:root{--bg:#1a1a1a;--surface:#232323;--surface-alt:#2b2b2b;--border:#3a3a3a;--accent-1:#84323e;--accent-2:#36d5cd;--text:#fff;--text-muted:#b8b8b8;--radius:8px;--navbar-height:68px}*{box-sizing:border-box}html,body{margin:0;padding:0}body{background:var(--bg);color:var(--text);min-height:100vh;font-family:Montserrat,sans-serif}h1,h2,h3,h4{margin:0 0 12px;font-weight:600}p{color:var(--text-muted);margin:0 0 12px;line-height:1.6}a{color:inherit}button{font-family:inherit}#root{min-height:100vh}.container{max-width:1100px;margin:0 auto;padding:0 24px}.page{padding-top:calc(var(--navbar-height) + 40px);min-height:100vh;padding-bottom:60px}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:20px}.btn{border-radius:var(--radius);cursor:pointer;border:none;justify-content:center;align-items:center;gap:8px;padding:10px 20px;font-size:14px;font-weight:600;transition:opacity .15s,transform .1s;display:inline-flex}.btn:hover{opacity:.9}.btn:active{transform:scale(.98)}.btn-primary{background:var(--accent-2);color:#1a1a1a}.btn-secondary{color:var(--text);border:1px solid var(--accent-1);background:0 0}.btn:disabled{opacity:.5;cursor:not-allowed}.tag{background:var(--accent-1);color:var(--text);letter-spacing:.03em;border-radius:999px;padding:4px 10px;font-size:12px;font-weight:600;display:inline-block}.form-field{text-align:left;flex-direction:column;gap:6px;margin-bottom:16px;display:flex}.form-field label{color:var(--text-muted);font-size:13px;font-weight:600}.form-field input[type=text],.form-field input[type=file],.form-field input[type=url]{background:var(--surface-alt);border:1px solid var(--border);border-radius:var(--radius);color:var(--text);width:100%;padding:10px 12px;font-family:inherit;font-size:14px}.form-field input:focus{outline:2px solid var(--accent-2)}.section-title{flex-wrap:wrap;justify-content:space-between;align-items:baseline;gap:10px;margin-bottom:20px;display:flex}.navbar{height:var(--navbar-height);background:var(--surface);border-bottom:2px solid var(--accent-1);z-index:100;position:fixed;top:0;left:0;right:0}.navbar-inner{justify-content:space-between;align-items:center;gap:20px;max-width:1200px;height:100%;margin:0 auto;padding:0 24px;display:flex}.navbar-logo{color:var(--text);flex-shrink:0;align-items:center;gap:10px;font-weight:700;text-decoration:none;display:flex}.navbar-logo img{object-fit:contain;width:42px;height:42px}.navbar-links{flex:1;justify-content:center;align-items:center;gap:6px;display:flex}.navbar-link{color:var(--text-muted);border-radius:var(--radius);padding:8px 14px;font-size:14px;font-weight:600;text-decoration:none;transition:color .15s,background .15s}.navbar-link:hover{color:var(--text);background:var(--surface-alt)}.navbar-link.is-active{color:var(--text);background:var(--accent-1)}.navbar-actions{flex-shrink:0;align-items:center;gap:12px;display:flex}.navbar-auth-btn{white-space:nowrap;text-decoration:none}.role-switcher{border:1px solid var(--border);border-radius:var(--radius);display:flex;overflow:hidden}.role-switcher button{background:var(--surface-alt);color:var(--text-muted);cursor:pointer;border:none;padding:8px 12px;font-size:12px;font-weight:600}.role-switcher button.is-active{background:var(--accent-2);color:#1a1a1a}.navbar-toggle{cursor:pointer;background:0 0;border:none;flex-direction:column;justify-content:center;gap:5px;width:32px;height:32px;padding:0;display:none}.navbar-toggle span{background:var(--text);width:100%;height:2px;transition:transform .2s,opacity .2s}.navbar-toggle.is-open span:first-child{transform:translateY(7px)rotate(45deg)}.navbar-toggle.is-open span:nth-child(2){opacity:0}.navbar-toggle.is-open span:nth-child(3){transform:translateY(-7px)rotate(-45deg)}.navbar-mobile-auth{display:none}@media (width<=860px){.navbar-logo span,.navbar-actions{display:none}.navbar-toggle{display:flex}.navbar-links{top:var(--navbar-height);background:var(--surface);border-bottom:2px solid var(--accent-1);flex-direction:column;align-items:stretch;gap:0;max-height:0;transition:max-height .25s;position:absolute;left:0;right:0;overflow:hidden}.navbar-links.is-open{max-height:500px}.navbar-link{text-align:left;border-radius:0;padding:14px 24px}.navbar-mobile-auth{border-top:1px solid var(--border);flex-direction:column;gap:12px;margin-top:8px;padding:16px 24px 20px;display:flex}.navbar-mobile-auth .role-switcher{align-self:flex-start}}.home-hero{text-align:center;max-width:640px;margin:0 auto 50px}.home-hero h1{margin:14px 0 6px;font-size:42px}.home-motto{color:var(--accent-2);letter-spacing:.06em;text-transform:uppercase;margin-bottom:18px;font-size:15px;font-weight:600}.home-grid{grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:18px;display:grid}.home-tile{color:var(--text);text-decoration:none;transition:transform .15s,border-color .15s}.home-tile:hover{border-color:var(--accent-2);transform:translateY(-3px)}.home-tile h3{color:var(--accent-2);margin-bottom:8px}.home-tile p{margin:0;font-size:14px}@media (width<=500px){.home-hero h1{font-size:32px}}.login-container{justify-content:center;display:flex}.login-card{text-align:center;width:100%;max-width:380px;padding:40px 32px}.login-ms-btn{width:100%;margin-top:8px}.login-error{color:var(--accent-2);margin-top:12px;margin-bottom:0;font-size:13px}.newsletter-upload{max-width:100%;margin-bottom:30px}.newsletter-upload h3{margin-bottom:16px}.newsletter-list{flex-direction:column;gap:12px;display:flex}.newsletter-item{color:var(--text);justify-content:space-between;align-items:center;gap:16px;text-decoration:none;transition:border-color .15s;display:flex}.newsletter-item:hover{border-color:var(--accent-2)}.newsletter-item h3{margin:0 0 4px;font-size:16px}.newsletter-item p{margin:0;font-size:13px}@media (width<=500px){.newsletter-item{flex-direction:column;align-items:flex-start}}.challenge-question,.challenge-submit,.challenge-result,.challenge-workings{max-width:600px;margin:0 0 20px}.challenge-question h3,.challenge-submit h3,.challenge-workings h3{margin-bottom:16px}.challenge-upload{max-width:100%;margin:0 0 20px}.challenge-question img,.challenge-workings img{border-radius:var(--radius);width:100%;display:block}.challenge-result{border-color:var(--accent-2)}.challenge-result.is-correct h3{color:var(--accent-2)}.challenge-result.is-incorrect h3{color:var(--accent-1)}.challenge-result p{margin:0}.challenge-result strong{color:var(--text)}.careers-intro{max-width:560px;margin-bottom:30px}.careers-grid{grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:16px;display:grid}.careers-card h3{color:var(--accent-2)}.careers-card p{margin:0;font-size:14px}.leaderboard-table{max-width:560px;padding:8px}.leaderboard-row{border-bottom:1px solid var(--border);grid-template-columns:50px 1fr auto;align-items:center;gap:12px;padding:14px 16px;display:grid}.leaderboard-row:last-child{border-bottom:none}.leaderboard-rank{color:var(--text-muted);font-weight:700}.leaderboard-row.is-top .leaderboard-rank{color:var(--accent-2)}.leaderboard-name{font-weight:600}.leaderboard-points{color:var(--accent-2);font-size:14px;font-weight:700}