:root{--bg-color:#f8fafc;--card-bg:#ffffffd9;--card-border:#00000014;--primary:#4f46e5;--primary-glow:#4f46e533;--text-main:#1e293b;--text-muted:#64748b;--accent:#e11d48;--font-sans:"Inter", "Noto Sans JP", sans-serif}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-color);color:var(--text-main);font-family:var(--font-sans);line-height:1.6;overflow-x:hidden}#root{flex-direction:column;min-height:100vh;display:flex}.glass{background:var(--card-bg);-webkit-backdrop-filter:blur(8px);border:1px solid var(--card-border);border-radius:12px;box-shadow:0 4px 6px -1px #0000001a,0 2px 4px -1px #0000000f}header{text-align:left;z-index:100;-webkit-backdrop-filter:blur(12px);border-bottom:1px solid var(--card-border);background:#f8fafce6;flex-direction:column;justify-content:center;padding:1.25rem 2rem;display:flex;position:sticky;top:0}h1{letter-spacing:-.02em;background:linear-gradient(135deg,#4338ca 0%,#a855f7 50%,#ec4899 100%);-webkit-text-fill-color:transparent;filter:drop-shadow(0 2px 4px #4f46e51a);-webkit-background-clip:text;background-clip:text;margin-bottom:.1rem;font-size:1.5rem;font-weight:900;line-height:1.1}.search-container{max-width:800px;margin:0 auto 2rem;padding:0 1rem}.search-input{border:1px solid var(--card-border);width:100%;color:var(--text-main);background:#fff;border-radius:9999px;outline:none;padding:1rem 1.5rem;font-size:1.1rem;transition:all .3s;box-shadow:0 4px 6px -1px #0000000d}.search-input:focus{border-color:var(--primary);box-shadow:0 0 0 4px var(--primary-glow)}.filters{border:1px solid var(--card-border);background:#fff;border-radius:12px;flex-direction:column;gap:1.25rem;margin-bottom:2rem;padding:1.5rem;display:flex;box-shadow:0 4px 6px -1px #0000000d}.filter-group{flex:1;align-items:center;gap:1rem;display:flex}.filter-row{gap:2rem;width:100%;display:flex}@media (width<=768px){.filter-row{flex-direction:column;gap:1.25rem}}.filter-group label{color:var(--text-muted);text-transform:uppercase;letter-spacing:.05em;min-width:60px;font-size:.85rem;font-weight:700}.chip-group{flex-wrap:wrap;gap:.5rem;display:flex}.filter-chip{cursor:pointer;color:var(--text-main);background:#f1f5f9;border:1px solid #0000;border-radius:8px;outline:none;padding:.5rem 1rem;font-size:.85rem;transition:all .2s}.filter-chip:hover{background:#e2e8f0}.filter-chip.active{background:var(--primary);color:#fff;box-shadow:0 4px 12px var(--primary-glow)}main{flex:1;width:100%;max-width:1200px;margin:0 auto;padding:1rem}.problem-grid{grid-template-columns:repeat(auto-fill,minmax(450px,1fr));gap:2.5rem;padding:1rem 0;display:grid}.problem-card{cursor:pointer;flex-direction:column;padding:1.5rem;transition:all .3s cubic-bezier(.4,0,.2,1);display:flex;position:relative}.problem-card:hover{border-color:var(--primary);transform:translateY(-6px)scale(1.01);box-shadow:0 25px 50px -12px #00000026}.problem-card:active{transform:translateY(-2px)scale(.99)}.problem-header{color:var(--text-muted);justify-content:space-between;align-items:center;margin-bottom:1rem;font-size:.85rem;display:flex}.problem-id{background:#ffffff0d;border-radius:4px;padding:2px 8px;font-family:monospace}.problem-meta{flex-wrap:wrap;gap:.5rem;margin-bottom:1rem;display:flex}.tag{color:#a5b4fc;background:#6366f11a;border-radius:12px;padding:2px 10px;font-size:.75rem}.level-tag{font-weight:700}.level-A{color:#4ade80}.level-B{color:#60a5fa}.level-C{color:#fbbf24}.level-D{color:#f87171}.problem-content{flex:1;min-height:100px;margin-bottom:1.5rem;font-size:1.05rem;overflow-x:auto}.problem-preview{border:1px solid var(--card-border);background:#fff;border-radius:8px;justify-content:center;align-items:center;margin-bottom:1.25rem;padding:1rem;transition:background-color .3s;display:flex}.problem-preview img{max-width:100%;height:auto;transition:transform .3s cubic-bezier(.34,1.56,.64,1);display:block}.problem-card:hover .problem-preview img{transform:scale(1.05)}.katex-display{margin:1em 0;overflow:auto hidden}.problem-footer{border-top:1px solid var(--card-border);justify-content:flex-end;align-items:center;padding-top:1rem;display:flex}.copy-hint{color:var(--text-muted);align-items:center;gap:.25rem;font-size:.75rem;transition:color .2s;display:flex}.problem-card:hover .copy-hint{color:var(--primary)}.copy-badge{background:var(--primary);color:#fff;box-shadow:0 10px 25px var(--primary-glow);z-index:10;border-radius:9999px;padding:.5rem 1.5rem;font-weight:700;animation:.3s cubic-bezier(.175,.885,.32,1.275) badgeIn;position:absolute;top:50%;left:50%;transform:translate(-50%,-50%)}@keyframes badgeIn{0%{opacity:0;transform:translate(-50%,-40%)scale(.8)}to{opacity:1;transform:translate(-50%,-50%)scale(1)}}@keyframes fadeIn{0%{opacity:0;transform:translateY(30px)}to{opacity:1;transform:translateY(0)}}.animate-in{animation:.5s forwards fadeIn}@media (width<=640px){header{padding:1rem}h1{font-size:1.25rem}.problem-grid{grid-template-columns:1fr}}