:root{
  --bg:#06070b;
  --card:rgba(255,255,255,.08);
  --card2:rgba(255,255,255,.06);
  --stroke:rgba(255,255,255,.14);
  --text:rgba(255,255,255,.92);
  --muted:rgba(255,255,255,.68);
  --accent:#6ee7ff;
  --accent2:#9b7bff;
  --good:#3ddc97;
  --bad:#ff5c7a;
  --shadow: 0 20px 60px rgba(0,0,0,.45);
  --radius:16px;
  --radius2:22px;
  --max:1100px;
  --blur: 18px;
  --ease: cubic-bezier(.2,.8,.2,1);
}

*{box-sizing:border-box}
html,body{height:100%}
html{background:var(--bg)}
body{
  margin:0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial, "Apple Color Emoji","Segoe UI Emoji";
  /* unified background (same on every page) */
  background:
    radial-gradient(1200px 800px at 20% 10%, rgba(120,140,255,.10), transparent 45%),
    radial-gradient(1000px 700px at 80% 30%, rgba(80,200,180,.10), transparent 50%),
    radial-gradient(900px 600px at 50% 85%, rgba(155,123,255,.07), transparent 55%),
    linear-gradient(180deg, #0b0f14, #0b0f14);
  color:var(--text);
  overflow-x:hidden;
}

a{color:inherit; text-decoration:none}
.page-shell{min-height:100%; display:flex; flex-direction:column}

.navbar{
  position:sticky; top:0; z-index:50;
  backdrop-filter: blur(var(--blur));
  -webkit-backdrop-filter: blur(var(--blur));
  background: linear-gradient(to bottom, rgba(10,12,18,.75), rgba(10,12,18,.35));
  border-bottom:1px solid rgba(255,255,255,.08);
}
.nav-inner{
  max-width:var(--max);
  margin:0 auto;
  padding:14px 18px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:14px;
}
.logo{
  font-weight:800;
  letter-spacing:.6px;
  display:flex; align-items:center; gap:10px;
}
.logo-badge{
  width:34px; height:34px; border-radius:12px;
  background: linear-gradient(135deg, rgba(110,231,255,.22), rgba(155,123,255,.22));
  border:1px solid rgba(255,255,255,.14);
  box-shadow: 0 10px 30px rgba(0,0,0,.35);
  position:relative;
}
.logo-badge:after{
  content:"";
  position:absolute; inset:6px;
  border-radius:10px;
  background: linear-gradient(135deg, rgba(110,231,255,.55), rgba(155,123,255,.55));
  filter: blur(.2px);
  opacity:.9;
}
.nav-links{
  display:flex; align-items:center; gap:10px;
}
.nav-links a{
  padding:10px 12px;
  border-radius:12px;
  color:var(--muted);
  transition: all .25s var(--ease);
}
.nav-links a:hover{background:rgba(255,255,255,.06); color:var(--text); transform:translateY(-1px)}
.mobile-menu-btn{
  display:none;
  border:1px solid rgba(255,255,255,.14);
  background:rgba(255,255,255,.06);
  color:var(--text);
  border-radius:12px;
  padding:10px 12px;
}
.mobile-menu{
  display:none;
  padding:10px 18px 16px;
  border-top:1px solid rgba(255,255,255,.08);
}
.mobile-menu a, .mobile-menu button{
  display:block;
  width:100%;
  text-align:left;
  margin-top:10px;
}

.btn{
  border:1px solid rgba(255,255,255,.14);
  background:rgba(255,255,255,.08);
  color:var(--text);
  border-radius:14px;
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:10px 14px;
  font-weight:700;
  cursor:pointer;
  transition: all .25s var(--ease);
  box-shadow: 0 10px 30px rgba(0,0,0,.20);
}
.btn:hover{transform: translateY(-1px); background:rgba(255,255,255,.11)}
.btn:active{transform: translateY(0px) scale(.99)}
.btn-primary{
  border-color: rgba(110,231,255,.35);
  background: linear-gradient(135deg, rgba(110,231,255,.18), rgba(155,123,255,.14));
}
.btn-primary:hover{
  background: linear-gradient(135deg, rgba(110,231,255,.26), rgba(155,123,255,.20));
}

.hero{
  position:relative;
  min-height: min(86vh, 720px);
  display:flex;
  align-items:center;
  justify-content:center;
  padding: 48px 18px 22px;
}
.hero-visual{
  position:absolute; inset:0;
  background:
    radial-gradient(900px 500px at 55% 35%, rgba(255,255,255,.07), transparent 60%),
    radial-gradient(700px 500px at 65% 55%, rgba(110,231,255,.07), transparent 60%),
    radial-gradient(900px 600px at 35% 55%, rgba(155,123,255,.06), transparent 60%);
  pointer-events:none;
}
.hero-video{
  position:absolute; inset:0;
  width:100%; height:100%;
  object-fit:cover;
  opacity:.22;
  filter: blur(.0px) saturate(1.2) contrast(1.05);
  transform: scale(1.04);
}
.hero:after{
  content:"";
  position:absolute; inset:0;
  background: linear-gradient(to bottom, rgba(6,7,11,.35), rgba(6,7,11,.92));
}
.hero-content{
  position:relative;
  max-width:var(--max);
  width:100%;
  z-index:2;
  display:flex;
  flex-direction:column;
  align-items:flex-start;
  gap:14px;
}
.hero-title{
  margin:0;
  font-size: clamp(28px, 4vw, 54px);
  line-height:1.03;
  letter-spacing:.5px;
}
.hero-subtitle{
  margin:0;
  color:var(--muted);
  max-width: 680px;
  font-size: clamp(14px, 2vw, 18px);
}
.hero-actions{display:flex; gap:10px; flex-wrap:wrap; align-items:center}
.pill{
  display:inline-flex; align-items:center; gap:10px;
  padding:10px 12px;
  border-radius:999px;
  border:1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.06);
  color:var(--muted);
  font-weight:650;
}

.section{padding: 22px 18px calc(40px + env(safe-area-inset-bottom));}
.section-inner{max-width:var(--max); margin:0 auto;}

.glass-card{
  background: linear-gradient(180deg, rgba(255,255,255,.10), rgba(255,255,255,.06));
  border: 1px solid rgba(255,255,255,.12);
  border-radius: var(--radius2);
  box-shadow: var(--shadow);
  backdrop-filter: blur(var(--blur));
  -webkit-backdrop-filter: blur(var(--blur));
  padding: 18px;
}

.grid{
  display:grid;
  grid-template-columns: 1fr;
  gap:14px;
}
@media (min-width: 860px){
  .grid{grid-template-columns: 1.15fr .85fr}
}

.kv{
  display:flex; gap:10px; flex-wrap:wrap;
}
.kv .tag{
  padding:8px 10px; border-radius:999px;
  border:1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.05);
  color: var(--muted);
  font-weight:650;
  font-size:13px;
}

.mode-cards{
  display:grid;
  grid-template-columns: 1fr;
  gap:12px;
  margin-top:12px;
}
@media(min-width:680px){
  .mode-cards{grid-template-columns: 1fr 1fr}
}
.mode-card{
  padding:16px;
  border-radius: var(--radius2);
  border:1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.06);
  transition: all .25s var(--ease);
  cursor:pointer;
}
.mode-card:hover{transform:translateY(-2px); background:rgba(255,255,255,.09)}
.mode-title{margin:0 0 6px; font-size:18px}
.mode-desc{margin:0; color:var(--muted); font-size:14px}

.quiz-top{
  display:flex; align-items:center; justify-content:space-between;
  gap:12px; flex-wrap:wrap;
}
.progress{
  display:flex; align-items:center; gap:10px; flex-wrap:wrap;
  color:var(--muted);
  font-weight:650;
}
.bar{
  width:220px; max-width:60vw;
  height:10px;
  border-radius:999px;
  border:1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.05);
  overflow:hidden;
}
.bar > i{
  display:block; height:100%;
  width:0%;
  background: linear-gradient(90deg, rgba(110,231,255,.75), rgba(155,123,255,.75));
  border-radius:999px;
  transition: width .25s var(--ease);
}

.qcard{
  padding:16px;
  border-radius: var(--radius2);
  border:1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.06);
}
.qhead{display:flex; gap:10px; align-items:flex-start; justify-content:space-between; flex-wrap:wrap}
.qnum{
  font-weight:900;
  letter-spacing:.5px;
  color: rgba(255,255,255,.86);
}
.qtext{margin:8px 0 0; color: rgba(255,255,255,.92); line-height:1.35}

.answers{display:grid; grid-template-columns:1fr; gap:10px; margin-top:12px}
@media(min-width:720px){ .answers{grid-template-columns:1fr 1fr} }

.choice{
  display:flex;
  gap:10px;
  align-items:flex-start;
  padding:12px 12px;
  border-radius:16px;
  border:1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.05);
  transition: all .2s var(--ease);
  cursor:pointer;
}
.choice:hover{transform:translateY(-1px); background:rgba(255,255,255,.08)}
.choice input{margin-top:3px; accent-color: #8ae9ff;}
.choice .letter{
  width:30px; height:30px; border-radius:12px;
  display:grid; place-items:center;
  font-weight:900;
  border:1px solid rgba(255,255,255,.14);
  background: rgba(255,255,255,.06);
}
.choice .ctext{color: rgba(255,255,255,.90); line-height:1.35}

.sticky-actions{
  position:sticky;
  bottom: calc(12px + env(safe-area-inset-bottom));
  margin-top:14px;
  z-index:20;
}
.actions-row{
  display:flex; gap:10px; flex-wrap:wrap; align-items:center; justify-content:space-between;
}
.actions-row .left, .actions-row .right{display:flex; gap:10px; flex-wrap:wrap}

/* Mobile: avoid squished buttons and keep a clean, consistent layout */
@media (max-width: 520px){
  .actions-row{
    flex-direction:column;
    align-items:stretch;
    justify-content:flex-start;
    gap:12px;
  }
  .actions-row .left,
  .actions-row .right{
    width:100%;
  }
  .actions-row .left{
    display:grid;
    grid-template-columns: 1fr 1fr;
    gap:10px;
  }
  .actions-row .right .btn,
  .actions-row .left .btn{
    width:100%;
  }
  .sticky-actions{
    bottom: calc(10px + env(safe-area-inset-bottom));
  }
}

.result{
  margin-top:12px;
  padding:14px;
  border-radius: var(--radius2);
  border:1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.05);
}
.score{
  font-size:22px;
  font-weight:950;
  margin:0 0 8px;
  letter-spacing:.2px;
}
.muted{color:var(--muted)}
.badge{
  display:inline-flex; align-items:center; gap:8px;
  padding:8px 10px;
  border-radius:999px;
  border:1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.05);
  font-weight:800;
}
.badge.good{border-color: rgba(61,220,151,.35); background: rgba(61,220,151,.12)}
.badge.bad{border-color: rgba(255,92,122,.35); background: rgba(255,92,122,.12)}

.hidden{display:none !important}

.footer{
  margin-top:auto;
  padding: 18px;
  color: rgba(255,255,255,.55);
  font-size:13px;
}
.footer .section-inner{display:flex; align-items:center; justify-content:space-between; gap:10px; flex-wrap:wrap}

.fade-in{
  animation: fadeIn .55s var(--ease) both;
}
@keyframes fadeIn{
  from{opacity:0; transform: translateY(10px)}
  to{opacity:1; transform: translateY(0)}
}

@media(max-width: 860px){
  .nav-links{display:none}
  .mobile-menu-btn{display:inline-flex}
  .mobile-menu{display:block}
}
/* Mobile: make action buttons fit nicely on ALL phones */
@media (max-width: 520px){
  .actions-row{
    flex-direction:column;
    align-items:stretch;
    justify-content:flex-start;
  }
  .actions-row .left,
  .actions-row .right{
    width:100%;
  }
  .actions-row .left{
    display:grid;
    grid-template-columns: 1fr 1fr;
  }
  .actions-row .right{
    display:block;
  }
  .actions-row .btn{
    width:100%;
    justify-content:center;
  }
}

.reorder-line{
  margin-bottom:12px;
  line-height:1.6;
}
/* =========================
   QUIZ PAGE ONLY – FIX BACKGROUND
   ========================= */

body.quiz-only {
  background: #070707 !important;
}

body.quiz-only .page-shell {
  background: #070707;
  min-height: 100vh;
}

/* tắt hoàn toàn nền màu của section */
body.quiz-only .section {
  background: transparent;
}
.qtext {
  white-space: pre-line;
}