* { margin: 0; padding: 0; box-sizing: border-box; }
        body { background: #f1f6fb; font-family: 'Inter', system-ui, -apple-system, sans-serif; color: #29435c; line-height: 1.5; padding: 40px 20px; }
        .container { max-width: 1400px; margin: 0 auto; }
        h1 { font-size: 2.5rem; background: #f1f6fb; -webkit-background-clip: text; background-clip: text; color: #29435c; margin-bottom: 10px; }
        .subtitle { color: #29435c; margin-bottom: 40px; font-size: 1.1rem; border-left: 3px solid #2a7aff; padding-left: 20px; }
        .back-link { display: inline-block; margin-bottom: 30px; color: #29435c; text-decoration: none; border: 1px solid #2a7aff; padding: 8px 20px; border-radius: 40px; transition: 0.2s; }
        .back-link:hover { background: #f1f6fb; color: #29435c; }
        footer { text-align: center; margin-top: 40px; padding-top: 30px; border-top: 1px solid rgba(91,192,255,0.2); font-size: 0.8rem; color: #29435c; }
        
        .gas-card { background: #f1f6fb; border-radius: 24px; border: 1px solid rgba(42,122,255,0.4); margin-bottom: 32px; overflow: hidden; transition: 0.2s; }
        .gas-card:hover { border-color: #2a7aff; box-shadow: none; }
        .card-header { background: #f1f6fb; padding: 20px 28px; border-bottom: 1px solid rgba(91,192,255,0.25); display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; }
        .gas-title { display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; }
        .gas-formula { font-size: 2rem; font-weight: 800; font-family: monospace; background: #f1f6fb; -webkit-background-clip: text; background-clip: text; color: #29435c; }
        .gas-name { font-size: 1rem; background: #f1f6fb; padding: 4px 14px; border-radius: 60px; color: #29435c; }
        .hazard-tag { background: #f1f6fb; border: 1px solid rgba(241,196,15,0.5); padding: 6px 16px; border-radius: 40px; font-size: 0.75rem; font-weight: 600; color: #29435c; display: inline-flex; align-items: center; gap: 6px; }
        .card-body { padding: 24px 28px; }
        .specs-wrapper { margin-bottom: 28px; overflow-x: auto; }
        .specs-table { width: 100%; border-collapse: collapse; font-size: 0.75rem; background: #f1f6fb; border-radius: 16px; overflow: hidden; }
        .specs-table th { background: #f1f6fb; padding: 12px 8px; font-weight: 700; color: #29435c; font-size: 0.7rem; border-bottom: 1px solid rgba(91,192,255,0.4); text-align: center; }
        .specs-table td { padding: 10px 8px; text-align: center; border-bottom: 1px solid rgba(91,192,255,0.12); color: #29435c; font-size: 0.73rem; }
        .specs-table tr:last-child td { border-bottom: none; }
        .grade-cell { font-weight: 700; color: #29435c; }
        .specs-note { font-size: 0.65rem; color: #29435c; margin-top: 8px; text-align: right; }
        .description-block { background: #f1f6fb; border-radius: 20px; padding: 18px 22px; margin-bottom: 24px; border-left: 3px solid #2a7aff; }
        .description-block p { font-size: 0.85rem; line-height: 1.55; color: #29435c; margin-bottom: 8px; }
        .description-block strong { color: #29435c; }
        .info-grid { display: grid; grid-template-columns: repeat(2,1fr); gap: 18px; margin-bottom: 20px; }
        .info-panel { background: #f1f6fb; border-radius: 20px; padding: 16px 18px; border: 1px solid rgba(42,122,255,0.2); }
        .info-panel:hover { border-color: rgba(91,192,255,0.4); background: #f1f6fb; }
        .panel-title { font-size: 0.7rem; text-transform: uppercase; letter-spacing: 2px; font-weight: 700; color: #29435c; margin-bottom: 10px; }
        .panel-content { font-size: 0.82rem; line-height: 1.5; color: #29435c; white-space: pre-wrap; }
        .card-footer { background: #f1f6fb; padding: 12px 28px; border-top: 1px solid rgba(91,192,255,0.15); display: flex; justify-content: flex-end; gap: 16px; flex-wrap: wrap; }
        .footer-badge { font-size: 0.7rem; color: #29435c; display: flex; align-items: center; gap: 5px; }
        .seo-text { background: #f1f6fb; border-radius: 24px; padding: 30px; margin: 40px 0; border-left: 4px solid #2a7aff; }
        .seo-text h2 { color: #29435c; margin-bottom: 15px; font-size: 1.3rem; }
        .seo-text p { margin-bottom: 12px; font-size: 0.9rem; color: #29435c; line-height: 1.6; }
        @media (max-width: 700px) { .card-header { flex-direction: column; align-items: flex-start; } .card-body { padding: 18px; } .info-grid { grid-template-columns: 1fr; } .specs-table th, .specs-table td { padding: 6px 4px; font-size: 0.65rem; } }