:root{
  /* --- Brand: red + navy from IT LEARN logo --- */
  --bg:#080d1f;
  --bg-2:#0e162e;
  --bg-3:#152043;
  --surface:#1a2750;
  --surface-2:#243466;
  --line:rgba(255,255,255,.08);
  --line-strong:rgba(255,255,255,.14);
  --text:#f1f5f9;
  --text-dim:#94a3b8;
  --text-mute:#64748b;

  --red:#dc2626;
  --red-2:#ef4444;
  --red-bright:#f87171;
  --red-soft:#fecaca;
  --red-deep:#991b1b;

  --navy:#1e3a8a;
  --navy-2:#3b82f6;
  --navy-bright:#60a5fa;
  --navy-soft:#bfdbfe;

  --gold:#fbbf24;
  --cream:#fef3c7;

  --grad: linear-gradient(135deg, #ef4444 0%, #dc2626 60%, #991b1b 100%);
  --grad-navy: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
  --grad-mix: linear-gradient(120deg, #ef4444 0%, #dc2626 40%, #1e40af 100%);
  --shadow-red: 0 20px 60px -20px rgba(220,38,38,.55);
  --shadow-navy: 0 20px 60px -20px rgba(30,58,138,.5);

  --display: "Bricolage Grotesque", ui-sans-serif, system-ui, sans-serif;
  --body: "Plus Jakarta Sans", ui-sans-serif, system-ui, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, monospace;
  --r-sm: 10px;
  --r: 16px;
  --r-lg: 24px;
  --r-xl: 32px;
}

*{box-sizing:border-box}
html,body{margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:var(--body);
  background:var(--bg);
  color:var(--text);
  font-size:16px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:hidden;
}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
button{font-family:inherit;cursor:pointer;border:0;background:none;color:inherit}

body{
  --bg-glow-1: rgba(220,38,38,.18);   /* top-right glow */
  --bg-glow-2: rgba(30,64,175,.22);   /* left glow */
  --bg-glow-3: rgba(220,38,38,.10);   /* bottom-right glow */
}
body::before{
  content:"";
  position:fixed;inset:0;
  background:
    radial-gradient(900px 500px at 85% -10%, var(--bg-glow-1), transparent 60%),
    radial-gradient(700px 500px at -5% 30%, var(--bg-glow-2), transparent 60%),
    radial-gradient(800px 600px at 100% 90%, var(--bg-glow-3), transparent 60%);
  pointer-events:none;
  z-index:0;
  transition: background .6s ease;
}
body::after{
  content:"";
  position:fixed;inset:0;
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='200' height='200'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/><feColorMatrix values='0 0 0 0 1  0 0 0 0 1  0 0 0 0 1  0 0 0 .04 0'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
  pointer-events:none;
  opacity:.5;
  z-index:0;
  mix-blend-mode:overlay;
}

main, header, footer{position:relative;z-index:1}

.wrap{max-width:1200px;margin:0 auto;padding:0 24px}
.wrap-narrow{max-width:980px;margin:0 auto;padding:0 24px}

h1,h2,h3,h4{font-family:var(--display);font-weight:600;letter-spacing:-.02em;line-height:1.05;margin:0}
h1{font-size:clamp(40px,6.5vw,84px);letter-spacing:-.035em;font-weight:500}
h2{font-size:clamp(32px,4.4vw,56px);letter-spacing:-.03em;font-weight:500}
h3{font-size:clamp(22px,2.4vw,30px);font-weight:600}
h4{font-size:18px;font-weight:600}
p{margin:0}
.eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  font-family:var(--mono);
  font-size:11px;font-weight:500;letter-spacing:.18em;text-transform:uppercase;
  color:var(--red-bright);
}
.eyebrow::before{
  content:"";width:24px;height:1px;background:var(--red);
}
.lead{font-size:18px;color:var(--text-dim);max-width:640px;margin:0 auto}

.gradient-text,
.navy-text{
  display:inline-block;
  font-style:italic;
  font-family:var(--display);
  -webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;
  padding:0 .25em 0 .05em;
  margin:0 -.15em 0 -.05em;
}
.gradient-text{
  background-image:linear-gradient(120deg,#fca5a5 0%, #ef4444 40%, #f87171 100%);
}
.navy-text{
  background-image:linear-gradient(120deg,#bfdbfe 0%, #60a5fa 50%, #3b82f6 100%);
}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:10px;
  padding:14px 22px;border-radius:999px;
  font-weight:600;font-size:15px;
  transition:transform .25s ease, box-shadow .25s ease, background .25s ease;
  white-space:nowrap;
}
.btn-primary{
  background:var(--grad);
  color:#fff;
  box-shadow: var(--shadow-red), inset 0 1px 0 rgba(255,255,255,.25);
}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 25px 70px -20px rgba(220,38,38,.75), inset 0 1px 0 rgba(255,255,255,.3)}
.btn-ghost{
  background:rgba(255,255,255,.04);
  border:1px solid var(--line-strong);
  color:var(--text);
  backdrop-filter: blur(10px);
}
.btn-ghost:hover{background:rgba(255,255,255,.08);transform:translateY(-2px)}
.btn-arrow::after{
  content:"→";display:inline-block;transition:transform .25s ease;
}
.btn-arrow:hover::after{transform:translateX(4px)}

/* ===== LOGO ===== */
.logo{
  display:inline-flex;align-items:center;line-height:1;
}
.logo-img{
  height:44px;width:auto;display:block;
  filter: drop-shadow(0 6px 12px rgba(220,38,38,.35));
}
/* Theme-swap: Logo_2 (icon) cho dark, Logo_1 (full + text navy) cho light */
.logo-light{display:none}
[data-theme="light"] .logo-dark{display:none}
[data-theme="light"] .logo-light{display:block}
.logo-footer{justify-content:center;display:inline-flex}
.logo-footer .logo-img{height:52px}

.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(8,13,31,.7);
  backdrop-filter:blur(18px) saturate(140%);
  -webkit-backdrop-filter:blur(18px) saturate(140%);
  border-bottom:1px solid var(--line);
}
.nav{
  display:flex;align-items:center;justify-content:space-between;
  padding:14px 24px;max-width:1200px;margin:0 auto;
}
.nav-links{display:none;gap:6px}
.nav-links a{
  padding:8px 14px;border-radius:999px;font-size:14px;color:var(--text-dim);
  transition:color .2s, background .2s;
}
.nav-links a:hover{color:var(--text);background:rgba(255,255,255,.05)}
@media(min-width:980px){.nav-links{display:flex}}
.nav-cta{display:flex;align-items:center;gap:10px}

.hero{
  padding:80px 24px 60px;
  text-align:center;
  position:relative;
}
.trust-pill{
  display:inline-flex;align-items:center;gap:14px;
  background:rgba(255,255,255,.04);
  border:1px solid var(--line-strong);
  padding:8px 16px 8px 8px;border-radius:999px;
  margin-bottom:32px;
}
.avatars{display:flex}
.avatars span{
  width:28px;height:28px;border-radius:50%;
  border:2px solid var(--bg-2);
  background-size:cover;background-position:center;
  margin-left:-8px;
}
.avatars span:first-child{margin-left:0}
.av1{background:url('https://api.dicebear.com/9.x/lorelei/svg?seed=Hero1&backgroundColor=fbbf24,f97316') center/cover, linear-gradient(135deg,#fbbf24,#f97316)}
.av2{background:url('https://api.dicebear.com/9.x/lorelei/svg?seed=Hero2&backgroundColor=3b82f6,1e40af') center/cover, linear-gradient(135deg,#3b82f6,#1e40af)}
.av3{background:url('https://api.dicebear.com/9.x/lorelei/svg?seed=Hero3&backgroundColor=ef4444,dc2626') center/cover, linear-gradient(135deg,#ef4444,#dc2626)}
.av4{background:url('https://api.dicebear.com/9.x/lorelei/svg?seed=Hero4&backgroundColor=10b981,3b82f6') center/cover, linear-gradient(135deg,#10b981,#3b82f6)}
.trust-pill small{font-size:13px;color:var(--text-dim)}
.trust-pill b{color:var(--text);font-weight:600}
.trust-pill .stars{color:var(--gold);letter-spacing:1px;font-size:13px}

.hero h1{max-width:15ch;margin:0 auto 22px}
.hero-sub{
  font-size:18px;color:var(--text-dim);max-width:580px;margin:0 auto 36px;
}
.hero-cta{display:flex;flex-wrap:wrap;gap:12px;justify-content:center;margin-bottom:60px}

.promo-card{
  max-width:920px;margin:0 auto;
  background:linear-gradient(180deg, rgba(220,38,38,.06), rgba(15,12,30,.6));
  border:1px solid var(--line-strong);
  border-radius:var(--r-xl);
  padding:14px;
  position:relative;
  overflow:hidden;
}
.promo-card::before{
  content:"";position:absolute;inset:-1px;
  background:linear-gradient(120deg, transparent 30%, rgba(248,113,113,.4), transparent 70%);
  border-radius:var(--r-xl);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  padding:1px;
  pointer-events:none;
}
.promo-head{
  display:flex;align-items:center;justify-content:space-between;
  padding:8px 14px;border-radius:14px;
  background:rgba(0,0,0,.3);
  font-size:13px;color:var(--text-dim);
  margin-bottom:14px;
}
.promo-head .dot{
  width:8px;height:8px;border-radius:50%;background:#ef4444;
  box-shadow:0 0 0 4px rgba(239,68,68,.2);
  margin-right:8px;
}
.promo-body{
  display:grid;grid-template-columns:1fr;
  border-radius:20px;overflow:hidden;
  background:linear-gradient(135deg,#3b1414 0%, #1a0e2a 50%, #0a1432 100%);
  min-height:340px;
  position:relative;
  padding:36px 28px;
  text-align:left;
}
@media(min-width:760px){
  .promo-body{grid-template-columns:1fr 1fr;min-height:380px}
}
.promo-text h2{
  font-size:clamp(28px,4vw,44px);
  line-height:1;
  margin-bottom:12px;
}
.promo-text p{color:var(--red-soft);font-size:15px;max-width:34ch}
@media(max-width:759px){
  .promo-text h2 br{display:none}
  .promo-text p{max-width:none}
}
.play-btn{
  width:64px;height:64px;border-radius:50%;
  background:rgba(255,255,255,.95);
  display:grid;place-items:center;
  margin-top:24px;
  box-shadow:0 0 0 0 rgba(255,255,255,.4);
  animation:pulse 2.4s infinite;
}
.play-btn svg{margin-left:3px}
@keyframes pulse{
  0%{box-shadow:0 0 0 0 rgba(255,255,255,.35)}
  70%{box-shadow:0 0 0 18px rgba(255,255,255,0)}
  100%{box-shadow:0 0 0 0 rgba(255,255,255,0)}
}
.promo-visual{
  position:relative;display:flex;align-items:center;justify-content:center;
  padding:20px 0;
}

/* Test case window */
.tc-window{
  width:100%;max-width:380px;
  background:#0d1224;
  border:1px solid var(--line-strong);
  border-radius:14px;
  font-family:var(--mono);
  font-size:11.5px;
  overflow:hidden;
  box-shadow:0 30px 60px -20px rgba(0,0,0,.6);
  transform:rotate(-2deg);
}
.tc-bar{
  display:flex;gap:6px;padding:10px 14px;align-items:center;
  background:rgba(255,255,255,.03);
  border-bottom:1px solid var(--line);
}
.tc-bar .tag{
  font-size:10px;padding:3px 8px;border-radius:5px;
  background:rgba(220,38,38,.18);color:var(--red-bright);
  letter-spacing:.05em;font-weight:600;
}
.tc-bar small{margin-left:auto;color:var(--text-mute);font-size:10.5px}
.tc-row{
  display:grid;grid-template-columns:60px 1fr 70px;
  padding:8px 14px;border-bottom:1px solid var(--line);
  font-size:11px;align-items:center;
}
.tc-row:last-child{border-bottom:0}
.tc-row .id{color:var(--text-mute);font-weight:500}
.tc-row .step{color:var(--text-dim)}
.tc-row .pass{color:#10b981;font-weight:600;text-align:right}
.tc-row .fail{color:var(--red-bright);font-weight:600;text-align:right}
.tc-row .pending{color:var(--gold);font-weight:600;text-align:right}

.feat-strip{
  display:grid;gap:0;
  grid-template-columns:repeat(2,1fr);
  border:1px solid var(--line);
  border-radius:var(--r);
  background:rgba(255,255,255,.02);
  margin-top:32px;
}
@media(min-width:760px){.feat-strip{grid-template-columns:repeat(4,1fr)}}
.feat-strip > div{
  padding:18px;display:flex;align-items:center;gap:10px;
  border-right:1px solid var(--line);
  font-size:14px;color:var(--text-dim);
  border-bottom:1px solid var(--line);
}
.feat-strip > div:nth-child(2n){border-right:0}
@media(min-width:760px){
  .feat-strip > div{border-bottom:0}
  .feat-strip > div:nth-child(2n){border-right:1px solid var(--line)}
  .feat-strip > div:last-child{border-right:0}
}
.feat-strip svg{flex-shrink:0;color:var(--red-bright)}

.trusted{padding:60px 24px 30px;text-align:center}
.trusted small{
  font-family:var(--mono);font-size:11px;letter-spacing:.2em;text-transform:uppercase;
  color:var(--text-mute);
}
.logos{
  display:flex;flex-wrap:wrap;justify-content:center;align-items:center;
  gap:48px;margin-top:24px;
}
.logos span{
  font-family:var(--display);font-weight:600;font-size:18px;
  color:var(--text-mute);opacity:.7;
  display:flex;align-items:center;gap:8px;
  transition:opacity .2s, color .2s;
}
.logos span:hover{opacity:1;color:var(--text-dim)}

section{padding:80px 0}
.section-head{text-align:center;margin-bottom:48px}
.section-head h2{margin:14px auto 14px;max-width:18ch}

.why-grid{display:grid;gap:18px;grid-template-columns:1fr}
@media(min-width:820px){.why-grid{grid-template-columns:repeat(3,1fr)}}
.why-card{
  background:linear-gradient(180deg, rgba(255,255,255,.04), rgba(255,255,255,.01));
  border:1px solid var(--line);
  border-radius:var(--r-lg);
  padding:28px;
  position:relative;overflow:hidden;
  transition:border-color .25s, transform .25s;
}
.why-card:hover{border-color:var(--line-strong);transform:translateY(-4px)}
.why-card .num{
  font-family:var(--mono);font-size:11px;color:var(--text-mute);
  letter-spacing:.15em;
}
.why-card h3{margin:14px 0 10px;font-size:22px;line-height:1.2}
.why-card p{color:var(--text-dim);font-size:14.5px}
.why-icon{
  width:48px;height:48px;border-radius:12px;
  display:grid;place-items:center;
  background:linear-gradient(135deg,#7a1f1f,#1a0f33);
  border:1px solid rgba(248,113,113,.25);
  color:var(--red-bright);
  margin-bottom:18px;
}

/* ===== AI SECTION ===== */
.ai-section{padding:100px 0;position:relative}
.ai-section::before{
  content:"";position:absolute;inset:0;
  background:
    radial-gradient(circle at 30% 30%, rgba(30,64,175,.18), transparent 50%),
    radial-gradient(circle at 70% 70%, rgba(220,38,38,.12), transparent 50%);
  pointer-events:none;
}
.ai-section .wrap{position:relative}
.ai-badge{
  display:inline-flex;align-items:center;gap:8px;
  padding:6px 14px;border-radius:999px;
  background:linear-gradient(135deg, rgba(59,130,246,.15), rgba(220,38,38,.1));
  border:1px solid rgba(59,130,246,.3);
  font-family:var(--mono);font-size:11px;letter-spacing:.18em;text-transform:uppercase;
  color:var(--navy-bright);margin-bottom:16px;
}
.ai-badge::before{content:"✦"}

.ai-hero{
  display:grid;gap:40px;grid-template-columns:1fr;align-items:center;
  margin-bottom:60px;
}
@media(min-width:880px){.ai-hero{grid-template-columns:1fr 1.2fr}}
.ai-hero h2{font-size:clamp(34px,4.4vw,52px);max-width:14ch}
.ai-hero p{color:var(--text-dim);font-size:16.5px;margin-top:18px;max-width:48ch}

.ai-tags{margin-top:24px;display:flex;flex-wrap:wrap;gap:10px}
.ai-tags span{
  padding:6px 12px;border-radius:999px;
  background:rgba(59,130,246,.12);
  border:1px solid rgba(59,130,246,.25);
  font-size:12.5px;color:var(--navy-bright);
}

.ai-prompt{
  background:linear-gradient(180deg, #0d152e, #080d1f);
  border:1px solid rgba(59,130,246,.25);
  border-radius:var(--r-lg);
  padding:0;overflow:hidden;
  box-shadow:0 30px 70px -20px rgba(30,64,175,.4);
  position:relative;
}
.ai-prompt::after{
  content:"";position:absolute;inset:-1px;border-radius:var(--r-lg);
  background:linear-gradient(135deg, rgba(59,130,246,.4), transparent 40%, rgba(220,38,38,.3));
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  padding:1px;
  pointer-events:none;
}
.ai-prompt-head{
  display:flex;align-items:center;gap:10px;padding:14px 18px;
  border-bottom:1px solid var(--line);
  background:rgba(255,255,255,.02);
  font-family:var(--mono);font-size:12px;color:var(--text-dim);
}
.ai-prompt-head .ai-dot{
  width:24px;height:24px;border-radius:50%;
  background:var(--grad-navy);
  display:grid;place-items:center;
  font-size:12px;font-weight:700;color:#fff;
}
.ai-msg{padding:18px 20px;border-bottom:1px solid var(--line)}
.ai-msg:last-child{border-bottom:0}
.ai-msg-label{
  font-family:var(--mono);font-size:10.5px;letter-spacing:.15em;text-transform:uppercase;
  color:var(--text-mute);margin-bottom:8px;
}
.ai-msg-user .ai-msg-label{color:var(--red-bright)}
.ai-msg-ai .ai-msg-label{color:var(--navy-bright)}
.ai-msg p{font-size:14px;line-height:1.55;color:var(--text)}
.ai-msg ol{margin:8px 0 0;padding-left:20px;font-size:13.5px;color:var(--text-dim);display:flex;flex-direction:column;gap:5px}
.ai-msg ol li::marker{color:var(--red-bright);font-weight:600}

.ai-grid{display:grid;gap:18px;grid-template-columns:1fr}
@media(min-width:680px){.ai-grid{grid-template-columns:repeat(2,1fr)}}
@media(min-width:1000px){.ai-grid{grid-template-columns:repeat(3,1fr)}}
.ai-card{
  background:linear-gradient(180deg, rgba(59,130,246,.06), rgba(255,255,255,.01));
  border:1px solid var(--line);
  border-radius:var(--r-lg);
  padding:26px;
  display:flex;flex-direction:column;gap:14px;
  transition:transform .25s, border-color .25s, background .25s;
  position:relative;
}
.ai-card:hover{
  transform:translateY(-4px);
  border-color:rgba(59,130,246,.35);
  background:linear-gradient(180deg, rgba(59,130,246,.1), rgba(255,255,255,.02));
}
.ai-card-head{display:flex;align-items:center;gap:12px}
.ai-card-icon{
  width:42px;height:42px;border-radius:11px;
  background:linear-gradient(135deg,#1e3a8a,#0f1d4e);
  border:1px solid rgba(96,165,250,.3);
  display:grid;place-items:center;
  color:var(--navy-bright);
}
.ai-card-num{
  font-family:var(--mono);font-size:11px;color:var(--text-mute);
  letter-spacing:.15em;margin-left:auto;
}
.ai-card h3{font-size:18px;line-height:1.25}
.ai-card p{color:var(--text-dim);font-size:14px}
.ai-card .tool-tag{
  margin-top:auto;font-family:var(--mono);font-size:11px;
  color:var(--navy-bright);
  padding:5px 10px;border-radius:6px;
  background:rgba(59,130,246,.12);
  border:1px solid rgba(59,130,246,.2);
  align-self:flex-start;letter-spacing:.05em;
}

.stats{
  display:grid;grid-template-columns:repeat(3,1fr);
  border:1px solid var(--line);
  border-radius:var(--r-lg);
  background:rgba(255,255,255,.02);
  overflow:hidden;
  margin-top:40px;
}
.stats > div{padding:24px;text-align:left;border-right:1px solid var(--line)}
.stats > div:last-child{border-right:0}
.stats h4{font-family:var(--display);font-size:36px;font-weight:500;letter-spacing:-.02em;color:var(--text)}
.stats p{font-size:13px;color:var(--text-dim);margin-top:6px}
@media(max-width:680px){
  .stats{grid-template-columns:1fr}
  .stats > div{border-right:0;border-bottom:1px solid var(--line)}
  .stats > div:last-child{border-bottom:0}
}

.curr-wrap{display:grid;gap:24px;grid-template-columns:1fr}
@media(min-width:880px){.curr-wrap{grid-template-columns:1fr 1fr;gap:36px}}
.modules{display:flex;flex-direction:column;gap:10px}
.module{
  background:rgba(255,255,255,.03);
  border:1px solid var(--line);
  border-radius:var(--r);
  overflow:hidden;
  transition:border-color .2s;
}
.module[open]{border-color:rgba(248,113,113,.35);background:rgba(220,38,38,.05)}
.module summary{
  list-style:none;cursor:pointer;
  display:flex;align-items:center;gap:14px;
  padding:18px 20px;
  font-weight:600;font-size:15px;
}
.module summary::-webkit-details-marker{display:none}
.module summary::after{
  content:"+";margin-left:auto;font-size:22px;color:var(--text-mute);
  font-family:var(--mono);font-weight:300;
}
.module[open] summary::after{content:"−";color:var(--red-bright)}
.module-tag{
  font-family:var(--mono);font-size:11px;letter-spacing:.1em;
  color:var(--red-bright);background:rgba(220,38,38,.12);
  padding:4px 8px;border-radius:6px;
  white-space:nowrap;
}
.module-tag.ai{
  color:var(--navy-bright);background:rgba(59,130,246,.14);
  border:1px solid rgba(59,130,246,.25);
}
.module-body{
  padding:0 20px 20px;color:var(--text-dim);font-size:14px;
  display:grid;gap:8px;
}
.module-body ul{margin:0;padding-left:18px}
.module-body li{margin:6px 0}

.curr-side{
  background:linear-gradient(180deg, rgba(220,38,38,.08), rgba(255,255,255,.01));
  border:1px solid var(--line-strong);
  border-radius:var(--r-lg);
  padding:32px;
  position:sticky;top:100px;
  height:fit-content;
}
.curr-side h3{margin-bottom:14px}
.curr-side p{color:var(--text-dim);font-size:14.5px;margin-bottom:24px}
.curr-side .check-list{display:flex;flex-direction:column;gap:12px;margin-bottom:24px}
.curr-side .check-list span{
  display:flex;align-items:flex-start;gap:10px;font-size:14px;color:var(--text-dim);
}
.curr-side .check-list svg{color:var(--red-bright);flex-shrink:0;margin-top:2px}

.t-grid{display:grid;gap:18px;grid-template-columns:1fr}
@media(min-width:760px){.t-grid{grid-template-columns:repeat(2,1fr)}}
@media(min-width:1020px){.t-grid{grid-template-columns:repeat(3,1fr)}}
.t-card{
  background:rgba(255,255,255,.03);
  border:1px solid var(--line);
  border-radius:var(--r-lg);
  padding:26px;
  display:flex;flex-direction:column;gap:18px;
}
.t-card .stars{color:var(--gold);letter-spacing:2px;font-size:14px}
.t-card blockquote{margin:0;font-size:17px;line-height:1.5;letter-spacing:-.01em;font-family:var(--display);font-weight:500}
.t-meta{display:flex;align-items:center;gap:12px;margin-top:auto}
.t-meta .ava{
  width:42px;height:42px;border-radius:50%;
  background-size:cover;
  border:1px solid var(--line);
}
.t-meta b{display:block;font-size:14px}
.t-meta small{font-size:12px;color:var(--text-mute)}
.t-card.featured{
  background:linear-gradient(180deg, rgba(220,38,38,.18), rgba(220,38,38,.04));
  border-color:rgba(248,113,113,.3);
}

.mentor-row{
  display:grid;gap:24px;grid-template-columns:1fr;
  margin-bottom:28px;
}
@media(min-width:820px){
  .mentor-row{grid-template-columns:380px 1fr;align-items:center}
  .mentor-row.reverse{grid-template-columns:1fr 380px}
}
.mentor-photo{
  border-radius:var(--r-lg);
  aspect-ratio:1/1.05;
  background:linear-gradient(135deg,#7a1f1f,#0f0a1f);
  border:1px solid var(--line-strong);
  position:relative;overflow:hidden;
  display:grid;place-items:center;
}
.mentor-photo svg{width:60%;height:auto;color:rgba(252,165,165,.5)}
.mentor-photo img{
  position:absolute;inset:0;
  width:100%;height:100%;
  object-fit:cover;object-position:center top;
  display:block;
  z-index:1;
}
.mentor-photo::after{
  content:"";position:absolute;inset:0;
  background:radial-gradient(circle at 50% 30%, rgba(248,113,113,.2), transparent 60%);
  z-index:2;pointer-events:none;
}
.mentor-info .role{
  font-family:var(--mono);font-size:11px;letter-spacing:.18em;text-transform:uppercase;color:var(--red-bright);
}
.mentor-info h3{font-size:32px;margin:8px 0 16px}
.mentor-info p{color:var(--text-dim);font-size:15px;margin-bottom:14px}
.mentor-tags{display:flex;flex-wrap:wrap;gap:8px;margin-top:18px}
.mentor-tags span{
  padding:6px 12px;border-radius:999px;
  background:rgba(255,255,255,.04);
  border:1px solid var(--line);
  font-size:12.5px;color:var(--text-dim);
}

.price-grid{
  display:grid;gap:18px;grid-template-columns:1fr;max-width:880px;margin:0 auto;
}
@media(min-width:760px){.price-grid{grid-template-columns:1fr 1fr}}
.price-grid-single{max-width:520px;grid-template-columns:1fr}
@media(min-width:760px){.price-grid-single{grid-template-columns:1fr}}
.price-card{
  background:rgba(255,255,255,.03);
  border:1px solid var(--line);
  border-radius:var(--r-lg);
  padding:32px;
  position:relative;
}
.price-card.feat{
  background:linear-gradient(180deg, #7f1d1d 0%, #450a0a 100%);
  border-color:rgba(248,113,113,.35);
  box-shadow:var(--shadow-red);
}
.price-card .label{
  display:inline-block;font-family:var(--mono);font-size:11px;letter-spacing:.15em;text-transform:uppercase;
  padding:5px 10px;border-radius:6px;
  background:rgba(248,113,113,.18);color:var(--red-soft);
  margin-bottom:18px;
}
.price-card.feat .label{background:rgba(255,255,255,.15);color:#fff}
.price-card h3{margin-bottom:16px;font-size:24px}
.price-card .price{display:flex;align-items:baseline;gap:6px;margin-bottom:6px}
.price-card .price span:first-child{font-family:var(--display);font-size:48px;font-weight:500;letter-spacing:-.03em}
.price-card .price small{color:var(--text-mute);font-size:13px}
.price-card .old{font-size:13px;color:var(--text-mute);text-decoration:line-through;margin-bottom:20px}
.price-card.feat .old{color:rgba(255,255,255,.5)}
.price-list{display:flex;flex-direction:column;gap:10px;margin:24px 0}
.price-list span{display:flex;align-items:flex-start;gap:10px;font-size:14px;color:var(--text-dim)}
.price-list svg{flex-shrink:0;margin-top:2px;color:var(--red-bright)}
.price-card.feat .price-list span{color:rgba(255,255,255,.85)}
.price-card.feat .price-list svg{color:var(--gold)}
.price-card .btn{width:100%}

.faq-list{display:flex;flex-direction:column;gap:10px;max-width:760px;margin:0 auto}
.faq{
  background:rgba(255,255,255,.03);
  border:1px solid var(--line);
  border-radius:var(--r);
  overflow:hidden;
}
.faq summary{
  list-style:none;cursor:pointer;
  padding:20px 24px;
  font-weight:600;font-size:15px;
  display:flex;align-items:center;gap:14px;
}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{
  content:"+";margin-left:auto;font-size:22px;color:var(--text-mute);font-family:var(--mono);font-weight:300;
}
.faq[open] summary::after{content:"−";color:var(--red-bright)}
.faq[open]{border-color:rgba(248,113,113,.3)}
.faq-body{padding:0 24px 22px;color:var(--text-dim);font-size:14.5px;line-height:1.7}

.final-cta{
  margin:40px auto 80px;
  max-width:1200px;
  border-radius:var(--r-xl);
  background:
    radial-gradient(circle at 80% 20%, rgba(248,113,113,.4), transparent 50%),
    radial-gradient(circle at 10% 90%, rgba(59,130,246,.25), transparent 60%),
    linear-gradient(135deg,#7f1d1d 0%, #1e1a3a 50%, #0f1530 100%);
  padding:60px 40px;
  display:grid;grid-template-columns:1fr;gap:30px;align-items:center;
  border:1px solid rgba(248,113,113,.25);
  position:relative;overflow:hidden;
}
.final-cta::before{
  content:"";position:absolute;
  width:300px;height:300px;border-radius:50%;
  background:radial-gradient(circle, rgba(251,191,36,.3), transparent 70%);
  top:-100px;right:-50px;
  filter:blur(40px);
}
@media(min-width:820px){.final-cta{grid-template-columns:1fr auto}}
.final-cta h2{font-size:clamp(32px,4vw,48px);max-width:14ch}
.final-cta p{color:var(--red-soft);max-width:38ch;margin-top:14px}
.final-cta-actions{display:flex;flex-wrap:wrap;gap:12px;position:relative;z-index:2}

footer{
  border-top:1px solid var(--line);
  padding:48px 24px 32px;
  text-align:center;
  color:var(--text-mute);font-size:13px;
}
.foot-links{
  display:flex;flex-wrap:wrap;justify-content:center;gap:24px;margin:18px 0;
}
.foot-links a{transition:color .2s}
.foot-links a:hover{color:var(--text-dim)}

.reveal{opacity:0;transform:translateY(20px);transition:opacity .8s ease, transform .8s ease}
.reveal.in{opacity:1;transform:translateY(0)}

::selection{background:rgba(220,38,38,.4);color:#fff}

/* ============================================================
 * CERTIFICATION BADGES (reusable across pages)
 * ============================================================ */

/* ----- Hero cert stamp: pill trắng có logo + text ngắn ----- */
.cert-stamp {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  background: #fff;
  border-radius: 18px;
  padding: 8px 22px 8px 8px;
  margin-bottom: 22px;
  box-shadow: 0 14px 40px -12px rgba(30, 64, 175, .35),
              0 0 0 1px rgba(255, 255, 255, .15);
  text-align: left;
}
.cert-stamp img {
  width: 56px; height: 56px;
  object-fit: contain;
  display: block;
  flex-shrink: 0;
}
.cert-stamp-text {
  display: flex; flex-direction: column;
  gap: 2px; line-height: 1.15;
}
.cert-stamp-text small {
  font-size: 10px;
  font-family: var(--mono);
  color: #64748b;
  letter-spacing: .15em;
  text-transform: uppercase;
  font-weight: 500;
}
.cert-stamp-text b {
  color: #1e3a8a;
  font-family: var(--display);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: -.01em;
}

/* Variant cho logo wide (vd: Postman) — chỉ hiển thị logo, không cần text */
.cert-stamp.cert-stamp-wide {
  padding: 10px 18px;
  gap: 0;
}
.cert-stamp.cert-stamp-wide img {
  width: auto;
  height: 38px;
}

/* ----- Price card cert seal: circle xoay nhẹ ở góc card ----- */
.price-cert-seal {
  position: absolute;
  top: -22px; right: -22px;
  width: 110px; height: 110px;
  object-fit: contain;
  background: #fff;
  border-radius: 50%;
  padding: 10px;
  box-shadow: 0 16px 40px -10px rgba(0, 0, 0, .5),
              0 0 0 4px rgba(248, 113, 113, .25);
  transform: rotate(8deg);
  transition: transform .3s ease;
  z-index: 2;
}
.price-card:hover .price-cert-seal {
  transform: rotate(0deg) scale(1.05);
}

/* Variant cho logo wide (Postman) — pill ngang thay vì tròn */
.price-cert-seal.price-cert-seal-wide {
  width: 150px;
  height: 60px;
  border-radius: 32px;
  padding: 8px 14px;
  top: -22px;
  right: 18px;
  transform: rotate(-4deg);
}
.price-card:hover .price-cert-seal-wide {
  transform: rotate(0deg) scale(1.05);
}

@media (max-width: 600px) {
  .price-cert-seal { width: 84px; height: 84px; top: -16px; right: -16px; }
  .price-cert-seal.price-cert-seal-wide {
    width: 120px; height: 50px;
    top: -16px; right: 12px;
  }
  .cert-stamp { padding: 6px 18px 6px 6px; gap: 10px; }
  .cert-stamp img { width: 46px; height: 46px; }
  .cert-stamp.cert-stamp-wide img { height: 32px; }
  .cert-stamp-text small { font-size: 9px; }
  .cert-stamp-text b { font-size: 12px; }
}

/* =====================================================
 * INTERVIEW SECTION — embed YouTube Shorts (9:16)
 *   Dùng trên trang khoá học để show demo phỏng vấn thử.
 * ===================================================== */
.interview-section {
  padding: 70px 0 50px;
}
.interview-wrap {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  max-width: 1080px;
  margin: 40px auto 0;
  align-items: center;
}
@media (min-width: 880px) {
  .interview-wrap {
    grid-template-columns: 340px 1fr;
    gap: 56px;
  }
}
.interview-video {
  position: relative;
  aspect-ratio: 9 / 16;
  width: 100%;
  max-width: 340px;
  margin: 0 auto;
  border-radius: var(--r-lg);
  overflow: hidden;
  background: #000;
  box-shadow: 0 30px 80px -20px rgba(220, 38, 38, .55),
              inset 0 1px 0 rgba(255, 255, 255, .08);
  border: 1px solid var(--line-strong);
}
.interview-video iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

/* Thumbnail click-to-play (mở YouTube tab mới) — fallback khi embed bị chặn */
.interview-thumb {
  position: absolute;
  inset: 0;
  display: block;
  text-decoration: none;
  overflow: hidden;
  border-radius: inherit;
}
.interview-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  display: block;
  transition: transform .55s ease;
}
.interview-thumb::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(0,0,0,.15) 0%, rgba(0,0,0,.55) 100%);
  transition: background .3s ease;
}
.interview-thumb:hover img { transform: scale(1.05); }
.interview-thumb:hover::after { background: linear-gradient(180deg, rgba(0,0,0,.05) 0%, rgba(0,0,0,.45) 100%); }

.play-icon {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 78px; height: 78px;
  border-radius: 50%;
  background: linear-gradient(135deg, #ef4444 0%, #dc2626 60%, #991b1b 100%);
  display: grid;
  place-items: center;
  box-shadow: 0 20px 50px -8px rgba(220,38,38,.75),
              inset 0 1px 0 rgba(255,255,255,.28);
  transition: transform .25s ease, box-shadow .25s ease;
  z-index: 2;
}
.interview-thumb:hover .play-icon {
  transform: translate(-50%, -50%) scale(1.08);
  box-shadow: 0 28px 70px -8px rgba(220,38,38,.9),
              inset 0 1px 0 rgba(255,255,255,.35);
}
.play-icon svg {
  width: 30px; height: 30px;
  fill: #fff;
  margin-left: 4px; /* visual centering of triangle */
}
.play-label {
  position: absolute;
  bottom: 18px; left: 50%;
  transform: translateX(-50%);
  display: inline-flex; align-items: center; gap: 6px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .15em;
  text-transform: uppercase;
  font-weight: 500;
  color: #fff;
  background: rgba(8,13,31,.6);
  padding: 7px 14px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,.12);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  white-space: nowrap;
  z-index: 2;
}
.play-label svg {
  width: 12px; height: 12px;
  fill: currentColor;
}
.interview-video::before {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  background: linear-gradient(135deg, rgba(248,113,113,.4), transparent 50%, rgba(96,165,250,.3));
  z-index: -1;
  filter: blur(20px);
  opacity: .6;
}
.interview-text h3 {
  font-family: var(--display);
  font-size: clamp(24px, 3vw, 32px);
  margin: 0 0 12px;
  letter-spacing: -.02em;
}
.interview-text p {
  color: var(--text-dim);
  font-size: 15.5px;
  line-height: 1.65;
  margin: 0 0 18px;
}
.interview-text ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.interview-text ul li {
  position: relative;
  padding-left: 28px;
  font-size: 14.5px;
  color: var(--text);
}
.interview-text ul li::before {
  content: "";
  position: absolute;
  left: 0; top: 4px;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: var(--grad);
  mask: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none' stroke='black' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'><polyline points='3 8 7 12 13 4'/></svg>") center/12px no-repeat;
  -webkit-mask: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none' stroke='black' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'><polyline points='3 8 7 12 13 4'/></svg>") center/12px no-repeat;
}

/* ============================================================
   THEME TOGGLE BUTTON — sun/moon
   ============================================================ */
.theme-toggle{
  display:inline-flex;align-items:center;justify-content:center;
  width:40px;height:40px;border-radius:999px;
  background:rgba(255,255,255,.04);
  border:1px solid var(--line-strong);
  color:var(--text-dim);
  cursor:pointer;
  transition:background .2s, color .2s, transform .2s, border-color .2s;
}
.theme-toggle:hover{
  color:var(--text);
  background:rgba(255,255,255,.08);
  transform:rotate(15deg);
}
.theme-toggle svg{width:18px;height:18px;display:block}
.theme-toggle .icon-sun{display:none}
.theme-toggle .icon-moon{display:block}
[data-theme="light"] .theme-toggle .icon-sun{display:block}
[data-theme="light"] .theme-toggle .icon-moon{display:none}

/* ============================================================
   LIGHT THEME — override tokens + critical surfaces
   ============================================================ */
:root[data-theme="light"]{
  --bg:#f8fafc;
  --bg-2:#f1f5f9;
  --bg-3:#e2e8f0;
  --surface:#ffffff;
  --surface-2:#f1f5f9;
  --line:rgba(15,23,42,.10);
  --line-strong:rgba(15,23,42,.18);
  --text:#0f172a;
  --text-dim:#334155;          /* slate-700 — đậm hơn để text body nổi */
  --text-mute:#475569;         /* slate-600 — đậm hơn */

  /* Brand "bright" variants quá nhạt trên nền trắng → đổi sang variant đậm */
  --red-bright:#dc2626;        /* red-600 thay vì red-300 */
  --navy-bright:#2563eb;       /* blue-600 thay vì blue-400 */

  --shadow-red: 0 20px 60px -25px rgba(220,38,38,.35);
  --shadow-navy: 0 20px 60px -25px rgba(30,58,138,.30);
}
[data-theme="light"] body{
  --bg-glow-1: rgba(220,38,38,.05);
  --bg-glow-2: rgba(59,130,246,.06);
  --bg-glow-3: rgba(220,38,38,.03);
}
[data-theme="light"] body::after{
  opacity:.25;
  mix-blend-mode:multiply;
}

/* Header — light translucent */
[data-theme="light"] .site-header{
  background:rgba(248,250,252,.78);
  border-bottom-color:var(--line);
}

/* Buttons / nav hover — đảo từ trắng-tint sang đen-tint */
[data-theme="light"] .btn-ghost{
  background:rgba(15,23,42,.04);
  border-color:var(--line-strong);
}
[data-theme="light"] .btn-ghost:hover{background:rgba(15,23,42,.08)}
[data-theme="light"] .nav-links a:hover{background:rgba(15,23,42,.05)}

/* Theme toggle — đổi tint nền cho light */
[data-theme="light"] .theme-toggle{background:rgba(15,23,42,.04)}
[data-theme="light"] .theme-toggle:hover{background:rgba(15,23,42,.08)}

/* Card surfaces — override hardcoded rgba(255,255,255,.0X) */
[data-theme="light"] .course-card,
[data-theme="light"] .post-card,
[data-theme="light"] .post-card-link{
  background:linear-gradient(180deg, #ffffff, #f8fafc);
  border-color:var(--line);
}
[data-theme="light"] .price-card:not(.feat),
[data-theme="light"] .feat-card,
[data-theme="light"] .testi-card,
[data-theme="light"] .faq-item,
[data-theme="light"] .stats-card,
[data-theme="light"] .compare-card,
[data-theme="light"] .blog-cats a,
[data-theme="light"] .pagination a{
  background:#ffffff;
  border-color:var(--line);
}
[data-theme="light"] .blog-cats a:hover,
[data-theme="light"] .pagination a:hover{background:#f1f5f9}

/* Featured price card — keep brand but tweak inner alpha for light bg */
[data-theme="light"] .price-card.feat .label{background:rgba(255,255,255,.22)}

/* Code/pre/inline-code in blog post */
[data-theme="light"] .post-content pre,
[data-theme="light"] .post-content code{
  background:#f1f5f9;
  color:#0f172a;
  border-color:var(--line);
}
[data-theme="light"] .post-content th{background:#f1f5f9}
[data-theme="light"] .post-content blockquote{background:#f1f5f9}

/* Form inputs / select / textarea (registration modal + admin shared) */
[data-theme="light"] .field input,
[data-theme="light"] .field select,
[data-theme="light"] .field textarea,
[data-theme="light"] .reg-form input,
[data-theme="light"] .reg-form select,
[data-theme="light"] .reg-form textarea{
  background:#ffffff;
  border-color:var(--line-strong);
  color:var(--text);
}

/* Logo drop-shadow — bớt đỏ trên nền sáng */
[data-theme="light"] .logo-img{
  filter: drop-shadow(0 4px 8px rgba(220,38,38,.20));
}

/* Page-nav (TOC) — surfaces */
[data-theme="light"] .page-nav-list,
[data-theme="light"] .page-nav-mobile-toggle{
  background:#ffffff;
  border-color:var(--line);
}
[data-theme="light"] .page-nav-list a:hover{background:#f1f5f9}

/* Gallery / lightbox dùng dark cố ý — không override */