/* ---------- Header / primary navigation ---------- */
#app-header{
  position:sticky;top:0;z-index:40;
  background:rgba(18,19,28,.82);
  backdrop-filter:blur(14px);
  -webkit-backdrop-filter:blur(14px);
  border-bottom:1px solid rgba(45,49,78,.65);
}
#app-header.hidden{display:none}
.header-inner{max-width:1080px;margin:0 auto;padding:10px 22px;display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:12px;min-width:0}
.brand-sub{font-size:11px;color:var(--muted);letter-spacing:.4px;text-transform:uppercase;white-space:nowrap}
.header-right{display:flex;align-items:center;gap:9px;flex-wrap:wrap;margin-left:auto}
.student-chip{display:flex;align-items:center;gap:9px;padding:7px 13px 7px 8px;border:1px solid var(--line);border-radius:999px;background:rgba(255,255,255,.03);font-size:13px;max-width:280px}
.student-chip #student-name-label{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.avatar{width:26px;height:26px;border-radius:50%;background:var(--grad);display:flex;align-items:center;justify-content:center;font-size:11.5px;font-weight:800;color:#fff;flex:0 0 auto}
.student-chip .cls{color:var(--muted);white-space:nowrap}
.teacher-tag{font-size:9.5px;font-weight:900;letter-spacing:1px;text-transform:uppercase;color:#F7E1B5;background:rgba(233,180,76,.14);border:1px solid rgba(233,180,76,.5);padding:2px 8px;border-radius:999px}

/* ---------- "Book a Masterclass Sprint" — permanent premium CTA ----------
   Requirement: pinned to the top-right corner of the primary nav,
   always visible on every view. Gold = the one non-crimson accent. */
.btn-book{
  display:inline-flex;align-items:center;gap:8px;
  font-family:var(--font);font-size:12.5px;font-weight:900;letter-spacing:.4px;
  padding:9px 16px;border-radius:11px;cursor:pointer;text-decoration:none;
  color:#241A05;background:var(--grad-gold);border:1px solid rgba(255,240,200,.55);
  box-shadow:0 6px 20px rgba(233,180,76,.35),inset 0 1px 0 rgba(255,255,255,.5);
  transition:transform .18s ease,box-shadow .18s ease;white-space:nowrap;
}
.btn-book:hover{transform:translateY(-1px);box-shadow:0 10px 26px rgba(233,180,76,.5),inset 0 1px 0 rgba(255,255,255,.5)}
.btn-book:focus-visible{outline:2px solid var(--gold);outline-offset:2px}
.btn-book svg{flex:0 0 auto}
.btn-book .book-short{display:none}

/* ---------- Layout / views ---------- */
main{max-width:1080px;margin:0 auto;padding:30px 22px 40px}
.view{display:none}
.view.active{display:block;animation:viewIn .5s cubic-bezier(.16,1,.3,1)}
@keyframes viewIn{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  font-family:var(--font);font-size:14px;font-weight:700;letter-spacing:.2px;
  padding:11px 20px;border-radius:12px;border:1px solid transparent;
  cursor:pointer;transition:transform .18s ease,box-shadow .18s ease,background .18s ease,border-color .18s ease,opacity .18s ease;
  text-decoration:none;color:var(--text);background:transparent;
}
.btn:focus-visible{outline:2px solid var(--crimson-light);outline-offset:2px}
.btn-primary{background:var(--grad);color:#fff;box-shadow:0 8px 24px rgba(214,40,40,.35)}
.btn-primary:hover{transform:translateY(-1px);box-shadow:0 12px 30px rgba(214,40,40,.5)}
.btn-ghost{border-color:var(--line-strong);color:#C9D0E8;background:rgba(255,255,255,.02)}
.btn-ghost:hover{background:rgba(255,255,255,.06)}
.btn-sm{padding:8px 15px;font-size:13px;border-radius:10px}
.btn-block{width:100%}
.btn:disabled{opacity:.45;cursor:not-allowed;transform:none!important;box-shadow:none}
.btn.busy{opacity:.6;pointer-events:none}

/* ---------- Cards & chips ---------- */
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}
.status-chip{font-size:10.5px;font-weight:800;letter-spacing:1.1px;text-transform:uppercase;padding:4px 11px;border-radius:999px;white-space:nowrap}
.s-new{color:#A5AECC;background:rgba(154,163,196,.12);border:1px solid rgba(154,163,196,.3)}
.s-progress{color:#F3D8A0;background:rgba(233,180,76,.12);border:1px solid rgba(233,180,76,.38)}
.s-mastered{color:#FFB4B9;background:rgba(214,40,40,.14);border:1px solid rgba(214,40,40,.5)}
.s-locked{color:var(--faint);background:rgba(255,255,255,.03);border:1px solid var(--line)}
.meta-chip{font-size:11px;font-weight:700;color:var(--muted);border:1px solid var(--line-strong);border-radius:999px;padding:4px 11px;white-space:nowrap}
.xp-chip{font-size:11px;font-weight:800;color:#F7E1B5;background:rgba(233,180,76,.14);border:1px solid rgba(233,180,76,.5);padding:4px 11px;border-radius:999px;white-space:nowrap}
.skill-chip{font-size:10.5px;font-weight:700;color:#9FB0DC;background:rgba(143,163,208,.08);border:1px solid rgba(143,163,208,.3);padding:4px 10px;border-radius:999px;white-space:nowrap;font-family:ui-monospace,SFMono-Regular,Consolas,monospace}
.error-code-chip{font-size:10px;font-weight:900;letter-spacing:1px;text-transform:uppercase;color:#F3C878;background:rgba(233,180,76,.1);border:1px solid rgba(233,180,76,.45);padding:3px 10px;border-radius:999px;white-space:nowrap}

/* ---------- Loading & fatal-error views ---------- */
.center-wrap{min-height:calc(100dvh - 200px);display:grid;place-items:center;padding:30px 0}
.loading-box{text-align:center}
.spinner{
  width:52px;height:52px;border-radius:50%;margin:0 auto 18px;
  border:4px solid rgba(214,40,40,.16);border-top-color:var(--crimson-light);
  animation:spin 0.9s linear infinite;
}
@keyframes spin{to{transform:rotate(360deg)}}
.loading-text{font-size:14px;color:var(--muted);font-weight:600;letter-spacing:.3px}
.fatal-card{width:min(500px,100%);padding:36px 34px;text-align:center;position:relative;overflow:hidden}
.fatal-card::before{content:"";position:absolute;top:0;left:0;right:0;height:3px;background:var(--grad)}
.fatal-title{font-size:19px;font-weight:800;margin-bottom:9px}
.fatal-msg{font-size:13.5px;color:var(--muted);line-height:1.65;margin-bottom:22px;white-space:pre-line}

/* ---------- Footer & toast ---------- */
#app-footer{max-width:1080px;margin:0 auto;padding:8px 22px 42px;text-align:center}
.footer-badge{
  display:inline-flex;align-items:center;gap:9px;font-size:12px;color:var(--muted);letter-spacing:.4px;
  padding:9px 18px;border-radius:999px;background:var(--card);border:1px solid var(--line);
}
.footer-badge .fd{width:6px;height:6px;border-radius:50%;background:var(--crimson-light);box-shadow:0 0 8px rgba(229,72,77,.8);flex:0 0 auto}
/* Quiet by design: findable when wanted, not competing with the work. */
.footer-links{display:block;margin-top:10px;font-size:12px;letter-spacing:.4px}
.footer-links a{color:var(--muted);text-decoration:none;border-bottom:1px solid var(--line);padding-bottom:1px}
.footer-links a:hover{color:var(--text);border-bottom-color:var(--crimson-light)}
#toast{
  position:fixed;bottom:26px;left:50%;transform:translate(-50%,16px);z-index:100;
  background:#1E2030;border:1px solid var(--line-strong);border-radius:13px;padding:13px 21px;
  font-size:13.5px;font-weight:700;box-shadow:0 16px 40px rgba(6,7,12,.65);
  opacity:0;pointer-events:none;transition:opacity .3s ease,transform .3s ease;max-width:min(460px,90vw);text-align:center;
}
#toast.show{opacity:1;transform:translate(-50%,0)}

/* ---------- Brand emblem & dynamic lockup ----------
   The emblem (green atom crest + red pulse) is the extracted vector
   mark from the master logo. It lives once in FORKHILL_CONFIG and is
   injected into every [data-emblem] slot; the wordmark beside it is
   pure HTML/CSS and is rewritten live by the branding chameleon.     */
.brand-emblem{display:inline-flex;align-items:center;justify-content:center;flex:0 0 auto}
.brand-emblem svg{display:block;width:100%;height:100%}
.brand .brand-emblem{width:62px;height:36px;filter:drop-shadow(0 2px 10px rgba(61,145,61,.35))}
.login-emblem{width:180px;height:104px;margin:0 auto 14px;filter:drop-shadow(0 6px 22px rgba(61,145,61,.3))}
.banner-emblem{width:78px;height:45px}
.cm-preview-emblem{width:66px;height:38px}
.dyn-brand .bn-fork{color:var(--text)}
.dyn-brand .bn-rest{
  background:linear-gradient(135deg,#8CCB8C 0%,#3d913d 80%);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.brand-text{min-width:0}
.brand-name{font-weight:800;font-size:14.5px;letter-spacing:.25px;white-space:nowrap}
.login-title.dyn-brand{font-size:24px}

/* ============================================================
   STUDY NAV — persistent, always visible, never a drawer.

   Desktop (>=1000px): a slim rail pinned to the left, vertically
   centred, with room reserved by shifting <main>.
   Mobile: a bottom bar, because that is where thumbs are and because
   a drawer would put a tap in front of every action.

   Hidden entirely on V1 courses and when signed out — js/studyNav.js
   empties the container and drops .has-study-nav from <body>.
   ============================================================ */
.study-nav{display:none}
.study-nav[hidden]{display:none !important}

.study-nav-inner{display:flex}
.study-nav-btn{
  display:flex;align-items:center;gap:11px;
  background:none;border:1px solid transparent;border-radius:12px;
  color:var(--muted);font:700 13px var(--font);cursor:pointer;
  padding:10px 12px;transition:color .18s ease,background .18s ease,border-color .18s ease;
}
.study-nav-btn:hover{color:var(--text);background:rgba(255,255,255,.05)}
.study-nav-btn:focus-visible{outline:2px solid var(--crimson-light);outline-offset:2px}
.study-nav-btn.current{color:var(--text);background:rgba(214,40,40,.12);border-color:rgba(229,72,77,.4)}
.study-nav-btn svg{flex:0 0 auto}

/* ---- desktop rail ---- */
@media (min-width:1000px){
  body.has-study-nav .study-nav{
    display:block;position:fixed;left:14px;top:50%;transform:translateY(-50%);z-index:35;
  }
  body.has-study-nav .study-nav-inner{
    flex-direction:column;gap:4px;padding:10px;
    border:1px solid var(--line);border-radius:18px;
    background:rgba(30,32,48,.82);backdrop-filter:blur(14px);
    box-shadow:0 18px 44px rgba(6,7,12,.45);
  }
  /* Room for the rail. Without this it sits on top of the content on a
     narrow-ish desktop window. */
  body.has-study-nav main{padding-left:210px}
}

/* Between the rail and the bar, labels would collide with content, so the
   rail collapses to icons only rather than overlapping anything. */
@media (min-width:1000px) and (max-width:1260px){
  body.has-study-nav .study-nav-label{display:none}
  body.has-study-nav .study-nav-btn{justify-content:center;padding:11px}
  body.has-study-nav main{padding-left:96px}
}

/* ---- mobile bottom bar ---- */
@media (max-width:999px){
  body.has-study-nav .study-nav{
    display:block;position:fixed;left:0;right:0;bottom:0;z-index:35;
    border-top:1px solid var(--line);
    background:rgba(18,19,28,.94);backdrop-filter:blur(14px);
    padding-bottom:env(safe-area-inset-bottom, 0px);
  }
  body.has-study-nav .study-nav-inner{justify-content:space-around;padding:6px 4px}
  body.has-study-nav .study-nav-btn{
    flex-direction:column;gap:3px;padding:7px 6px;min-width:0;flex:1 1 0;
    font-size:10.5px;font-weight:800;letter-spacing:.2px;
  }
  body.has-study-nav .study-nav-label{
    max-width:100%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;
  }
  /* Clear the bar so the last card is never trapped underneath it. */
  body.has-study-nav main{padding-bottom:96px}
  body.has-study-nav #app-footer{padding-bottom:96px}
}

@media print{.study-nav{display:none !important}}