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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: #f5f5f5;
    padding: 20px;
    color: #333;
    line-height: 1.6;
}

header {
    max-width: 1200px;
    margin: 0 auto 30px;
    padding: 20px;
    background: white;
    border-bottom: 2px solid #333;
}

h1 {
    font-size: 1.8rem;
    margin-bottom: 5px;
}

.subtitle {
    color: #666;
    font-size: 0.9rem;
}

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

.container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.calculator-section,
.pack-sizes-section {
    background: white;
    padding: 20px;
    border: 1px solid #ddd;
}

h2 {
    font-size: 1.3rem;
    margin-bottom: 15px;
    border-bottom: 1px solid #eee;
    padding-bottom: 8px;
}

h3 {
    font-size: 1.1rem;
    margin: 20px 0 10px;
}

h4 {
    font-size: 1rem;
    margin: 15px 0 8px;
    color: #666;
}

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

label {
    display: block;
    margin-bottom: 5px;
    font-weight: 500;
    font-size: 0.9rem;
}

input[type="number"] {
    width: 100%;
    padding: 8px;
    border: 1px solid #ccc;
    font-size: 1rem;
}

input[type="number"]:focus {
    outline: none;
    border-color: #333;
}

button {
    background: #000;
    color: white;
    border: none;
    padding: 10px 20px;
    font-size: 0.9rem;
    cursor: pointer;
    width: 100%;
}

button:hover {
    background: #333;
}

button:disabled {
    background: #999;
    cursor: not-allowed;
}

.input-button-group {
    display: flex;
    gap: 10px;
}

.input-button-group input {
    flex: 1;
}

.input-button-group button {
    width: auto;
}

.error {
    background: #fee;
    border: 1px solid #fcc;
    color: #c00;
    padding: 10px;
    margin-top: 10px;
    font-size: 0.9rem;
}

.hidden {
    display: none;
}

.result {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid #eee;
}

.result-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    margin-bottom: 15px;
}

.result-item {
    background: #f9f9f9;
    padding: 10px;
    border: 1px solid #eee;
}

.result-item .label {
    font-size: 0.8rem;
    color: #666;
}

.result-item .value {
    font-size: 1.4rem;
    font-weight: bold;
    margin-top: 3px;
}

.pack-breakdown,
.size-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.pack-item,
.size-item {
    background: #fafafa;
    padding: 10px;
    border: 1px solid #eee;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.pack-size,
.size-value {
    font-weight: 500;
}

.pack-count {
    font-weight: bold;
}

.delete-btn {
    background: #c00;
    color: white;
    border: none;
    width: 25px;
    height: 25px;
    font-size: 1.2rem;
    cursor: pointer;
    padding: 0;
    line-height: 1;
}

.delete-btn:hover {
    background: #900;
}

footer {
    max-width: 1200px;
    margin: 30px auto 0;
    padding: 20px;
    text-align: center;
    color: #666;
    font-size: 0.9rem;
    border-top: 1px solid #ddd;
    background: white;
}

footer a {
    color: #333;
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

.not-found {
    background: white;
    padding: 60px 30px;
    text-align: center;
    border: 1px solid #ddd;
    max-width: 600px;
    margin: 0 auto;
}

.not-found h2 {
    font-size: 3rem;
    margin-bottom: 15px;
}

.not-found p {
    font-size: 1.1rem;
    color: #666;
    margin-bottom: 20px;
}

.btn {
    display: inline-block;
    background: #333;
    color: white;
    padding: 10px 25px;
    text-decoration: none;
}

.btn:hover {
    background: #000;
}

@media (max-width: 768px) {
    .container {
        grid-template-columns: 1fr;
    }

    .result-grid {
        grid-template-columns: 1fr;
    }
}