* {
            box-sizing: border-box;
        }
        body {
            font-family: system-ui, -apple-system, sans-serif;
            background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
            min-height: 100vh;
            margin: 0;
            padding: 2rem;
            color: #eee;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
        }
        h1 {
            margin-bottom: 1.5rem;
            font-size: 1.75rem;
            font-weight: 600;
        }
        .calculator {
            background: rgba(255, 255, 255, 0.06);
            border: 1px solid rgba(255, 255, 255, 0.12);
            border-radius: 16px;
            padding: 2rem;
            width: 100%;
            max-width: 360px;
            box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
        }
        .field {
            margin-bottom: 1.25rem;
        }
        label {
            display: block;
            margin-bottom: 0.4rem;
            font-size: 0.9rem;
            color: #b0b0b0;
        }
        input {
            width: 100%;
            padding: 0.75rem 1rem;
            font-size: 1rem;
            border: 1px solid rgba(255, 255, 255, 0.2);
            border-radius: 10px;
            background: rgba(255, 255, 255, 0.08);
            color: #fff;
        }
        input:focus {
            outline: none;
            border-color: #6366f1;
            box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
        }
        input::placeholder {
            color: rgba(255, 255, 255, 0.4);
        }
        button {
            width: 100%;
            padding: 0.9rem;
            margin-top: 0.5rem;
            font-size: 1rem;
            font-weight: 600;
            color: #fff;
            background: linear-gradient(135deg, #6366f1, #8b5cf6);
            border: none;
            border-radius: 10px;
            cursor: pointer;
            transition: transform 0.15s, box-shadow 0.15s;
        }
        button:hover {
            transform: translateY(-1px);
            box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
        }
        button:active {
            transform: translateY(0);
        }
        .results {
            margin-top: 1.75rem;
            padding-top: 1.75rem;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
        }
        .results p {
            margin: 0.5rem 0;
            font-size: 1rem;
        }
        .results .total {
            font-size: 1.15rem;
            font-weight: 600;
            color: #a5b4fc;
        }
        .results .per-person {
            font-size: 1.25rem;
            font-weight: 700;
            color: #c4b5fd;
        }
        .error {
            color: #f87171;
            font-size: 0.9rem;
            margin-top: 0.5rem;
        }