:root{
  --accent:#16A6A1;
  --accent-hi:#1F6655;
  --accent-bright:#49C9C2;
  --accent-hover:#31B8B2;
  --radius-lg:18px;
  --radius-md:14px;
  --radius-sm:10px;
  --ease-premium:cubic-bezier(.16,1,.3,1);
  --nav-max:1120px;
  --content-max:1120px;
  --section-y:120px;
}

body.theme-dark{
  --ink:#0B1014;
  --ink-2:#111820;
  --ink-3:#182028;
  --paper:#E9EFEC;
  --muted:#9A968D;
  --muted-2:#6F6C64;
  --line:#242422;
  --theory:#3E3B36;
  --paper-bg:#D9D5CB;
  --paper-bg-soon:#141A1F;
  --paper-ink:#1C1B18;
  --paper-muted:#5A5245;
  --paper-muted-2:#6E6656;
  --paper-line:rgba(0,0,0,.12);
  --paper-theory:#B8B3A6;
  --gold:#C2A35B;
  --accent-readable:var(--accent-bright);
  --header-bg:rgba(11,12,13,.86);
  --header-bg-scrolled:rgba(11,16,20,.95);
  --header-shadow:0 12px 36px rgba(0,0,0,.18);
  --header-border-scrolled:rgba(73,201,194,.16);
  --mobile-menu-bg:rgba(11,16,20,.98);
}

body.theme-light{
  --ink:#E8E6E1;
  --ink-2:#DEDBD4;
  --ink-3:#D2CFC6;
  --paper:#1C1B18;
  --muted:#5A5245;
  --muted-2:#6E6656;
  --line:rgba(0,0,0,.12);
  --theory:#B8B3A6;
  --paper-bg:#D9D5CB;
  --paper-ink:#1C1B18;
  --paper-muted:#5A5245;
  --paper-muted-2:#6E6656;
  --paper-line:rgba(0,0,0,.12);
  --accent-readable:var(--accent-hi);
  --header-bg:rgba(232,230,225,.90);
  --header-bg-scrolled:rgba(232,230,225,.97);
  --header-shadow:0 12px 32px rgba(0,0,0,.08);
  --header-border-scrolled:rgba(31,102,85,.18);
  --mobile-menu-bg:rgba(232,230,225,.99);
}

*{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;}
body{
  background:var(--ink);
  color:var(--paper);
  font-family:-apple-system,BlinkMacSystemFont,"Helvetica Neue",Arial,sans-serif;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
body.page-course{--content-max:1040px;--section-y:90px;line-height:1.65;}
.serif{font-family:"Noto Serif SC",Georgia,"Times New Roman",serif;}
.mono{font-family:"Courier New",Courier,monospace;letter-spacing:.1em;text-transform:uppercase;}
body.page-home .mono{letter-spacing:.12em;}
a{color:inherit;text-decoration:none;}
img{max-width:100%;display:block;}
.wrap{max-width:var(--content-max);margin:0 auto;padding:0 28px;}
section{padding:var(--section-y) 0;}
section[id],#register{scroll-margin-top:92px;}

.skip-link{
  position:fixed;left:16px;top:12px;z-index:200;
  transform:translateY(-160%);
  background:var(--paper);color:var(--ink);
  padding:9px 12px;border-radius:var(--radius-sm);
  font-size:12px;transition:transform .25s ease;
}
.skip-link:focus{transform:translateY(0);}
a:focus-visible,button:focus-visible,summary:focus-visible{
  outline:2px solid var(--accent-readable);
  outline-offset:3px;
}

/* ---------- HEADER / NAV ---------- */
header{
  position:fixed;top:0;left:0;right:0;z-index:50;
  background:var(--header-bg);
  backdrop-filter:blur(10px);
  -webkit-backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
  transition:background .55s var(--ease-premium),border-color .55s ease,box-shadow .55s var(--ease-premium);
}
header.scrolled{
  background:var(--header-bg-scrolled);
  border-bottom-color:var(--header-border-scrolled);
  box-shadow:var(--header-shadow);
}
nav{
  display:flex;align-items:center;justify-content:space-between;
  padding:18px 28px;max-width:var(--nav-max);margin:0 auto;
  transition:padding .55s var(--ease-premium);
}
header.scrolled nav{padding-top:12px;padding-bottom:12px;}
.logo{font-size:15px;font-weight:600;letter-spacing:.06em;transition:opacity .3s ease;white-space:nowrap;}
body.page-home .logo{letter-spacing:.08em;}
.logo span{color:var(--muted);font-weight:400;}
.logo:hover{opacity:.86;}
.navlinks{display:flex;gap:28px;align-items:center;font-size:13px;color:var(--muted);}
body.page-home .navlinks{gap:32px;font-size:14px;}
.navlinks a{position:relative;padding:9px 0;transition:color .32s ease;}
.navlinks a::after{
  content:"";position:absolute;left:0;right:0;bottom:1px;height:1px;
  background:var(--accent-readable);transform:scaleX(0);transform-origin:left;
  transition:transform .48s var(--ease-premium);opacity:.9;
}
.navlinks a:hover,.navlinks a.active{color:var(--paper);}
.navlinks a:hover::after,.navlinks a.active::after{transform:scaleX(1);}
.nav-actions{display:flex;align-items:center;gap:12px;}

.cta-btn,.btn-primary{
  display:inline-flex;align-items:center;justify-content:center;
  background:var(--accent);border:1px solid var(--accent);
  border-radius:var(--radius-sm);color:#071415;font-weight:600;
  transition:transform .45s var(--ease-premium),background .35s ease,box-shadow .45s var(--ease-premium),border-color .35s ease;
}
.cta-btn{padding:10px 18px;font-size:12px;letter-spacing:.04em;}
body.page-home .cta-btn{padding-left:20px;padding-right:20px;font-size:13px;}
.btn-primary{padding:14px 26px;font-size:14px;letter-spacing:.03em;}
body.page-home .btn-primary{padding-left:28px;padding-right:28px;}
.cta-btn:hover,.btn-primary:hover{
  background:var(--accent-hover);border-color:var(--accent-hover);
  transform:translateY(-2px);box-shadow:0 12px 30px rgba(22,166,161,.17);
}

.mobile-toggle{
  display:none;width:44px;height:44px;border:1px solid var(--line);border-radius:var(--radius-sm);
  background:transparent;color:var(--paper);align-items:center;justify-content:center;
  flex-direction:column;gap:6px;cursor:pointer;
}
.mobile-toggle span{display:block;width:18px;height:1px;background:currentColor;transition:transform .38s var(--ease-premium),opacity .25s ease;}
.mobile-toggle[aria-expanded="true"] span:first-child{transform:translateY(3.5px) rotate(45deg);}
.mobile-toggle[aria-expanded="true"] span:last-child{transform:translateY(-3.5px) rotate(-45deg);}
.mobile-menu{
  display:grid;grid-template-rows:0fr;opacity:0;overflow:hidden;
  background:var(--mobile-menu-bg);border-bottom:1px solid transparent;
  transition:grid-template-rows .52s var(--ease-premium),opacity .32s ease,border-color .35s ease;
}
.mobile-menu > *{min-height:0;}
.mobile-menu.open{grid-template-rows:1fr;opacity:1;border-bottom-color:var(--line);}
.mobile-menu a{display:none;}
.mobile-menu a.active{color:var(--paper);font-weight:600;}

/* ---------- UNIFIED REVEAL ---------- */
.reveal{opacity:1;transform:none;transition:opacity .95s ease,transform .95s ease;}
.js .reveal{opacity:0;transform:translate3d(0,28px,0);}
.js .reveal.in{opacity:1;transform:translate3d(0,0,0);transition-delay:var(--reveal-delay,0ms);}

/* ---------- SHARED INSTRUCTOR LINKS ---------- */
.instructor-links{display:flex;gap:8px;flex-wrap:wrap;}
.instructor-link{
  display:inline-flex;align-items:center;justify-content:center;gap:6px;
  min-height:34px;padding:7px 11px;border:1px solid var(--line);border-radius:999px;
  color:var(--muted);font-size:11px;letter-spacing:.035em;white-space:nowrap;
  transition:color .35s ease,border-color .35s ease,background .35s ease,transform .55s var(--ease-premium),box-shadow .55s var(--ease-premium);
}
.instructor-link .ext{font-size:12px;line-height:1;opacity:.62;transition:transform .55s var(--ease-premium),opacity .35s ease;}
@media (hover:hover) and (pointer:fine){
  .instructor-link:hover{color:var(--paper);border-color:rgba(73,201,194,.48);background:rgba(73,201,194,.055);transform:translateY(-2px);box-shadow:0 10px 24px rgba(0,0,0,.12);}
  .instructor-link:hover .ext{transform:translate(2px,-2px);opacity:1;}
}

/* ---------- BACK TO TOP ---------- */
.back-to-top{
  position:fixed;right:max(22px,env(safe-area-inset-right));bottom:max(22px,env(safe-area-inset-bottom));z-index:45;
  width:46px;height:46px;display:grid;place-items:center;border-radius:14px;cursor:pointer;
  border:1px solid rgba(73,201,194,.30);background:color-mix(in srgb,var(--ink-2) 88%,transparent);color:var(--accent-readable);
  box-shadow:0 18px 44px rgba(0,0,0,.18),inset 0 0 0 1px rgba(255,255,255,.018);
  backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);
  opacity:0;visibility:hidden;pointer-events:none;transform:translate3d(0,12px,0) scale(.94);
  transition:opacity .34s ease,visibility .34s ease,transform .56s var(--ease-premium),border-color .35s ease,background .35s ease,box-shadow .56s var(--ease-premium);
}
.back-to-top svg{width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round;}
.back-to-top.is-visible{opacity:1;visibility:visible;pointer-events:auto;transform:translate3d(0,0,0) scale(1);}
body.page-home .back-to-top{bottom:max(62px,calc(env(safe-area-inset-bottom) + 22px));}
@media (hover:hover) and (pointer:fine){
  .back-to-top:hover{transform:translate3d(0,-4px,0) scale(1.02);border-color:rgba(73,201,194,.68);background:color-mix(in srgb,var(--ink-2) 95%,transparent);box-shadow:0 22px 52px rgba(0,0,0,.24),0 0 26px rgba(22,166,161,.12),inset 0 0 0 1px rgba(73,201,194,.12);}
}

/* ---------- FOOTER ---------- */
.footer-bottom{
  display:flex;justify-content:space-between;flex-wrap:wrap;gap:20px;
  font-size:12px;color:var(--muted-2);padding-top:28px;border-top:1px solid var(--line);
}
body.page-course .footer-bottom{gap:16px;padding-top:24px;}

@media(max-width:860px){
  body.page-home{--section-y:80px;}
  body.page-home .navlinks{display:none;}
  body.page-home .desktop-cta{display:none;}
  body.page-home .mobile-toggle{display:flex;}
  body.page-home .mobile-menu.open{padding:10px 28px 18px;}
  body.page-home .mobile-menu.open a{display:block;padding:13px 0;border-top:1px solid var(--line);font-size:14px;color:var(--muted);}
  body.page-home .mobile-menu.open a:first-child{border-top:0;}
  body.page-home .mobile-menu.open .mobile-wa{color:var(--accent-readable);margin-top:4px;}
}

@media(max-width:760px){
  body.page-course{--section-y:64px;}
  body.page-course .navlinks{display:none;}
  body.page-course .desktop-cta{display:none;}
  body.page-course .mobile-toggle{display:flex;}
  body.page-course .mobile-menu.open{padding:10px 28px 18px;}
  body.page-course .mobile-menu.open a{display:block;padding:13px 0;border-top:1px solid var(--line);font-size:14px;color:var(--muted);}
  body.page-course .mobile-menu.open a:first-child{border-top:0;}
  body.page-course .mobile-menu.open .mobile-wa{color:var(--accent-readable);}
}

@media(max-width:620px){
  .back-to-top{right:max(16px,env(safe-area-inset-right));bottom:max(16px,env(safe-area-inset-bottom));width:42px;height:42px;border-radius:13px;}
  body.page-home .back-to-top{bottom:max(16px,env(safe-area-inset-bottom));}
}

@media(max-width:520px){
  nav{padding-left:18px;padding-right:18px;}
  .logo{font-size:13px;letter-spacing:.055em;}
  .wrap{padding-left:20px;padding-right:20px;}
}

@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto;}
  .reveal{opacity:1!important;transform:none!important;transition:none!important;}
  header,nav,.mobile-toggle span,.cta-btn,.btn-primary,.instructor-link,.instructor-link .ext,.back-to-top{transition:none!important;}
}