:root{
    --navy:#13243f;--navy-2:#1e3a63;--ink:#1a1f2b;--muted:#6b7280;
    --line:#e7e9ee;--bg:#ffffff;--bg-soft:#f6f7f9;--maxw:980px;
  }
  *{box-sizing:border-box;margin:0;padding:0}
  html{scroll-behavior:smooth}
  body{font-family:'Roboto',system-ui,-apple-system,Segoe UI,sans-serif;color:var(--ink);background:var(--bg);line-height:1.6;-webkit-font-smoothing:antialiased;font-weight:400}
  .wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}
  section{padding:104px 0;scroll-margin-top:72px}
  h1,h2,h3{font-weight:700;letter-spacing:-0.02em;color:var(--navy);line-height:1.2}
  .eyebrow{font-size:12px;letter-spacing:.18em;text-transform:uppercase;color:var(--navy-2);font-weight:700;margin-bottom:18px;opacity:.85}
  .muted{color:var(--muted)}

  /* Header */
  header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.82);backdrop-filter:saturate(180%) blur(12px);border-bottom:1px solid var(--line)}
  .nav{display:flex;align-items:center;justify-content:space-between;height:64px}
  .brand{font-weight:700;color:var(--navy);letter-spacing:-0.01em;font-size:16px;text-decoration:none}
  .brand span{color:var(--navy-2);font-weight:400}
  .menu{display:flex;gap:30px}
  .menu a{color:var(--ink);text-decoration:none;font-size:14px;font-weight:500;opacity:.75;transition:opacity .2s}
  .menu a:hover{opacity:1}
  .nav .cta{display:inline-block;background:var(--navy);color:#fff;padding:9px 18px;border-radius:999px;font-size:14px;font-weight:500;text-decoration:none;transition:background .2s}
  .nav .cta:hover{background:var(--navy-2)}
  @media(max-width:760px){.menu{display:none}}

  /* Hero */
  .hero{padding:118px 0 92px}
  .hero h1{font-size:clamp(40px,7.4vw,72px);font-weight:900;letter-spacing:-0.03em}
  .hero .subtitle{font-size:clamp(18px,2.4vw,22px);color:var(--navy-2);margin-top:22px;font-weight:500;max-width:36ch}
  .hero .lead{margin-top:26px;max-width:64ch}
  .hero .lead p{color:var(--muted);font-size:16.5px;margin-top:15px;line-height:1.7}
  .hero .lead p strong{color:var(--ink);font-weight:700}
  .hero .actions{margin-top:38px;display:flex;gap:14px;flex-wrap:wrap}
  .btn{display:inline-flex;align-items:center;gap:8px;padding:13px 26px;border-radius:999px;font-size:15px;font-weight:500;text-decoration:none;transition:.2s}
  .btn-primary{background:var(--navy);color:#fff}
  .btn-primary:hover{background:var(--navy-2)}
  .btn-ghost{color:var(--navy);border:1px solid var(--line)}
  .btn-ghost:hover{border-color:var(--navy)}
  .hero-grid{display:grid;grid-template-columns:1.05fr .95fr;gap:54px;align-items:center}
  .hero-art{border-radius:18px;overflow:hidden;border:1px solid var(--line);box-shadow:0 22px 54px rgba(19,36,63,.12)}
  .hero-art img{display:block;width:100%;aspect-ratio:4/5;object-fit:cover;object-position:50% 38%}
  @media(max-width:820px){.hero-grid{grid-template-columns:1fr;gap:34px}.hero-art{max-width:520px}.hero-art img{aspect-ratio:16/10}}

  /* Image blocks */
  .showcase{margin-top:26px;border-radius:16px;overflow:hidden;border:1px solid var(--line)}
  .showcase img{display:block;width:100%}
  .banner{margin-bottom:46px;border-radius:16px;overflow:hidden;border:1px solid var(--line)}
  .banner img{display:block;width:100%;aspect-ratio:16/6;object-fit:cover;object-position:50% 44%}
  @media(max-width:640px){.banner img{aspect-ratio:3/2}}

  /* Section head */
  .shead{max-width:640px;margin-bottom:50px}
  .shead h2{font-size:clamp(26px,4vw,38px)}
  .shead p{color:var(--muted);margin-top:14px;font-size:16px;line-height:1.7}

  /* Formats */
  .formats{display:grid;grid-template-columns:repeat(2,1fr);gap:1px;background:var(--line);border:1px solid var(--line);border-radius:14px;overflow:hidden}
  .fcard{background:#fff;padding:32px 30px;transition:background .2s}
  .fcard:hover{background:var(--bg-soft)}
  .fcard .ic{width:42px;height:42px;border-radius:11px;background:var(--bg-soft);border:1px solid var(--line);display:flex;align-items:center;justify-content:center;margin-bottom:18px}
  .fcard:hover .ic{background:#fff}
  .fcard .ic svg{width:22px;height:22px;stroke:var(--navy);fill:none;stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round}
  .fcard .ft{font-size:18px;font-weight:500;color:var(--navy)}
  .fcard .fd{color:var(--muted);font-size:15px;margin-top:10px;line-height:1.6}
  @media(max-width:640px){.formats{grid-template-columns:1fr}}

  /* Course cards */
  .subtrack + .subtrack{margin-top:56px}
  .st-head{margin-bottom:26px}
  .st-label{font-size:13px;font-weight:700;color:var(--navy-2);letter-spacing:.06em;text-transform:uppercase}
  .st-head p{color:var(--muted);font-size:15.5px;margin-top:12px;max-width:64ch;line-height:1.65}
  .st-head .cond{color:var(--ink);font-size:14.5px;margin-top:12px}
  .st-head .cond b{color:var(--navy-2);font-weight:700}
  .course{border:1px solid var(--line);border-radius:16px;padding:30px;background:#fff;margin-bottom:18px;transition:box-shadow .25s,transform .25s}
  .course:hover{box-shadow:0 12px 34px rgba(19,36,63,.08);transform:translateY(-2px)}
  .course-top{display:flex;justify-content:space-between;align-items:flex-start;gap:18px;flex-wrap:wrap}
  .course .cn{font-size:22px;font-weight:700;color:var(--navy);letter-spacing:-0.01em}
  .course .cen{font-size:14px;font-style:italic;color:var(--navy-2);margin-top:4px}
  .course .dur{flex-shrink:0;font-size:13px;font-weight:500;color:var(--navy);background:var(--bg-soft);border:1px solid var(--line);padding:7px 15px;border-radius:999px;white-space:nowrap}
  .course-body{display:grid;grid-template-columns:1fr 1.45fr;gap:36px;margin-top:26px;padding-top:24px;border-top:1px solid var(--line)}
  .clabel{font-size:11.5px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--navy-2);margin-bottom:9px}
  .course-body .who2{color:var(--ink);font-size:15px;line-height:1.65}
  .course-body .cond2{color:var(--muted);font-size:14px;margin-top:16px;line-height:1.6}
  .course-body .cond2 b{color:var(--navy-2);font-weight:700}
  .score{margin-top:18px;padding:15px 17px;border-radius:12px;background:var(--navy);color:#fff}
  .score .sl{font-size:11px;letter-spacing:.08em;text-transform:uppercase;opacity:.78}
  .score .sv{font-size:15.5px;font-weight:500;margin-top:4px;line-height:1.45}
  .gintro{color:var(--ink);font-size:15px;margin-bottom:12px;line-height:1.6}
  .goals{list-style:none;display:grid;gap:9px}
  .goals li{position:relative;padding-left:24px;color:var(--ink);font-size:14.5px;line-height:1.55}
  .goals li::before{content:"";position:absolute;left:2px;top:8px;width:6px;height:6px;border-radius:50%;background:var(--navy-2)}
  .after{margin-top:22px}
  .gsub{margin-top:16px}
  .gsub .gstitle{font-size:14px;font-weight:700;color:var(--navy);margin-bottom:8px}
  .nextstep{margin-top:18px;padding:14px 16px;border-radius:12px;background:var(--bg-soft);border:1px solid var(--line);border-left:3px solid var(--navy-2)}
  .nextstep .sl{font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--navy-2);font-weight:700}
  .nextstep .nv{font-size:15px;font-weight:500;color:var(--navy);margin-top:4px}
  @media(max-width:720px){.course-body{grid-template-columns:1fr;gap:26px}}
  @media(max-width:520px){}

  /* Commitment */
  .commit{display:grid;grid-template-columns:1fr 1fr;gap:22px}
  .ccol{border:1px solid var(--line);border-radius:16px;padding:28px 30px;background:#fff}
  .ccol.lead-col{background:var(--navy);border-color:var(--navy)}
  .ccol.lead-col .ctag{color:#9db4d8;border-bottom-color:rgba(255,255,255,.16)}
  .ccol.lead-col .goals li{color:#eaf0f8}
  .ccol.lead-col .goals li::before{background:#4f7fc4}
  .ctag{font-size:12px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--navy-2);margin-bottom:18px;padding-bottom:14px;border-bottom:1px solid var(--line)}
  .commit-note{margin-top:24px;padding:22px 26px;border-left:3px solid var(--navy-2);background:var(--bg-soft);border-radius:0 12px 12px 0;color:var(--navy);font-size:16px;line-height:1.6}
  @media(max-width:720px){.commit{grid-template-columns:1fr}}

  /* Overview map / flowchart */
  .map{display:grid;grid-template-columns:1.65fr 1fr;gap:26px;margin-top:8px}
  .mapcol{border:1px solid var(--line);border-radius:18px;padding:26px 24px;background:#fff}
  .maphead{font-size:13px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;color:var(--navy-2);text-align:center;margin-bottom:8px}
  .mapsub{font-size:12.5px;color:var(--muted);text-align:center;margin-bottom:20px}
  .node{border:1px solid var(--line);border-radius:12px;padding:12px 16px;background:#fff;text-align:center}
  .node .nname{font-weight:700;color:var(--navy);font-size:15px}
  .node .nsub{font-size:12px;color:var(--muted);margin-top:2px}
  .node.accent{background:var(--navy);border-color:var(--navy)}
  .node.accent .nname{color:#fff}
  .node.accent .nsub{color:#9db4d8}
  .varr{display:flex;justify-content:center;color:var(--navy-2);font-size:15px;line-height:1;margin:7px 0}
  .branch-label{text-align:center;font-size:12.5px;color:var(--muted);font-style:italic;margin:4px 0 14px}
  .branch-cols{display:grid;grid-template-columns:1fr 1fr;gap:14px}
  .bcol{border:1px dashed #cdd5e1;border-radius:14px;padding:16px 13px;background:var(--bg-soft)}
  .bcol .btitle{font-size:11px;font-weight:700;color:var(--navy-2);text-align:center;text-transform:uppercase;letter-spacing:.03em;margin-bottom:12px;line-height:1.3}
  @media(max-width:820px){.map{grid-template-columns:1fr}}
  @media(max-width:430px){.branch-cols{grid-template-columns:1fr}}
  .grouptag{display:block;width:fit-content;margin:0 auto 16px;text-align:center;font-size:11.5px;font-weight:700;letter-spacing:.02em;color:var(--navy-2);background:var(--bg-soft);border:1px solid var(--line);border-radius:999px;padding:6px 15px}

  /* TOEIC exam info */
  .skillrow{display:flex;flex-wrap:wrap;gap:12px;margin:36px 0 6px}
  .skillpill{flex:1;min-width:130px;border:1px solid var(--line);border-radius:14px;padding:18px 14px;text-align:center;background:#fff}
  .skillpill .sk{font-weight:700;color:var(--navy);font-size:16px}
  .skillpill .skv{font-size:12.5px;color:var(--muted);margin-top:4px}
  .examgrid{display:grid;grid-template-columns:1fr 1fr;gap:22px;margin-top:44px}
  .examcard{border:1px solid var(--line);border-radius:16px;padding:30px 28px;background:#fff}
  .examcard h3{font-size:20px;color:var(--navy)}
  .examcard .esub{color:var(--muted);font-size:14.5px;margin:8px 0 22px;line-height:1.65}
  .epart{margin-top:20px;padding-top:20px;border-top:1px solid var(--line)}
  .epart.first{margin-top:0;padding-top:0;border-top:none}
  .epart .eh{display:flex;justify-content:space-between;align-items:baseline;gap:12px}
  .epart .en{font-weight:700;color:var(--navy);font-size:15px}
  .epart .em{font-size:12.5px;color:var(--navy-2);font-weight:500;white-space:nowrap}
  .epart .goals{margin-top:11px}
  .examfoot{margin-top:22px;padding-top:18px;border-top:1px solid var(--line);display:flex;gap:22px;flex-wrap:wrap}
  .examfoot .ff{font-size:13.5px;color:var(--ink)}
  .examfoot .ff b{color:var(--navy);font-weight:700}
  .subsec{margin-top:58px;max-width:760px}
  .subsec h3{font-size:clamp(20px,3vw,26px);color:var(--navy)}
  .subsec p{color:var(--ink);font-size:16px;line-height:1.75;margin-top:14px}
  .subsec .goals{margin-top:14px}
  .steps{counter-reset:s;list-style:none;display:grid;gap:13px;margin-top:16px}
  .steps li{position:relative;padding-left:44px;color:var(--ink);font-size:15px;line-height:1.5;padding-top:3px}
  .steps li::before{counter-increment:s;content:counter(s);position:absolute;left:0;top:0;width:29px;height:29px;border-radius:50%;background:var(--navy);color:#fff;font-size:13px;font-weight:700;display:flex;align-items:center;justify-content:center}
  @media(max-width:760px){.examgrid{grid-template-columns:1fr}}

  /* Connect levels */
  .levels{display:grid;gap:0;border-top:1px solid var(--line)}
  .level{display:grid;grid-template-columns:172px 1fr auto;gap:28px;align-items:start;padding:24px 4px;border-bottom:1px solid var(--line);transition:padding-left .25s,background .25s}
  .level:hover{background:var(--bg-soft);padding-left:14px}
  .level .name{font-size:21px;font-weight:700;color:var(--navy);display:flex;flex-direction:column;gap:8px;line-height:1.15}
  .level .name .tag{font-size:11px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;color:var(--navy-2);border:1px solid var(--line);padding:3px 9px;border-radius:6px;width:fit-content}
  .level .desc .who{color:var(--ink);font-size:15px;font-weight:500}
  .level .desc .goal{color:var(--muted);font-size:14.5px;margin-top:6px}
  .level .meta{color:var(--navy-2);font-size:14px;font-weight:700;white-space:nowrap}
  @media(max-width:640px){.level{grid-template-columns:1fr;gap:10px}.level .meta{justify-self:start}}

  /* Why TOEIC layout */
  .why-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:48px;align-items:start}
  .why-art{position:sticky;top:88px;border-radius:16px;overflow:hidden;border:1px solid var(--line);box-shadow:0 16px 40px rgba(19,36,63,.10)}
  .why-art img{display:block;width:100%}
  @media(max-width:820px){.why-grid{grid-template-columns:1fr;gap:30px}.why-art{position:static;max-width:600px}}

  /* Prose */
  .prose{max-width:64ch}
  .prose p{color:var(--ink);font-size:16.5px;margin-top:18px;line-height:1.78}
  .prose p:first-child{margin-top:0}
  .prose-quote{max-width:62ch;margin-top:36px;padding:24px 28px;border-left:3px solid var(--navy-2);background:var(--bg-soft);border-radius:0 12px 12px 0;font-size:18px;font-weight:500;color:var(--navy);line-height:1.55}

  /* Teacher */
  .teacher{display:grid;grid-template-columns:300px 1fr;gap:56px;align-items:start}
  .portrait{width:100%;aspect-ratio:3/4;border-radius:16px;overflow:hidden;background:linear-gradient(160deg,var(--navy),var(--navy-2));display:flex;align-items:center;justify-content:center;position:relative;border:1px solid var(--line)}
  .portrait img{width:100%;height:100%;object-fit:cover;object-position:center top;display:block}
  .portrait .mono{color:#fff;font-size:64px;font-weight:700;letter-spacing:.04em;opacity:.9}
  .teacher h2{font-size:clamp(26px,4vw,36px)}
  .teacher .role{color:var(--navy-2);font-weight:500;margin:8px 0 0}
  .teacher .teacher-intro{color:var(--muted);font-size:15.5px;margin:18px 0 24px;max-width:56ch;line-height:1.7}
  .creds{list-style:none;display:grid;gap:12px}
  .creds li{position:relative;padding-left:26px;color:var(--ink);font-size:15.5px}
  .creds li::before{content:"";position:absolute;left:0;top:9px;width:8px;height:8px;border-radius:2px;background:var(--navy-2)}
  @media(max-width:760px){.teacher{grid-template-columns:1fr;gap:32px}.portrait{max-width:260px}}

  /* Philosophy */
  .principle{background:var(--bg-soft);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
  .principle .box{max-width:680px}
  .principle p{font-size:16.5px;color:var(--ink);margin-top:18px;line-height:1.75}
  .principle p.firm{color:var(--navy);font-weight:700;font-size:18px;margin-top:24px}

  /* Contact */
  .contact{text-align:center}
  .contact h2{font-size:clamp(28px,4.5vw,42px)}
  .contact p{color:var(--muted);margin:16px auto 0;font-size:17px;max-width:60ch;line-height:1.7}
  .contact .phone{display:inline-block;margin-top:34px;font-size:clamp(26px,5vw,40px);font-weight:700;color:var(--navy);text-decoration:none;letter-spacing:-0.02em}
  .contact .phone:hover{color:var(--navy-2)}
  .contact .sub{margin-top:10px;font-size:14px;color:var(--muted)}

  /* Footer */
  footer{border-top:1px solid var(--line);padding:34px 0}
  .foot{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:12px;color:var(--muted);font-size:14px}
  .foot a{color:var(--navy-2);text-decoration:none}

  .reveal{opacity:0;transform:translateY(18px);transition:opacity .7s ease,transform .7s ease}
  .reveal.in{opacity:1;transform:none}
  /* refined heading reveal (slight secondary rise) */
  .reveal h2, .reveal .cn{opacity:0;transform:translateY(12px);transition:opacity .9s ease .08s, transform .9s cubic-bezier(.22,.61,.27,1) .08s}
  .reveal.in h2, .reveal.in .cn{opacity:1;transform:none}
  /* typed headings stay put; the typing itself is the effect */
  h2.twh{opacity:1 !important;transform:none !important;transition:none !important}
  /* typewriter cursor */
  .tw-cursor{display:inline-block;width:3px;height:.78em;background:var(--navy-2);margin-left:7px;vertical-align:baseline;border-radius:1px;animation:blink 1.05s steps(1) infinite}
  .tw-cursor.done{animation:none;opacity:0;transition:opacity .5s ease}
  @keyframes blink{50%{opacity:0}}
  /* sequential roadmap reveal */
  .step{opacity:0;transform:translateY(12px);transition:opacity .5s ease, transform .55s cubic-bezier(.2,.6,.2,1)}
  .step.in{opacity:1;transform:none}
  @media (prefers-reduced-motion: reduce){
    .reveal, .reveal h2, .reveal .cn, .step{opacity:1 !important;transform:none !important;transition:none !important}
    .tw-cursor{display:none}
  }

  .menu a.active{opacity:1;color:var(--navy);font-weight:700}

/* ===== Blog / Article ===== */
.article-head{max-width:760px;margin:0 auto;padding:104px 24px 0}
.article-cat{font-size:12px;letter-spacing:.16em;text-transform:uppercase;color:var(--navy-2);font-weight:700;margin-bottom:18px}
.article-head h1{font-size:clamp(30px,5vw,46px);font-weight:900;letter-spacing:-0.02em;line-height:1.16}
.article-meta{display:flex;align-items:center;gap:11px;margin-top:22px;color:var(--muted);font-size:14.5px}
.article-meta .who{color:var(--navy);font-weight:700}
.article-meta .dot{opacity:.5}
.article-figure{margin:38px auto;max-width:760px}
.article-figure img{display:block;width:100%;border-radius:14px;border:1px solid var(--line)}
.article-figure figcaption{margin-top:12px;text-align:center;font-size:13px;color:var(--muted)}
.article-body{max-width:760px;margin:0 auto;padding:6px 24px 0}
.article-body p{font-size:17px;line-height:1.8;color:var(--ink);margin-top:20px}
.article-body p.note{color:var(--muted);font-size:15.5px}
.article-body h2{font-size:clamp(22px,3.4vw,30px);color:var(--navy);margin-top:54px}
.article-body h3{font-size:19px;color:var(--navy);margin-top:36px}
.article-body ul{margin:18px 0 0;padding:0;list-style:none;display:grid;gap:10px}
.article-body ul li{position:relative;padding-left:24px;font-size:16.5px;line-height:1.65;color:var(--ink)}
.article-body ul li::before{content:"";position:absolute;left:2px;top:10px;width:6px;height:6px;border-radius:50%;background:var(--navy-2)}
.article-body blockquote{margin:22px 0;padding:14px 22px;border-left:3px solid var(--navy-2);background:var(--bg-soft);border-radius:0 10px 10px 0;font-size:18px;color:var(--navy);font-style:italic}
.article-body strong{font-weight:700;color:var(--navy)}
.article-refs{max-width:760px;margin:46px auto 0;padding:0 24px}
.article-refs h2{font-size:22px;color:var(--navy)}
.article-refs ol{list-style:none;padding:0;margin-top:18px;display:grid;gap:13px}
.article-refs li{font-size:13.5px;line-height:1.6;color:var(--muted)}
.article-refs li a{color:var(--navy-2);text-decoration:none;word-break:break-word}
.article-divider{max-width:760px;margin:50px auto 0;padding:0 24px}
.article-divider hr{border:none;border-top:1px solid var(--line)}
.article-foot{max-width:760px;margin:40px auto 0;padding:30px 24px 0;border-top:1px solid var(--line);display:flex;gap:14px;flex-wrap:wrap;align-items:center}
.article-foot .ab{font-size:14.5px;color:var(--muted)}

/* Blog listing */
.post-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:24px}
.post-card{display:flex;flex-direction:column;border:1px solid var(--line);border-radius:16px;overflow:hidden;background:#fff;text-decoration:none;transition:box-shadow .25s,transform .25s}
.post-card:hover{box-shadow:0 14px 34px rgba(19,36,63,.10);transform:translateY(-3px)}
.post-card .thumb{height:210px;overflow:hidden;border-bottom:1px solid var(--line);background:var(--bg-soft)}
.post-card .thumb img{width:100%;height:100%;object-fit:cover;object-position:center 16%;display:block}
.post-card .pc-body{padding:24px 24px 26px}
.post-card .pc-cat{font-size:11.5px;letter-spacing:.1em;text-transform:uppercase;color:var(--navy-2);font-weight:700}
.post-card .pc-title{font-size:19px;font-weight:700;color:var(--navy);margin-top:10px;line-height:1.32}
.post-card .pc-ex{color:var(--muted);font-size:14.5px;margin-top:11px;line-height:1.6}
.post-card .pc-meta{margin-top:16px;font-size:13px;color:var(--muted)}
@media(max-width:640px){.article-figure{max-width:100%}}

/* Article flow box (arrow diagrams) */
.article-body .flow{display:block;margin:24px auto;max-width:430px;text-align:center;background:var(--bg-soft);border:1px solid var(--line);border-radius:12px;padding:20px 22px;color:var(--navy);font-weight:500;line-height:1.95;font-size:16px}
.article-body .flow .ar{color:var(--navy-2);opacity:.6;font-weight:400}
.article-body blockquote em{font-style:italic;color:var(--navy)}

/* Footer + contact socials */
.foot .foot-right{display:flex;gap:18px;flex-wrap:wrap;align-items:center}
.contact .socials{margin-top:20px;display:flex;gap:14px;justify-content:center;flex-wrap:wrap}
.contact .socials a{color:var(--navy-2);text-decoration:none;font-size:14.5px;font-weight:500;border:1px solid var(--line);padding:9px 20px;border-radius:999px;transition:border-color .2s,color .2s}
.contact .socials a:hover{border-color:var(--navy);color:var(--navy)}

/* ===================================================================
   2026 refresh — one-page layout: mobile nav, accordion, section rhythm
   =================================================================== */

/* --- Nav: mobile menu --- */
.nav-right{display:flex;align-items:center;gap:12px}
.burger{display:none;width:40px;height:40px;border:1px solid var(--line);background:#fff;border-radius:10px;cursor:pointer;padding:0;align-items:center;justify-content:center;flex-direction:column;gap:4px;transition:border-color .2s}
.burger:hover{border-color:var(--navy)}
.burger span{display:block;width:17px;height:1.8px;background:var(--navy);border-radius:2px;transition:transform .25s,opacity .2s}
.burger[aria-expanded="true"] span:nth-child(1){transform:translateY(5.8px) rotate(45deg)}
.burger[aria-expanded="true"] span:nth-child(2){opacity:0}
.burger[aria-expanded="true"] span:nth-child(3){transform:translateY(-5.8px) rotate(-45deg)}
@media(max-width:880px){
  .menu{display:none;position:absolute;top:64px;left:0;right:0;flex-direction:column;gap:0;background:#fff;border-bottom:1px solid var(--line);box-shadow:0 20px 44px rgba(19,36,63,.12);padding:6px 0}
  .menu.open{display:flex}
  .menu a{padding:14px 24px;font-size:15.5px;opacity:.9;border-bottom:1px solid var(--line)}
  .menu a:last-child{border-bottom:none}
  .burger{display:flex}
}
@media(max-width:400px){
  .nav .cta{padding:8px 14px;font-size:13px}
  .brand{font-size:15px}
}

/* --- Section rhythm --- */
.tsec-soft{background:var(--bg-soft);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.sec-cta{margin-top:46px;display:flex;gap:14px;flex-wrap:wrap;justify-content:center}
.mapnote{margin-top:20px;padding-top:16px;border-top:1px solid var(--line);font-size:12.5px;color:var(--muted);text-align:center;line-height:1.65}

/* --- Course block heading --- */
.course-head{max-width:720px;margin-bottom:38px}
.ch-tag{font-size:12px;letter-spacing:.18em;text-transform:uppercase;color:var(--navy-2);font-weight:700;margin-bottom:16px;opacity:.85}
.course-head h2{font-size:clamp(30px,5.2vw,46px);font-weight:900;letter-spacing:-0.03em}
.ch-lead{color:var(--muted);font-size:18px;margin-top:14px;line-height:1.65}
.subtrack{margin-top:66px}
.commit{margin-top:34px}
.tsec-soft .commit-note{background:#fff}

/* --- Accordion (native <details>) --- */
.acc{border:1px solid var(--line);border-radius:14px;background:#fff;margin-bottom:12px;transition:box-shadow .25s,border-color .25s}
.acc[open]{border-color:#ccd5e2;box-shadow:0 12px 32px rgba(19,36,63,.07)}
.acc summary{list-style:none;cursor:pointer;display:flex;align-items:center;justify-content:space-between;gap:20px;padding:22px 26px;border-radius:13px;transition:background .2s}
.acc summary::-webkit-details-marker{display:none}
.acc summary::marker{content:""}
.acc summary:hover{background:var(--bg-soft)}
.acc summary:focus-visible{outline:2px solid var(--navy-2);outline-offset:2px}
.acc-main{min-width:0}
.acc-name{font-size:19px;font-weight:700;color:var(--navy);letter-spacing:-0.01em;line-height:1.3}
.acc-en{display:block;font-size:13.5px;font-style:italic;font-weight:400;color:var(--navy-2);margin-top:4px;letter-spacing:0}
.acc-who{color:var(--muted);font-size:14.5px;margin-top:9px;line-height:1.55}
.acc-side{display:flex;align-items:center;gap:14px;flex-shrink:0}
.acc-ic{position:relative;width:27px;height:27px;border-radius:50%;border:1px solid var(--line);flex-shrink:0;transition:background .2s,border-color .2s}
.acc-ic::before,.acc-ic::after{content:"";position:absolute;left:50%;top:50%;background:var(--navy-2);transition:opacity .2s,background .2s}
.acc-ic::before{width:11px;height:1.7px;transform:translate(-50%,-50%)}
.acc-ic::after{width:1.7px;height:11px;transform:translate(-50%,-50%)}
.acc[open] .acc-ic{background:var(--navy);border-color:var(--navy)}
.acc[open] .acc-ic::before{background:#fff}
.acc[open] .acc-ic::after{opacity:0}
.acc-body{padding:24px 26px 28px;border-top:1px solid var(--line)}
.acc[open] .acc-body{animation:accIn .32s ease both}
@keyframes accIn{from{opacity:0;transform:translateY(-6px)}to{opacity:1;transform:none}}
.acc-grid{display:grid;grid-template-columns:1fr 1.45fr;gap:38px}
.acc-p{color:var(--ink);font-size:15.5px;line-height:1.75;margin-top:16px}
.acc-p:first-child{margin-top:0}
.acc-plain .acc-name{font-size:17px;font-weight:500}
.acc-plain summary{padding:19px 26px}
.acc-body .skillrow{margin:24px 0 0}
.acc-body .examgrid{margin-top:24px}
.acc-body .examcard{background:var(--bg-soft)}
.acc-body .steps{margin-top:18px}
@media(max-width:760px){
  .acc-grid{grid-template-columns:1fr;gap:26px}
  .acc summary{padding:20px 20px;gap:14px}
  .acc-plain summary{padding:17px 20px}
  .acc-body{padding:20px 20px 24px}
  .acc-name{font-size:17.5px}
  .acc-side .dur{display:none}
}

/* --- Teacher section spacing on the one-pager --- */
.teacher .teacher-intro{margin-bottom:16px}
.teacher .creds{margin-top:22px}

/* --- Why-grid used with heading inside --- */
@media(max-width:820px){.why-grid .prose{max-width:none}}
@media (prefers-reduced-motion: reduce){
  .acc[open] .acc-body{animation:none}
}

/* --- Blog preview grid: 3 cột trên desktop --- */
.post-grid{grid-template-columns:repeat(auto-fill,minmax(270px,1fr))}
@media(max-width:900px){.post-grid{grid-template-columns:repeat(auto-fill,minmax(280px,1fr))}}

/* ===================================================================
   Khối lập luận: ba con đường, hai thứ đạt được, hộp thời gian
   =================================================================== */

/* --- Ba con đường --- */
.paths{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--line);border:1px solid var(--line);border-radius:16px;overflow:hidden}
.path{background:#fff;padding:30px 28px 32px}
.path h3{font-size:19px;color:var(--navy);letter-spacing:-0.01em;line-height:1.3}
.prow{margin-top:20px}
.prow .pl{font-size:11px;font-weight:700;letter-spacing:.09em;text-transform:uppercase;color:var(--muted);margin-bottom:7px}
.prow p{font-size:14.5px;line-height:1.68;color:var(--ink)}
.prow.stuck{margin-top:20px;padding-top:20px;border-top:1px solid var(--line)}
.prow.stuck .pl{color:var(--navy-2)}
@media(max-width:880px){.paths{grid-template-columns:1fr}}

.closing{margin-top:34px;font-size:18px;line-height:1.6;color:var(--navy);font-weight:500;max-width:60ch}

/* --- Hai thứ đạt được --- */
.gains{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin-top:36px}
.gain{border:1px solid var(--line);border-radius:16px;padding:26px 28px;background:#fff}
.gain .gt{font-size:19px;font-weight:700;color:var(--navy);margin-bottom:10px}
.gain p{font-size:15px;line-height:1.7;color:var(--ink)}
.gains-note{margin-top:18px;font-size:15px;color:var(--muted);line-height:1.65}
@media(max-width:720px){.gains{grid-template-columns:1fr}}

/* --- Hộp nói rõ về thời gian --- */
.timebox{margin-top:40px;padding:26px 30px;border:1px solid var(--line);border-left:3px solid var(--navy);border-radius:0 14px 14px 0;background:var(--bg-soft)}
.timebox .tb-label{font-size:11.5px;font-weight:700;letter-spacing:.09em;text-transform:uppercase;color:var(--navy-2);margin-bottom:12px}
.timebox p{font-size:16px;line-height:1.75;color:var(--ink)}
.timebox p + p{margin-top:14px}
.tsec-soft .timebox{background:#fff}

/* --- Hero tiếng Việt: câu dài hơn tiếng Anh nên cần cột rộng và cỡ chữ nhỏ hơn --- */
.hero h1{font-size:clamp(30px,4.6vw,46px);letter-spacing:-0.02em;line-height:1.18;text-wrap:balance}
.hero-top{margin-bottom:40px}
.hero-grid{display:block}
.hero-art{margin-top:46px;max-width:none;border-radius:16px}
.hero-art img{aspect-ratio:1536/920;object-fit:cover;object-position:50% 50%}
@media(max-width:820px){.hero-art{margin-top:34px}.hero-art img{aspect-ratio:1536/920}}
@media(min-width:881px){.prow:not(.stuck) p{min-height:5.1em}}

/* --- Header trên màn hình hẹp: giữ thương hiệu và nút trên một dòng --- */
.brand{white-space:nowrap}
.nav .cta{white-space:nowrap}
.cta-short{display:none}
@media(max-width:560px){
  .cta-long{display:none}
  .cta-short{display:inline}
}

/* --- Ảnh giảng viên bám theo khi cuộn, tránh khoảng trống dưới ảnh --- */
@media(min-width:761px){
  .teacher .portrait{position:sticky;top:96px}
}

/* --- Tiêu đề nhỏ trong khối .prose --- */
.prose h3{font-size:21px;font-weight:700;color:var(--navy);letter-spacing:-0.01em;margin-bottom:16px;line-height:1.35}
.prose h3 + p{margin-top:0}

/* --- Danh sách đánh số có tiêu đề + phần giải thích --- */
.steps-long li{padding-top:2px;padding-bottom:4px}
.steps-long li b{display:block;color:var(--navy);font-weight:700;font-size:15.5px;line-height:1.5;margin-bottom:6px}
.steps-long li .ex{display:block;color:var(--muted);font-size:15px;line-height:1.7}
.steps-long{gap:22px}

/* ===================================================================
   Trang syllabus khoá học (seed.html)
   =================================================================== */
.syl-hero{background:var(--bg-soft);border-bottom:1px solid var(--line);padding:88px 0 62px}
.syl-hero .eyebrow{margin-bottom:20px}
.syl-hero h1{font-size:clamp(52px,9vw,88px);font-weight:900;letter-spacing:-0.035em;line-height:1;color:var(--navy)}
.syl-sub{margin-top:16px;font-size:clamp(17px,2.4vw,21px);color:var(--navy-2);font-weight:500}
.syl-doc{margin-top:10px;font-size:15px;color:var(--muted);line-height:1.6;max-width:60ch}
.syl-actions{margin-top:32px;display:flex;gap:14px;flex-wrap:wrap}

/* Sơ đồ vị trí khoá + thông tin nhanh */
.syl-map-sec{padding:64px 0 10px}
.syl-figtitle{font-size:12px;font-weight:700;letter-spacing:.16em;text-transform:uppercase;color:var(--navy-2);margin-bottom:20px}
.syl-fig{border:1px solid var(--line);border-radius:16px;overflow:hidden;background:#fff}
.syl-fig img{display:block;width:100%;height:auto}
.syl-facts{margin-top:34px;border:1px solid var(--line);border-radius:16px;overflow:hidden;background:#fff}
.syl-facts .fact{display:grid;grid-template-columns:170px 1fr;border-bottom:1px solid var(--line)}
.syl-facts .fact:last-child{border-bottom:none}
.syl-facts .fk{padding:15px 20px;background:var(--bg-soft);font-size:13px;font-weight:700;color:var(--navy);letter-spacing:.02em}
.syl-facts .fv{padding:15px 20px;font-size:15px;color:var(--ink);line-height:1.65}
@media(max-width:620px){
  .syl-facts .fact{grid-template-columns:1fr;gap:0}
  .syl-facts .fk{padding-bottom:6px;background:#fff;border-bottom:none}
  .syl-facts .fv{padding-top:0}
}

/* Mục lục */
.syl-toc{margin-top:26px;border:1px solid var(--line);border-left:3px solid var(--navy);border-radius:0 14px 14px 0;padding:22px 26px;background:var(--bg-soft)}
.syl-toc .toc-label{font-size:11.5px;font-weight:700;letter-spacing:.09em;text-transform:uppercase;color:var(--navy-2);margin-bottom:12px}
.syl-toc ol{margin:0;padding-left:20px;display:grid;gap:7px}
.syl-toc li{font-size:15px;color:var(--muted)}
.syl-toc a{color:var(--navy);text-decoration:none;border-bottom:1px solid transparent;transition:border-color .2s}
.syl-toc a:hover{border-bottom-color:var(--navy-2)}

/* Thân syllabus */
.syl{padding:56px 0 96px}
.syl-h2{font-size:clamp(23px,3.4vw,30px);font-weight:700;color:var(--navy);letter-spacing:-0.02em;line-height:1.25;margin:72px 0 8px;padding-bottom:16px;border-bottom:1px solid var(--line);scroll-margin-top:84px;display:flex;gap:14px;align-items:baseline}
.syl > .wrap > .syl-h2:first-child{margin-top:0}
.syl-num{flex-shrink:0;font-size:13px;font-weight:700;color:var(--navy-2);background:var(--bg-soft);border:1px solid var(--line);border-radius:8px;padding:4px 10px;letter-spacing:.04em;position:relative;top:-3px}
.syl-h3{font-size:19px;font-weight:700;color:var(--navy);letter-spacing:-0.01em;line-height:1.4;margin:44px 0 4px;padding-left:15px;border-left:3px solid var(--navy-2)}
.syl-h3 strong{font-weight:700}
.syl p{font-size:16px;line-height:1.78;color:var(--ink);margin-top:16px;max-width:74ch}
.syl p.syl-lead{margin-top:30px;font-size:12px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--navy-2)}
.syl p.syl-lead + ul{margin-top:12px}
.syl ul{list-style:none;padding:0;margin:6px 0 0;display:grid;gap:10px;max-width:74ch}
.syl ul li{position:relative;padding-left:24px;font-size:16px;line-height:1.7;color:var(--ink)}
.syl ul li p{margin:0;font-size:16px}
.syl ul li::before{content:"";position:absolute;left:2px;top:11px;width:6px;height:6px;border-radius:50%;background:var(--navy-2)}

/* Dải phân chặng */
.syl-stage{margin:76px 0 8px;background:var(--navy);color:#fff;border-radius:14px;padding:18px 26px}
.syl-stage p{margin:0;color:#dbe5f4;font-size:15.5px;max-width:none;line-height:1.5}
.syl-stage strong{color:#fff;font-weight:700;letter-spacing:.01em}

/* Bảng */
.tblwrap{margin:20px 0 0;border:1px solid var(--line);border-radius:14px;overflow-x:auto;background:#fff}
.syl-table{width:100%;border-collapse:collapse;font-size:15px}
.syl-table col{}
.syl-table td,.syl-table th{padding:14px 18px;border-bottom:1px solid var(--line);vertical-align:top;line-height:1.68;color:var(--ink);text-align:left}
.syl-table tr:last-child td{border-bottom:none}
.syl-table p{margin:0;font-size:15px;line-height:1.68;max-width:none}
.syl-table p + p{margin-top:9px}
.syl-table strong{color:var(--navy);font-weight:700}
.syl-table.kv td:first-child{background:var(--bg-soft);color:var(--navy);font-weight:500;width:210px;min-width:180px}
.syl-table.has-head thead th{background:var(--navy);color:#fff;font-size:12px;font-weight:700;letter-spacing:.07em;text-transform:uppercase;border-bottom:none;white-space:nowrap}
.syl-table.has-head thead th strong{color:#fff}
.syl-table.has-head tbody tr:nth-child(even){background:var(--bg-soft)}
.syl-table.has-head td{white-space:normal}
.syl-table.has-head td:first-child{font-weight:500;color:var(--navy);white-space:nowrap}
@media(max-width:760px){
  .syl-table{font-size:14.5px}
  .syl-table td,.syl-table th{padding:12px 14px}
  .syl-table.kv td:first-child{width:auto;min-width:130px}
  .syl-table.has-head{min-width:640px}
  .syl-h2{gap:10px}
}

/* --- Dải thông báo lớp đang tuyển sinh --- */
.openbar-sec{padding:0 0 8px}
.openbar{display:flex;align-items:center;gap:18px;flex-wrap:wrap;text-decoration:none;background:var(--navy);border-radius:16px;padding:20px 26px;transition:background .2s}
.openbar:hover{background:#1a3357}
.ob-tag{flex-shrink:0;font-size:11px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--navy);background:#fff;border-radius:999px;padding:6px 14px}
.ob-txt{flex:1;min-width:220px;color:#cfdcef;font-size:15.5px;line-height:1.55}
.ob-txt b{color:#fff;font-weight:700}
.ob-go{flex-shrink:0;color:#fff;font-size:14.5px;font-weight:500;border-bottom:1px solid rgba(255,255,255,.35)}
@media(max-width:640px){.openbar{padding:18px 20px;gap:12px}.ob-go{border-bottom:none}}

/* --- Nút trong thẻ khoá học --- */
.acc-cta{margin-top:22px;padding-top:20px;border-top:1px solid var(--line)}

/* --- Thẻ gấp/mở cho từng buổi học trong syllabus --- */
.syl-hint{font-size:15px;color:var(--muted);margin-top:14px}
.syl-acc{margin-bottom:10px}
.syl-acc summary{padding:18px 24px}
.syl-acc .acc-name{font-size:17.5px;line-height:1.4}
.syl-acc .acc-en{display:inline;font-size:15px;font-style:normal;color:var(--muted);font-weight:400}
.syl-acc .acc-en::before{content:"· "}
.syl-acc .acc-body{padding:0;border-top:1px solid var(--line)}
.syl-acc .acc-body .tblwrap{margin:0;border:none;border-radius:0}
.syl-stage + .syl-acc{margin-top:14px}
@media(max-width:760px){
  .syl-acc summary{padding:16px 18px}
  .syl-acc .acc-name{font-size:16px}
  .syl-acc .acc-en{display:block;margin-top:4px}
  .syl-acc .acc-en::before{content:""}
}