@import "https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap";
:root{--bg-primary:#fff;--bg-secondary:#fff;--bg-tertiary:#f4f4f4;--bg-elevated:#fff;--bg-hover:#000;--text-primary:#000;--text-secondary:#000;--text-tertiary:#4a4a4a;--text-muted:#666;--accent-primary:#000;--accent-primary-solid:#000;--accent-primary-hover:#333;--border-primary:#000;--border-secondary:#000;--border-hover:#000;--shadow-sm:2px 2px 0px #000;--shadow-md:4px 4px 0px #000;--shadow-lg:8px 8px 0px #000;--shadow-xl:12px 12px 0px #000;--shadow-glow:none;--shadow-glow-strong:none;--font-sans:"Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;--font-mono:"JetBrains Mono","SF Mono",monospace;--space-1:4px;--space-2:8px;--space-3:12px;--space-4:16px;--space-5:20px;--space-6:24px;--space-8:32px;--space-10:40px;--space-12:48px;--space-16:64px;--space-20:80px;--radius-sm:4px;--radius-md:8px;--radius-lg:12px;--radius-xl:16px;--radius-full:9999px;--transition-fast:.15s cubic-bezier(.4,0,.2,1);--transition-normal:.25s cubic-bezier(.4,0,.2,1)}[data-theme=light],[data-theme=dark]{--bg-primary:#fff;--text-primary:#000;--border-primary:#000}.bg-dots{opacity:.15;background-image:radial-gradient(#000 1.5px,#0000 1.5px);background-size:24px 24px}.btn-game{text-transform:uppercase;letter-spacing:.05em;color:#000;z-index:1;background:#fff;border:2px solid #000;justify-content:center;align-items:center;font-weight:700;transition:all .2s cubic-bezier(.4,0,.2,1);display:inline-flex;position:relative;overflow:hidden;box-shadow:4px 4px #000}.btn-game:hover{color:#fff;background:#000;transform:translate(-2px,-2px);box-shadow:6px 6px #000}.btn-game:active{transform:translate(2px,2px);box-shadow:0 0 #000}*,:before,:after{box-sizing:border-box;margin:0;padding:0}html{scroll-behavior:smooth;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;font-size:16px}body{font-family:var(--font-sans);background:var(--bg-primary);color:var(--text-primary);min-height:100vh;line-height:1.6;overflow-x:hidden}h1,h2,h3,h4,h5,h6{letter-spacing:-.02em;color:var(--text-primary);font-weight:600;line-height:1.25}h1{font-size:2.5rem;font-weight:700}h2{font-size:1.75rem}h3{font-size:1.25rem}h4{font-size:1rem}p{color:var(--text-secondary);line-height:1.6}a{color:var(--text-primary);transition:opacity var(--transition-fast);text-decoration:none}a:hover{opacity:.7}.container{width:100%;max-width:1120px;padding:0 var(--space-6);margin:0 auto}.section{padding:var(--space-16)0}.card{background:var(--bg-secondary);border:1px solid var(--border-primary);border-radius:var(--radius-lg);padding:var(--space-6);transition:all var(--transition-normal)}.card:hover{background:var(--bg-tertiary);border-color:var(--border-secondary);box-shadow:var(--shadow-md),var(--shadow-glow);transform:translateY(-2px)}.card-elevated{background:var(--bg-elevated);border:1px solid var(--border-secondary);border-radius:var(--radius-lg);box-shadow:var(--shadow-md)}.btn{justify-content:center;align-items:center;gap:var(--space-2);padding:var(--space-3)var(--space-5);font-family:var(--font-sans);border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-fast);white-space:nowrap;border:none;font-size:.875rem;font-weight:500;line-height:1;display:inline-flex}.btn-primary{background:var(--accent-primary);color:#fff;font-weight:600;box-shadow:0 4px 12px #667eea4d}.btn-primary:hover{background:var(--accent-primary-hover);box-shadow:0 6px 20px #667eea66,var(--shadow-glow);transform:translateY(-2px)}.btn-lg{padding:var(--space-4)var(--space-8);border-radius:var(--radius-lg);font-size:1rem;box-shadow:0 6px 20px #667eea40}.btn-lg:hover{box-shadow:0 8px 28px #667eea59,var(--shadow-glow-strong)}input,textarea,select{width:100%;padding:var(--space-3)var(--space-4);font-family:var(--font-sans);color:var(--text-primary);background:var(--bg-tertiary);border:1px solid var(--border-primary);border-radius:var(--radius-md);transition:all var(--transition-fast);outline:none;font-size:.9375rem}input:focus,textarea:focus,select:focus{border-color:var(--text-tertiary);background:var(--bg-elevated)}input::placeholder,textarea::placeholder{color:var(--text-muted)}.badge{padding:var(--space-1)var(--space-3);border-radius:var(--radius-full);background:var(--bg-tertiary);color:var(--text-secondary);border:1px solid var(--border-primary);align-items:center;font-size:.75rem;font-weight:500;display:inline-flex}.badge-easy{background:var(--color-easy-bg);color:var(--color-easy);border:1px solid #30d1584d}.badge-medium{background:var(--color-medium-bg);color:var(--color-medium);border:1px solid #ffd60a4d}.badge-hard{background:var(--color-hard-bg);color:var(--color-hard);border:1px solid #ff453a4d}.modal-backdrop{-webkit-backdrop-filter:blur(8px);z-index:100;background:#000000b3;position:fixed;inset:0}.modal-content{background:var(--bg-elevated);border:1px solid var(--border-secondary);border-radius:var(--radius-xl);box-shadow:var(--shadow-lg);z-index:101;max-width:90vw;max-height:90vh;position:fixed;top:50%;left:50%;overflow:auto;transform:translate(-50%,-50%)}.progress-bar{background:var(--bg-tertiary);border-radius:var(--radius-full);width:100%;height:4px;overflow:hidden}.progress-fill{background:var(--text-primary);border-radius:var(--radius-full);height:100%;transition:width var(--transition-slow)}.stat-card{gap:var(--space-2);padding:var(--space-6);background:var(--bg-secondary);border:1px solid var(--border-primary);border-radius:var(--radius-lg);flex-direction:column;display:flex}.stat-value{color:var(--text-primary);font-size:2rem;font-weight:700;line-height:1}.stat-label{color:var(--text-tertiary);text-transform:uppercase;letter-spacing:.05em;font-size:.8125rem}.xp-container{width:100%}.xp-header{margin-bottom:var(--space-2);justify-content:space-between;font-size:.8125rem;display:flex}.xp-current{color:var(--text-primary);font-weight:600}.xp-target{color:var(--text-tertiary)}.xp-bar{background:var(--bg-tertiary);border-radius:var(--radius-full);height:6px;overflow:hidden}.xp-fill{background:linear-gradient(90deg,var(--text-tertiary),var(--text-primary));border-radius:var(--radius-full);height:100%;transition:width var(--transition-slow)}.level-badge{background:var(--text-primary);width:48px;height:48px;color:var(--bg-primary);border-radius:var(--radius-lg);justify-content:center;align-items:center;font-size:1.25rem;font-weight:700;display:flex}.streak-badge{align-items:center;gap:var(--space-2);padding:var(--space-2)var(--space-4);background:var(--bg-tertiary);border:1px solid var(--border-secondary);border-radius:var(--radius-full);font-size:.875rem;font-weight:600;display:inline-flex}.grid{gap:var(--space-4);display:grid}.grid-2{grid-template-columns:repeat(2,1fr)}.grid-3{grid-template-columns:repeat(3,1fr)}.grid-4{grid-template-columns:repeat(4,1fr)}@media (max-width:1024px){.grid-4,.grid-3{grid-template-columns:repeat(2,1fr)}}@media (max-width:640px){.grid-4,.grid-3,.grid-2{grid-template-columns:1fr}h1{font-size:1.75rem}h2{font-size:1.375rem}}::selection{background:var(--text-primary);color:var(--bg-primary)}:focus-visible{outline:2px solid var(--text-tertiary);outline-offset:2px}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}@keyframes slideUp{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.animate-fadeIn{animation:fadeIn var(--transition-normal)}.animate-slideUp{animation:slideUp var(--transition-slow)}.card-gradient{border-radius:var(--radius-lg);padding:var(--space-6);transition:all var(--transition-normal);background:linear-gradient(135deg,#667eea14 0%,#764ba214 100%);border:1px solid #667eea33;position:relative;overflow:hidden}.card-gradient:before{content:"";opacity:0;transition:opacity var(--transition-normal);background:linear-gradient(135deg,#667eea0d 0%,#764ba20d 100%);position:absolute;inset:0}.card-gradient:hover:before{opacity:1}.card-gradient:hover{box-shadow:0 8px 24px #667eea33,var(--shadow-glow);border-color:#667eea66;transform:translateY(-4px)}.problem-card{align-items:center;gap:var(--space-4);padding:var(--space-5)var(--space-6);background:var(--bg-secondary);border:1px solid var(--border-primary);border-radius:var(--radius-lg);transition:all var(--transition-normal);cursor:pointer;display:flex}.problem-card:hover{background:var(--bg-tertiary);border-color:var(--border-secondary);box-shadow:var(--shadow-md);transform:translate(4px)}.problem-title{color:var(--text-primary);flex:1;font-size:.9375rem;font-weight:500}.problem-meta{align-items:center;gap:var(--space-3);color:var(--text-tertiary);font-size:.8125rem;display:flex}.glass{-webkit-backdrop-filter:blur(20px);background:#ffffff08;border:1px solid #ffffff14}@keyframes shimmer{0%{background-position:-1000px 0}to{background-position:1000px 0}}.skeleton{background:linear-gradient(90deg,var(--bg-secondary)0%,var(--bg-tertiary)50%,var(--bg-secondary)100%);border-radius:var(--radius-md);background-size:2000px 100%;animation:2s linear infinite shimmer}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:2px solid var(--accent-primary-solid);outline-offset:2px}::selection{color:var(--text-primary);background:#667eea4d}::selection{color:var(--text-primary);background:#667eea4d}::-webkit-scrollbar{width:8px;height:8px}::-webkit-scrollbar-track{background:var(--bg-secondary)}::-webkit-scrollbar-thumb{background:var(--bg-tertiary);border-radius:4px}::-webkit-scrollbar-thumb:hover{background:var(--bg-hover)}