*{box-sizing:border-box}:root{--bg:#f7f8fb;--text:#1f2937;--muted:#6b7280;--card:#ffffff;--border:#e5e7eb;--primary:#1a2a6c;--primary-dark:#152255}body{font-family:"Segoe UI",Tahoma,Geneva,Verdana,sans-serif;line-height:1.6;color:var(--text);background:var(--bg);max-width:1200px;margin:0 auto;padding:0 16px 32px}.skip-link{position:absolute;left:-9999px;top:auto;width:1px;height:1px;overflow:hidden}.skip-link:focus{left:16px;top:16px;width:auto;height:auto;padding:8px 12px;background:var(--primary);color:#fff;border-radius:8px;z-index:1000}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}header{text-align:center;padding:1.25rem 0;background:linear-gradient(135deg,var(--primary, #1a2a6c),var(--header-end, #2c3e50));color:#fff;border-radius:10px;margin-bottom:1.5rem;box-shadow:0 4px 6px rgba(0,0,0,.1)}header h1{font-size:2rem;margin-bottom:.25rem}.header-content{position:relative}.home-btn{position:absolute;left:1rem;top:50%;transform:translateY(-50%);display:flex;align-items:center;justify-content:center;width:36px;height:36px;background:rgba(255,255,255,.2);border-radius:8px;border:1px solid rgba(255,255,255,.3);box-shadow:0 2px 8px rgba(0,0,0,.25);transition:all .2s ease;z-index:10;color:#fff}.home-btn:hover{background:rgba(255,255,255,.3);border-color:rgba(255,255,255,.5);transform:translateY(-50%) scale(1.05);box-shadow:0 4px 12px rgba(0,0,0,.35)}.home-btn:focus-visible{outline:3px solid rgba(255,255,255,.8);outline-offset:2px}.home-btn svg{width:20px;height:20px;stroke:#fff}.btn,.subheader{align-items:center;justify-content:center}.subheader{margin-top:.25rem;font-size:1rem;font-weight:500;opacity:.9;display:flex;gap:.5rem}main{display:flex;flex-direction:column;gap:1.25rem}section{background:var(--card);border:1px solid var(--border);border-radius:14px;padding:1.25rem 1.5rem;box-shadow:0 1px 2px rgba(16,24,40,.05)}section h2{margin:0 0 .5rem;color:var(--text);font-size:1.25rem}section p{color:var(--muted)}.btn{display:inline-flex;padding:8px 12px;min-height:40px;border:1px solid var(--btn-border, #24305b);border-radius:8px;background:var(--btn-bg, #10163a);color:var(--btn-fg, #dbe5ff);text-decoration:none;transition:all .15s ease;font-weight:600;cursor:pointer}.btn:hover{border-color:var(--btn-border-hover, #3a4e9f);transform:translateY(-1px)}.btn-primary{background:var(--primary, #1a2a6c);border-color:var(--primary, #1a2a6c);color:#fff}.btn-primary:hover{filter:brightness(1.08)}.btn:disabled{opacity:.6;cursor:not-allowed}.btn:focus-visible{outline:3px solid var(--focus-ring, rgba(26,42,108,.35));outline-offset:2px;background-color:var(--btn-bg-hover, #1c2040)}.tool-container{background:var(--card);border:1px solid var(--border);border-radius:14px;padding:1.5rem;box-shadow:0 1px 2px rgba(16,24,40,.05)}.tool-controls{display:flex;justify-content:center;align-items:center;margin-bottom:1.5rem}.panel-actions{align-items:center;flex-wrap:wrap;flex-shrink:0}.panel-actions .action-btn+.action-btn{margin-left:.25rem}.action-btn{display:flex;align-items:center;justify-content:center;width:2.25rem;height:2.25rem;border:1px solid transparent;background:0 0;border-radius:.5rem;color:var(--muted);cursor:pointer;transition:all .2s cubic-bezier(.4,0,.2,1)}.action-btn:focus-visible,.action-btn:hover{background:rgba(0,0,0,.05);color:var(--primary);border-color:var(--border);transform:scale(1.05)}.action-btn:focus-visible{outline:var(--focus-outline-width) solid var(--focus-outline-color);outline-offset:var(--focus-outline-offset);box-shadow:0 0 0 calc(var(--focus-outline-offset) + 1px) var(--focus-outline-color)}.action-btn svg{width:1.125rem;height:1.125rem}.panel-body{padding:0;flex-grow:1;display:flex;flex-direction:column;position:relative}.line-numbers{position:absolute;top:0;left:0;width:40px;height:100%;padding:1rem 0;padding-right:10px;background-color:#f8fafc;color:var(--muted);text-align:right;border-right:1px solid var(--border);user-select:none;font-family:"Monaco","Menlo","Ubuntu Mono",monospace;font-size:.9rem;line-height:1.5;white-space:pre}.io-panels{display:flex;gap:1.5rem}.panel{flex:1;display:flex;flex-direction:column;border:1px solid var(--border);border-radius:14px;overflow:hidden}.panel-header{display:flex;justify-content:space-between;align-items:center;padding:.75rem 1rem;background-color:#f8fafc;border-bottom:1px solid var(--border);position:sticky;top:0;z-index:10}.panel-title{font-size:1rem;font-weight:600;margin:0}.panel-actions{display:flex;gap:.25rem}.compare-input{width:100%;min-height:400px;max-height:70vh;border:0;padding:1rem 1.25rem 1rem 50px;font-family:"Monaco","Menlo","Ubuntu Mono",monospace;font-size:.9rem;line-height:1.5;color:var(--text);background:0 0;resize:none;outline:0;flex-grow:1;overflow-y:auto;overflow-x:auto;word-wrap:break-word;transition:height .1s ease}.compare-input:focus{outline:0;box-shadow:0 0 0 3px rgba(26,42,108,.15)}.diff-change,.diff-del,.diff-ins{scroll-margin-top:60px}.diff-del,.diff-del-gap{background-color:#fdd}.diff-ins,.diff-ins-gap{background-color:#ddf}.diff-word-del{background-color:#fbb;text-decoration:line-through}.diff-word-ins{background-color:#bbf}.diff-summary a,.merge-btn{cursor:pointer;font-weight:700}.merge-btn{padding:0 5px;border-radius:3px;background-color:var(--primary);color:#fff;border:0}.hidden-textarea{display:none}.diff-summary{margin-bottom:1rem;padding:1rem;background-color:#eff6ff;border:1px solid #bfdbfe;color:#1e40af;border-radius:8px;font-weight:500}.diff-summary a{color:#c82333;text-decoration:underline}@media (max-width:768px){.io-panels{flex-direction:column}.tool-content{grid-template-columns:1fr;gap:1rem}}footer{text-align:center;padding:1.25rem 0;margin-top:1.5rem;color:#fff;background:linear-gradient(135deg,var(--primary, #1a2a6c),var(--header-end, #2c3e50));border-radius:10px;box-shadow:0 4px 6px rgba(0,0,0,.1)}.user-guide{background:var(--card);border:1px solid var(--border);border-radius:14px;padding:2rem;margin-top:2rem;box-shadow:0 1px 2px rgba(16,24,40,.05)}.user-guide h2{margin:0 0 1.5rem;color:var(--text);font-size:1.5rem;font-weight:600;text-align:center}.guide-section{margin-bottom:2rem}.guide-section li:last-child,.guide-section:last-child{margin-bottom:0}.guide-section h3{margin:0 0 1rem;font-size:1.1rem}.guide-section ol,.guide-section ul{margin:0;padding-left:1.5rem}.guide-section li{margin-bottom:.5rem;line-height:1.6;color:var(--muted)}.guide-section h3,.guide-section strong{color:var(--text);font-weight:600}@media (max-width:640px){.user-guide{padding:1.5rem 1rem;margin-top:1.5rem}.user-guide h2{font-size:1.25rem}.guide-section h3{font-size:1rem}}