* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
            background: linear-gradient(135deg, #0a1929 0%, #1a2332 100%);
            color: #e0e0e0;
            min-height: 100vh;
            padding: 20px;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
        }

        .header {
            text-align: center;
            margin-bottom: 40px;
            background: #1e2936;
            padding: 30px;
            border-radius: 16px;
            box-shadow: 0 20px 60px rgba(0,0,0,0.4);
        }

        .header h1 {
            color: #ffffff;
            font-size: 2.5rem;
            margin-bottom: 10px;
            letter-spacing: 2px;
        }

        .header p {
            color: #b0b0b0;
            font-size: 1.1rem;
        }

        .info-section {
            background: #1e2936;
            color: #e0e0e0;
            padding: 25px;
            border-radius: 16px;
            margin-bottom: 30px;
            box-shadow: 0 20px 60px rgba(0,0,0,0.4);
        }

        .info-section h3 {
            margin-bottom: 15px;
            font-size: 1.3em;
            color: #ffffff;
            border-bottom: 2px solid #3a4555;
            padding-bottom: 10px;
        }

        .info-section p {
            color: #b0b0b0;
            line-height: 1.6;
            margin-bottom: 15px;
        }

        .principle {
            background: #2a3441;
            color: #51cf66;
            padding: 12px 15px;
            border-radius: 8px;
            margin: 10px 0;
            font-weight: 600;
            font-size: 0.95rem;
            border-left: 4px solid #51cf66;
        }

        .calculator-section {
            margin-bottom: 40px;
        }

        .section-title {
            background: #1e2936;
            border-radius: 16px;
            padding: 20px;
            margin-bottom: 20px;
            text-align: center;
            box-shadow: 0 20px 60px rgba(0,0,0,0.4);
        }

        .section-title h2 {
            color: #ffffff;
            font-size: 1.8rem;
            margin-bottom: 5px;
            border-bottom: 2px solid #4a9eff;
            padding-bottom: 10px;
        }

        .section-title p {
            color: #b0b0b0;
            margin-top: 10px;
        }

        .calculator-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(450px, 1fr));
            gap: 25px;
        }

        .calculator-card {
            background: #1e2936;
            border-radius: 16px;
            padding: 25px;
            box-shadow: 0 20px 60px rgba(0,0,0,0.4);
            display: flex;
            flex-direction: column;
            min-height: 450px;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }

        .calculator-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 25px 70px rgba(0,0,0,0.5);
        }

        .card-title {
            color: #ffffff;
            font-size: 1.4rem;
            font-weight: 600;
            margin-bottom: 20px;
            text-align: center;
            border-bottom: 2px solid #4a9eff;
            padding-bottom: 10px;
        }

        .input-group {
            margin-bottom: 15px;
        }

        .input-group label {
            display: block;
            color: #b0b0b0;
            font-weight: 500;
            margin-bottom: 8px;
            font-size: 0.95em;
        }

        .input-group input,
        .input-group select {
            width: 100%;
            padding: 12px 16px;
            background: #2a3441;
            border: 2px solid #3a4555;
            border-radius: 8px;
            font-size: 1em;
            color: #ffffff;
            transition: border-color 0.3s ease;
        }

        .input-group input:focus,
        .input-group select:focus {
            outline: none;
            border-color: #4a9eff;
        }

        .calculate-btn {
            background: #4a9eff;
            color: white;
            border: none;
            padding: 15px;
            border-radius: 8px;
            font-size: 1.1em;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            margin-top: auto;
        }

        .calculate-btn:hover {
            background: #3a8eef;
            transform: translateY(-2px);
        }

        .result {
            background: linear-gradient(135deg, #51cf66, #40bf56);
            color: white;
            padding: 15px;
            border-radius: 8px;
            margin-top: 15px;
            text-align: center;
            font-weight: 600;
            font-size: 1.1rem;
            min-height: 120px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
        }

        .result.warning {
            background: linear-gradient(135deg, #f6ad55, #ed8936);
        }

        .result.info {
            background: linear-gradient(135deg, #4a9eff, #3a8eef);
        }

        .formula-display {
            background: #2a3441;
            border: 2px solid #3a4555;
            border-radius: 8px;
            padding: 15px;
            margin-bottom: 20px;
            text-align: center;
            color: #4a9eff;
            font-weight: 600;
            font-size: 0.95rem;
            line-height: 1.6;
        }

        .unit-info {
            background: #2a3441;
            border-radius: 8px;
            padding: 12px;
            margin-bottom: 15px;
            font-size: 0.9rem;
            color: #b0b0b0;
            border-left: 4px solid #4a9eff;
        }

        .step-display {
            background: #2a3441;
            border-radius: 8px;
            padding: 12px;
            margin: 10px 0;
            font-size: 0.9rem;
            line-height: 1.5;
            color: #e0e0e0;
            border: 1px solid #3a4555;
        }

        .preset-chambers {
            background: #2a3441;
            border-radius: 8px;
            padding: 12px;
            margin-bottom: 15px;
            border-left: 4px solid #51cf66;
        }

        .preset-btn {
            background: #51cf66;
            color: white;
            border: none;
            padding: 6px 12px;
            border-radius: 6px;
            font-size: 0.8rem;
            cursor: pointer;
            margin: 3px;
            transition: all 0.2s ease;
            font-weight: 600;
        }

        .preset-btn:hover {
            background: #40bf56;
            transform: translateY(-1px);
        }

        .conversion-section {
            background: #1e2936;
            border-radius: 16px;
            padding: 25px;
            box-shadow: 0 20px 60px rgba(0,0,0,0.4);
            margin-bottom: 30px;
        }

        .conversion-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 20px;
            margin-top: 20px;
        }

        .conversion-card {
            background: #2a3441;
            border-radius: 12px;
            padding: 20px;
            border-left: 4px solid #4a9eff;
        }

        .conversion-title {
            color: #ffffff;
            font-weight: 600;
            margin-bottom: 15px;
            font-size: 1.1em;
        }

        .cta-section {
            background: #2a3441;
            border-radius: 16px;
            padding: 30px;
            text-align: center;
            box-shadow: 0 20px 60px rgba(0,0,0,0.4);
            border: 2px solid #4a9eff;
            margin-bottom: 30px;
        }

        .cta-section h3 {
            color: #ffffff;
            margin-bottom: 15px;
            font-size: 1.5em;
        }

        .cta-section p {
            color: #b0b0b0;
            margin-bottom: 25px;
            line-height: 1.6;
            font-size: 1.1em;
        }

        .cta-button {
            display: inline-block;
            padding: 16px 40px;
            background: #51cf66;
            color: white;
            text-decoration: none;
            border-radius: 8px;
            font-weight: 600;
            font-size: 1.1em;
            transition: all 0.3s ease;
        }

        .cta-button:hover {
            background: #40bf56;
            transform: translateY(-2px);
            box-shadow: 0 8px 25px rgba(81, 207, 102, 0.3);
        }

        .footer {
            margin-top: 30px;
            padding-top: 20px;
            border-top: 1px solid #3a4555;
            text-align: center;
            color: #b0b0b0;
            font-size: 0.9em;
        }

        @media (max-width: 768px) {
            .calculator-grid {
                grid-template-columns: 1fr;
            }
            .header h1 {
                font-size: 2em;
            }
        }