:root{
  --paper:#faf9f6;
  --card:#ffffff;
  --ink:#1a2530;
  --ink-soft:#4a5866;
  --ink-faint:#8a97a3;
  --accent:#0e4d64;
  --accent-soft:#e8f0f3;
  --gold:#b98a2f;
  --line:#e6e2da;
  --serif:'Newsreader', Georgia, serif;
  --sans:'Inter', -apple-system, sans-serif;
  --maxw:1080px;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:76px}
body{background:var(--paper);color:var(--ink);font-family:var(--sans);font-size:16px;line-height:1.7;-webkit-font-smoothing:antialiased}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}

/* ---------- Bilingual ---------- */
.vi{display:none}
body.vi-mode .vi{display:revert}
body.vi-mode .en{display:none}

/* ---------- Nav ---------- */
nav{position:sticky;top:0;z-index:50;background:rgba(250,249,246,.85);backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}
.nav-inner{max-width:var(--maxw);margin:0 auto;padding:14px 24px;display:flex;align-items:center;justify-content:space-between;gap:18px}
.brand{font-family:var(--serif);font-weight:600;font-size:1.15rem;letter-spacing:.01em;color:var(--ink);white-space:nowrap}
.brand span{color:var(--gold)}
.nav-right{display:flex;align-items:center;gap:26px}
.nav-links{display:flex;gap:26px;font-size:.88rem;font-weight:500}
.nav-links a{color:var(--ink-soft)}
.nav-links a:hover{color:var(--accent);text-decoration:none}
@media(max-width:760px){.nav-links{display:none}}
.lang-switch{display:flex;border:1.5px solid var(--line);border-radius:999px;overflow:hidden;font-size:.76rem;font-weight:700;letter-spacing:.04em}
.lang-switch button{border:0;background:transparent;padding:6px 13px;cursor:pointer;color:var(--ink-faint);font:inherit;transition:.15s}
.lang-switch button.active{background:var(--accent);color:#fff}
.menu-btn{display:none;border:1.5px solid var(--line);background:transparent;border-radius:9px;width:38px;height:38px;cursor:pointer;align-items:center;justify-content:center;flex:none}
.menu-btn svg{width:19px;height:19px;stroke:var(--ink);stroke-width:2.2;fill:none;stroke-linecap:round}
@media(max-width:760px){.menu-btn{display:flex}}
.mobile-menu{display:none;flex-direction:column;border-top:1px solid var(--line);padding:6px 24px 16px}
.mobile-menu.open{display:flex}
.mobile-menu a{padding:12px 2px;font-weight:500;font-size:.95rem;color:var(--ink-soft);border-bottom:1px dashed var(--line)}
.mobile-menu a:last-child{border-bottom:none}
.mobile-menu a:hover{color:var(--accent);text-decoration:none}
@media(min-width:761px){.mobile-menu{display:none!important}}

/* ---------- Hero ---------- */
.hero{padding:88px 0 72px;border-bottom:1px solid var(--line)}
.hero-grid{display:grid;grid-template-columns:1.4fr 1fr;gap:56px;align-items:center}
@media(max-width:820px){.hero-grid{grid-template-columns:1fr;gap:40px}}
.kicker{font-size:.78rem;font-weight:600;letter-spacing:.18em;text-transform:uppercase;color:var(--gold);margin-bottom:18px}
h1{font-family:var(--serif);font-weight:500;font-size:clamp(2.4rem,5vw,3.6rem);line-height:1.12;letter-spacing:-.01em;margin-bottom:14px}
.role{font-size:1.12rem;color:var(--ink-soft);margin-bottom:22px}
.role strong{color:var(--ink);font-weight:600}
.tagline{font-family:var(--serif);font-style:italic;font-size:1.18rem;color:var(--ink-soft);max-width:34em;margin-bottom:32px}
.cta-row{display:flex;gap:14px;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;gap:8px;padding:11px 22px;border-radius:8px;font-size:.9rem;font-weight:600;transition:.18s}
.btn-primary{background:var(--accent);color:#fff}
.btn-primary:hover{background:#0a3c4f;text-decoration:none}
.btn-ghost{border:1.5px solid var(--line);color:var(--ink)}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent);text-decoration:none}
.portrait-wrap{position:relative;justify-self:center}
.portrait{width:min(300px,70vw);aspect-ratio:3/4;object-fit:cover;border-radius:14px;box-shadow:0 24px 60px -18px rgba(14,77,100,.35);display:block;height:auto}
.portrait-wrap::before{content:'';position:absolute;inset:-16px -16px 16px 16px;border:1.5px solid var(--gold);border-radius:14px;z-index:-1;opacity:.5}
.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;margin-top:56px}
.stat{background:linear-gradient(145deg,#125a75 0%,#0a3c4f 85%);border-radius:16px;padding:30px 18px;text-align:center;position:relative;overflow:hidden;box-shadow:0 18px 40px -14px rgba(10,60,79,.55),inset 0 1px 0 rgba(255,255,255,.12);transition:box-shadow .25s}
.stat::after{content:'';position:absolute;inset:0;background:radial-gradient(circle at 80% 12%,rgba(185,138,47,.22),transparent 55%);pointer-events:none}
.stat:hover{box-shadow:0 26px 54px -16px rgba(10,60,79,.65),inset 0 1px 0 rgba(255,255,255,.16)}
.stat b{display:block;font-family:var(--serif);font-size:2.3rem;font-weight:600;color:#e9c97c;text-shadow:0 2px 12px rgba(0,0,0,.28)}
.stat span{font-size:.85rem;font-weight:500;color:rgba(255,255,255,.88);letter-spacing:.01em}

/* ---------- Sections ---------- */
section{padding:76px 0;border-bottom:1px solid var(--line)}
.sec-head{display:flex;align-items:baseline;gap:18px;margin-bottom:40px}
.sec-num{font-family:var(--serif);font-style:italic;color:var(--gold);font-size:1rem}
h2{font-family:var(--serif);font-weight:500;font-size:2rem;letter-spacing:-.01em}
.sec-sub{margin-top:-30px;margin-bottom:40px;color:var(--ink-faint);font-size:.95rem;max-width:44em}

/* About */
.about-grid{display:grid;grid-template-columns:1fr 1fr;gap:44px}
@media(max-width:820px){.about-grid{grid-template-columns:1fr}}
.about-grid p{color:var(--ink-soft);margin-bottom:18px;text-align:justify;text-justify:inter-word}

/* Expertise */
.chip-groups{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:22px}
.chip-group{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:24px}
.chip-group h3{font-family:var(--serif);font-weight:600;font-size:1.05rem;margin-bottom:14px;color:var(--accent)}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{font-size:.8rem;font-weight:500;padding:5px 12px;border-radius:999px;background:var(--accent-soft);color:var(--accent)}

/* Auto-scrolling gallery */
.gallery{margin-top:46px;overflow:hidden;position:relative}
.gallery::before,.gallery::after{content:'';position:absolute;top:0;bottom:0;width:70px;z-index:2;pointer-events:none}
.gallery::before{left:0;background:linear-gradient(90deg,var(--paper),transparent)}
.gallery::after{right:0;background:linear-gradient(-90deg,var(--paper),transparent)}
.g-track{display:flex;width:max-content;will-change:transform}
.g-item{position:relative;flex:none;width:420px;height:236px;border-radius:14px;overflow:hidden;margin-right:22px;box-shadow:0 16px 36px -14px rgba(26,37,48,.35);background-size:cover;background-position:center}
.g-item>img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;display:block}
.g-cap{z-index:1}



.g-cap{position:absolute;left:0;right:0;bottom:0;padding:26px 18px 12px;background:linear-gradient(transparent,rgba(10,37,48,.85));color:#fff;font-size:.85rem;font-weight:600;letter-spacing:.02em}

/* Experience as separate page */
#experience{display:none}
body.page-experience .hero{display:none}
body.page-experience section:not(#experience){display:none}
body.page-experience #experience{display:block;border-bottom:none;min-height:60vh}
.back-link{display:inline-flex;align-items:center;gap:6px;margin-bottom:28px;font-weight:600;font-size:.9rem}
.sub-sec{margin-top:70px}

/* Timeline */
.timeline{position:relative;padding-left:28px}
.timeline::before{content:'';position:absolute;left:5px;top:6px;bottom:6px;width:1.5px;background:var(--line)}
.t-item{position:relative;padding-bottom:38px}
.t-item:last-child{padding-bottom:0}
.t-item::before{content:'';position:absolute;left:-28px;top:7px;width:11px;height:11px;border-radius:50%;background:var(--paper);border:2.5px solid var(--accent)}
.t-date{font-size:.8rem;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--gold)}
.t-item h3{font-family:var(--serif);font-weight:600;font-size:1.25rem;margin:4px 0 2px}
.t-org{color:var(--ink-soft);font-size:.95rem;margin-bottom:8px}
.t-item p{color:var(--ink-soft);font-size:.93rem;max-width:56em}

/* Writing */
.post-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:22px}
.post{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:26px;display:flex;flex-direction:column;transition:.2s}
.post:hover{transform:translateY(-3px);box-shadow:0 14px 34px -16px rgba(26,37,48,.18)}
.post-tag{font-size:.72rem;font-weight:600;letter-spacing:.12em;text-transform:uppercase;color:var(--gold);margin-bottom:10px}
.post h3{font-family:var(--serif);font-weight:600;font-size:1.2rem;line-height:1.35;margin-bottom:10px}
.post h3 a{color:var(--ink)}
.post p{font-size:.9rem;color:var(--ink-soft);flex:1}
.post-meta{margin-top:16px;font-size:.8rem;color:var(--ink-faint);display:flex;justify-content:space-between}
.read{color:var(--accent);font-weight:600}

/* Udemy course */
.course-card{display:flex;gap:36px;align-items:center;background:linear-gradient(145deg,#125a75 0%,#0a3c4f 85%);border-radius:18px;padding:38px 44px;position:relative;overflow:hidden;box-shadow:0 22px 48px -16px rgba(10,60,79,.55),inset 0 1px 0 rgba(255,255,255,.12)}
.course-card::after{content:'';position:absolute;inset:0;background:radial-gradient(circle at 88% 10%,rgba(185,138,47,.25),transparent 55%);pointer-events:none}
.course-ic{font-size:3.4rem;flex:none;width:92px;height:92px;border-radius:20px;background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.18);display:flex;align-items:center;justify-content:center}
.course-body h3{font-family:var(--serif);font-weight:600;font-size:1.55rem;color:#e9c97c;margin-bottom:10px;text-shadow:0 2px 12px rgba(0,0,0,.25)}
.course-body p{color:rgba(255,255,255,.88);font-size:.97rem;max-width:46em;margin-bottom:22px}
.btn-gold{background:var(--gold);color:#fff;box-shadow:0 10px 24px -8px rgba(185,138,47,.6),inset 0 1px 0 rgba(255,255,255,.25)}
.btn-gold:hover{background:#a67926;text-decoration:none;box-shadow:0 14px 30px -8px rgba(185,138,47,.7)}

/* Tools & News */
.tool-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:18px}
.tool{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:20px 22px;display:flex;gap:14px;align-items:flex-start;transition:.2s}
.tool:hover{border-color:var(--accent)}
.tool-ic{width:38px;height:38px;flex:none;border-radius:9px;background:var(--accent-soft);display:flex;align-items:center;justify-content:center;font-size:1.1rem}
.tool h3{font-size:.95rem;font-weight:600;margin-bottom:3px}
.tool p{font-size:.83rem;color:var(--ink-soft)}

/* Clients */
.client-cols{columns:2;gap:44px;font-size:.93rem;color:var(--ink-soft)}
@media(max-width:640px){.client-cols{columns:1}}
.client-cols li{break-inside:avoid;padding:9px 0;border-bottom:1px dashed var(--line);list-style:none;display:flex;justify-content:space-between;gap:14px}
.client-cols li em{font-style:normal;color:var(--ink-faint);font-size:.8rem;white-space:nowrap}

/* Education */
.edu-grid{display:grid;grid-template-columns:1fr 1fr;gap:22px}
@media(max-width:720px){.edu-grid{grid-template-columns:1fr}}
.edu{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:24px}
.edu h3{font-family:var(--serif);font-weight:600;font-size:1.08rem;margin-bottom:4px}
.edu p{font-size:.9rem;color:var(--ink-soft)}
.certs{margin-top:26px;display:flex;flex-wrap:wrap;gap:10px}
.cert{display:inline-flex;align-items:center;gap:8px;background:var(--card);border:1px solid var(--line);border-radius:999px;padding:8px 18px;font-size:.85rem;font-weight:500}
.cert::before{content:'✓';color:var(--gold);font-weight:700}

/* ---------- 3D & Motion ---------- */
.tilt{transform-style:preserve-3d;will-change:transform;transition:transform .18s ease-out,box-shadow .25s}
.tilt .tilt-inner{transform:translateZ(24px)}
.portrait-wrap{perspective:900px}
.glare{position:absolute;inset:0;border-radius:14px;pointer-events:none;background:radial-gradient(circle at var(--gx,50%) var(--gy,50%),rgba(255,255,255,.28),transparent 55%);opacity:0;transition:opacity .25s;z-index:2}
.portrait-wrap:hover .glare{opacity:1}

.reveal{opacity:0;transform:perspective(900px) translateY(30px) rotateX(7deg);transform-origin:50% 100%;transition:opacity .7s cubic-bezier(.16,1,.3,1),transform .7s cubic-bezier(.16,1,.3,1)}
.reveal.in{opacity:1;transform:perspective(900px) translateY(0) rotateX(0)}

.hero{position:relative;overflow:hidden}
.orb{position:absolute;border-radius:50%;filter:blur(60px);opacity:.5;pointer-events:none;animation:float 14s ease-in-out infinite}
.orb-1{width:380px;height:380px;background:radial-gradient(circle,#bcd9e4,transparent 70%);top:-120px;right:-80px}
.orb-2{width:300px;height:300px;background:radial-gradient(circle,#ead9b0,transparent 70%);bottom:-100px;left:-90px;animation-delay:-7s}
.orb-3{width:200px;height:200px;background:radial-gradient(circle,#cfe3d8,transparent 70%);top:38%;left:44%;animation-delay:-3s;opacity:.35}
@keyframes float{0%,100%{transform:translate3d(0,0,0) scale(1)}50%{transform:translate3d(24px,-28px,0) scale(1.06)}}
.hero .wrap{position:relative;z-index:1}

.btn{transform:translateZ(0);box-shadow:0 2px 0 rgba(10,60,79,0),0 6px 18px -8px rgba(14,77,100,.35)}
.btn:active{transform:translateY(2px) scale(.98)}
.btn-primary{box-shadow:0 8px 22px -8px rgba(14,77,100,.55),inset 0 1px 0 rgba(255,255,255,.18)}
.btn-primary:hover{box-shadow:0 12px 28px -8px rgba(14,77,100,.6)}

.post:hover,.tool:hover,.chip-group:hover{box-shadow:0 22px 44px -18px rgba(26,37,48,.25)}
.stat b{transition:transform .3s}
.stat:hover b{transform:scale(1.12)}

@media (prefers-reduced-motion: reduce){
  .tilt,.reveal,.orb,.btn{transition:none!important;animation:none!important}
  .reveal{opacity:1;transform:none}
}

/* Footer */
footer{padding:70px 0 46px;text-align:center}
footer h2{margin-bottom:12px}
.foot-sub{color:var(--ink-soft);max-width:36em;margin:0 auto 28px}
.foot-links{display:flex;gap:22px;justify-content:center;margin-bottom:40px;font-weight:600;font-size:.92rem}
.copy{font-size:.8rem;color:var(--ink-faint)}

/* ---------- Mobile polish (cuối file để thắng các rule gốc) ---------- */
@media(max-width:640px){
  .hero{padding:52px 0 46px}
  section{padding:54px 0}
  .hero-grid{gap:34px}
  .portrait-wrap::before{inset:-10px -10px 10px 10px}
  .stats{grid-template-columns:1fr;gap:14px;margin-top:42px}
  .stat{display:flex;align-items:baseline;justify-content:flex-start;gap:12px;text-align:left;padding:18px 22px}
  .stat b{font-size:1.7rem}
  h2{font-size:1.62rem}
  .tagline{font-size:1.08rem}
  .sec-head{margin-bottom:28px}
  .about-grid{gap:6px}
  .about-grid p{text-align:left}
  .cta-row .btn{flex:1;justify-content:center}
  .post,.chip-group,.tool,.edu{padding:20px}
  .client-cols li{font-size:.88rem}
  .g-item{width:280px;height:168px;margin-right:14px}
  .gallery::before,.gallery::after{width:36px}
  .course-card{flex-direction:column;align-items:flex-start;gap:20px;padding:28px 24px}
  .course-ic{width:68px;height:68px;font-size:2.4rem;border-radius:16px}
  .course-body h3{font-size:1.3rem}
  .course-body .btn{width:100%;justify-content:center}
}