:root{--bg:#f7f8fa;--surface:#ffffff;--text:#1c2333;--muted:#5c6577;--border:#e3e6ec;--accent:#2563eb;--accent-dark:#1d4ed8;--kofi:#13c0ff;--result-bg:#eefbf2;--result-border:#34d399;--error:#dc2626;--radius:10px}*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--text);line-height:1.6}a{color:var(--accent)}.page-wrap{max-width:860px;margin:0 auto;padding:0 16px;min-height:100vh;display:flex;flex-direction:column}.page-main{flex:1 1}.site-header{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:8px;padding:14px 0;border-bottom:1px solid var(--border);margin-bottom:24px}.site-logo{font-weight:700;font-size:18px;text-decoration:none;color:var(--text)}.lang-switcher{display:flex;flex-wrap:wrap;gap:4px}.lang-link{padding:4px 8px;border-radius:6px;font-size:12px;font-weight:600;text-decoration:none;color:var(--muted)}.lang-link:hover{background:var(--border)}.lang-link.active{background:var(--accent);color:#fff}.visually-hidden{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}.hero h1{font-size:30px;margin:0 0 8px}.hero-intro{color:var(--muted);margin:0 0 24px}.category-section h2{font-size:20px;margin:28px 0 12px}.calc-grid{list-style:none;padding:0;margin:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));grid-gap:10px;gap:10px}.calc-card{display:block;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:12px 14px;text-decoration:none;color:var(--text);font-weight:500;transition:border-color .15s,box-shadow .15s}.calc-card:hover{border-color:var(--accent);box-shadow:0 2px 8px rgba(37,99,235,.12)}.calc-page h1{font-size:28px;margin:0 0 16px}.calculator-form{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:20px;margin-bottom:24px}.input-group{margin-bottom:14px}.input-group label{display:block;font-size:14px;font-weight:600;margin-bottom:4px}.input-group input,.input-group select{width:100%;padding:10px 12px;font-size:16px;border:1px solid var(--border);border-radius:8px;background:#fff;color:var(--text)}.input-group input:focus,.input-group select:focus{outline:2px solid var(--accent);outline-offset:1px;border-color:var(--accent)}.calc-button{width:100%;padding:12px;font-size:16px;font-weight:600;color:#fff;background:var(--accent);border:none;border-radius:8px;cursor:pointer;transition:background .15s}.calc-button:hover{background:var(--accent-dark)}.calc-error{color:var(--error);font-size:14px;margin:12px 0 0}.result-box{margin-top:16px;padding:14px 16px;background:var(--result-bg);border:1px solid var(--result-border);border-radius:8px}.result-label{display:block;font-size:12px;text-transform:uppercase;letter-spacing:.05em;color:var(--muted)}.result-text{margin:4px 0 0;font-size:22px;font-weight:700}.content-section{color:var(--text);font-size:15px}.related-calcs h2{font-size:18px;margin:24px 0 8px}.related-calcs ul{padding-left:20px;margin:0}.back-link{margin-top:28px}.site-footer{margin-top:48px;padding:24px 0 32px;border-top:1px solid var(--border);text-align:center}.kofi-text{color:var(--muted);font-size:14px;margin:0 0 10px}.kofi-button{display:inline-block;padding:10px 20px;background:var(--kofi);color:#fff;text-decoration:none;border-radius:6px;font-weight:600;font-size:14px}.kofi-button:hover{opacity:.85}.footer-note{margin-top:20px;font-size:12px;color:var(--muted)}.redirect-page{display:flex;min-height:100vh;align-items:center;justify-content:center;font-family:system-ui,sans-serif}@media (max-width:480px){.hero h1{font-size:24px}.calc-page h1{font-size:22px}}