:root {
  --bg: #0b0c0c;
  --panel: #121414;
  --panel-2: #171919;
  --line: #292d2d;
  --text: #f3f4ef;
  --muted: #929994;
  --lime: #c7ff38;
  --orange: #ff6b35;
  --cyan: #40e0d0;
  --mono: "DM Mono", monospace;
  --sans: "Manrope", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--text); font-family: var(--sans); min-height: 100vh; }
button, textarea, input { font: inherit; }
button { cursor: pointer; }
.noise { position: fixed; inset: 0; pointer-events: none; opacity: .025; z-index: 9; background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 180 180' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.8'/%3E%3C/svg%3E"); }

.sidebar { position: fixed; inset: 0 auto 0 0; width: 250px; border-right: 1px solid var(--line); padding: 28px 20px; display: flex; flex-direction: column; background: #0d0f0f; z-index: 8; }
.brand { color: var(--text); text-decoration: none; font: 700 12px var(--mono); letter-spacing: 2px; display: flex; align-items: center; gap: 11px; margin: 0 8px 50px; }
.brand-mark { font: 800 28px var(--sans); color: var(--lime); letter-spacing: -3px; }
.logo-mark { width: 62px; height: 62px; border-radius: 10px; overflow: visible; background: transparent; filter: drop-shadow(0 0 18px rgba(64,224,208,.18)); flex: 0 0 auto; }
.logo-mark img { width: 100%; height: 100%; object-fit: contain; display: block; }
.nav { display: grid; gap: 7px; }
.nav-item { border: 0; color: var(--muted); background: transparent; text-align: left; padding: 13px 14px; border-radius: 8px; font-weight: 600; }
.nav-item span { font: 18px var(--mono); display: inline-block; width: 32px; }
.nav-item:hover, .nav-item.active { background: var(--panel-2); color: var(--text); }
.nav-item.active { box-shadow: inset 3px 0 var(--lime); }
.sidebar-bottom { margin-top: auto; }
.level-card { background: var(--panel); border: 1px solid var(--line); border-radius: 10px; padding: 16px; }
.level-label { display: flex; justify-content: space-between; align-items: center; text-transform: uppercase; font: 10px var(--mono); color: var(--muted); }
.level-label strong { color: var(--lime); font-size: 19px; }
.progress-track { height: 5px; margin: 13px 0 9px; background: #252929; overflow: hidden; border-radius: 10px; }
.progress-track span { display: block; height: 100%; width: 0; background: var(--lime); transition: width .4s; }
.level-card small { color: var(--muted); font: 10px var(--mono); }
.reset-btn { width: 100%; color: #666d69; border: 0; background: transparent; padding: 15px; font: 10px var(--mono); text-transform: uppercase; }

main { margin-left: 250px; min-height: 100vh; }
.topbar { height: 72px; border-bottom: 1px solid var(--line); display: flex; align-items: center; justify-content: flex-end; padding: 0 5vw; gap: 28px; }
.status, .streak { font: 10px var(--mono); color: var(--muted); letter-spacing: .5px; }
.status i { display: inline-block; width: 7px; height: 7px; border-radius: 50%; background: var(--lime); margin-right: 8px; box-shadow: 0 0 9px var(--lime); }
.streak strong { color: var(--text); }
.account-btn { border: 1px solid var(--line); background: var(--panel); color: var(--text); padding: 9px 13px; border-radius: 5px; font: 10px var(--mono); }
.account-btn:hover { border-color: var(--lime); color: var(--lime); }
.menu-toggle { display: none; margin-right: auto; border: 0; background: transparent; color: var(--text); font-size: 20px; }
.view { display: none; padding: 55px 6vw 80px; max-width: 1440px; margin: auto; animation: appear .35s ease; }
.view.active { display: block; }
@keyframes appear { from { opacity: 0; transform: translateY(6px); } }
.eyebrow { font: 500 10px var(--mono); letter-spacing: 1.5px; color: var(--lime); margin: 0 0 18px; }

.hero { min-height: 390px; display: grid; grid-template-columns: 1.3fr 1fr; align-items: center; border-bottom: 1px solid var(--line); padding-bottom: 45px; }
h1 { font-size: clamp(38px, 5vw, 68px); line-height: 1.03; letter-spacing: -3px; margin: 0; max-width: 780px; }
h1 em, .page-title em { font-style: normal; color: var(--lime); }
.hero-copy { color: var(--muted); line-height: 1.7; max-width: 570px; margin: 25px 0 30px; }
.primary-btn, .secondary-btn { border-radius: 6px; padding: 14px 20px; font-weight: 700; border: 1px solid var(--lime); }
.primary-btn { background: var(--lime); color: #10120d; }
.primary-btn span { margin-left: 18px; }
.primary-btn:hover { box-shadow: 0 0 28px rgba(199,255,56,.18); transform: translateY(-1px); }
.hero-spinner { width: 360px; height: 360px; position: relative; justify-self: end; display: grid; place-items: center; isolation: isolate; }
.hero-spinner::before { content: ""; position: absolute; inset: 36px; border-radius: 50%; background: radial-gradient(circle, rgba(64,224,208,.16), rgba(199,255,56,.05) 38%, transparent 68%); filter: blur(18px); opacity: .75; animation: pulseGlow 2.4s ease-in-out infinite; }
.spinner-ring { position: absolute; border: 1px solid #323636; border-radius: 50%; inset: 24px; animation: spin 18s linear infinite; }
.spinner-ring::after { content: ""; position: absolute; width: 10px; height: 10px; background: var(--orange); border-radius: 50%; top: 42px; left: 58px; box-shadow: 0 0 14px var(--orange); }
.spinner-ring-two { inset: 72px; animation-direction: reverse; animation-duration: 11s; border-style: dashed; opacity: .65; }
.spinner-ring-two::after { background: var(--cyan); right: 5px; left: auto; top: 96px; box-shadow: 0 0 14px var(--cyan); }
.logo-spin { position: relative; z-index: 2; width: 220px; height: 220px; background-image: url("logo-spin-sprite.png"); background-repeat: no-repeat; background-size: 1320px 220px; background-position: 0 0; filter: drop-shadow(0 0 22px rgba(64,224,208,.34)); animation: logoSprite 2.4s steps(6) infinite; }
.spinner-tag { position: absolute; z-index: 3; background: rgba(18,20,20,.78); border: 1px solid var(--line); color: var(--muted); padding: 7px 10px; font: 9px var(--mono); text-transform: uppercase; backdrop-filter: blur(6px); }
.tag-a { right: -6px; top: 72px; }.tag-b { left: 5px; bottom: 72px; }
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes logoSprite { to { background-position: -1320px 0; } }
@keyframes pulseGlow { 50% { opacity: 1; transform: scale(1.05); } }

.section-heading { display: flex; justify-content: space-between; align-items: end; margin: 50px 0 22px; }
.section-heading h2 { margin: 0; font-size: 27px; }
.section-heading > span { color: var(--muted); font: 10px var(--mono); }
.course-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; }
.course-card { min-height: 185px; border: 1px solid var(--line); background: var(--panel); padding: 20px; border-radius: 9px; position: relative; transition: .2s; }
.course-card:hover { border-color: #505650; transform: translateY(-3px); }
.course-card.done { border-color: rgba(199,255,56,.32); }
.course-card.locked { opacity: .42; }
.course-card .num { color: #565c58; font: 10px var(--mono); }
.course-card .lang { position: absolute; right: 15px; top: 15px; font: 9px var(--mono); border: 1px solid var(--line); padding: 4px 6px; color: var(--muted); }
.course-card h3 { margin: 38px 0 8px; font-size: 16px; }
.course-card p { color: var(--muted); font-size: 12px; line-height: 1.5; }
.card-action { padding: 0; border: 0; background: transparent; color: var(--lime); font: 10px var(--mono); text-transform: uppercase; }
.daily-card { margin-top: 18px; padding: 24px; border: 1px solid #343936; border-radius: 9px; display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 22px; background: linear-gradient(90deg, #151817, #101211); }
.daily-card .eyebrow { margin-bottom: 6px; }.daily-card h3 { margin: 0 0 4px; }.daily-card p { margin: 0; color: var(--muted); font-size: 13px; }
.daily-icon { width: 48px; height: 48px; border: 1px solid var(--lime); color: var(--lime); display: grid; place-items: center; border-radius: 50%; }
.secondary-btn { background: transparent; color: var(--lime); font-size: 12px; }

.page-title { margin-bottom: 38px; }
.courses-intro { max-width: 690px; color: var(--muted); line-height: 1.7; margin: -22px 0 28px; }
.curriculum-stats { display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--line); border-radius: 8px; margin-bottom: 28px; overflow: hidden; }
.curriculum-stats div { padding: 20px; display: flex; flex-direction: column; border-right: 1px solid var(--line); background: var(--panel); }
.curriculum-stats div:last-child { border-right: 0; }.curriculum-stats strong { color: var(--lime); font: 600 24px var(--mono); }.curriculum-stats span { color: var(--muted); font: 9px var(--mono); text-transform: uppercase; margin-top: 4px; }
.filter-row { display: flex; gap: 8px; margin-bottom: 20px; }
.filter { border: 1px solid var(--line); background: transparent; color: var(--muted); padding: 9px 14px; border-radius: 5px; font-size: 12px; }
.filter.active { background: var(--text); color: var(--bg); }
.course-list { display: grid; gap: 10px; }
.list-item { display: grid; grid-template-columns: 45px 1fr auto auto; align-items: center; gap: 18px; padding: 22px; background: var(--panel); border: 1px solid var(--line); border-radius: 8px; }
.list-icon { height: 45px; background: #202323; display: grid; place-items: center; font: 700 12px var(--mono); color: var(--lime); }
.difficulty.diff-easy { color: #7dd87d; border-color: rgba(125,216,125,.35); }
.difficulty.diff-medium { color: #ffd166; border-color: rgba(255,209,102,.35); }
.difficulty.diff-intermediate { color: #ff9f68; border-color: rgba(255,159,104,.35); }
.difficulty.diff-hard { color: #ff6b6b; border-color: rgba(255,107,107,.35); }
.course-card .lang.lang-easy { color: #7dd87d; border-color: rgba(125,216,125,.4); }
.course-card .lang.lang-medium { color: #ffd166; border-color: rgba(255,209,102,.4); }
.course-card .lang.lang-intermediate { color: #ff9f68; border-color: rgba(255,159,104,.4); }
.course-card .lang.lang-hard { color: #ff6b6b; border-color: rgba(255,107,107,.4); }

.track-switch { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; margin: 0 0 26px; }
.track-btn { display: flex; align-items: center; gap: 14px; text-align: left; padding: 18px 20px; background: var(--panel); border: 1px solid var(--line); border-radius: 10px; color: inherit; cursor: pointer; transition: border-color .15s, background .15s; }
.track-btn:hover { border-color: rgba(199,255,56,.35); }
.track-btn.active { border-color: var(--lime); background: rgba(199,255,56,.06); }
.track-icon { font-size: 24px; line-height: 1; }
.track-text { display: flex; flex-direction: column; gap: 4px; min-width: 0; }
.track-text strong { font-size: 15px; }
.track-text small { color: var(--muted); font-size: 11px; line-height: 1.5; }
.track-count { margin-left: auto; font: 11px var(--mono); color: var(--muted); white-space: nowrap; }
.track-btn.active .track-count { color: var(--lime); }

.difficulty-legend { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin-bottom: 28px; }
.difficulty-item { display: flex; gap: 10px; align-items: flex-start; padding: 14px; background: var(--panel); border: 1px solid var(--line); border-radius: 8px; }
.difficulty-item strong { display: block; font-size: 12px; margin-bottom: 2px; }
.difficulty-item span:last-child { color: var(--muted); font: 10px var(--mono); }
.difficulty-emoji { font-size: 18px; line-height: 1; }

.progress-path { display: grid; gap: 22px; }
.level-section { border: 1px solid var(--line); border-radius: 10px; background: var(--panel); overflow: hidden; }
.level-section.level-locked { opacity: .55; }
.level-section.level-complete { border-color: rgba(199,255,56,.28); }
.level-header { display: flex; justify-content: space-between; gap: 20px; padding: 22px 24px; border-bottom: 1px solid var(--line); background: #121514; }
.level-header h2 { margin: 8px 0 4px; font-size: 20px; }
.level-header p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.55; }
.level-badge { font: 9px var(--mono); color: var(--lime); letter-spacing: 1px; text-transform: uppercase; }
.level-header-meta { display: flex; flex-direction: column; align-items: flex-end; gap: 8px; flex-shrink: 0; }
.difficulty-pill { font: 10px var(--mono); padding: 6px 10px; border-radius: 20px; border: 1px solid var(--line); white-space: nowrap; }
.level-progress-label { color: var(--muted); font: 11px var(--mono); }

.exercise-track { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 8px; padding: 16px; }
.exercise-node { display: grid; grid-template-columns: 28px 1fr auto; gap: 8px; align-items: center; padding: 12px 14px; border: 1px solid #2a2e2c; border-radius: 7px; background: #0e100f; color: var(--text); text-align: left; transition: .15s; }
.exercise-node code { font: 11px var(--mono); color: var(--lime); background: none; padding: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.exercise-index { color: #5a605c; font: 9px var(--mono); }
.exercise-state { color: var(--muted); font-size: 12px; }
.exercise-node:hover:not(:disabled) { border-color: #4a504c; transform: translateY(-1px); }
.exercise-node.done { border-color: rgba(199,255,56,.25); background: rgba(199,255,56,.04); }
.exercise-node.done code { color: #b8e86a; }
.exercise-node.locked, .exercise-node:disabled { opacity: .45; cursor: not-allowed; }
.chapter-button.done span:first-child { border-color: var(--lime); color: var(--lime); }
.chapter-button.locked { opacity: .45; cursor: not-allowed; }
.practice-from-lesson { margin-top: 24px; width: 100%; justify-content: center; display: inline-flex; }

@media (max-width: 900px) {
  .track-switch { grid-template-columns: 1fr; }
  .difficulty-legend { grid-template-columns: repeat(2, 1fr); }
  .level-header { flex-direction: column; }
  .level-header-meta { align-items: flex-start; flex-direction: row; flex-wrap: wrap; }
}
@media (max-width: 720px) {
  .difficulty-legend { grid-template-columns: 1fr; }
  .exercise-track { grid-template-columns: 1fr; }
}
.list-icon.lang-cpp { color: var(--cyan); }
.list-icon.lang-shell { color: var(--orange); }
.list-icon.lang-git { color: #ffd166; }
.list-icon.lang-rush { color: #ff9f68; }
.list-icon.lang-intro { color: var(--cyan); }
.course-card .lang.lang-c { color: var(--lime); border-color: rgba(199,255,56,.4); }
.course-card .lang.lang-cpp { color: var(--cyan); border-color: rgba(64,224,208,.4); }
.course-card .lang.lang-shell { color: var(--orange); border-color: rgba(255,107,53,.4); }
.course-card .lang.lang-git { color: #ffd166; border-color: rgba(255,209,102,.4); }
.course-card .lang.lang-rush { color: #ff9f68; border-color: rgba(255,159,104,.4); }
.course-card .lang.lang-intro { color: var(--cyan); border-color: rgba(64,224,208,.4); }
.list-item h3 { margin: 0 0 5px; font-size: 15px; }.list-item p { margin: 0; color: var(--muted); font-size: 12px; }
.lesson-count { color: var(--muted); font: 10px var(--mono); }
.list-item button { background: transparent; color: var(--text); border: 1px solid var(--line); padding: 9px 12px; border-radius: 5px; }
.course-topics { display: flex; flex-wrap: wrap; gap: 5px; margin-top: 9px; }.course-topics span { color: #7e857f; background: #1b1e1d; border-radius: 3px; padding: 3px 6px; font: 8px var(--mono); }

.back-course { border: 0; background: transparent; color: var(--muted); padding: 0; margin-bottom: 22px; font: 10px var(--mono); }.back-course:hover { color: var(--lime); }
.lesson-layout { display: grid; grid-template-columns: 280px minmax(0, 780px); gap: 55px; align-items: start; }
.lesson-outline { position: sticky; top: 30px; border: 1px solid var(--line); border-radius: 9px; overflow: hidden; background: var(--panel); }
.outline-head { padding: 20px; border-bottom: 1px solid var(--line); }.outline-head span { color: var(--lime); font: 8px var(--mono); }.outline-head h2 { margin: 8px 0 0; font-size: 16px; }
.chapter-button { width: 100%; display: grid; grid-template-columns: 28px 1fr; gap: 10px; align-items: center; padding: 14px 17px; border: 0; border-bottom: 1px solid #222625; color: var(--muted); background: transparent; text-align: left; font-size: 11px; }
.chapter-button:last-child { border-bottom: 0; }.chapter-button span:first-child { width: 23px; height: 23px; display: grid; place-items: center; border: 1px solid #3a3f3c; border-radius: 50%; font: 8px var(--mono); }
.chapter-button:hover, .chapter-button.active { color: var(--text); background: #1a1e1c; }.chapter-button.active { box-shadow: inset 3px 0 var(--lime); }.chapter-button.active span:first-child { border-color: var(--lime); color: var(--lime); }
.lesson-content { padding-bottom: 60px; }.lesson-meta { display: flex; gap: 18px; color: var(--lime); font: 9px var(--mono); margin-bottom: 18px; }.lesson-meta span:last-child { color: var(--muted); }
.lesson-content > h1 { font-size: clamp(36px, 5vw, 58px); margin-bottom: 20px; }.lesson-lead { color: #bec4bf; font-size: 17px; line-height: 1.75; margin-bottom: 34px; }
.lesson-block { margin: 34px 0; }.lesson-block h2 { font-size: 22px; margin: 0 0 13px; }.lesson-block p, .lesson-block li { color: var(--muted); font-size: 14px; line-height: 1.75; }.lesson-block ul { padding-left: 20px; }
.code-example { margin: 22px 0; border: 1px solid var(--line); border-radius: 7px; overflow: hidden; background: #0c0e0e; }.code-label { display: flex; justify-content: space-between; padding: 9px 13px; border-bottom: 1px solid var(--line); color: #626964; font: 8px var(--mono); }.code-label button { border: 0; background: transparent; color: var(--lime); font: inherit; }.code-example pre { margin: 0; padding: 20px; overflow-x: auto; color: #dfe4de; font: 13px/1.75 var(--mono); }
.lesson-note { padding: 17px; border-left: 3px solid var(--lime); background: rgba(199,255,56,.04); color: #abb2ac; font-size: 13px; line-height: 1.65; }.lesson-note strong { color: var(--lime); }
.lesson-actions { display: flex; justify-content: space-between; align-items: center; border-top: 1px solid var(--line); margin-top: 45px; padding-top: 24px; }

.theory-hero { display: flex; justify-content: space-between; gap: 35px; align-items: end; }
.theory-hero .page-title { margin-bottom: 38px; }
.theory-summary { flex: 0 0 auto; margin-bottom: 38px; padding: 20px 24px; border: 1px solid var(--line); border-radius: 9px; background: var(--panel); }
.theory-summary strong { display: block; color: var(--lime); font: 600 30px var(--mono); }
.theory-summary span { color: var(--muted); font: 9px var(--mono); text-transform: uppercase; }
.theory-search { max-width: 600px; display: flex; align-items: center; gap: 10px; margin-bottom: 24px; padding: 0 14px; border: 1px solid var(--line); border-radius: 7px; background: var(--panel); }
.theory-search span { color: var(--lime); font: 18px var(--mono); }
.theory-search input { width: 100%; padding: 13px 0; border: 0; outline: 0; color: var(--text); background: transparent; font: 11px var(--mono); }
.theory-layout { display: grid; grid-template-columns: 290px minmax(0, 800px); gap: 30px; align-items: start; }
.theory-catalog { max-height: calc(100vh - 120px); position: sticky; top: 24px; overflow-y: auto; border: 1px solid var(--line); border-radius: 9px; background: #101212; }
.theory-module { border-bottom: 1px solid var(--line); }
.theory-module:last-child { border-bottom: 0; }
.theory-module-button { width: 100%; display: grid; grid-template-columns: 34px 1fr; gap: 9px; align-items: center; padding: 14px; border: 0; color: var(--muted); background: transparent; text-align: left; }
.theory-module-button > span { width: 30px; height: 30px; display: grid; place-items: center; border: 1px solid #343936; border-radius: 50%; color: var(--lime); font: 8px var(--mono); }
.theory-module-button strong, .theory-module-button small { display: block; }
.theory-module-button strong { color: var(--text); font-size: 11px; }
.theory-module-button small { margin-top: 3px; color: #666d69; font: 8px var(--mono); text-transform: uppercase; }
.theory-module.active .theory-module-button { background: #191d1b; box-shadow: inset 3px 0 var(--lime); }
.theory-lesson-list { display: none; padding: 3px 8px 10px 47px; }
.theory-module.active .theory-lesson-list { display: grid; }
.theory-lesson-list button { padding: 8px 9px; border: 0; border-radius: 4px; color: #757c77; background: transparent; text-align: left; font-size: 10px; }
.theory-lesson-list button:hover, .theory-lesson-list button.active { color: var(--text); background: #202421; }
.theory-lesson-list button.active { color: var(--lime); }
.theory-empty { padding: 20px; color: var(--muted); font-size: 12px; }
.theory-reader { min-height: 650px; padding: 34px; border: 1px solid var(--line); border-radius: 10px; background: var(--panel); scroll-margin-top: 20px; }
.theory-reader-head { padding-bottom: 28px; border-bottom: 1px solid var(--line); }
.theory-reader-head > span { color: var(--lime); font: 9px var(--mono); letter-spacing: 1px; }
.theory-reader-head h2 { margin: 12px 0 10px; font-size: clamp(28px, 4vw, 44px); letter-spacing: -1.5px; }
.theory-reader-head p { margin: 0; color: #b4bbb6; font-size: 15px; line-height: 1.7; }
.theory-section { margin: 28px 0; }
.theory-section h3 { margin: 0 0 9px; font-size: 17px; }
.theory-section p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.8; }
.theory-code { margin-top: 30px; }
.theory-actions { display: grid; grid-template-columns: 1fr auto 1fr; gap: 14px; align-items: center; margin-top: 36px; padding-top: 24px; border-top: 1px solid var(--line); }
.theory-actions > span { color: var(--muted); font: 9px var(--mono); }
.theory-actions .primary-btn { justify-self: end; }
.theory-actions button:disabled { opacity: .35; cursor: not-allowed; }

.shell-intro { max-width: 720px; color: var(--muted); line-height: 1.7; margin: -22px 0 34px; }
.shell-layout { display: grid; grid-template-columns: 285px 1fr; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; min-height: 680px; background: var(--panel); }
.command-library { border-right: 1px solid var(--line); background: #101212; min-width: 0; }
.library-head { padding: 19px; border-bottom: 1px solid var(--line); }
.library-head > div { display: flex; justify-content: space-between; color: var(--muted); font: 10px var(--mono); margin-bottom: 13px; }
.library-head strong { color: var(--lime); }
.library-head input { width: 100%; background: #191c1b; color: var(--text); border: 1px solid var(--line); border-radius: 5px; padding: 10px; outline: none; font: 11px var(--mono); }
.library-head input:focus { border-color: var(--lime); }
.command-groups { max-height: 605px; overflow: auto; padding: 10px; }
.command-group h3 { margin: 14px 9px 7px; color: #646b67; font: 9px var(--mono); letter-spacing: 1px; }
.command-item { width: 100%; display: grid; grid-template-columns: 62px 1fr; gap: 8px; border: 0; border-radius: 5px; padding: 10px; text-align: left; color: var(--muted); background: transparent; font-size: 11px; }
.command-item code { background: none; padding: 0; color: var(--text); }
.command-item:hover, .command-item.active { background: #1c201e; color: var(--text); }
.command-item.active { box-shadow: inset 2px 0 var(--lime); }
.shell-workspace { min-width: 0; display: flex; flex-direction: column; background: #0c0e0e; }
.command-doc { padding: 27px 30px 24px; border-bottom: 1px solid var(--line); background: #151817; }
.command-title { display: flex; align-items: center; gap: 13px; }
.command-prompt { width: 38px; height: 38px; display: grid; place-items: center; color: var(--lime); background: #20251d; border-radius: 6px; font: 18px var(--mono); }
.command-title h2 { margin: 0; font: 500 22px var(--mono); }.command-title p { margin: 3px 0 0; color: var(--muted); font-size: 10px; }
.doc-category { margin-left: auto; border: 1px solid var(--line); color: var(--muted); padding: 5px 8px; font: 8px var(--mono); }
.doc-description { color: #c3c8c4; font-size: 13px; line-height: 1.65; margin: 19px 0; }
.doc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.doc-grid > div { display: flex; flex-direction: column; gap: 8px; }
.doc-grid small { color: #666d69; font: 8px var(--mono); }
.doc-grid code, .example-code { min-height: 38px; display: flex; align-items: center; justify-content: space-between; border: 1px solid var(--line); background: #0f1111; color: var(--lime); border-radius: 4px; padding: 9px 11px; text-align: left; font: 11px var(--mono); }
.example-code:hover { border-color: var(--lime); }.example-code span { color: var(--muted); }
.tip-box { margin-top: 15px; display: flex; gap: 12px; background: rgba(64,224,208,.05); border-left: 2px solid var(--cyan); padding: 10px 13px; font-size: 10px; }
.tip-box b { color: var(--cyan); white-space: nowrap; }.tip-box span { color: var(--muted); }
.big-terminal { flex: 1; min-height: 305px; padding-bottom: 18px; overflow: hidden; }
.terminal-bar { height: 42px; padding: 0 16px; display: flex; align-items: center; border-bottom: 1px solid #202323; color: #666d69; font: 9px var(--mono); }
.terminal-bar > div { display: flex; gap: 5px; margin-right: 18px; }.terminal-bar i { width: 7px; height: 7px; border-radius: 50%; background: #3e4340; }.terminal-bar i:first-child { background: var(--orange); }
.terminal-bar b { color: var(--lime); }.terminal-bar button { margin-left: auto; color: #626864; background: transparent; border: 0; font: 8px var(--mono); }
.shell-output { height: 225px; overflow-y: auto; padding: 17px 20px 5px; color: #c3c8c4; white-space: pre-wrap; font: 12px/1.65 var(--mono); }
.shell-output .welcome-line { color: #747b76; }.shell-output b, .shell-output .output-command { color: var(--lime); }.shell-output .error-output { color: #ff8560; }
.shell-line { display: flex; align-items: center; gap: 3px; padding: 0 20px; color: #929994; font: 12px var(--mono); }
.shell-user { color: var(--cyan); }.shell-path { color: var(--lime); }
.shell-line input { flex: 1; min-width: 0; border: 0; outline: 0; background: transparent; color: var(--text); font: inherit; padding-left: 7px; }
.terminal-help { height: 34px; display: flex; gap: 22px; padding: 0 20px; align-items: center; border-top: 1px solid var(--line); color: #555b57; font: 8px var(--mono); }

.playground { display: grid; grid-template-columns: 350px 1fr; min-height: 570px; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
.challenge-pane { padding: 28px; background: var(--panel); display: flex; flex-direction: column; border-right: 1px solid var(--line); }
.pane-top { display: flex; justify-content: space-between; font: 9px var(--mono); color: var(--muted); }
.difficulty { color: var(--lime); }.challenge-pane h2 { margin: 50px 0 15px; font-size: 25px; }
.challenge-pane > p { color: var(--muted); line-height: 1.7; font-size: 14px; }
code { font: 12px var(--mono); color: var(--lime); background: #20231e; padding: 2px 5px; border-radius: 3px; }
.hint { margin-top: 25px; padding: 15px; border-left: 2px solid var(--orange); background: rgba(255,107,53,.05); }
.hint strong { font: 10px var(--mono); color: var(--orange); text-transform: uppercase; }.hint p { color: var(--muted); font-size: 12px; line-height: 1.6; margin-bottom: 0; }
.challenge-nav { margin-top: auto; display: flex; justify-content: space-between; align-items: center; color: var(--muted); font: 10px var(--mono); }
.challenge-nav button { color: var(--text); border: 1px solid var(--line); background: transparent; width: 34px; height: 34px; }
.editor-pane { display: flex; flex-direction: column; min-width: 0; background: #0e1010; }
.tabs { height: 50px; display: flex; align-items: stretch; border-bottom: 1px solid var(--line); background: var(--panel); }
.tab { padding: 0 20px; border: 0; border-right: 1px solid var(--line); color: var(--muted); background: transparent; font: 11px var(--mono); }
.tab.active { color: var(--text); background: #0e1010; border-top: 2px solid var(--lime); }
.run-btn { margin: 9px 10px 9px auto; padding: 0 15px; background: var(--lime); border: 0; border-radius: 4px; font: 700 10px var(--mono); }
.editor-wrap { flex: 1; display: grid; grid-template-columns: 48px 1fr; padding-top: 20px; }
.line-numbers { color: #4d5350; font: 14px/1.8 var(--mono); text-align: right; padding-right: 14px; user-select: none; }
textarea { resize: none; border: 0; outline: 0; background: transparent; color: #e7e9e4; font: 14px/1.8 var(--mono); padding: 0 20px; caret-color: var(--lime); }
.result-bar { height: 42px; border-top: 1px solid var(--line); display: flex; align-items: center; padding: 0 18px; color: var(--muted); font: 10px var(--mono); gap: 9px; }
.dot { width: 7px; height: 7px; background: #555; border-radius: 50%; }.result-bar.success .dot { background: var(--lime); box-shadow: 0 0 8px var(--lime); }.result-bar.error .dot { background: var(--orange); }
.terminal { flex: 1; color: #aab0ac; padding: 22px; font: 13px/1.7 var(--mono); overflow: auto; }
.terminal span, .terminal b { color: var(--lime); }.terminal label { display: flex; gap: 10px; }.terminal input { flex: 1; border: 0; outline: 0; color: var(--text); background: transparent; font: inherit; }
.hidden { display: none !important; }
.toast { position: fixed; right: 24px; bottom: 24px; padding: 14px 20px; background: var(--text); color: var(--bg); border-radius: 6px; font-size: 12px; font-weight: 700; transform: translateY(90px); transition: .3s; z-index: 20; }
.toast.show { transform: translateY(0); }
.modal-backdrop { position: fixed; inset: 0; z-index: 30; display: grid; place-items: center; padding: 20px; background: rgba(0,0,0,.75); backdrop-filter: blur(8px); }
.auth-modal { width: min(430px, 100%); position: relative; padding: 32px; background: #141716; border: 1px solid #343936; border-radius: 10px; box-shadow: 0 30px 90px rgba(0,0,0,.55); }
.modal-close { position: absolute; right: 15px; top: 12px; border: 0; background: transparent; color: var(--muted); font-size: 24px; }
.auth-modal h2 { margin: 0 0 9px; font-size: 26px; }.auth-copy { margin: 0 0 22px; color: var(--muted); font-size: 12px; line-height: 1.6; }
.auth-modal form { display: grid; gap: 14px; }
.auth-modal label { display: grid; gap: 7px; color: #a9afab; font: 9px var(--mono); text-transform: uppercase; }
.auth-modal input { width: 100%; border: 1px solid var(--line); outline: 0; border-radius: 5px; padding: 12px; background: #0c0e0e; color: var(--text); font: 12px var(--mono); text-transform: none; }
.auth-modal input:focus { border-color: var(--lime); }.auth-submit { width: 100%; margin-top: 3px; }

.account-modal { width: min(520px, 100%); max-height: min(92vh, 820px); overflow: auto; position: relative; padding: 32px; background: #141716; border: 1px solid #343936; border-radius: 10px; box-shadow: 0 30px 90px rgba(0,0,0,.55); }
.account-head { display: flex; align-items: center; gap: 15px; margin: 4px 0 24px; }
.account-avatar { display: grid; place-items: center; width: 54px; height: 54px; flex: 0 0 54px; border-radius: 50%; background: linear-gradient(135deg, rgba(199,255,56,.95), rgba(64,224,208,.9)); color: #0b0c0c; font-size: 26px; box-shadow: 0 0 28px rgba(64,224,208,.14); }
.account-head h2 { margin: 0 0 3px; font-size: 22px; }
.account-email { margin: 0; color: var(--muted); font: 11px var(--mono); }
.account-icon-section { margin: -6px 0 22px; }
.account-icon-section p { margin: 0 0 10px; color: var(--muted); font: 9px var(--mono); text-transform: uppercase; letter-spacing: .7px; }
.account-icons { display: grid; grid-template-columns: repeat(8, 1fr); gap: 8px; }
.account-icon-option { height: 38px; border: 1px solid var(--line); border-radius: 8px; background: #0c0e0e; color: var(--text); font-size: 19px; transition: transform .15s, border-color .15s, background .15s; }
.account-icon-option:hover { transform: translateY(-1px); border-color: rgba(64,224,208,.55); }
.account-icon-option.active { background: rgba(199,255,56,.12); border-color: var(--lime); box-shadow: 0 0 16px rgba(199,255,56,.12); }
.save-icon-btn { width: 100%; margin-top: 10px; padding: 11px; border: 1px solid var(--lime); border-radius: 5px; background: transparent; color: var(--lime); font: 10px var(--mono); text-transform: uppercase; letter-spacing: .8px; transition: background .2s, color .2s; }
.save-icon-btn:hover { background: var(--lime); color: #10120d; }
.save-icon-btn:disabled { opacity: .5; cursor: default; }
.account-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin-bottom: 22px; }
.account-stat { padding: 14px 8px; text-align: center; background: #0c0e0e; border: 1px solid var(--line); border-radius: 7px; }
.account-stat strong { display: block; font-size: 22px; color: var(--lime); line-height: 1.1; }
.account-stat span { font: 8px var(--mono); text-transform: uppercase; letter-spacing: .5px; color: var(--muted); }
.account-progress { margin-bottom: 24px; }
.account-progress-label { display: flex; justify-content: space-between; font: 9px var(--mono); text-transform: uppercase; color: var(--muted); }
.account-progress-label b { color: var(--text); }
.account-section-title { margin: 0 0 12px; color: var(--lime); font: 9px var(--mono); text-transform: uppercase; letter-spacing: .8px; }
.account-password-form { display: grid; gap: 12px; padding: 18px; margin-bottom: 18px; background: #0c0e0e; border: 1px solid var(--line); border-radius: 9px; }
.account-password-form label { display: grid; gap: 7px; color: #a9afab; font: 9px var(--mono); text-transform: uppercase; }
.account-password-form input { width: 100%; border: 1px solid var(--line); outline: 0; border-radius: 5px; padding: 12px; background: #121414; color: var(--text); font: 12px var(--mono); text-transform: none; }
.account-password-form input:focus { border-color: var(--lime); }
.account-message { min-height: 15px; margin: -2px 0 0; color: var(--muted); font-size: 11px; }
.account-message.success { color: var(--lime); }.account-message.error { color: var(--orange); }
.password-btn { width: 100%; padding: 12px; border: 1px solid var(--lime); border-radius: 5px; background: var(--lime); color: #10120d; font: 700 11px var(--mono); text-transform: uppercase; letter-spacing: .7px; }
.password-btn:disabled { opacity: .55; cursor: default; }
.danger-zone { padding: 18px; margin-bottom: 12px; background: rgba(255,107,53,.06); border: 1px solid rgba(255,107,53,.28); border-radius: 9px; }
.danger-zone .account-section-title { color: var(--orange); }
.danger-zone p:not(.account-section-title) { margin: -2px 0 14px; color: var(--muted); font-size: 12px; line-height: 1.55; }
.delete-account-btn { width: 100%; padding: 12px; border: 1px solid var(--orange); border-radius: 5px; background: rgba(255,107,53,.08); color: var(--orange); font: 11px var(--mono); text-transform: uppercase; letter-spacing: 1px; transition: background .2s, color .2s; }
.delete-account-btn:hover { background: var(--orange); color: #0b0c0c; }
.delete-account-btn:disabled { opacity: .5; cursor: default; }
.logout-btn { width: 100%; padding: 13px; border: 1px solid var(--orange); border-radius: 5px; background: transparent; color: var(--orange); font: 11px var(--mono); text-transform: uppercase; letter-spacing: 1px; transition: background .2s, color .2s; }
.logout-btn:hover { background: var(--orange); color: #0b0c0c; }
.logout-btn:disabled { opacity: .5; cursor: default; }
.auth-switch { width: 100%; margin-top: 17px; border: 0; background: transparent; color: var(--muted); font-size: 11px; }
.auth-forgot { width: 100%; margin-top: 8px; border: 0; background: transparent; color: var(--cyan); font-size: 11px; }
.auth-forgot:hover, .auth-switch:hover { color: var(--lime); }.auth-error { min-height: 15px; margin: 0; color: var(--orange); font-size: 11px; }

@media (max-width: 1000px) {
  .course-grid { grid-template-columns: repeat(2, 1fr); }
  .hero-spinner { transform: scale(.82); }
  .playground { grid-template-columns: 1fr; }
  .challenge-pane { min-height: 400px; border-right: 0; border-bottom: 1px solid var(--line); }
  .editor-pane { min-height: 520px; }
  .shell-layout { grid-template-columns: 230px 1fr; }
  .lesson-layout { grid-template-columns: 230px 1fr; gap: 28px; }
  .theory-layout { grid-template-columns: 240px 1fr; gap: 20px; }
}
@media (max-width: 720px) {
  .sidebar { transform: translateX(-100%); transition: .3s; }.sidebar.open { transform: translateX(0); }
  main { margin-left: 0; }.menu-toggle { display: block; }
  .view { padding: 40px 20px 60px; }.hero { grid-template-columns: 1fr; }.hero-spinner { display: none; }
  h1 { letter-spacing: -2px; }.course-grid { grid-template-columns: 1fr; }
  .daily-card { grid-template-columns: auto 1fr; }.daily-card button { grid-column: 1 / -1; }
  .list-item { grid-template-columns: 40px 1fr; }.list-item .lesson-count, .list-item button { grid-column: 2; }
  .status { display: none; }.page-title { font-size: 42px; }
  .topbar { gap: 12px; padding: 0 18px; }.account-btn { max-width: 115px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .account-stats { grid-template-columns: repeat(2, 1fr); }
  .shell-layout { grid-template-columns: 1fr; }
  .command-library { border-right: 0; border-bottom: 1px solid var(--line); }
  .command-groups { max-height: 250px; }
  .doc-grid { grid-template-columns: 1fr; }
  .command-doc { padding: 22px 18px; }
  .terminal-help { display: none; }
  .curriculum-stats { grid-template-columns: repeat(2, 1fr); }.curriculum-stats div:nth-child(2) { border-right: 0; }
  .lesson-layout { grid-template-columns: 1fr; }.lesson-outline { position: static; }.lesson-content > h1 { letter-spacing: -2px; }
  .theory-hero { align-items: start; flex-direction: column; }.theory-summary { margin-top: -18px; }
  .theory-layout { grid-template-columns: 1fr; }.theory-catalog { max-height: 360px; position: static; }
  .theory-reader { padding: 24px 18px; }.theory-actions { grid-template-columns: 1fr 1fr; }.theory-actions > span { display: none; }
}