:root{--bg: #333333;--bg-card: #3d3d3d;--bg-input: #2a2a2a;--border: #4a4a4a;--border-light: #5c5c5c;--accent: #2d7d46;--accent-hover: #87c163;--accent-subtle: #2f4a38;--text: #f0f0f0;--text-muted: #b5b5b5;--text-dim: #888888;--success: #87c163;--success-bg: #2c3e2a;--error: #e06c6c;--error-bg: #4a2f2f;--mono: "Ubuntu Mono", "JetBrains Mono", monospace}*{box-sizing:border-box}html,body{margin:0;padding:0}body{background:var(--bg);color:var(--text);font-family:Ubuntu,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;font-size:16px;line-height:1.5;-webkit-font-smoothing:antialiased}.app{min-height:100vh;display:flex;flex-direction:column}.nav{position:sticky;top:0;z-index:10;background:#333333b8;backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);border-bottom:1px solid var(--border)}.nav-inner{max-width:960px;margin:0 auto;padding:.75rem 1.25rem;display:flex;align-items:center;justify-content:space-between;gap:1rem;flex-wrap:wrap}.nav-title{font-weight:700;font-size:1.15rem;letter-spacing:-.01em;white-space:nowrap}.nav-tabs{display:flex;flex-wrap:wrap;gap:.25rem}.nav-tab{background:transparent;border:none;border-bottom:2px solid transparent;color:var(--text-muted);font-family:inherit;font-size:.9rem;font-weight:500;padding:.4rem .6rem;cursor:pointer;transition:color .15s ease,border-color .15s ease}.nav-tab:hover{color:var(--text)}.nav-tab.active{color:var(--accent);border-bottom-color:var(--accent)}.main{flex:1;width:100%;max-width:960px;margin:0 auto;padding:2rem 1.25rem 3rem}.panel{display:flex;flex-direction:column;gap:1.25rem}.panel-title{margin:0;font-size:1.6rem;font-weight:700;letter-spacing:-.02em}.panel-subtitle{margin:-.75rem 0 0;color:var(--text-muted);max-width:60ch}.footer{border-top:1px solid var(--border);padding:1.5rem 1.25rem;text-align:center}.footer p{margin:0 auto;max-width:60ch;color:var(--text-dim);font-size:.85rem}.card{background:var(--bg-card);border:1px solid var(--border);border-radius:12px;padding:1.5rem;display:flex;flex-direction:column;gap:1rem}.field{display:flex;flex-direction:column;gap:.4rem}.field-label{font-size:.85rem;font-weight:600;color:var(--text-muted)}.input,.textarea{width:100%;background:var(--bg-input);border:1px solid var(--border);border-radius:8px;color:var(--text);font-family:inherit;font-size:.95rem;padding:.65rem .75rem;resize:vertical;transition:border-color .15s ease}.input:focus,.textarea:focus{outline:none;border-color:var(--accent)}.input::placeholder,.textarea::placeholder{color:var(--text-dim)}.textarea{line-height:1.45}.textarea.mono{font-family:var(--mono);font-size:.82rem;letter-spacing:-.01em}.textarea[readonly]{color:var(--text-muted)}.btn-primary{align-self:flex-start;display:inline-flex;align-items:center;gap:.5rem;background:var(--accent);color:#fff;border:none;border-radius:8px;font-family:inherit;font-size:.95rem;font-weight:600;padding:.65rem 1.25rem;cursor:pointer;transition:background .15s ease}.btn-primary:hover:not(:disabled){background:var(--accent-hover);color:#16321f}.btn-primary:disabled{opacity:.65;cursor:not-allowed}.btn-secondary{background:transparent;color:var(--accent);border:1px solid var(--border-light);border-radius:6px;font-family:inherit;font-size:.8rem;font-weight:600;padding:.3rem .75rem;cursor:pointer;transition:background .15s ease,border-color .15s ease}.btn-secondary:hover{background:var(--accent-subtle);border-color:var(--accent)}.output-header{display:flex;align-items:center;justify-content:space-between;gap:1rem}.status-error{background:var(--error-bg);border:1px solid var(--error);color:var(--error);border-radius:8px;padding:.65rem .85rem;font-size:.88rem}.notice-success{background:var(--success-bg);border:1px solid var(--success);color:var(--success);border-radius:8px;padding:.75rem .95rem;font-size:.9rem}.info-note{background:var(--accent-subtle);border-left:3px solid var(--accent);border-radius:6px;padding:.65rem .85rem;color:var(--text-muted);font-size:.85rem}.result-badge{border-radius:12px;padding:2rem 1.5rem;text-align:center;border:1px solid}.result-valid{background:var(--success-bg);border-color:var(--success)}.result-invalid{background:var(--error-bg);border-color:var(--error)}.result-headline{font-size:1.8rem;font-weight:700;letter-spacing:.02em}.result-valid .result-headline{color:var(--success)}.result-invalid .result-headline{color:var(--error)}.result-detail{margin-top:.6rem;color:var(--text-muted);font-size:.92rem;max-width:52ch;margin-left:auto;margin-right:auto}.spinner{width:16px;height:16px;border:2px solid rgba(255,255,255,.35);border-top-color:#fff;border-radius:50%;display:inline-block;animation:spin .7s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.accordion{display:flex;flex-direction:column;gap:.75rem}.accordion-item{background:var(--bg-card);border:1px solid var(--border);border-radius:12px;overflow:hidden;transition:border-color .15s ease}.accordion-item.open{border-color:var(--border-light)}.accordion-header{width:100%;background:transparent;border:none;color:var(--text);font-family:inherit;font-size:1rem;font-weight:600;text-align:left;padding:1.1rem 1.5rem;cursor:pointer;display:flex;align-items:center;justify-content:space-between;gap:1rem}.accordion-header:hover{color:var(--accent-hover)}.chevron{font-size:1.4rem;line-height:1;color:var(--text-muted);transform:rotate(90deg);transition:transform .25s ease}.accordion-item.open .chevron{transform:rotate(-90deg)}.accordion-body{max-height:0;overflow:hidden;transition:max-height .3s ease}.accordion-item.open .accordion-body{max-height:400px}.accordion-body p{margin:0;padding:0 1.5rem 1.25rem;color:var(--text-muted);font-size:.92rem;line-height:1.6}@media (max-width: 640px){.nav-inner{flex-direction:column;align-items:flex-start}.nav-tabs{width:100%}.main{padding:1.5rem 1rem 2.5rem}.card{padding:1.1rem}.panel-title{font-size:1.4rem}.btn-primary{align-self:stretch;justify-content:center}}