:root{
  --navy:#06101d;
  --navy2:#0a1727;
  --ink:#f7f3e9;
  --muted:rgba(247,243,233,.74);
  --gold:#e9c36c;
  --gold2:#f6d98d;
  --blue:#87cfff;
  --glass:rgba(5,14,27,.68);
  --line:rgba(233,195,108,.35);
  --shadow:0 24px 80px rgba(0,0,0,.34);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;background:var(--navy)}
body{
  isolation:isolate;
  margin:0;
  min-width:320px;
  color:var(--ink);
  font-family:"Segoe UI",system-ui,-apple-system,BlinkMacSystemFont,Arial,sans-serif;
  background:var(--navy);
}
a{color:inherit}
button,input{font:inherit}
.page-bg{position:fixed;inset:0;z-index:-3;overflow:hidden;background:#07111c}
.page-bg img,.page-bg video{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.page-bg img{filter:saturate(.88) contrast(1.02) brightness(.82)}
.page-bg video{opacity:.4;mix-blend-mode:screen;pointer-events:none}
.page-shade{
  position:absolute;inset:0;
  background:
    radial-gradient(circle at 70% 30%,rgba(20,55,79,.06),transparent 28%),
    linear-gradient(90deg,rgba(1,7,15,.24) 0%,rgba(1,7,15,.28) 42%,rgba(2,8,16,.83) 100%),
    linear-gradient(0deg,rgba(2,8,16,.75),transparent 44%);
}
.topbar{
  position:fixed;z-index:50;top:0;left:0;right:0;
  height:92px;padding:0 clamp(24px,4vw,78px);
  display:flex;align-items:center;justify-content:space-between;gap:24px;
  background:linear-gradient(180deg,rgba(3,9,17,.86),rgba(3,9,17,.32) 74%,transparent);
  backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px);
}
.brand{display:flex;align-items:center;gap:15px;text-decoration:none;min-width:max-content}
.brand-mark{font-family:Georgia,serif;font-size:28px;color:var(--gold);transform:translateY(-3px)}
.brand strong{
  display:block;font:600 clamp(22px,1.6vw,31px)/1 Georgia,"Times New Roman",serif;
  letter-spacing:.09em;
}
.brand small{display:block;margin-top:5px;color:var(--gold2);font:16px/1.1 Georgia,"Times New Roman",serif}
.topnav{display:flex;align-items:center;gap:clamp(18px,2vw,38px);font-size:14px}
.topnav a{text-decoration:none;color:rgba(255,255,255,.82);transition:.18s ease}
.topnav a:hover{color:var(--gold2)}
.topnav .home-link{
  padding:11px 16px;border:1px solid rgba(233,195,108,.32);border-radius:999px;
  background:rgba(5,13,25,.35);
}

.hero{
  min-height:100svh;
  display:grid;grid-template-columns:minmax(0,1.35fr) minmax(390px,.65fr);
  gap:clamp(40px,5vw,90px);align-items:center;
  padding:130px clamp(28px,6vw,120px) 68px;
  max-width:1920px;margin:0 auto;
}
.hero-content{max-width:980px;text-shadow:0 3px 20px rgba(0,0,0,.6)}
.eyebrow{
  display:flex;align-items:center;gap:12px;
  color:var(--gold2);letter-spacing:.2em;font-size:13px;font-weight:700;
}
.eyebrow span{width:62px;height:1px;background:linear-gradient(90deg,var(--gold),transparent)}
.eyebrow.small{font-size:12px;margin:0 0 14px}
.hero h1{
  margin:20px 0 22px;
  font:500 clamp(48px,5.3vw,102px)/.98 Georgia,"Times New Roman",serif;
  letter-spacing:-.035em;
}
h1 em,h2 em{color:var(--gold2);font-weight:400}
.lead{
  max-width:900px;margin:0;
  font:clamp(17px,1.28vw,25px)/1.6 Georgia,"Times New Roman",serif;
  color:rgba(251,248,240,.9);
}
.mode-row{display:grid;grid-template-columns:repeat(4,minmax(135px,1fr));gap:12px;margin-top:32px;max-width:900px}
.mode{
  min-height:105px;padding:18px 16px;border-radius:20px;
  background:linear-gradient(145deg,rgba(5,17,31,.76),rgba(13,28,45,.46));
  border:1px solid rgba(240,212,146,.3);box-shadow:0 12px 32px rgba(0,0,0,.18);
  backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);
}
.mode>span{display:block;color:var(--gold2);font-size:21px;margin-bottom:9px}
.mode strong{display:block;font:600 17px/1.1 Georgia,serif}
.mode small{display:block;margin-top:7px;color:rgba(255,255,255,.65);font-size:12px;line-height:1.25}
.scroll-hint{
  display:inline-flex;align-items:center;gap:13px;margin-top:34px;
  text-decoration:none;color:rgba(255,255,255,.72);font-size:14px;
}
.scroll-hint b{font-size:26px;color:var(--gold);animation:bob 1.8s ease-in-out infinite}
@keyframes bob{50%{transform:translateY(6px)}}

.login-card{
  position:relative;isolation:isolate;overflow:hidden;
  width:min(100%,540px);justify-self:end;
  padding:clamp(28px,2.7vw,48px);
  border:1px solid rgba(241,211,142,.46);border-radius:30px;
  background:linear-gradient(145deg,rgba(4,13,25,.88),rgba(8,23,39,.76));
  box-shadow:var(--shadow);
  backdrop-filter:blur(20px) saturate(120%);-webkit-backdrop-filter:blur(20px) saturate(120%);
}
.login-glow{
  position:absolute;z-index:-1;width:280px;height:280px;border-radius:50%;
  top:-150px;right:-100px;background:rgba(123,202,255,.12);filter:blur(20px);
}
.login-icon{
  width:54px;height:54px;border-radius:17px;display:grid;place-items:center;
  color:var(--gold2);font:28px Georgia,serif;border:1px solid rgba(233,195,108,.4);
  background:rgba(233,195,108,.08);
}
.login-kicker{margin:23px 0 5px;color:var(--gold2);font-size:13px;letter-spacing:.16em;text-transform:uppercase}
.login-card h2{margin:0;font:500 clamp(38px,3vw,58px)/1.05 Georgia,serif}
.login-copy{margin:12px 0 26px;color:rgba(255,255,255,.68);line-height:1.55}
.login-card label{display:block;margin:17px 0 8px;color:rgba(255,255,255,.82);font-size:13px;font-weight:650}
.field{
  min-height:58px;display:grid;grid-template-columns:38px 1fr;align-items:center;
  border:1px solid rgba(255,255,255,.16);border-radius:15px;
  background:rgba(0,0,0,.18);transition:.18s ease;
}
.field:focus-within{border-color:rgba(233,195,108,.72);box-shadow:0 0 0 4px rgba(233,195,108,.08)}
.field-icon{text-align:center;color:rgba(233,195,108,.65);font-size:9px}
.field input{
  width:100%;height:56px;border:0;outline:0;background:transparent;color:#fff;
  padding:0 13px 0 0;font-size:17px;
}
.field input::placeholder{color:rgba(255,255,255,.34)}
.pin-field{grid-template-columns:38px 1fr auto}
#student-pin{letter-spacing:.28em;font-size:21px}
.pin-toggle{
  margin-right:8px;border:0;background:transparent;color:var(--gold2);
  padding:9px 10px;border-radius:10px;cursor:pointer;font-size:12px;
}
.pin-toggle:hover{background:rgba(233,195,108,.09)}
.form-error{min-height:20px;margin:9px 0 0;color:#ffcfbf;font-size:13px}
.login-button{
  width:100%;min-height:62px;margin-top:8px;padding:0 20px;
  display:flex;align-items:center;justify-content:space-between;
  border:0;border-radius:16px;cursor:pointer;
  color:#07111d;background:linear-gradient(135deg,var(--gold2),#d9ae52);
  font-weight:800;box-shadow:0 12px 34px rgba(217,174,82,.2);
  transition:.18s ease;
}
.login-button:hover{transform:translateY(-2px);filter:brightness(1.04);box-shadow:0 16px 40px rgba(217,174,82,.28)}
.login-button b{font-size:24px}
.login-help{margin:18px 0 0;color:rgba(255,255,255,.52);font-size:12px;line-height:1.45}
.backend-note{
  margin-top:15px;padding:13px 15px;border-radius:14px;
  background:rgba(120,205,255,.08);border:1px solid rgba(120,205,255,.2);
}
.backend-note strong,.backend-note span{display:block}
.backend-note strong{color:#bce7ff;font-size:13px}
.backend-note span{margin-top:4px;color:rgba(255,255,255,.66);font-size:12px;line-height:1.4}

.content-section{
  position:relative;padding:clamp(85px,9vw,150px) clamp(28px,6vw,120px);
  border-top:1px solid rgba(255,255,255,.05);
}
.content-section:before{
  content:"";position:absolute;inset:0;z-index:-1;
  backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);
}
.section-dark{background:linear-gradient(180deg,rgba(4,12,23,.94),rgba(7,18,31,.97))}
.section-warm{background:linear-gradient(145deg,rgba(21,19,16,.95),rgba(8,17,27,.96))}
.section-inner{width:min(1600px,100%);margin:0 auto}
.section-title{display:grid;grid-template-columns:110px 1fr;gap:28px;align-items:start;margin-bottom:58px}
.section-title.compact{margin-bottom:42px}
.section-number{font:500 clamp(48px,5vw,82px)/1 Georgia,serif;color:rgba(233,195,108,.28)}
.section-title h2,.independence h2{
  margin:0;font:500 clamp(38px,4.4vw,78px)/1.04 Georgia,serif;letter-spacing:-.025em;
}
.feature-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.feature-card{
  min-height:315px;padding:32px;border-radius:24px;
  border:1px solid rgba(255,255,255,.09);
  background:linear-gradient(145deg,rgba(255,255,255,.055),rgba(255,255,255,.018));
  transition:.22s ease;
}
.feature-card:hover{transform:translateY(-7px);border-color:rgba(233,195,108,.35);background:rgba(255,255,255,.07)}
.feature-icon{
  width:54px;height:54px;border-radius:17px;display:grid;place-items:center;
  color:var(--gold2);font:28px Georgia,serif;background:rgba(233,195,108,.09);
  border:1px solid rgba(233,195,108,.25);
}
.feature-card h3{margin:24px 0 12px;font:600 25px/1.15 Georgia,serif}
.feature-card p,.step p,.independence p,.faq-grid p{
  margin:0;color:rgba(255,255,255,.68);font-size:16px;line-height:1.62;
}

.steps{display:grid;grid-template-columns:repeat(4,1fr);gap:0;border-top:1px solid rgba(233,195,108,.24)}
.step{position:relative;padding:34px 28px 10px 0;display:grid;grid-template-columns:62px 1fr;gap:16px}
.step:after{content:"";position:absolute;top:-5px;left:0;width:9px;height:9px;border-radius:50%;background:var(--gold2);box-shadow:0 0 16px rgba(233,195,108,.5)}
.step-no{font:500 36px/1 Georgia,serif;color:rgba(233,195,108,.48)}
.step h3{margin:0 0 9px;font:600 23px Georgia,serif}

.independence{background:linear-gradient(115deg,rgba(4,12,23,.98),rgba(11,29,42,.96))}
.independence-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:clamp(50px,7vw,120px);align-items:center}
.independence .big-copy{margin:30px 0 18px;color:rgba(255,255,255,.92);font:clamp(20px,1.6vw,29px)/1.55 Georgia,serif}
.quote-card{
  position:relative;padding:48px;border:1px solid rgba(233,195,108,.33);border-radius:30px;
  background:linear-gradient(145deg,rgba(233,195,108,.08),rgba(255,255,255,.025));
  box-shadow:0 24px 60px rgba(0,0,0,.18);
}
.quote-mark{position:absolute;top:18px;right:34px;font:90px/.8 Georgia,serif;color:rgba(233,195,108,.16)}
.quote-card strong{display:block;font:500 clamp(30px,3vw,52px)/1.08 Georgia,serif;color:var(--gold2)}
.quote-card p{margin:18px 0 24px;font-size:19px}
.mini-line{display:block;width:90px;height:1px;background:var(--gold);margin-bottom:22px}
.quote-card small{color:rgba(255,255,255,.6);line-height:1.5;font-size:14px}

.faq-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}
.faq-grid article{padding:26px 28px;border:1px solid rgba(255,255,255,.08);border-radius:20px;background:rgba(255,255,255,.028)}
.faq-grid h3{margin:0 0 10px;font:600 22px Georgia,serif}

footer{
  min-height:110px;padding:30px clamp(28px,6vw,120px);
  display:flex;align-items:center;gap:30px;justify-content:space-between;
  background:#030914;color:rgba(255,255,255,.55);font-size:13px;
}
footer a{text-decoration:none}
.footer-brand{color:#fff;font:600 21px Georgia,serif;letter-spacing:.08em}
footer a:last-child{color:var(--gold2)}

@media (max-width:1180px){
  .topnav a:not(.home-link){display:none}
  .hero{grid-template-columns:1fr;min-height:auto;padding-top:130px}
  .login-card{justify-self:stretch;width:100%;max-width:720px}
  .mode-row,.feature-grid,.steps{grid-template-columns:repeat(2,1fr)}
  .independence-grid{grid-template-columns:1fr}
}
@media (max-width:700px){
  .topbar{height:78px;padding:0 18px}
  .brand small{font-size:13px}
  .topnav .home-link{font-size:0;padding:10px 13px}
  .topnav .home-link:after{content:"←";font-size:21px}
  .hero{padding:112px 18px 52px;gap:30px}
  .hero h1{font-size:clamp(43px,13vw,64px)}
  .lead{font-size:17px}
  .mode-row,.feature-grid,.steps,.faq-grid{grid-template-columns:1fr}
  .mode{min-height:auto}
  .login-card{padding:25px 20px;border-radius:22px}
  .content-section{padding:72px 18px}
  .section-title{grid-template-columns:1fr;gap:8px;margin-bottom:36px}
  .section-number{font-size:42px}
  .step{padding-right:0}
  .quote-card{padding:34px 24px}
  footer{align-items:flex-start;flex-direction:column;gap:11px}
}
@media (prefers-reduced-motion:reduce){
  .page-bg video{display:none}
  html{scroll-behavior:auto}.scroll-hint b{animation:none}
  *{transition:none!important}
}
/* 2026-09-22: public activity catalogue, independent of account/API state. */
.student-entry{max-width:1240px;margin:auto;padding:130px 28px 64px;position:relative}
.student-entry h1{font:500 clamp(34px,5vw,60px)/1.15 Georgia,serif;margin:12px 0 18px}
.entry-intro{max-width:780px;font-size:19px;line-height:1.6;margin-bottom:28px}
.entry-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}
.entry-card{padding:28px;border:1px solid rgba(233,195,108,.4);border-radius:24px;background:rgba(7,17,29,.94)}
.entry-card h2{font:500 clamp(24px,3vw,34px)/1.2 Georgia,serif;color:var(--gold2);margin:0 0 14px}
.entry-card p{line-height:1.5;min-height:48px}
.entry-card ul{list-style:none;padding:0;margin:20px 0 0}
.entry-card a{display:flex;justify-content:space-between;gap:12px;padding:12px 0;border-bottom:1px solid #ffffff25;text-decoration:none;color:#fff}
.entry-card a:hover,.entry-card a:focus-visible{color:var(--gold2);text-decoration:underline}
.entry-account{display:flex;flex-wrap:wrap;gap:24px;margin-top:28px}.entry-account a{color:var(--gold2)}
@media(max-width:700px){.student-entry{padding:110px 18px 40px}.entry-grid{grid-template-columns:1fr}.entry-card{padding:22px}.entry-card p{min-height:0}}

/* 2026-09-22: a single, compact topic list beside the welcome copy. */
.student-entry{max-width:1420px;display:grid;grid-template-columns:minmax(0,1fr) minmax(300px,480px);align-items:start;gap:clamp(28px,6vw,100px);padding-top:126px;min-height:760px}.entry-welcome{padding-top:30px}.entry-welcome h1{max-width:640px;font-size:clamp(40px,5vw,76px)}.entry-card{padding:24px 28px}.entry-card h2{font-size:27px}.entry-card p{min-height:0;margin:8px 0;font-size:16px}.entry-card ul{margin-top:14px}.entry-card a{padding:10px 0;font-size:16px}.entry-account{margin-top:16px}.entry-invite{display:inline-block;color:var(--gold2);text-underline-offset:5px}.promotion-note{border-left:3px solid #d2b05f;padding:10px 16px;line-height:1.6;font-size:16px}.student-entry [hidden]{display:none!important}
.topnav a[data-account-link],.topnav a[href="gomoku.html"]{display:inline-block!important}
@media(max-width:760px){.student-entry{grid-template-columns:1fr;padding:100px 18px 36px;gap:24px;min-height:0}.entry-welcome{padding-top:0}.entry-welcome h1{font-size:37px}.entry-intro{font-size:17px;margin-bottom:16px}.topnav{gap:14px;flex-wrap:wrap;font-size:13px}.topbar{gap:10px}.brand-mark{display:none}.brand strong{font-size:21px}.brand small{font-size:12px}.entry-card{padding:21px}.entry-card ul{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));column-gap:20px}.entry-card a{font-size:14px;align-items:center;min-height:54px}.entry-card h2{font-size:25px}}
@media(max-width:380px){.topbar{padding:0 12px}.topnav{gap:9px}.brand small{display:none}}