/* ============================================================
   ExamHK Finance · Free Practice prototype
   Tokens and components derived from reference design tokens
   ============================================================ */

:root{
  --exam-primary:#273462;
  --exam-primary-light:#3b4a76;
  --exam-accent:#d4af37;
  --exam-accent-light:#e8c766;
  --exam-accent-dark:#a8862a;
  --bg:#fcfbf7;
  --fg:#111827;
  --muted:#667085;
  --surface:#f5f6fa;

  --border:#e2e8f0;
  --border-soft:#eef2f7;
  --border-medium:#dbe3ef;
  --border-strong:#cbd5e1;

  --gray-50:#f8fafc;
  --gray-300:#cbd5e1;
  --gray-400:#94a3b8;
  --gray-500:#64748b;
  --gray-700:#374151;

  --green-bg:#f0fdf4;
  --green-bd:#86efac;
  --red-bg:#fef2f2;
  --red-bd:#fca5a5;
  --blue-bg:#eef2ff;
  --blue-bg-2:#edf2ff;
  --picked-bg:rgba(39,52,98,.05);
  --gold-tint:rgba(212,175,55,.12);

  --shadow-card:0 1px 2px rgba(15,23,42,.06);
  --shadow-quiz:0 12px 32px rgba(39,52,98,.12);
  --shadow-card-lg:0 6px 20px rgba(39,52,98,.06);
  --shadow-rail:0 12px 30px rgba(0,0,0,.16);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
[hidden]{display:none!important}
body{
  margin:0;
  color:var(--fg);
  background:var(--bg);
  font:16px/1.6 Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,"Noto Sans TC",Arial,sans-serif;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
a{color:inherit;text-decoration:none}
button{font:inherit}

/* Layout helpers */
.container{width:min(1280px,100% - 2rem);margin-inline:auto;padding-inline:1rem}
.muted{color:var(--muted);line-height:1.7}

/* ============== Display headings (serif) ============== */
.display{font-family:Georgia,"Times New Roman",serif}
.eyebrow{
  color:var(--exam-accent-dark);
  letter-spacing:.2em;
  text-transform:uppercase;
  font-size:.75rem;
  font-weight:800;
  margin:0;
}

/* ============== Buttons ============== */
.btn{
  cursor:pointer;
  text-align:center;
  border:1px solid transparent;
  border-radius:8px;
  justify-content:center;
  align-items:center;
  gap:.45rem;
  min-height:44px;
  padding:.72rem 1.55rem;
  font-weight:700;
  transition:all .2s;
  display:inline-flex;
  text-decoration:none;
}
.btn svg{width:1rem;height:1rem}
.btn-accent{
  background:linear-gradient(135deg,var(--exam-accent),var(--exam-accent-light));
  color:#111827;
}
.btn-accent:hover:not(:disabled){
  background:linear-gradient(135deg,var(--exam-accent-light),#f4d98a);
  transform:translateY(-1px);
  box-shadow:0 8px 20px rgba(212,175,55,.35);
}
.btn-primary{background:var(--exam-primary);color:#fff}
.btn-primary:hover{background:var(--exam-primary-light);transform:translateY(-1px)}
.btn:disabled{opacity:.45;cursor:not-allowed;transform:none;box-shadow:none}

/* ============== Top nav ============== */
.nav{
  z-index:50;
  -webkit-backdrop-filter:blur(10px);
  backdrop-filter:blur(10px);
  background:rgba(255,255,255,.96);
  border-bottom:1px solid #e5e7eb;
  position:sticky;
  top:0;
  box-shadow:0 1px 3px rgba(15,23,42,.07);
}
.nav-inner{
  justify-content:space-between;
  align-items:center;
  gap:1rem;
  min-height:72px;
  display:flex;
}
.nav .brand{align-items:center;display:flex}
.logo-wrap{
  background:#fff;
  border-radius:8px;
  align-items:center;
  width:172px;
  min-height:52px;
  padding:.55rem .7rem;
  display:flex;
  box-shadow:var(--shadow-rail);
}
.logo-text{
  display:flex;
  flex-direction:column;
  line-height:1;
  font-family:Georgia,serif;
}
.logo-text strong{color:var(--exam-primary);font-size:1.05rem;letter-spacing:.02em}
.logo-text em{
  color:var(--exam-accent-dark);
  font-style:normal;
  font-weight:700;
  font-size:.78rem;
  margin-top:.15rem;
  letter-spacing:.18em;
  text-transform:uppercase;
}
.links{display:flex;gap:.5rem;align-items:center}
.links a{
  color:var(--gray-700);
  padding:.5rem .7rem;
  font-weight:700;
  border-radius:6px;
  transition:color .15s,background .15s;
}
.links a:hover{color:var(--exam-primary);background:var(--gray-50)}
.nav-controls{align-items:center;gap:.55rem;display:flex}
.nav-action{
  color:#374151;
  cursor:pointer;
  background:transparent;
  border:0;
  padding:0;
  font-weight:700;
  display:inline-flex;
  align-items:center;
  gap:.35rem;
  text-decoration:none;
}
.nav-action:hover{color:var(--exam-primary)}
.nav .btn-accent.start{padding:.62rem 1.2rem;min-height:42px}
.nav .btn-accent.start svg{width:1rem;height:1rem}

/* Language toggle */
.language-toggle{
  min-height:38px;
  color:var(--exam-primary);
  cursor:pointer;
  background:#fffdf8;
  border:1px solid #d9ccb0;
  border-radius:8px;
  align-items:center;
  gap:.4rem;
  padding:.24rem;
  font-family:inherit;
  font-size:.72rem;
  font-weight:900;
  display:inline-flex;
  box-shadow:0 1px 2px rgba(15,23,42,.05);
}
.language-toggle:hover{border-color:var(--exam-accent);background:#fff}
.language-toggle svg{width:1rem;height:1rem;color:var(--exam-accent-dark);flex:none;margin-left:.35rem}
.language-options{
  background:var(--blue-bg-2);
  border-radius:7px;
  grid-template-columns:1fr 1fr;
  gap:.15rem;
  padding:.13rem;
  display:inline-grid;
}
.language-choice{
  color:#64748b;
  white-space:nowrap;
  border-radius:6px;
  place-items:center;
  min-width:2.35rem;
  height:1.55rem;
  font-size:.68rem;
  line-height:1;
  display:grid;
}
.language-choice.is-active{
  background:var(--exam-primary);
  color:#fff;
  box-shadow:0 1px 2px rgba(15,23,42,.14);
}

/* ============== Study layout (rail + main) ============== */
.study-layout{display:flex;align-items:flex-start}
.rail{background:#fff;border-right:1px solid #e5e7eb}
.rail.desktop{
  flex-direction:column;
  width:17rem;
  min-height:calc(100vh - 72px);
  transition:width .2s;
  display:flex;
  position:sticky;
  top:72px;
}
.rail.desktop.collapsed{width:4.75rem}
.rail.desktop.collapsed .rail-head p,
.rail.desktop.collapsed .rail-copy,
.rail.desktop.collapsed .rail-actions .rail-primary span{display:none}
.collapse{
  color:#94a3b8;
  cursor:pointer;
  background:transparent;
  border:0;
  align-self:flex-end;
  place-items:center;
  width:2.4rem;
  height:2.25rem;
  display:grid;
  margin:.35rem .5rem 0 0;
}
.collapse:hover{color:#475569}
.collapse svg{width:1.1rem;height:1.1rem}

.rail-content{flex-direction:column;flex:1;min-height:0;display:flex}
.rail-head{border-bottom:1px solid var(--border-soft);min-height:65px;padding:.75rem 1rem}
.rail-head h3{
  color:var(--exam-primary);
  text-overflow:ellipsis;
  white-space:nowrap;
  margin:0;
  font-size:.88rem;
  line-height:1.25;
}
.rail-head p{color:var(--gray-400);margin:.25rem 0 0;font-size:.68rem}
.rail-nav{flex:1;min-height:0;padding:.5rem 0;overflow-y:auto}

.rail-item{
  text-align:left;
  color:var(--gray-700);
  cursor:pointer;
  background:transparent;
  border:0;
  border-right:2px solid transparent;
  align-items:center;
  gap:.75rem;
  width:100%;
  padding:.72rem 1rem;
  transition:background .18s,color .18s,border-color .18s;
  display:flex;
  font-weight:700;
}
.rail-item:hover:not(.blocked),
.rail-item.active{
  color:var(--exam-primary);
  border-right-color:var(--exam-accent);
  background:var(--gold-tint);
}
.rail-item.blocked{color:#9ca3af;cursor:default}
.rail-icon{flex:0 0 1.25rem;place-items:center;display:grid;position:relative}
.rail-icon svg:not(.lock){width:1rem;height:1rem;color:var(--exam-primary)}
.rail-icon .lock{color:var(--gray-400);width:.68rem;height:.68rem;position:absolute;top:-.42rem;right:-.38rem}
.rail-copy{gap:.12rem;min-width:0;display:grid}
.rail-copy b{
  text-overflow:ellipsis;
  white-space:nowrap;
  font-size:.78rem;
  font-weight:700;
  overflow:hidden;
}
.rail-copy small{
  text-overflow:ellipsis;
  white-space:nowrap;
  color:var(--gray-400);
  font-size:.65rem;
  overflow:hidden;
}

.rail-actions{
  border-top:1px solid var(--border-soft);
  flex:none;
  grid-template-columns:minmax(0,1fr);
  gap:.5rem;
  padding:.75rem;
  display:grid;
}
.rail-secondary,
.rail-primary{
  text-align:center;
  overflow-wrap:anywhere;
  white-space:normal;
  border-radius:8px;
  justify-content:center;
  align-items:center;
  width:100%;
  min-width:0;
  min-height:34px;
  padding:.55rem .65rem;
  font-size:.74rem;
  font-weight:800;
  line-height:1.2;
  transition:opacity .18s,background .18s;
  display:inline-flex;
}
.rail-secondary{color:var(--exam-primary);background:var(--gray-50);border:1px solid var(--border)}
.rail-secondary:hover{background:#eef2f7}
.rail-primary{background:var(--exam-accent);color:#111827;border:0}
.rail-primary:hover{opacity:.9}
.rail-primary svg{width:1rem;height:1rem}

/* Main column */
.study-main{flex:1;min-width:0}
.free-test-stage{padding:2.5rem 0 3rem}
.breadcrumb{
  color:var(--gray-500);
  font-size:.78rem;
  display:flex;
  gap:.45rem;
  align-items:center;
  margin-bottom:1rem;
}
.breadcrumb a:hover{color:var(--exam-primary)}
.breadcrumb strong{color:var(--exam-primary);font-weight:800}

.test-header{margin-bottom:1.5rem}
.hero-badges{
  display:flex;
  gap:.5rem;
  flex-wrap:wrap;
  margin-bottom:1rem;
}
.badge{
  display:inline-flex;
  align-items:center;
  gap:.4rem;
  font-size:.68rem;
  font-weight:800;
  letter-spacing:.08em;
  padding:.3rem .6rem;
  border-radius:999px;
  border:1px solid var(--border-medium);
  background:var(--gray-50);
  color:var(--exam-primary);
}
.badge svg{width:.9rem;height:.9rem}
.badge-gold{
  background:#fff7d6;
  border-color:#e8c766;
  color:var(--exam-accent-dark);
}
.badge-gold svg{color:var(--exam-accent-dark)}
.badge-blue{
  background:#fff;
  border-color:var(--border-medium);
  color:var(--exam-primary);
}
.badge-blue svg{color:var(--exam-primary)}

.test-header h1.display{
  color:var(--exam-primary);
  font-size:clamp(2rem,3.4vw,2.6rem);
  line-height:1.15;
  margin:0 0 .8rem;
}
.test-header .lead{
  color:var(--gray-500);
  font-size:1.02rem;
  line-height:1.65;
  max-width:760px;
  margin:0;
}

/* ============== Syllabus panel ============== */
.syllabus-panel{margin:2rem 0 2.5rem}
.syllabus-head{margin-bottom:1.25rem}
.syllabus-head h2.display{
  color:var(--exam-primary);
  font-size:clamp(1.6rem,2.6vw,2.1rem);
  margin:.4rem 0 .6rem;
}
.syllabus-head p{max-width:760px;margin:0}
.syllabus-grid{
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:1rem;
}
.topic-card{
  background:#fff;
  border:1px solid var(--border-medium);
  border-radius:10px;
  padding:1.05rem 1.1rem;
  display:flex;
  flex-direction:column;
  gap:.55rem;
  transition:border-color .2s,box-shadow .2s;
}
.topic-card:hover{border-color:var(--exam-accent);box-shadow:var(--shadow-card-lg)}
.topic-head{display:flex;align-items:center;gap:.55rem}
.topic-icon{
  width:1.6rem;
  height:1.6rem;
  color:var(--exam-accent-dark);
  background:var(--blue-bg-2);
  border-radius:6px;
  display:grid;
  place-items:center;
  flex:none;
}
.topic-icon svg{width:1rem;height:1rem}
.topic-card h3{
  color:var(--exam-primary);
  margin:0;
  font-size:.92rem;
  line-height:1.25;
  letter-spacing:.01em;
  flex:1;
  min-width:0;
}
.topic-weight{
  color:var(--exam-accent-dark);
  background:#fff7d6;
  border:1px solid #e8c766;
  border-radius:999px;
  padding:.18rem .5rem;
  font-size:.68rem;
  font-weight:800;
  flex:none;
  font-family:Inter,sans-serif;
  letter-spacing:.04em;
}
.topic-card ul{
  margin:0;
  padding-left:1.15rem;
  color:var(--gray-500);
  font-size:.84rem;
  line-height:1.7;
}
.topic-card ul li{padding-left:.15rem}

/* ============== Quiz card ============== */
.quiz{max-width:860px;margin:0 auto}

.mode-picker{
  background:#fff;
  border:1px solid var(--border-medium);
  border-radius:10px;
  grid-template-columns:minmax(0,1fr) minmax(260px,.55fr);
  align-items:center;
  gap:1rem;
  margin-bottom:1.25rem;
  padding:1rem;
  display:grid;
  box-shadow:var(--shadow-card-lg);
}
.mode-picker b{display:block;color:var(--exam-primary);font-size:.9rem}
.mode-picker span{display:block;color:var(--gray-500);margin-top:.25rem;font-size:.78rem;line-height:1.5}
.mode-picker select{
  width:100%;
  min-height:44px;
  color:var(--exam-primary);
  background:#fff;
  border:1px solid var(--border-strong);
  border-radius:8px;
  padding:.65rem .75rem;
  font-weight:800;
  font-size:.9rem;
}

.progress{
  color:var(--exam-primary);
  border-bottom:6px solid #dfe3ec;
  justify-content:space-between;
  align-items:center;
  margin-bottom:1.5rem;
  padding-bottom:18px;
  font-size:.86rem;
  display:flex;
  position:relative;
}
.progress b{font-weight:800}
.progress i{
  background:var(--exam-accent);
  height:6px;
  transition:all .3s;
  position:absolute;
  bottom:-6px;
  left:0;
}

.question{
  padding:max(1.25rem,min(4vw,2.5rem));
  box-shadow:var(--shadow-quiz);
}
.question-meta{
  justify-content:space-between;
  align-items:center;
  gap:.75rem;
  display:flex;
  margin-bottom:.8rem;
}
.topic{
  color:var(--exam-accent-dark);
  text-transform:uppercase;
  letter-spacing:.12em;
  margin:0;
  font-size:.7rem;
  font-weight:900;
}
.question-meta span{
  color:var(--gray-500);
  background:var(--gray-50);
  border:1px solid var(--border-medium);
  border-radius:999px;
  flex:none;
  padding:.3rem .55rem;
  font-size:.68rem;
  font-weight:800;
  letter-spacing:.04em;
}

.question h2{
  color:var(--exam-primary);
  white-space:pre-line;
  font:700 max(1.3rem,min(3vw,1.8rem))/1.45 Georgia,serif;
  margin:.25rem 0 1rem;
}
.multi-hint{
  color:var(--gray-500);
  font-size:.85rem;
  margin:-.5rem 0 .85rem;
  padding-left:.05rem;
}
.multi-hint::before{content:"•";color:var(--exam-accent-dark);margin-right:.4rem;font-weight:900}

.choices{display:grid;gap:.75rem}
.choices button{
  text-align:left;
  cursor:pointer;
  color:var(--fg);
  background:#fff;
  border:2px solid var(--border);
  border-radius:8px;
  align-items:center;
  gap:1rem;
  padding:.9rem 1rem;
  transition:all .15s;
  display:flex;
  font-size:.95rem;
  width:100%;
  font-weight:600;
}
.choices button:hover:not(:disabled){
  border-color:var(--exam-accent);
  background:var(--picked-bg);
}
.choices button:disabled{cursor:default}
.choices button b{
  min-width:32px;
  height:32px;
  color:var(--exam-primary);
  background:var(--blue-bg);
  border-radius:6px;
  place-items:center;
  display:grid;
  font-weight:800;
  font-size:.95rem;
  flex:none;
}
.choices button span{white-space:pre-line;flex:1;line-height:1.45}
.choices button .check{
  display:none;
  width:1.1rem;
  height:1.1rem;
  color:#16a34a;
  flex:none;
}
.choices button .cross{
  display:none;
  width:1.1rem;
  height:1.1rem;
  color:#dc2626;
  flex:none;
}
.choices button.picked{
  border-color:var(--exam-accent);
  background:var(--picked-bg);
}
.choices button.picked b{
  background:var(--exam-accent);
  color:#111827;
}
.choices button.correct{
  background:var(--green-bg);
  border-color:var(--green-bd);
}
.choices button.correct b{
  background:#16a34a;
  color:#fff;
}
.choices button.correct .check{display:block}
.choices button.wrong{
  background:var(--red-bg);
  border-color:var(--red-bd);
}
.choices button.wrong b{
  background:#dc2626;
  color:#fff;
}
.choices button.wrong .cross{display:block}

/* Explanation panel */
.explanation{
  border-left:4px solid var(--exam-accent);
  background:var(--blue-bg);
  border-radius:8px;
  margin:1.5rem 0;
  padding:1.2rem;
}
.explanation-result{
  justify-content:space-between;
  align-items:center;
  gap:1rem;
  margin-bottom:.85rem;
  display:flex;
}
.explanation-result>b{color:var(--exam-primary);font-size:1.05rem;font-weight:800}
.explanation-result.is-correct>b{color:#16a34a}
.explanation-result.is-wrong>b{color:#dc2626}
.explanation-result span{
  color:#475569;
  background:#fff;
  border-radius:999px;
  padding:.3rem .55rem;
  font-size:.72rem;
  font-weight:800;
  letter-spacing:.04em;
}
.explanation section{
  border-top:1px solid var(--border-strong);
  margin-top:.8rem;
  padding-top:.8rem;
}
.explanation h3{
  color:var(--exam-primary);
  letter-spacing:.06em;
  text-transform:uppercase;
  margin:0 0 .3rem;
  font-size:.78rem;
  font-weight:800;
}
.explanation p,.explanation li{
  color:#475569;
  white-space:pre-line;
  line-height:1.65;
  font-size:.92rem;
}
.explanation p{margin:0}
.explanation p.is-pending{color:#94a3b8;font-style:italic}
.explanation ul{margin:0;padding-left:1.2rem}
.explanation li+li{margin-top:.3rem}

.actions{justify-content:flex-end;margin-top:1.5rem;display:flex}
.next{white-space:nowrap;min-width:13rem;max-width:100%}
.next svg{width:1rem;height:1rem;transition:transform .2s}
.next:hover:not(:disabled) svg{transform:translateX(2px)}

.card{
  background:#fff;
  border:1px solid var(--border);
  border-radius:12px;
  box-shadow:var(--shadow-card);
}
.empty,.result{text-align:center;padding:3rem}
.result h2{
  color:var(--exam-primary);
  font-family:Georgia,serif;
  font-size:clamp(2.4rem,5vw,3.2rem);
  margin:.6rem 0 .5rem;
  font-weight:700;
}
.result .muted{margin:0 auto 1.4rem;max-width:520px}
.result .btn-primary{margin:0 auto}

/* ============== Premium upsell ============== */
.study-system{
  margin-top:3rem;
  background:linear-gradient(180deg,rgba(248,250,255,.98),rgba(237,241,252,.98));
  border:1px solid var(--border-medium);
  border-radius:18px;
  padding:3rem 0;
}
.system-wrap{
  width:min(1100px,100% - 2rem);
  margin-inline:auto;
  padding-inline:1rem;
}
.section-kicker{
  color:var(--exam-accent-dark);
  text-transform:uppercase;
  letter-spacing:.2em;
  font-size:.72rem;
  font-weight:900;
  margin:0 0 .5rem;
}
.study-system h2.display{
  color:var(--exam-primary);
  font-size:clamp(1.7rem,2.8vw,2.2rem);
  margin:0 0 1.5rem;
  max-width:780px;
}
.system-grid{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:1rem;
}
.system-grid article{
  background:#fff;
  border:1px solid var(--border-medium);
  border-radius:12px;
  padding:1.1rem 1.15rem;
  display:flex;
  flex-direction:column;
  gap:.45rem;
  transition:transform .2s,box-shadow .2s;
}
.system-grid article:hover{transform:translateY(-2px);box-shadow:var(--shadow-card-lg)}
.system-grid article svg{
  width:1.4rem;
  height:1.4rem;
  color:var(--exam-accent-dark);
}
.system-grid article h3{
  color:var(--exam-primary);
  margin:.15rem 0 .1rem;
  font-size:.95rem;
  letter-spacing:.01em;
}
.system-grid article p{
  color:var(--gray-500);
  margin:0;
  font-size:.85rem;
  line-height:1.65;
}

.premium-plan-box{
  margin-top:1.5rem;
  background:#fff;
  border:1px solid var(--border-medium);
  border-radius:14px;
  padding:1.25rem;
  display:grid;
  grid-template-columns:minmax(0,.85fr) minmax(320px,1.15fr);
  gap:1.2rem;
  align-items:center;
  box-shadow:var(--shadow-card);
}
.premium-plan-box h3{
  color:var(--exam-primary);
  margin:0 0 .25rem;
  font-size:1rem;
}
.plan-buttons{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:.65rem;
}
.plan-button{
  border:1px solid var(--border-medium);
  border-radius:10px;
  background:#f8fafc;
  padding:.85rem .9rem;
  display:flex;
  flex-direction:column;
  gap:.2rem;
  text-align:center;
  transition:border-color .2s,background .2s,transform .2s;
}
.plan-button:hover{border-color:var(--exam-accent);transform:translateY(-1px);background:#fff}
.plan-button b{
  color:var(--exam-primary);
  font-family:Georgia,serif;
  font-size:1.4rem;
  font-weight:700;
}
.plan-button b span{font-size:.78rem;color:var(--gray-500);font-family:Inter,sans-serif;font-weight:700;margin-left:.25rem;letter-spacing:.06em}
.plan-button small{
  color:var(--gray-500);
  font-size:.78rem;
}
.plan-button.primary{
  background:linear-gradient(135deg,var(--exam-accent),var(--exam-accent-light));
  border-color:transparent;
}
.plan-button.primary b,
.plan-button.primary small{color:#111827}

/* ============== Footer ============== */
.site-footer{
  background:var(--exam-primary);
  color:rgba(255,255,255,.8);
  margin-top:auto;
  padding:0;
}
.site-footer .footer-grid{
  grid-template-columns:1fr auto;
  gap:2rem;
  padding-top:3rem;
  padding-bottom:2.5rem;
  display:grid;
}
.site-footer .footer-grid>div:not(:first-child){flex-direction:column;gap:.55rem;display:flex}
.site-footer .footer-grid h3{
  color:#fff;
  margin-bottom:.75rem;
  font-size:.95rem;
}
.site-footer .footer-grid a{
  color:rgba(255,255,255,.7);
  font-size:.875rem;
  transition:color .15s;
}
.site-footer .footer-grid a:hover{color:var(--exam-accent)}
.site-footer .legal{
  text-align:center;
  color:rgba(255,255,255,.45);
  border-top:1px solid rgba(255,255,255,.1);
  padding-top:1.5rem;
  padding-bottom:2rem;
  font-size:.75rem;
}
.site-footer .legal p{
  max-width:900px;
  margin:0 auto 1rem;
  line-height:1.55;
}

/* ============== Responsive ============== */
@media (max-width: 1024px){
  .study-layout{flex-direction:column}
  .rail.desktop{
    width:100%;
    min-height:auto;
    height:auto;
    position:relative;
    top:0;
    border-right:0;
    border-bottom:1px solid var(--border-soft);
  }
  .rail.desktop .collapse{display:none}
  .syllabus-grid{grid-template-columns:1fr}
  .system-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .premium-plan-box{grid-template-columns:1fr}
}
@media (max-width: 720px){
  .container{padding-inline:.75rem}
  .nav-inner{min-height:64px}
  .links{display:none}
  .system-grid{grid-template-columns:1fr}
  .mode-picker{grid-template-columns:1fr}
  .actions{justify-content:stretch}
  .next{white-space:normal;width:100%;min-width:0}
  .question{padding:1.25rem}
}