/* ===== The Game Theory Lab ===== */
:root{
  --bg:#0b1020; --bg2:#0e1830; --panel:#101c38; --line:#22335c;
  --text:#e8eefc; --muted:#8ea0c0; --soft:#c8d6ef;
  --cyan:#4fd1ff; --amber:#ffb454; --green:#7bf1a8; --red:#ff7b7b;
  --grad:linear-gradient(92deg,#4fd1ff,#7bf1a8 55%,#ffb454);
  --radius:16px; --wrap:1080px;
  --font-body:'Inter',system-ui,sans-serif; --font-display:'Fraunces',Georgia,serif;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{background:var(--bg);color:var(--text);font-family:var(--font-body);line-height:1.65;overflow-x:hidden}
img,svg{max-width:100%}
a{color:var(--cyan)}

/* progress bar */
.progress-bar{position:fixed;top:0;left:0;height:3px;width:0;background:var(--grad);z-index:100}

/* ===== nav ===== */
.nav{position:fixed;top:0;left:0;right:0;z-index:90;display:flex;align-items:center;justify-content:space-between;
  padding:.8rem 1.4rem;background:rgba(11,16,32,.75);backdrop-filter:blur(12px);border-bottom:1px solid transparent;transition:border-color .3s}
.nav.scrolled{border-bottom-color:var(--line)}
.brand{font-family:var(--font-display);font-weight:700;font-size:1.15rem;color:var(--text);text-decoration:none}
.brand em{color:var(--cyan);font-style:normal}
.brand-mark{color:var(--amber)}
.nav-links{display:flex;gap:1.4rem}
.nav-links a{color:var(--soft);text-decoration:none;font-size:.92rem;font-weight:500}
.nav-links a:hover{color:var(--cyan)}
.nav-burger{display:none;background:none;border:1px solid var(--line);color:var(--text);font-size:1.3rem;border-radius:8px;padding:.1rem .6rem;cursor:pointer}

/* ===== side toc ===== */
.toc{position:fixed;left:1.2rem;top:50%;transform:translateY(-50%);z-index:80;display:flex;flex-direction:column;gap:.45rem;font-size:.78rem;opacity:0;transition:opacity .4s;pointer-events:none}
.toc.visible{opacity:1;pointer-events:auto}
.toc-title{color:var(--muted);text-transform:uppercase;letter-spacing:.1em;font-size:.65rem;margin-bottom:.2rem}
.toc a{color:var(--muted);text-decoration:none;border-left:2px solid var(--line);padding-left:.6rem;transition:all .2s}
.toc a:hover{color:var(--text)}
.toc a.active{color:var(--cyan);border-left-color:var(--cyan)}

/* ===== hero ===== */
.hero{position:relative;min-height:100svh;display:flex;align-items:center;justify-content:center;text-align:center;padding:6rem 1.5rem 4rem}
#heroCanvas{position:absolute;inset:0;width:100%;height:100%}
.hero-inner{position:relative;max-width:820px}
.hero-kicker{color:var(--amber);text-transform:uppercase;letter-spacing:.18em;font-size:.78rem;font-weight:600;margin-bottom:1rem}
.hero h1{font-family:var(--font-display);font-size:clamp(2.4rem,6vw,4.2rem);line-height:1.12;font-weight:700}
.grad{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero-sub{color:var(--soft);font-size:clamp(1rem,2vw,1.2rem);margin:1.4rem auto 2rem;max-width:640px}
.hero-cta{display:flex;gap:1rem;justify-content:center;flex-wrap:wrap}
.hero-stats{display:flex;gap:3rem;justify-content:center;margin-top:3rem;flex-wrap:wrap}
.hero-stats .stat{font-family:var(--font-display);font-size:2.4rem;font-weight:700;color:var(--cyan);display:block}
.hero-stats small{color:var(--muted)}
.scroll-cue{position:absolute;bottom:1.6rem;left:50%;transform:translateX(-50%);color:var(--muted);text-decoration:none;animation:bob 2s infinite}
@keyframes bob{0%,100%{transform:translate(-50%,0)}50%{transform:translate(-50%,8px)}}

/* ===== buttons ===== */
.btn{display:inline-block;padding:.75rem 1.5rem;border-radius:999px;font-weight:600;text-decoration:none;font-size:.95rem;border:none;cursor:pointer;font-family:var(--font-body);transition:transform .15s,box-shadow .15s}
.btn:hover{transform:translateY(-2px)}
.btn:active{transform:translateY(0)}
.btn-primary{background:var(--grad);color:#08101f}
.btn-primary:hover{box-shadow:0 6px 24px rgba(79,209,255,.35)}
.btn-ghost{background:transparent;color:var(--text);border:1px solid var(--line)}
.btn-ghost:hover{border-color:var(--cyan)}
.btn-sm{padding:.45rem .9rem;font-size:.82rem}
.btn-coop{background:var(--green);color:#08101f}
.btn-defect{background:var(--red);color:#08101f}
.btn-yt{background:#ff0033;color:#fff}
.btn-tt{background:#fff;color:#000}

/* ===== sections ===== */
.section{padding:6rem 1.5rem}
.section-alt{background:var(--bg2)}
.wrap{max-width:var(--wrap);margin:0 auto}
.kicker{color:var(--amber);text-transform:uppercase;letter-spacing:.16em;font-size:.75rem;font-weight:700;margin-bottom:.6rem}
h2{font-family:var(--font-display);font-size:clamp(1.8rem,4vw,2.7rem);font-weight:700;margin-bottom:1rem}
.lede{color:var(--soft);font-size:1.08rem;max-width:700px;margin-bottom:2.5rem}

/* reveal animation */
.reveal{opacity:0;transform:translateY(28px);transition:opacity .7s ease,transform .7s ease}
.reveal.in{opacity:1;transform:none}
@media (prefers-reduced-motion:reduce){.reveal{opacity:1;transform:none;transition:none}}

/* pillars */
.pillars{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:1.2rem;margin-top:2rem}
.pillar{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:1.5rem}
.pillar span{font-size:1.8rem}
.pillar h3{margin:.5rem 0 .4rem;font-size:1.1rem}
.pillar p{color:var(--muted);font-size:.92rem}

/* ===== model cards ===== */
.model{background:var(--panel);border:1px solid var(--line);border-radius:20px;padding:2rem;margin:2.2rem auto;box-shadow:0 8px 40px rgba(0,0,0,.25)}
.model-head{display:flex;align-items:center;gap:1.2rem;flex-wrap:wrap;margin-bottom:1.4rem}
.model-num{font-family:var(--font-display);font-size:2.6rem;font-weight:700;color:transparent;-webkit-text-stroke:1.5px var(--cyan)}
.model-head h3{font-family:var(--font-display);font-size:1.6rem}
.model-tag{color:var(--muted);font-size:.9rem}
.model-use{margin-left:auto;background:var(--bg2);border:1px solid var(--line);color:var(--amber);font-size:.78rem;padding:.35rem .8rem;border-radius:999px;white-space:nowrap}
.model-body{display:grid;grid-template-columns:1.2fr 1fr;gap:2rem;align-items:start}
.model-fig{background:var(--bg);border:1px solid var(--line);border-radius:var(--radius);padding:1rem}
.model-fig figcaption{color:var(--muted);font-size:.82rem;text-align:center;margin-top:.5rem}

/* tabs */
.tabs{display:flex;gap:.5rem;margin-bottom:1rem;flex-wrap:wrap}
.tab{background:var(--bg2);border:1px solid var(--line);color:var(--soft);padding:.4rem .95rem;border-radius:999px;cursor:pointer;font-size:.85rem;font-family:var(--font-body);transition:all .2s}
.tab:hover{border-color:var(--cyan)}
.tab.active{background:var(--cyan);color:#08101f;border-color:var(--cyan);font-weight:600}
.pane{display:none;animation:fadein .35s ease}
.pane.active{display:block}
@keyframes fadein{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}
.eq{background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:.7rem 1rem;margin:.8rem 0;overflow-x:auto}
.eq-note{color:var(--muted);font-size:.88rem}

/* ===== games ===== */
.game{background:var(--panel);border:1px solid var(--line);border-radius:20px;padding:2rem;margin-bottom:2rem}
.game-head h3{font-family:var(--font-display);font-size:1.35rem;margin-bottom:.4rem}
.game-head p{color:var(--soft);font-size:.95rem;margin-bottom:1.2rem}
.game-controls{display:flex;gap:.8rem;flex-wrap:wrap;margin:1rem 0}
.scoreboard{display:flex;gap:2rem;flex-wrap:wrap;margin:1rem 0}
.scoreboard div{background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:.6rem 1.2rem;min-width:110px;text-align:center}
.scoreboard small{display:block;color:var(--muted);font-size:.72rem;text-transform:uppercase;letter-spacing:.08em}
.scoreboard span{font-family:var(--font-display);font-size:1.5rem;font-weight:700;color:var(--cyan)}
.history{display:flex;gap:.35rem;flex-wrap:wrap;margin:.8rem 0;min-height:2rem}
.history .h-cell{width:26px;height:26px;border-radius:6px;display:grid;place-items:center;font-size:.8rem}
.h-cc{background:rgba(123,241,168,.25);border:1px solid var(--green)}
.h-dd{background:rgba(255,123,123,.25);border:1px solid var(--red)}
.h-mix{background:rgba(255,180,84,.25);border:1px solid var(--amber)}
.game-lesson{color:var(--muted);font-size:.86rem;border-top:1px dashed var(--line);padding-top:.8rem;margin-top:.6rem}

/* penalty pitch */
.pitch{margin:1rem 0}
.goal{position:relative;height:150px;max-width:480px;border:4px solid #fff;border-bottom:none;border-radius:8px 8px 0 0;background:linear-gradient(#123, #0e1f16);margin-bottom:1rem;overflow:hidden}
.keeper{position:absolute;top:38%;left:50%;transform:translateX(-50%);font-size:2.2rem;transition:left .35s cubic-bezier(.3,1.4,.5,1)}
.ball{position:absolute;bottom:6px;left:50%;transform:translateX(-50%);font-size:1.6rem;transition:all .35s ease}
.goal.flash-goal{box-shadow:inset 0 0 40px rgba(123,241,168,.5)}
.goal.flash-save{box-shadow:inset 0 0 40px rgba(255,123,123,.5)}

/* nash slider */
.nash-ui label{color:var(--soft)}
.nash-ui input[type=range]{width:100%;max-width:480px;margin:.8rem 0;accent-color:var(--cyan)}
.nash-hint{font-size:.95rem;color:var(--amber);min-height:1.6rem;font-weight:600}

/* ===== flashcards ===== */
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:1.1rem}
.card{perspective:900px;height:190px;cursor:pointer}
.card-inner{position:relative;width:100%;height:100%;transition:transform .55s;transform-style:preserve-3d}
.card.flipped .card-inner{transform:rotateY(180deg)}
.card-face{position:absolute;inset:0;backface-visibility:hidden;border-radius:14px;border:1px solid var(--line);padding:1rem;display:flex;flex-direction:column;justify-content:center;align-items:center;text-align:center}
.card-front{background:var(--panel)}
.card-front .c-num{color:var(--amber);font-size:.75rem;letter-spacing:.1em}
.card-front .c-emoji{font-size:2rem;margin:.3rem 0}
.card-front h4{font-family:var(--font-display);font-size:1.02rem}
.card-front small{color:var(--muted);margin-top:.3rem}
.card-back{background:var(--bg2);transform:rotateY(180deg);justify-content:center;gap:.4rem}
.card-back p{font-size:.83rem;color:var(--soft)}
.card-back code{color:var(--cyan);font-size:.78rem;word-break:break-word}

/* ===== cheat sheet ===== */
.table-scroll{overflow-x:auto;border:1px solid var(--line);border-radius:var(--radius)}
.cheat{width:100%;border-collapse:collapse;min-width:560px}
.cheat th,.cheat td{padding:.7rem 1rem;text-align:left;border-bottom:1px solid var(--line);font-size:.92rem}
.cheat th{background:var(--panel);color:var(--amber);text-transform:uppercase;font-size:.75rem;letter-spacing:.08em}
.cheat tr:hover td{background:rgba(79,209,255,.06)}
.cheat td:nth-child(2){color:var(--cyan);font-weight:600}
.cheat td:nth-child(3){color:var(--muted);font-style:italic}

/* ===== educators ===== */
.edu-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:1.4rem}
.edu-card{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:1.6rem}
.edu-card h3{font-family:var(--font-display);margin-bottom:.9rem;font-size:1.15rem}
.edu-card ol,.edu-card ul{padding-left:1.2rem;color:var(--soft);font-size:.92rem}
.edu-card li{margin-bottom:.4rem}
/* quiz */
.quiz .q-question{font-weight:600;margin-bottom:.8rem}
.quiz .q-opt{display:block;width:100%;text-align:left;background:var(--bg);border:1px solid var(--line);color:var(--soft);border-radius:10px;padding:.55rem .9rem;margin-bottom:.5rem;cursor:pointer;font-family:var(--font-body);font-size:.88rem;transition:all .2s}
.quiz .q-opt:hover{border-color:var(--cyan)}
.quiz .q-opt.correct{border-color:var(--green);background:rgba(123,241,168,.15)}
.quiz .q-opt.wrong{border-color:var(--red);background:rgba(255,123,123,.15)}
.quiz .q-meta{color:var(--muted);font-size:.8rem;margin-bottom:.6rem}
.quiz .q-score{font-family:var(--font-display);font-size:1.4rem;color:var(--cyan)}

/* ===== episodes ===== */
.episodes{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:1.2rem;margin-bottom:2rem}
.ep{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:1.4rem;position:relative;transition:transform .2s,border-color .2s}
.ep:hover{transform:translateY(-4px);border-color:var(--cyan)}
.ep-num{color:var(--amber);font-size:.75rem;letter-spacing:.12em;font-weight:700}
.ep h4{font-family:var(--font-display);font-size:1.15rem;margin:.4rem 0}
.ep p{color:var(--muted);font-size:.88rem}
.ep-badge{position:absolute;top:1rem;right:1rem;background:var(--bg2);border:1px solid var(--line);color:var(--cyan);font-size:.7rem;padding:.2rem .6rem;border-radius:999px}
.socials{display:flex;gap:1rem;flex-wrap:wrap}
.note{color:var(--muted);font-size:.82rem;margin-top:1rem}

/* ===== footer ===== */
.footer{border-top:1px solid var(--line);padding:2.5rem 1.5rem;text-align:center}
.footer-small{color:var(--muted);font-size:.8rem;max-width:760px;margin:.8rem auto 0}

/* ===== responsive ===== */
@media (max-width:1250px){.toc{display:none}}
@media (max-width:820px){
  .nav-links{display:none}
  .nav-burger{display:block}
  .nav-links.open{display:flex;position:absolute;top:100%;left:0;right:0;flex-direction:column;background:var(--bg2);padding:1rem 1.5rem;border-bottom:1px solid var(--line)}
  .model-body{grid-template-columns:1fr}
  .model-use{margin-left:0}
  .hero-stats{gap:1.6rem}
}