/* LearnHub — "field notes" academic design direction
   Palette: Ink #1B2430, Chalk #F5F3EE, Amber #E8A33D, Sage #4F7864, Slate #5B6472
   Display: Fraunces (serif, characterful) / Body: Inter / Utility: JetBrains Mono
*/
@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,400;9..144,600;9..144,700&family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@500&display=swap');

:root{
  --ink:#1B2430;
  --chalk:#F5F3EE;
  --amber:#E8A33D;
  --sage:#4F7864;
  --slate:#5B6472;
  --line:#DDD7C9;
  --white:#fff;
  --radius:10px;
}

*{box-sizing:border-box;}
html,body{margin:0;padding:0;}
body{
  font-family:'Inter',sans-serif;
  background:var(--chalk);
  color:var(--ink);
  line-height:1.5;
}
a{color:inherit;text-decoration:none;}
h1,h2,h3,h4{font-family:'Fraunces',serif;font-weight:600;margin:0 0 .4em;letter-spacing:-.01em;}
img{max-width:100%;display:block;}
.container{max-width:1180px;margin:0 auto;padding:0 24px;}

/* Header */
.site-header{
  border-bottom:2px solid var(--ink);
  background:var(--chalk);
  position:sticky;top:0;z-index:50;
}
.site-header .container{display:flex;align-items:center;justify-content:space-between;height:68px;}
.brand{font-family:'Fraunces',serif;font-weight:700;font-size:22px;display:flex;align-items:center;gap:8px;}
.brand .dot{width:10px;height:10px;background:var(--amber);border-radius:50%;display:inline-block;}
.nav-links{display:flex;gap:28px;align-items:center;font-weight:500;font-size:15px;}
.nav-links a:hover{color:var(--sage);}
.btn{
  display:inline-block;padding:10px 18px;border-radius:var(--radius);font-weight:600;
  border:2px solid var(--ink);cursor:pointer;font-size:14px;font-family:'Inter',sans-serif;
  transition:transform .12s ease;
}
.btn:hover{transform:translateY(-2px);}
.btn-primary{background:var(--ink);color:var(--chalk);}
.btn-outline{background:transparent;color:var(--ink);}
.btn-amber{background:var(--amber);border-color:var(--amber);color:var(--ink);}
.btn-sm{padding:6px 12px;font-size:13px;}

/* Hero */
.hero{padding:64px 0 40px;border-bottom:2px solid var(--ink);}
.hero .eyebrow{
  font-family:'JetBrains Mono',monospace;font-size:12px;letter-spacing:.08em;
  text-transform:uppercase;color:var(--sage);margin-bottom:14px;display:block;
}
.hero h1{font-size:44px;max-width:680px;}
.hero p{max-width:560px;color:var(--slate);font-size:17px;}
.hero-form{display:flex;gap:10px;margin-top:26px;max-width:520px;}
.hero-form input{
  flex:1;padding:13px 16px;border:2px solid var(--ink);border-radius:var(--radius);
  font-size:15px;background:var(--white);
}

/* Course grid */
.section-title{display:flex;justify-content:space-between;align-items:baseline;margin:48px 0 18px;}
.section-title .index{font-family:'JetBrains Mono',monospace;color:var(--slate);font-size:13px;}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:22px;margin-bottom:50px;}
.card{
  background:var(--white);border:2px solid var(--ink);border-radius:var(--radius);
  overflow:hidden;display:flex;flex-direction:column;
}
.card .thumb{height:150px;background:linear-gradient(135deg,var(--ink),#333d4d);
  display:flex;align-items:center;justify-content:center;color:var(--chalk);
  font-family:'Fraunces',serif;font-size:20px;text-align:center;padding:10px;}
.card-body{padding:16px;flex:1;display:flex;flex-direction:column;gap:8px;}
.card-body h3{font-size:18px;}
.tag{
  font-family:'JetBrains Mono',monospace;font-size:11px;text-transform:uppercase;
  color:var(--sage);letter-spacing:.05em;
}
.stars{color:var(--amber);font-size:14px;letter-spacing:1px;}
.price{font-weight:700;margin-top:auto;font-size:16px;}

/* Course detail layout */
.course-layout{display:grid;grid-template-columns:2fr 1fr;gap:30px;padding:30px 0 60px;align-items:start;}
.player-wrap{background:var(--ink);border-radius:var(--radius);overflow:hidden;position:relative;}
.player-wrap video, .player-wrap iframe{width:100%;display:block;aspect-ratio:16/9;border:0;}
.live-badge{
  position:absolute;top:12px;left:12px;background:#D6472F;color:#fff;
  font-family:'JetBrains Mono',monospace;font-size:12px;padding:4px 10px;border-radius:20px;
  display:flex;align-items:center;gap:6px;z-index:5;
}
.live-badge .pulse{width:8px;height:8px;background:#fff;border-radius:50%;animation:pulse 1.4s infinite;}
@keyframes pulse{0%{opacity:1;}50%{opacity:.3;}100%{opacity:1;}}

.curriculum{border:2px solid var(--ink);border-radius:var(--radius);overflow:hidden;}
.curriculum h4{padding:14px 16px;margin:0;border-bottom:2px solid var(--ink);background:var(--white);}
.lesson-item{
  display:flex;align-items:center;gap:10px;padding:12px 16px;border-bottom:1px solid var(--line);
  background:var(--white);cursor:pointer;font-size:14px;
}
.lesson-item:last-child{border-bottom:0;}
.lesson-item:hover{background:var(--chalk);}
.lesson-item.active{background:var(--amber);}
.lesson-num{font-family:'JetBrains Mono',monospace;color:var(--slate);font-size:12px;width:22px;}

/* Tabs: about / Q&A / reviews */
.tabs{display:flex;gap:0;border-bottom:2px solid var(--ink);margin-top:28px;}
.tab-btn{padding:10px 18px;font-weight:600;cursor:pointer;border:none;background:none;font-size:14px;
  border-bottom:3px solid transparent;margin-bottom:-2px;font-family:'Inter',sans-serif;}
.tab-btn.active{border-color:var(--amber);}
.tab-panel{display:none;padding:22px 0;}
.tab-panel.active{display:block;}

/* Q&A chat */
.qa-list{display:flex;flex-direction:column;gap:14px;max-height:420px;overflow-y:auto;padding-right:6px;}
.qa-item{border:2px solid var(--ink);border-radius:var(--radius);padding:14px;background:var(--white);}
.qa-item .meta{font-family:'JetBrains Mono',monospace;font-size:11px;color:var(--slate);margin-bottom:6px;}
.qa-answers{margin-top:10px;padding-left:14px;border-left:3px solid var(--line);display:flex;flex-direction:column;gap:8px;}
.qa-form{display:flex;gap:8px;margin-top:16px;}
.qa-form textarea{flex:1;padding:10px 12px;border:2px solid var(--ink);border-radius:var(--radius);font-family:inherit;resize:vertical;min-height:44px;}

/* Ratings */
.rating-summary{display:flex;align-items:center;gap:18px;margin-bottom:18px;}
.rating-big{font-family:'Fraunces',serif;font-size:48px;font-weight:700;}
.star-input{font-size:26px;color:var(--line);cursor:pointer;display:inline-flex;gap:4px;}
.star-input span.on{color:var(--amber);}
.review-item{border-top:1px solid var(--line);padding:14px 0;}

/* Forms */
.form-card{max-width:440px;margin:60px auto;border:2px solid var(--ink);border-radius:var(--radius);padding:32px;background:var(--white);}
.form-card h2{margin-bottom:6px;}
.field{margin-bottom:16px;}
.field label{display:block;font-weight:600;font-size:13px;margin-bottom:6px;}
.field input, .field select, .field textarea{
  width:100%;padding:11px 13px;border:2px solid var(--ink);border-radius:var(--radius);
  font-size:14px;font-family:inherit;background:var(--white);
}
.alert{padding:12px 14px;border-radius:var(--radius);margin-bottom:16px;font-size:14px;}
.alert-error{background:#FBE3DD;border:2px solid #D6472F;}
.alert-ok{background:#E4EFE8;border:2px solid var(--sage);}

footer{border-top:2px solid var(--ink);padding:30px 0;margin-top:60px;color:var(--slate);font-size:14px;}

@media(max-width:860px){
  .course-layout{grid-template-columns:1fr;}
  .hero h1{font-size:32px;}
}