*,*::before,*::after{box-sizing:border-box}
:root{
  --bg:#0e0e10;--surface:#17171a;--surface2:#1f1f24;
  --accent:#c8a96e;--accent-dim:#8a7048;
  --text:#f0ede8;--muted:#9a9589;--border:rgba(200,169,110,0.2);
}
body{margin:0;background:var(--bg);color:var(--text);font-family:system-ui,-apple-system,sans-serif;line-height:1.5}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}

.nav{position:sticky;top:0;z-index:100;background:var(--bg);border-bottom:1px solid var(--border);padding:0 2rem;height:56px;display:flex;align-items:center;justify-content:space-between}
.nav-brand{font-size:12px;font-variant:small-caps;letter-spacing:3px;color:var(--accent);font-weight:600}
.nav-links{display:flex;align-items:center;gap:1rem}
.nav-links a{color:var(--muted);font-size:14px}
.btn{display:inline-block;padding:8px 20px;border-radius:4px;font-size:14px;font-weight:500;cursor:pointer;transition:all .15s;text-decoration:none}
.btn-primary{border:1px solid var(--accent);color:var(--accent);background:transparent}
.btn-primary:hover{background:var(--accent);color:var(--bg);text-decoration:none}
.btn-gold{background:var(--accent);color:var(--bg);border:1px solid var(--accent);font-weight:600}
.btn-gold:hover{background:#dfc07e;text-decoration:none}
.btn-ghost{border:1px solid var(--border);color:var(--muted);background:transparent}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent);text-decoration:none}

section{padding:80px 2rem}
.container{max-width:1100px;margin:0 auto}
.section-label{font-size:11px;letter-spacing:3px;color:var(--accent);text-transform:uppercase;margin-bottom:.75rem;display:block}
.section-title{font-size:32px;font-weight:300;color:var(--text);margin:0 0 1.5rem}

.hero{padding:120px 2rem 100px;text-align:center}
.hero-eyebrow{font-size:11px;letter-spacing:3px;color:var(--accent);text-transform:uppercase;margin-bottom:1.5rem}
.hero h1{font-size:52px;font-weight:300;color:#f0ede8;margin:0 0 1.5rem;line-height:1.1}
.hero-sub{font-size:18px;color:var(--muted);max-width:540px;margin:0 auto 2.5rem}
.hero-buttons{display:flex;gap:1rem;justify-content:center;flex-wrap:wrap}
.hero-note{margin-top:1rem;font-size:12px;color:var(--muted)}

#tiers .tier-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:1.25rem;margin-top:2.5rem}
.tier-card{background:var(--surface);border:1px solid var(--border);border-radius:8px;overflow:hidden}
.tier-card-bar{height:5px}
.tier-card-body{padding:1.5rem}
.tier-card h3{font-size:16px;font-weight:600;margin:0 0 .4rem;color:var(--text)}
.tier-card p{font-size:14px;color:var(--muted);margin:0 0 .75rem}
.tier-badge{font-size:11px;letter-spacing:1px;color:var(--accent-dim);margin-bottom:1rem;display:block}

#how-it-works{background:var(--surface)}
.features{display:grid;grid-template-columns:repeat(3,1fr);gap:2rem;margin-top:2.5rem}
.feature-icon{font-size:20px;color:var(--accent);margin-bottom:.75rem}
.feature h3{font-size:15px;font-weight:600;margin:0 0 .5rem}
.feature p{font-size:14px;color:var(--muted);margin:0}

.email-section{text-align:center}
.email-form{display:flex;gap:.75rem;justify-content:center;margin-top:2rem;flex-wrap:wrap}
.email-form input[type=email]{padding:10px 16px;border-radius:4px;border:1px solid var(--border);background:var(--surface2);color:var(--text);font-size:14px;width:280px}
.email-form input::placeholder{color:var(--muted)}
.email-form input:focus{outline:none;border-color:var(--accent)}
.email-msg{margin-top:1rem;font-size:14px;color:var(--muted);min-height:1.5em}

footer{background:var(--surface);border-top:1px solid var(--border);padding:1.5rem 2rem;display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:1rem;font-size:13px;color:var(--muted)}
.footer-brand{color:var(--accent);font-weight:600}
footer a{color:var(--muted)}
footer a:hover{color:var(--accent)}

.modal-overlay{position:fixed;inset:0;background:rgba(0,0,0,.75);z-index:1000;display:none;align-items:center;justify-content:center}
.modal-overlay.open{display:flex}
.modal{background:var(--surface);border:1px solid var(--border);border-radius:8px;padding:2rem;width:360px;max-width:90vw}
.modal h2{font-size:20px;font-weight:400;margin:0 0 .5rem}
.modal p{font-size:14px;color:var(--muted);margin:0 0 1.5rem}
.modal input{width:100%;padding:10px 12px;margin-bottom:.75rem;background:var(--surface2);border:1px solid var(--border);color:var(--text);border-radius:4px;font-size:14px}
.modal input:focus{outline:none;border-color:var(--accent)}
.modal-toggle{font-size:13px;color:var(--muted);margin-top:.75rem;text-align:center}
.modal-toggle span{color:var(--accent);cursor:pointer;text-decoration:underline}
.modal-error{font-size:13px;color:#e07070;margin-top:.25rem;min-height:1.2em}
.modal-close{float:right;cursor:pointer;color:var(--muted);font-size:18px;line-height:1;margin-top:-4px}

.topbar{position:fixed;top:0;left:0;right:0;height:48px;background:var(--bg);border-bottom:1px solid var(--accent);display:flex;align-items:center;justify-content:space-between;padding:0 1.5rem;z-index:100}
.topbar-brand{font-size:11px;font-variant:small-caps;letter-spacing:2px;color:var(--accent)}
.topbar-right{font-size:13px;color:var(--muted)}

.game-wrap{padding-top:48px;display:flex;flex-direction:column;align-items:center;min-height:100vh}
.tier-tabs{display:flex;border-bottom:1px solid var(--border);width:100%;max-width:620px}
.tier-tab{flex:1;padding:12px 0;text-align:center;font-size:13px;color:var(--muted);cursor:pointer;border-bottom:2px solid transparent;transition:all .15s;user-select:none}
.tier-tab.active{color:var(--accent);border-bottom-color:var(--accent)}
.tier-tab:hover{color:var(--text)}

.stats-bar{display:flex;gap:1.5rem;padding:10px 1rem;font-size:13px;color:var(--muted);max-width:620px;width:100%;justify-content:center;flex-wrap:wrap}
.stat-val{color:var(--text)}

.game-area{display:flex;flex-direction:column;align-items:center;padding:0 1rem 2rem;width:100%;max-width:620px}

.grid-wrap{position:relative;width:min(504px,90vw);height:min(504px,90vw);margin:0 auto}
.sudoku-grid{width:100%;height:100%;display:grid;grid-template-columns:repeat(9,1fr);grid-template-rows:repeat(9,1fr);border:2px solid rgba(200,169,110,0.6)}
.cell{border-right:1px solid rgba(200,169,110,0.12);border-bottom:1px solid rgba(200,169,110,0.12);display:flex;align-items:center;justify-content:center;font-size:clamp(14px,3.5vw,22px);color:var(--text);cursor:pointer;position:relative;user-select:none;transition:background .1s}
.cell:hover{background:rgba(200,169,110,0.06)}
.cell.selected{background:rgba(200,169,110,0.2) !important}
.cell.given{color:var(--accent);font-weight:600}
.cell.error{background:rgba(224,112,112,0.15) !important;color:#e07070}
.cage-sum{position:absolute;top:2px;left:2px;font-size:clamp(6px,1.1vw,8px);color:var(--accent);font-weight:700;line-height:1;z-index:2;pointer-events:none}
.cell[data-c="2"]{border-right:2px solid rgba(200,169,110,0.4)}
.cell[data-c="5"]{border-right:2px solid rgba(200,169,110,0.4)}
.cell[data-r="2"]{border-bottom:2px solid rgba(200,169,110,0.4)}
.cell[data-r="5"]{border-bottom:2px solid rgba(200,169,110,0.4)}

.numpad{display:grid;grid-template-columns:repeat(5,1fr);gap:6px;width:min(504px,90vw);margin-top:12px}
.numpad-btn{padding:13px 0;background:var(--surface);border:1px solid var(--border);color:var(--text);border-radius:4px;font-size:17px;cursor:pointer;transition:all .15s;text-align:center;user-select:none}
.numpad-btn:hover{border-color:var(--accent);color:var(--accent)}
.numpad-btn:active{background:var(--surface2)}
.numpad-btn.erase,.numpad-btn.notes-btn{font-size:11px;color:var(--muted);letter-spacing:.5px;text-transform:uppercase}
.numpad-btn.notes-btn.on{color:var(--accent);border-color:var(--accent)}

.win-overlay{position:fixed;inset:0;background:rgba(0,0,0,.8);z-index:200;display:none;align-items:center;justify-content:center}
.win-overlay.open{display:flex}
.win-box{background:var(--surface);border:1px solid var(--accent);border-radius:8px;padding:2.5rem;width:360px;max-width:90vw;text-align:center}
.win-box h2{color:var(--accent);font-size:24px;font-weight:400;margin:0 0 .5rem}
.win-time{font-size:42px;font-weight:300;color:var(--text);margin:.5rem 0 1rem}
.share-text{font-size:12px;color:var(--muted);background:var(--surface2);padding:8px 12px;border-radius:4px;margin:.75rem 0;text-align:left;word-break:break-all}
.win-btns{display:flex;gap:.75rem;flex-wrap:wrap;justify-content:center;margin-top:1.25rem}

@media(max-width:640px){
  .hero h1{font-size:32px}
  #tiers .tier-grid{grid-template-columns:1fr}
  .features{grid-template-columns:1fr}
  footer{flex-direction:column;text-align:center}
  .nav,.topbar{padding:0 1rem}
  .hero{padding:80px 1rem 60px}
  section{padding:60px 1rem}
  .stats-bar{gap:.75rem;font-size:12px}
}