:#f0eee6;padding:16px 18px;border-radius:12px;overflow-x:auto;font-size:13.5px;line-height:1.5;margin:1.3em 0}
.lesson pre code{background:none;color:inherit;padding:0;font-family:"Poppins",ui-monospace,monospace}

@media(max-width:860px){.sidebar{display:none}.content{padding:30px 22px}.display{font-size:40px}}
.course-num{flex:0 0 38px;width:38px;height:38px;border-radius:50%;background:var(--orange);color:#fff;font-family:var(--head);font-weight:600;font-size:17px;display:flex;align-items:center;justify-content:center}
.card-body{flex:1}
.card-struct{font-family:var(--head);font-size:12px;color:var(--blue);margin-top:7px;line-height:1.5}