:root {
  --bg: #0d1117; --bg2: #161b22; --card: #1c2330;
  --text: #e6edf3; --muted: #8b949e; --accent: #2ea043; --accent2: #58a6ff;
  --danger: #f85149; --radius: 14px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif; background: var(--bg); color: var(--text); line-height: 1.7; }
.container { max-width: 1000px; margin: 0 auto; padding: 0 24px; }

/* NAV */
#nav { position: fixed; top: 0; left: 0; right: 0; z-index: 100; background: rgba(13,17,23,.9); backdrop-filter: blur(12px); border-bottom: 1px solid rgba(255,255,255,.07); }
.nav-inner { max-width: 1000px; margin: 0 auto; padding: 14px 24px; display: flex; justify-content: space-between; align-items: center; gap: 16px; }
.logo { font-size: 20px; font-weight: 800; color: var(--text); text-decoration: none; }
.logo span { color: var(--accent); font-weight: 600; }
.nav-links { display: flex; gap: 24px; }
.nav-links a { color: var(--muted); text-decoration: none; font-size: 15px; font-weight: 500; }
.nav-links a:hover { color: var(--text); }
.progress-mini { display: flex; align-items: center; gap: 10px; font-size: 13px; color: var(--muted); }
.progress-bar { width: 100px; height: 8px; background: rgba(255,255,255,.1); border-radius: 99px; overflow: hidden; }
#progressFill { height: 100%; width: 0; background: linear-gradient(90deg, var(--accent), var(--accent2)); transition: width .5s var(--ease); }

/* VIEWS */
main { padding-top: 70px; }
.view { display: none; padding: 60px 0 100px; animation: fadeIn .4s var(--ease); }
.view.active { display: block; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(16px); } }

/* HERO */
.hero { text-align: center; padding: 80px 0; background: radial-gradient(600px 300px at 50% 0%, rgba(46,160,67,.12), transparent); }
.hero-badge { display: inline-block; background: rgba(46,160,67,.15); color: var(--accent); padding: 8px 20px; border-radius: 99px; font-size: 14px; font-weight: 600; margin-bottom: 28px; border: 1px solid rgba(46,160,67,.3); }
.hero h1 { font-size: clamp(38px, 6vw, 64px); font-weight: 800; letter-spacing: -1.5px; line-height: 1.1; margin-bottom: 24px; }
.hero h1 em { font-style: normal; color: var(--accent); }
.hero-sub { font-size: 19px; color: var(--muted); max-width: 640px; margin: 0 auto 36px; }
.hero-cta { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin-bottom: 60px; }
.hero-stats { display: flex; justify-content: center; gap: 56px; flex-wrap: wrap; }
.hero-stats strong { display: block; font-size: 36px; }
.hero-stats span { color: var(--muted); font-size: 14px; }

/* BUTTONS */
.btn { display: inline-block; padding: 14px 32px; border-radius: 10px; font-weight: 600; font-size: 15px; text-decoration: none; border: none; cursor: pointer; transition: transform .2s var(--ease), box-shadow .2s; color: var(--text); background: var(--card); }
.btn:hover { transform: translateY(-2px); }
.btn-primary { background: var(--accent); color: #fff; box-shadow: 0 8px 24px rgba(46,160,67,.3); }
.btn-ghost { background: transparent; border: 1px solid rgba(255,255,255,.15); }
.btn-sm { padding: 8px 18px; font-size: 13px; }

/* SECTIONS */
.eyebrow { text-transform: uppercase; letter-spacing: 3px; font-size: 12px; color: var(--accent); font-weight: 700; margin-bottom: 12px; }
h2 { font-size: clamp(28px, 4vw, 40px); font-weight: 800; letter-spacing: -1px; margin-bottom: 16px; }
.section-sub { color: var(--muted); margin-bottom: 40px; max-width: 700px; }

/* CARDS */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; margin-top: 40px; }
.card { background: var(--card); border-radius: var(--radius); padding: 32px; border: 1px solid rgba(255,255,255,.06); transition: transform .3s var(--ease); }
.card:hover { transform: translateY(-4px); }
.card-icon { font-size: 40px; margin-bottom: 16px; }
.card h3 { font-size: 19px; margin-bottom: 10px; }
.card p { color: var(--muted); font-size: 15px; margin-bottom: 14px; }
.card a { color: var(--accent2); font-weight: 600; text-decoration: none; }
.principles { padding: 80px 0; }

/* TIMELINE */
.timeline { margin-top: 40px; display: flex; flex-direction: column; gap: 4px; }
.tl-item { display: flex; gap: 24px; padding: 24px; border-radius: var(--radius); transition: background .2s; }
.tl-item:hover { background: var(--bg2); }
.tl-num { width: 48px; height: 48px; flex-shrink: 0; border-radius: 50%; background: var(--card); border: 2px solid rgba(255,255,255,.12); display: flex; align-items: center; justify-content: center; font-weight: 800; font-size: 18px; }
.tl-item.done .tl-num { background: var(--accent); border-color: var(--accent); color: #fff; }
.tl-body h3 { font-size: 20px; margin-bottom: 6px; }
.tl-body p { color: var(--muted); font-size: 15px; margin-bottom: 8px; }
.tl-progress { font-size: 13px; color: var(--accent2); font-weight: 600; }

/* MODULES */
.module-card { background: var(--card); border-radius: var(--radius); padding: 28px; margin-bottom: 20px; border: 1px solid rgba(255,255,255,.06); }
.module-head { display: flex; gap: 18px; align-items: center; margin-bottom: 18px; }
.module-icon { font-size: 36px; }
.module-head h3 { font-size: 20px; }
.module-head p { color: var(--muted); font-size: 14px; }
.module-pct { margin-left: auto; font-size: 13px; color: var(--accent2); font-weight: 700; white-space: nowrap; }
.lesson-links { display: flex; flex-wrap: wrap; gap: 10px; }
.lesson-link { background: var(--bg2); border: 1px solid rgba(255,255,255,.08); color: var(--text); padding: 10px 18px; border-radius: 8px; font-size: 14px; cursor: pointer; transition: all .2s; }
.lesson-link:hover { border-color: var(--accent); }
.lesson-link.done { border-color: var(--accent); color: var(--accent); }
.lesson { background: var(--card); border-radius: var(--radius); padding: 40px; border: 1px solid rgba(255,255,255,.06); }
.lesson h2 { margin: 20px 0; }
.lesson h4 { margin: 20px 0 10px; color: var(--accent2); }
.lesson p, .lesson li { color: #c9d1d9; margin-bottom: 12px; font-size: 16px; }
.lesson ul, .lesson ol { padding-left: 24px; margin-bottom: 16px; }
.lesson code { background: rgba(88,166,255,.12); color: var(--accent2); padding: 2px 8px; border-radius: 6px; font-size: 14px; }
.lesson .btn-primary { margin-top: 24px; }

/* QUIZ */
.quiz-list { display: flex; flex-direction: column; gap: 14px; margin-top: 32px; }
.quiz-item { display: flex; justify-content: space-between; align-items: center; background: var(--card); border: 1px solid rgba(255,255,255,.06); border-radius: var(--radius); padding: 22px 28px; cursor: pointer; color: var(--text); font-size: 16px; text-align: left; transition: all .2s; }
.quiz-item:hover { border-color: var(--accent); transform: translateX(4px); }
.quiz-item span { color: var(--muted); font-size: 14px; }
.quiz-card { background: var(--card); border-radius: var(--radius); padding: 40px; margin-top: 24px; border: 1px solid rgba(255,255,255,.06); }
.quiz-progress { color: var(--muted); font-size: 14px; margin-bottom: 16px; }
.quiz-card h3 { font-size: 22px; margin-bottom: 24px; }
#quizOptions { display: flex; flex-direction: column; gap: 12px; }
.quiz-opt { background: var(--bg2); border: 1px solid rgba(255,255,255,.1); color: var(--text); padding: 16px 20px; border-radius: 10px; font-size: 15px; text-align: left; cursor: pointer; transition: all .2s; }
.quiz-opt:hover:not(:disabled) { border-color: var(--accent2); }
.quiz-opt.correct { border-color: var(--accent); background: rgba(46,160,67,.15); }
.quiz-opt.wrong { border-color: var(--danger); background: rgba(248,81,73,.1); }
.quiz-opt:disabled { cursor: default; opacity: .85; }
#quizFeedback { margin-top: 20px; font-size: 17px; font-weight: 600; }
#quizFeedback.ok { color: var(--accent); }
#quizFeedback.bad { color: var(--danger); }
#backToQuiz, #backToModules { margin-bottom: 8px; }

footer { padding: 40px 0; border-top: 1px solid rgba(255,255,255,.07); text-align: center; }
footer p { color: var(--muted); font-size: 14px; }

@media (max-width: 700px) {
  .nav-links { display: none; }
  .hero-stats { gap: 32px; }
  .lesson { padding: 24px; }
  .quiz-card { padding: 24px; }
}

.lesson-nav { display: flex; gap: 12px; margin-top: 28px; flex-wrap: wrap; }
.lesson-nav .btn { flex: 1; min-width: 140px; text-align: center; }

.module-quiz { margin-bottom: 18px; }