/* =========================================================================
   course.css — style dùng chung cho các trang chi tiết khoá chuyên sâu
   Đồng bộ theme coral (Claude) với index.html. Nội dung bọc trong .hoc-scope.
   ========================================================================= */

/* ===== Coral (Claude) theme — single variant (đồng bộ index.html) ===== */
.hoc-scope{
  --acc:#cc785c; --acc-soft:#e0a98f;
  --glow:rgba(204,120,92,.40); --glow-strong:rgba(204,120,92,.66);
  --acc-wash:rgba(204,120,92,.08); --acc-wash2:rgba(204,120,92,.1);
  --on-acc:#ffffff;
  --ease:cubic-bezier(.16,1,.3,1);
  /* dark surfaces */
  --d-bg82:rgba(20,20,19,.86); --d-bg55:rgba(20,20,19,.6); --d-card74:rgba(37,35,32,.8);
  --d-card6:rgba(37,35,32,.7); --d-card55:rgba(37,35,32,.62);
  --grid:rgba(204,120,92,.06); --grid2:rgba(204,120,92,.045);
  --d-bg2:#252320; --d-bg:#181715; --d-bg3:#1f1e1b; --logo-tile:#252320;
  --d-line:#38332b; --d-line2:#463f35; --d-line3:#524a3d;
  --d-h:#faf9f5; --d-t1:#ddd6c9; --d-t5:#cbc1b0; --d-t2:#b3aa9b; --d-t3:#9a9082;
  --d-link:#cabfae; --d-t1b:#ece3d4; --d-t4:#a89e8c; --d-vn:#8e8576;
  /* light surfaces */
  --l-bg:#faf9f5; --l-bg2:#f5f0e8; --l-card:#fffdf8; --l-card2:#f8f3ea; --build-bg:#f3ede1;
  --in-bg:#f5f0e8; --l-line:#e6dfd8; --l-div:#ece5db; --in-border:#d8cfbf;
  --l-h:#141413; --l-h2:#252523; --l-t0:#141413; --l-t1:#3d3d3a; --l-t2:#3d3d3a;
  --l-t3:#6c6a64; --l-t4:#8e8b82; --l-t5:#a09d96; --l-mute:#b0a89b; --l-dash:#cabfae; --err:#c64545;
}
html,body{margin:0;padding:0;background:#181715;overflow-x:hidden;max-width:100%}
html{scroll-behavior:smooth}
.hoc-scope{font-family:'Be Vietnam Pro',system-ui,sans-serif;color:var(--l-t2);background:var(--l-bg);line-height:1.6;-webkit-font-smoothing:antialiased}
.hoc-scope *{box-sizing:border-box}
.hoc-scope ::selection{background:var(--acc);color:var(--on-acc)}
.hoc-scope [id]{scroll-margin-top:78px}
.hoc-scope h1,.hoc-scope h2,.hoc-scope h3,.hoc-scope p{margin:0}
.exo{font-family:'Exo 2',sans-serif}

/* ===== NAV (đồng bộ index.html) ===== */
.cs-nav{position:sticky;top:0;z-index:30;display:flex;align-items:center;justify-content:space-between;gap:24px;padding:14px 40px;background:var(--d-bg82);backdrop-filter:blur(16px) saturate(140%);-webkit-backdrop-filter:blur(16px) saturate(140%);border-bottom:1px solid var(--d-line)}
.cs-brand{display:flex;align-items:center;gap:11px;text-decoration:none}
.cs-brand-tile{display:grid;place-items:center;width:38px;height:38px;border-radius:11px;background:var(--logo-tile);border:1px solid var(--d-line);box-shadow:0 0 18px var(--glow)}
.cs-brand-name{font-family:'Exo 2',sans-serif;font-weight:800;font-size:19px;letter-spacing:.3px}
.cs-brand-name .a{color:var(--d-h)}.cs-brand-name .b{color:var(--acc);text-shadow:0 0 10px var(--glow)}.cs-brand-name .c{color:var(--d-vn);font-size:14px}
.cs-brand-tag{font-family:'Be Vietnam Pro',sans-serif;font-weight:600;font-size:8px;letter-spacing:3px;color:var(--acc-soft);margin-top:3px}
.cs-nav-links{display:flex;align-items:center;gap:26px}
.cs-nav-links a{color:var(--d-link);text-decoration:none;font-size:14px;font-weight:500;transition:color .25s var(--ease)}
.cs-nav-links a:hover{color:var(--acc-soft)}
.cs-nav-links a.active{color:var(--acc)}
.cs-nav-cta{display:inline-flex!important;align-items:center;gap:7px;padding:9px 18px;border-radius:10px;background:var(--acc);color:var(--on-acc)!important;font-weight:700;font-size:13.5px;text-decoration:none;box-shadow:0 0 0 1px var(--acc),0 8px 22px var(--glow);transition:all .25s var(--ease)}
.cs-nav-cta:hover{box-shadow:0 0 0 1px var(--acc),0 8px 30px var(--glow-strong);transform:translateY(-1px)}

/* ===== layout helpers ===== */
.cs-wrap{max-width:1080px;margin:0 auto}
.cs-narrow{max-width:760px;margin:0 auto}
.cs-sec{padding:72px 40px}
.cs-eyebrow{font-family:'Be Vietnam Pro',sans-serif;font-size:12px;font-weight:700;letter-spacing:2.4px;text-transform:uppercase;color:var(--acc)}
.cs-h2{font-family:'Exo 2',sans-serif;font-weight:700;font-size:clamp(23px,2.7vw,33px);color:var(--l-h);margin:12px 0 0;letter-spacing:-.01em;text-wrap:balance}
.cs-lead{font-size:16px;color:var(--l-t3);margin:16px 0 0}

/* ===== buttons / chips ===== */
.cs-btn{display:inline-flex;align-items:center;gap:8px;padding:13px 24px;border-radius:11px;font-weight:700;font-size:15px;text-decoration:none;transition:all .25s var(--ease)}
.cs-btn-primary{background:var(--acc);color:var(--on-acc);box-shadow:0 10px 30px var(--glow)}
.cs-btn-primary:hover{box-shadow:0 12px 40px var(--glow-strong);transform:translateY(-2px)}
.cs-btn-ghost{border:1px solid var(--d-line3);color:var(--d-t1b);background:transparent}
.cs-btn-ghost:hover{border-color:var(--acc);box-shadow:0 0 22px var(--glow)}
.cs-chip{display:inline-flex;align-items:center;gap:6px;font-family:'Be Vietnam Pro',sans-serif;font-size:11.5px;font-weight:700;letter-spacing:1px;text-transform:uppercase;color:var(--acc-soft);padding:6px 12px;border-radius:999px;background:rgba(204,120,92,.12);border:1px solid var(--d-line2)}

/* ===== HERO (dark) ===== */
.cs-hero{position:relative;overflow:hidden;background:var(--d-bg);padding:64px 40px 72px}
.cs-hero-glow{position:absolute;top:-110px;right:6%;width:380px;height:380px;border-radius:50%;background:var(--acc);opacity:.13;filter:blur(95px);pointer-events:none}
.cs-hero-inner{position:relative;max-width:880px;margin:0 auto}
.cs-crumb{font-size:13px;color:var(--d-t3);margin-bottom:22px}
.cs-crumb a{color:var(--d-t1);text-decoration:none}
.cs-crumb a:hover{color:var(--acc-soft)}
.cs-crumb span{color:var(--d-vn)}
.cs-hero h1{font-family:'Exo 2',sans-serif;font-weight:800;font-size:clamp(28px,4.4vw,46px);line-height:1.12;letter-spacing:-.01em;color:var(--d-h);margin:18px 0 0;text-wrap:balance}
.cs-hero-sub{font-size:17px;color:var(--d-t2);margin:18px 0 0;max-width:640px;line-height:1.6}
.cs-hero-chips{display:flex;flex-wrap:wrap;gap:9px;margin-top:22px}
.cs-hero-cta{display:flex;flex-wrap:wrap;gap:14px;margin-top:30px;align-items:center}

/* ===== generic light card ===== */
.cs-card{border-radius:20px;padding:28px;background:var(--l-card);border:1px solid var(--l-line);transition:all .25s var(--ease)}
.cs-card-hover:hover{border-color:var(--acc);box-shadow:0 12px 34px var(--glow);transform:translateY(-2px)}

/* ===== "Bạn sẽ build" feature grid ===== */
.cs-build{display:grid;grid-template-columns:1.1fr 1fr;gap:24px;align-items:start}
.cs-feat-list{display:flex;flex-direction:column;gap:13px}
.cs-feat{display:flex;gap:12px;align-items:flex-start;font-size:14.5px;color:var(--l-t2)}
.cs-feat .tick{flex:none;display:grid;place-items:center;width:22px;height:22px;border-radius:7px;background:var(--acc-wash);color:var(--acc);font-size:12px;margin-top:1px}
.cs-build-box{padding:22px;border-radius:18px;background:linear-gradient(135deg,var(--l-card),var(--acc-wash));border:1px solid var(--acc)}
.cs-build-box .lbl{font-family:'Be Vietnam Pro',sans-serif;font-size:11.5px;font-weight:700;letter-spacing:1.2px;text-transform:uppercase;color:var(--acc)}
.cs-build-box .prod{font-family:'Exo 2',sans-serif;font-weight:700;font-size:19px;color:var(--l-h2);margin:10px 0 0;line-height:1.3}

/* ===== Giáo trình (accordion) ===== */
.cs-lessons{display:flex;flex-direction:column;gap:12px;margin-top:30px}
.cs-lesson{border:1px solid var(--l-line);border-radius:14px;background:var(--l-card);overflow:hidden;transition:border-color .25s var(--ease)}
.cs-lesson[open]{border-color:var(--acc)}
.cs-lesson summary{list-style:none;cursor:pointer;display:flex;align-items:center;gap:16px;padding:18px 20px}
.cs-lesson summary::-webkit-details-marker{display:none}
.cs-lesson .num{flex:none;font-family:'Exo 2',sans-serif;font-weight:800;font-size:18px;color:var(--acc);width:30px;text-align:center}
.cs-lesson .lt{flex:1;font-weight:700;font-size:15.5px;color:var(--l-h2)}
.cs-lesson .car{flex:none;color:var(--l-t4);transition:transform .25s var(--ease)}
.cs-lesson[open] .car{transform:rotate(180deg)}
.cs-lesson .body{padding:0 20px 18px 66px}
.cs-lesson .body ul{margin:0;padding-left:18px}
.cs-lesson .body li{font-size:14px;color:var(--l-t3);margin:6px 0;line-height:1.55}

/* ===== two-column "cho ai" ===== */
.cs-twocol{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.cs-fit-title{display:flex;align-items:center;gap:9px;font-family:'Exo 2',sans-serif;font-weight:700;font-size:17px;color:var(--l-h2)}
.cs-fit ul{margin:14px 0 0;padding:0;list-style:none;display:flex;flex-direction:column;gap:10px}
.cs-fit li{display:flex;gap:10px;align-items:flex-start;font-size:14.5px;color:var(--l-t2)}
.cs-fit li .mk{flex:none;margin-top:1px}

/* ===== outcome stats ===== */
.cs-stats{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:28px}
.cs-stat{padding:22px;border-radius:16px;background:var(--d-card6);border:1px solid var(--d-line)}
.cs-stat .v{font-family:'Exo 2',sans-serif;font-weight:800;font-size:26px;color:var(--acc-soft)}
.cs-stat .l{font-size:13px;color:var(--d-t3);margin-top:6px;line-height:1.45}

/* ===== quyền lợi (3 cột) ===== */
.cs-perks{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin-top:28px}
.cs-perk h3{font-family:'Exo 2',sans-serif;font-weight:700;font-size:17px;color:var(--l-h2);margin:10px 0 0}
.cs-perk p{font-size:13.5px;color:var(--l-t3);margin:10px 0 0}
.cs-perk .tag{font-family:'Be Vietnam Pro',sans-serif;font-size:11.5px;font-weight:700;letter-spacing:.6px;color:var(--acc)}

/* ===== học phí ===== */
.cs-price{display:grid;grid-template-columns:1.2fr 1fr;gap:30px;align-items:center;border-radius:22px;padding:34px;background:linear-gradient(135deg,var(--d-bg3),var(--d-bg2));border:1px solid var(--d-line);box-shadow:0 0 34px var(--glow)}
.cs-price .big{font-family:'Exo 2',sans-serif;font-weight:800;font-size:30px;color:var(--d-h);margin-top:6px}
.cs-price .note{font-size:13px;color:var(--d-t3);margin-top:10px;line-height:1.55}

/* ===== FAQ ===== */
.cs-faq{display:flex;flex-direction:column;gap:10px;margin-top:28px}
.cs-faq details{border-bottom:1px solid var(--l-div);padding:6px 0}
.cs-faq summary{list-style:none;cursor:pointer;display:flex;justify-content:space-between;gap:16px;padding:14px 2px;font-weight:600;font-size:15.5px;color:var(--l-h2)}
.cs-faq summary::-webkit-details-marker{display:none}
.cs-faq summary .pm{flex:none;color:var(--acc);font-size:20px;line-height:1;transition:transform .25s var(--ease)}
.cs-faq details[open] summary .pm{transform:rotate(45deg)}
.cs-faq .ans{padding:0 2px 16px;font-size:14.5px;color:var(--l-t3);line-height:1.65;max-width:760px}

/* ===== khoá khác ===== */
.cs-other-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(238px,1fr));gap:18px;margin-top:28px}
.cs-other{display:flex;flex-direction:column;border-radius:16px;padding:22px;background:var(--l-card);border:1px solid var(--l-line);text-decoration:none;transition:all .25s var(--ease)}
.cs-other:hover{border-color:var(--acc);box-shadow:0 12px 30px var(--glow);transform:translateY(-2px)}
.cs-other .ot{font-family:'Exo 2',sans-serif;font-weight:700;font-size:16px;color:var(--l-h2);margin:10px 0 0;line-height:1.3}
.cs-other .od{font-size:13px;color:var(--l-t3);margin:8px 0 14px}
.cs-other .go{margin-top:auto;font-size:13.5px;font-weight:600;color:var(--acc)}

/* ===== CTA dải cuối ===== */
.cs-finalcta{text-align:center;background:var(--d-bg);position:relative;overflow:hidden}
.cs-finalcta .glow{position:absolute;top:-80px;left:50%;transform:translateX(-50%);width:460px;height:220px;background:var(--acc);opacity:.1;filter:blur(85px);pointer-events:none}

/* ===== FOOTER (đồng bộ index.html) ===== */
.cs-footer{background:var(--d-bg);padding:54px 40px 40px;position:relative;overflow:hidden}
.cs-footer .fglow{position:absolute;top:-80px;left:50%;transform:translateX(-50%);width:420px;height:200px;background:var(--acc);opacity:.08;filter:blur(80px);pointer-events:none}
.cs-footer-inner{position:relative;max-width:1080px;margin:0 auto}
.cs-footer-top{display:flex;flex-wrap:wrap;gap:30px;justify-content:space-between;align-items:flex-start}
.cs-footer-name{font-family:'Exo 2',sans-serif;font-weight:800;font-size:24px;letter-spacing:.3px}
.cs-footer-name .a{color:var(--d-h)}.cs-footer-name .b{color:var(--acc);text-shadow:0 0 12px var(--glow)}.cs-footer-name .c{color:var(--d-vn);font-size:17px}
.cs-footer p{font-size:13.5px;color:var(--d-t3);margin:16px 0 0;line-height:1.6}
.cs-footer .member{margin-top:14px;font-size:12px;color:var(--d-vn);letter-spacing:.4px}
.cs-footer .col{font-size:13.5px;color:var(--d-t2);line-height:1.9}
.cs-footer .col a{color:var(--acc-soft);text-decoration:none}
.cs-footer .copy{margin-top:30px;padding-top:18px;border-top:1px solid var(--d-line);font-size:12px;color:var(--d-vn)}

/* ===== reveal anim ===== */
.cs-reveal{opacity:0;transform:translateY(18px);transition:opacity .6s var(--ease),transform .6s var(--ease)}
.cs-reveal.in{opacity:1;transform:none}
@media (prefers-reduced-motion:reduce){.cs-reveal{opacity:1;transform:none;transition:none}}

/* ===== modal tư vấn khoá ===== */
button.cs-btn{border:0;cursor:pointer;font-family:'Be Vietnam Pro',sans-serif}
.cs-modal{position:fixed;inset:0;z-index:100;display:flex;align-items:center;justify-content:center;padding:20px;background:rgba(20,20,19,.66);backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px);opacity:0;visibility:hidden;transition:opacity .28s var(--ease),visibility .28s var(--ease)}
.cs-modal.open{opacity:1;visibility:visible}
.cs-modal-dialog{position:relative;width:100%;max-width:540px;max-height:90vh;overflow-y:auto;background:var(--l-card);border:1px solid var(--l-line);border-radius:22px;padding:30px;box-shadow:0 24px 70px rgba(26,25,21,.4);transform:translateY(16px) scale(.98);transition:transform .32s var(--ease)}
.cs-modal.open .cs-modal-dialog{transform:none}
.cs-modal-close{position:absolute;top:16px;right:16px;width:34px;height:34px;display:grid;place-items:center;border:1px solid var(--l-line);border-radius:9px;background:var(--l-bg2);color:var(--l-t3);font-size:18px;line-height:1;cursor:pointer;transition:all .2s var(--ease)}
.cs-modal-close:hover{border-color:var(--acc);color:var(--acc)}
.cs-modal-title{font-family:'Exo 2',sans-serif;font-weight:700;font-size:21px;color:var(--l-h2);margin:8px 36px 0 0;line-height:1.25}
.cs-modal-sub{font-size:14px;color:var(--l-t3);margin:10px 0 0}
.cs-form{margin-top:22px}
.cs-form .row{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.cs-form label{display:block}
.cs-form .lbl{display:block;font-size:13px;font-weight:600;color:var(--l-t1);margin:14px 0 6px}
.cs-form .row label .lbl{margin-top:0}
.cs-input{width:100%;padding:11px 13px;border-radius:10px;border:1px solid var(--in-border);background:var(--in-bg);font-size:14.5px;color:var(--l-t0);font-family:inherit;outline:none;transition:border-color .2s,box-shadow .2s}
.cs-input:focus{border-color:var(--acc);box-shadow:0 0 0 3px var(--glow)}
textarea.cs-input{resize:vertical}
.cs-check{display:flex;gap:10px;align-items:flex-start;margin-top:16px;cursor:pointer}
.cs-check input{margin-top:3px;width:16px;height:16px;accent-color:var(--acc);flex:none}
.cs-check span{font-size:13px;color:var(--l-t3)}
.cs-err{display:none;font-size:12px;color:var(--err);margin-top:5px}
.cs-form .submit-btn{width:100%;margin-top:20px;padding:15px;border:0;border-radius:12px;background:var(--acc);color:var(--on-acc);font-family:'Be Vietnam Pro',sans-serif;font-weight:700;font-size:15.5px;cursor:pointer;box-shadow:0 10px 28px var(--glow);transition:all .25s var(--ease)}
.cs-form .submit-btn:hover{box-shadow:0 12px 40px var(--glow-strong);transform:translateY(-1px)}
.cs-form .submit-btn:disabled{opacity:.7;cursor:default;transform:none}
.cs-modal-ok{text-align:center;padding:20px 6px}
.cs-modal-ok .ic{display:grid;place-items:center;width:64px;height:64px;border-radius:50%;margin:0 auto;background:var(--acc);color:var(--on-acc);font-size:30px;box-shadow:0 0 30px var(--glow-strong)}
.cs-modal-ok h3{font-family:'Exo 2',sans-serif;font-weight:700;font-size:22px;color:var(--l-h2);margin:18px 0 0}
.cs-modal-ok p{font-size:15px;color:var(--l-t3);margin:12px 0 0}
.cs-modal-ok a{display:inline-block;margin-top:16px;color:var(--acc);font-weight:600;font-size:14.5px;text-decoration:none}

/* ===== responsive ===== */
@media (max-width:980px){
  .cs-build,.cs-twocol,.cs-price{grid-template-columns:1fr!important}
  .cs-stats,.cs-perks,.cs-other-grid{grid-template-columns:1fr!important}
}
@media (max-width:600px){
  .cs-nav-links a:not(.cs-nav-cta){display:none}
  .cs-nav{padding:12px 20px}
  .cs-hero{padding:40px 20px 52px}
  .cs-sec{padding:52px 20px}
  .cs-footer{padding-left:20px;padding-right:20px}
  .cs-lesson .body{padding-left:20px}
  .cs-form .row{grid-template-columns:1fr}
  .cs-form .row label .lbl{margin-top:14px}
  .cs-modal-dialog{padding:24px 20px}
  .cs-hero-cta{flex-direction:column;align-items:stretch}
  .cs-hero-cta .cs-btn{width:100%;justify-content:center}
  .cs-price{text-align:center}
}