h1 {
    text-align: center;
    font-size: 1.6em;
    font-weight: 500;
    margin-bottom: 1.5rem;
}

.calculator-container {
    display: flex;
    flex-wrap: wrap;
    gap: 2rem;
    justify-content: center;
}

.calculator-card {
    background: #ffffff;
    border-radius: 12px;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.08);
    padding: 1.5rem 2rem;
    flex: 1 1 400px;
    max-width: 500px;
    transition: transform 0.3s, box-shadow 0.3s;
}

.calculator-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.calculator-card h2 {
    text-align: center;
    font-size: 1.3em;
    font-weight: 500;
    margin-bottom: 2rem;
    color: #333;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.input-group {
    margin-bottom: 1.5rem;
}

.input-group label {
    display: block;
    font-weight: 600;
    color: #333;
    margin-bottom: 0.5rem;
}

.input-wrapper {
    display: flex;
    gap: 10px;
    align-items: center;
}

.input-wrapper input[type="number"],
.input-wrapper select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ccc;
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.input-wrapper input::placeholder {
    color: #bbb;
}

.input-wrapper input:focus, .input-wrapper select:focus {
    outline: none;
    border-color: #007bff;
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.15);
}

.input-wrapper .cost-unit {
    white-space: nowrap;
    color: #6c757d;
}

.button-group {
    display: flex;
    gap: 1rem;
    padding-top: 1rem;
}

.btn {
    flex: 1;
    background: #007bff;
    color: #ffffff;
    cursor: pointer;
    padding: 12px 20px;
    border: none;
    border-radius: 6px;
    font-size: 1em;
    font-weight: 500;
    transition: background-color 0.2s, transform 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn:hover {
    background: #0056b3;
    transform: translateY(-2px);
}

.btn.btn-secondary {
    background-color: #6c757d;
}

.btn.btn-secondary:hover {
    background-color: #5a6268;
}

.result-card {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.5s, transform 0.5s;
}

.result-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.results-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.result-item {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 8px;
    text-align: center;
    cursor: pointer;
    transition: background-color 0.2s;
}

.result-item:hover {
    background-color: #e9ecef;
}

.result-item.highlight {
    grid-column: 1 / -1;
    background: #e9f5ff;
    border: 1px solid #007bff;
}

.result-label {
    display: block;
    font-size: 0.9em;
    color: #6c757d;
    margin-bottom: 0.5rem;
}

.result-value {
    display: block;
    font-size: 1.8em;
    font-weight: bold;
    color: #007bff;
}

.result-unit {
    font-size: 0.9em;
    color: #6c757d;
}

.highlight .result-value {
    font-size: 2.2em;
}

.toast-notification {
    position: absolute;
    background-color: #333;
    color: #fff;
    padding: 10px 20px;
    border-radius: 5px;
    z-index: 1000;
    transition: opacity 0.3s;
}

@media (max-width: 992px) {
    .calculator-container {
        flex-direction: column;
        align-items: center;
    }
    .calculator-card {
        max-width: 600px;
    }
}

@media (max-width: 600px) {
    .results-grid {
        grid-template-columns: 1fr;
    }
    .result-item.highlight {
        grid-column: auto;
    }
    .result-value {
        font-size: 1.6em;
    }
    .highlight .result-value {
        font-size: 2em;
    }
    .button-group {
        flex-direction: column;
    }
}