/* KCET Physics — dark, kinetic theme (v2, 2026-07-24) */
:root{
  --bg:#0a0e1f;
  --bg-alt:#0f1530;
  --surface:#131b3a;
  --surface-2:#182246;
  --text:#eef1ff;
  --muted:#94a1c9;
  --muted-2:#6b7aa8;
  --primary:#5eead4;
  --primary-dark:#9fb2e0;
  --accent:#ffb454;
  --primary-light:rgba(94,234,212,.14);
  --accent-light:rgba(255,180,84,.14);
  --border:rgba(255,255,255,.09);
  --border-strong:rgba(255,255,255,.16);
  --success:#34d399;
  --danger:#fb7185;
  --danger-border:#f43f5e;
  --warning:rgba(255,180,84,.12);
  --warning-border:var(--accent);
  --shadow:0 16px 34px rgba(0,0,0,.35);
  --font-head:'Space Grotesk',sans-serif;
  --font-body:'Inter',sans-serif;
}
*{box-sizing:border-box}
body{margin:0;font-family:var(--font-body);background:var(--bg);color:var(--text)}

/* ── header / nav ── */
.site-header{display:flex;justify-content:space-between;align-items:center;padding:16px 7%;background:rgba(10,14,31,.85);backdrop-filter:blur(10px);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:10}
.brand{display:flex;align-items:center;gap:12px;color:var(--text);text-decoration:none;font-family:var(--font-head)}
.brand-mark{width:42px;height:42px;background:linear-gradient(135deg,var(--primary),#3fc7ff);color:#03211c;display:grid;place-items:center;border-radius:12px;font-weight:700}
.brand-logo{display:block;width:38px;height:46px;flex-shrink:0}
.brand-logo img{width:100%;height:100%;object-fit:contain;display:block}
.brand small{display:block;color:var(--muted-2);font-size:.72rem;font-weight:500;margin-top:2px;font-family:var(--font-body)}
nav{display:flex;align-items:center;gap:22px}
nav a{color:var(--muted);text-decoration:none;font-weight:600;font-size:.92rem}
nav a:hover,nav a.active{color:var(--text)}
nav a.active{color:var(--primary)}
.nav-soon{color:var(--muted-2);font-weight:600;font-size:.82rem;display:flex;align-items:center;gap:5px;cursor:default}
.nav-soon .tag{background:var(--surface-2);border:1px solid var(--border);border-radius:999px;padding:2px 8px;font-size:.68rem;letter-spacing:.3px}
.nav-cta{display:flex;align-items:center;gap:12px}

main{width:min(1120px,90%);margin:0 auto;padding:36px 0 50px}

/* ── hero ── */
.hero{display:grid;grid-template-columns:1.5fr .8fr;gap:26px;align-items:stretch;position:relative;overflow:hidden}
.hero-text,.hero-card,.content-card,.chapter-card,.feature-card,.question-panel,.nudge-panel,.simulation-placeholder,.mode-card,.result-card{background:var(--surface);border:1px solid var(--border);border-radius:20px;box-shadow:var(--shadow)}
.hero-text{padding:42px;position:relative;z-index:2}
.hero-card{padding:28px;position:relative;z-index:2}
.hero-card h3{margin-top:0}
.hero-card ol{padding-left:20px;line-height:2;color:var(--muted)}

h1,h2,h3{font-family:var(--font-head);font-weight:600}
h1{font-size:clamp(2rem,4vw,3.4rem);line-height:1.08;margin:12px 0 16px;color:var(--text)}
h1 em,h1 .accent-word{font-style:normal;color:var(--primary)}
h2{color:var(--text);margin-top:28px}
h3{color:var(--text)}
p{line-height:1.7;color:var(--muted)}

.pill,.status{display:inline-block;background:var(--primary-light);color:var(--primary);border-radius:999px;padding:7px 12px;font-weight:600;font-size:.82rem}

.hero-actions,.practice-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:22px}
.button{border:1px solid var(--border);background:transparent;color:var(--text);border-radius:12px;padding:11px 18px;font-weight:600;text-decoration:none;cursor:pointer;font-size:.92rem;transition:border-color .15s,background .15s}
.button:hover{border-color:var(--border-strong);background:var(--surface-2)}
.button.primary{background:var(--primary);color:#03211c;border-color:var(--primary)}
.button.primary:hover{background:#7ff2df}

/* ── trajectory decoration (home hero) ── */
.trajectory{position:absolute;top:0;right:-40px;width:420px;height:100%;z-index:1;opacity:.85;pointer-events:none}
.ball{offset-path:path('M20,300 C140,40 280,40 400,300');offset-rotate:0deg;animation:fly 3.4s ease-in-out infinite}
@keyframes fly{0%{offset-distance:0%;opacity:0}8%{opacity:1}92%{opacity:1}100%{offset-distance:100%;opacity:0}}
.eyebrow{display:inline-flex;align-items:center;gap:8px;background:var(--surface-2);border:1px solid var(--border);color:var(--primary);font-size:.78rem;font-weight:600;padding:6px 14px;border-radius:999px;margin-bottom:14px}
.eyebrow .dot{width:6px;height:6px;border-radius:50%;background:var(--primary)}
.stat-row{display:flex;gap:32px;flex-wrap:wrap;margin-top:24px}
.stat b{display:block;font-size:1.4rem;font-family:var(--font-head);color:var(--text)}
.stat span{color:var(--muted-2);font-size:.78rem}

/* ── grids / cards ── */
.grid-section,.chapter-list,.mode-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:18px;margin-top:24px}
.feature-card,.chapter-card,.content-card,.simulation-placeholder,.mode-card{padding:24px;transition:border-color .15s,transform .15s}
.feature-card:hover,.chapter-card:hover{border-color:var(--primary);transform:translateY(-2px)}
.mode-card{border-top:3px solid var(--accent)}
.page-heading{margin-bottom:24px}
.two-column{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:24px}
.clean-list{padding-left:22px;line-height:1.8}
.warning{background:var(--warning);border-color:var(--warning-border)}
.formula-stack{display:grid;gap:14px}
.formula-card{background:var(--surface);border:1px solid var(--border);border-radius:16px;padding:18px;box-shadow:var(--shadow)}
.formula-card code{display:block;background:var(--primary-light);color:var(--primary);padding:10px;border-radius:10px;margin:10px 0;font-weight:600;font-family:var(--font-body)}
.formula-card small{color:var(--muted);line-height:1.5}

/* ── practice / coach / drills ── */
.practice-app,.coach-app{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:22px}
.question-panel,.nudge-panel{padding:26px}
.question-meta{display:flex;justify-content:space-between;gap:12px;color:var(--muted);font-weight:600}
.options{display:grid;gap:12px;margin-top:20px}
.option{border:1px solid var(--border);background:var(--surface-2);border-radius:14px;padding:14px;cursor:pointer;transition:border-color .15s,background .15s}
.option:hover{border-color:var(--border-strong)}
.option.selected{border-color:var(--primary);background:var(--primary-light)}
.nudge-box,.feedback-box,.step-list{min-height:80px;border:1px dashed var(--border);border-radius:14px;padding:14px;color:var(--muted);line-height:1.6;margin-top:12px}
.feedback-box.correct{color:var(--success);border-color:var(--success)}
.feedback-box.wrong{color:var(--danger);border-color:var(--danger-border)}
.target-box{display:inline-block;margin:16px 0;padding:8px 12px;border-radius:999px;background:var(--accent-light);color:var(--accent);font-weight:600}
.coach-block{background:var(--surface-2);border:1px solid var(--border);border-radius:16px;padding:16px;margin-top:14px}
.step-item{background:var(--primary-light);color:var(--text);border-radius:12px;padding:10px;margin-bottom:10px}
.test-toolbar{display:flex;justify-content:space-between;align-items:center;background:var(--surface);border:1px solid var(--border);border-radius:18px;padding:16px 20px;box-shadow:var(--shadow);margin-bottom:20px;font-weight:600}
.test-question{background:var(--surface);border:1px solid var(--border);border-radius:18px;padding:22px;margin-bottom:16px;box-shadow:var(--shadow)}
.result-card{display:none;padding:24px;margin-top:22px}
.result-card.show{display:block}
.explanation{margin-top:12px;padding:12px;background:var(--surface-2);border-radius:12px;color:var(--muted);line-height:1.6}

.site-footer{padding:26px;text-align:center;color:var(--muted-2);border-top:1px solid var(--border);font-size:.85rem}

@media(max-width:800px){
  .hero,.two-column,.practice-app,.coach-app{grid-template-columns:1fr}
  .site-header{align-items:flex-start;flex-direction:column;gap:12px}
  .trajectory{display:none}
}

/* ── dynamic drill ── */
.dynamic-layout{display:grid;grid-template-columns:320px minmax(0,1fr);gap:22px}
.pattern-panel{background:var(--surface);border:1px solid var(--border);border-radius:20px;box-shadow:var(--shadow);padding:24px}
.pattern-list{display:grid;gap:12px}
.pattern-card{border:1px solid var(--border);background:var(--surface-2);border-radius:16px;padding:14px;cursor:pointer;transition:border-color .15s,background .15s}
.pattern-card:hover,.pattern-card.active{border-color:var(--accent);background:var(--accent-light)}
.pattern-card strong{display:block;color:var(--text);margin-bottom:6px;font-family:var(--font-head);font-weight:600}
.pattern-card small{display:block;color:var(--muted);line-height:1.45}
@media(max-width:800px){.dynamic-layout{grid-template-columns:1fr}}

/* ── mode navigation bar (practice pages) ── */
.mode-nav{display:flex;align-items:center;gap:14px;flex-wrap:wrap;background:var(--surface);border:1px solid var(--border);border-radius:14px;padding:10px 14px;margin-bottom:20px;position:sticky;top:78px;z-index:5}
.mode-back{color:var(--primary);text-decoration:none;font-weight:600;font-size:.88rem;white-space:nowrap}
.mode-back:hover{text-decoration:underline}
.mode-pills{display:flex;gap:8px;flex-wrap:wrap}
.mode-pill{color:var(--muted);text-decoration:none;font-weight:600;font-size:.82rem;padding:7px 13px;border-radius:999px;border:1px solid var(--border);transition:color .15s,border-color .15s,background .15s}
.mode-pill:hover{color:var(--text);border-color:var(--border-strong)}
.mode-pill.active{background:var(--primary);color:#03211c;border-color:var(--primary)}
@media(max-width:800px){.mode-nav{position:static}}

/* ── unit / syllabus lists ── */
.unit-list{display:grid;gap:16px}
.unit-card{background:var(--surface);border:1px solid var(--border);border-radius:20px;box-shadow:var(--shadow);padding:20px;display:flex;justify-content:space-between;gap:16px;align-items:center}
.planned-badge{display:inline-block;background:var(--surface-2);color:var(--muted-2);border:1px solid var(--border);border-radius:999px;padding:8px 12px;font-weight:600;font-size:.82rem}
.breadcrumb{color:var(--muted-2);font-weight:600;margin:10px 0 4px;font-size:.88rem}
.breadcrumb a{color:var(--primary);text-decoration:none}
.breadcrumb a:hover{text-decoration:underline}
@media(max-width:800px){.unit-card{align-items:flex-start;flex-direction:column}}


/* v5.2 home page positioning cleanup */
.production-hero .hero-text p{
  max-width: 760px;
  font-size: 1.02rem;
}
.product-loop-card ol{
  margin-bottom: 0;
}
.product-loop-card li strong{
  color: var(--primary);
}
.section-intro{
  margin: 40px 0 10px;
  max-width: 820px;
}
.section-intro h2{
  margin: 14px 0 8px;
  font-size: clamp(1.6rem,2.8vw,2.35rem);
}
.differentiator-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(230px,1fr));
  gap:18px;
  margin-top:22px;
}
.differentiator-card{
  background:linear-gradient(180deg,rgba(24,34,70,.96),rgba(19,27,58,.96));
  border:1px solid var(--border);
  border-radius:20px;
  padding:24px;
  box-shadow:var(--shadow);
  position:relative;
  overflow:hidden;
}
.differentiator-card::before{
  content:"";
  position:absolute;
  left:0;
  top:0;
  right:0;
  height:4px;
  background:linear-gradient(90deg,var(--primary),var(--accent));
}
.diff-icon{
  width:44px;
  height:44px;
  border-radius:14px;
  display:grid;
  place-items:center;
  background:var(--primary-light);
  font-size:1.35rem;
  margin-bottom:14px;
}
.differentiator-card h3{
  margin:0 0 8px;
}
.differentiator-card p{
  margin:0;
  font-size:.93rem;
}
.product-proof-grid .feature-card{
  min-height: 230px;
}
.early-access-note{
  border-radius:20px;
  padding:22px 26px;
  margin-top:26px;
}
.early-access-note p{
  margin:0;
  color:var(--text);
}
.early-access-note a{
  color:var(--primary);
  font-weight:700;
}
@media(max-width:820px){
  .production-hero{
    grid-template-columns:1fr;
  }
  .trajectory{
    opacity:.35;
  }
}