:root {
    --primary-color: #2563eb;
    --text-color: #1f2937;
    --bg-color: #f9fafb;
    --border-color: #e5e7eb;
    --hover-color: #3b82f6;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Noto Sans TC', sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.5;
}

.container {
    max-width: 2000px;
    margin: 0 auto;
    padding: 8px;
}

.header {
    text-align: center;
    margin-bottom: 10px;
}

.header h1 {
    font-size: 1.5rem;
    margin-bottom: 4px;
}

.github-link {
    color: var(--text-color);
    text-decoration: none;
    font-size: 0.75rem;
    display: inline-block;
    margin: 2px 0;
}

.github-link:hover {
    color: var(--primary-color);
}

.main-content {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

@media (min-width: 768px) {
    .main-content {
        flex-direction: row;
    }
}

.calculator-main {
    background: white;
    border-radius: 12px;
    padding: 8px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    flex: 2;
    display: flex;
    flex-direction: column;
}

.presets {
    flex: 1;
    overflow-y: auto;
    max-height: calc(100vh - 100px);
}

.section-title {
    font-size: 1rem;
    margin-bottom: 8px;
    padding-bottom: 4px;
    border-bottom: 2px solid var(--border-color);
}

.input-group {
    margin-bottom: 8px;
}

.input-group label {
    display: block;
    margin-bottom: 2px;
    font-size: 0.75rem;
    font-weight: 500;
}

.input-row {
    display: flex;
    gap: 4px;
    align-items: center;
}

input[type="number"],
select {
    flex: 1;
    padding: 6px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.875rem;
    width: 100%;
}

.unit {
    font-size: 0.75rem;
    color: #666;
    min-width: 30px;
}

.results-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    margin: 8px 0;
}

.result-item {
    background: var(--bg-color);
    padding: 6px;
    border-radius: 6px;
}

.result-item label {
    display: block;
    font-size: 0.625rem;
    color: #666;
    margin-bottom: 2px;
}

.result-item span,
.result-item input {
    font-size: 0.875rem;
    font-weight: 500;
    width: 100%;
}

.button-group {
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
    margin-top: 8px;
}

button {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 6px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.75rem;
    transition: background-color 0.2s;
    flex: 1;
    min-width: 70px;
}

button:hover {
    background-color: var(--hover-color);
}

.preset-section {
    background: white;
    border-radius: 12px;
    padding: 8px;
    margin-bottom: 8px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.preset-buttons {
    display: grid;
    grid-template-columns: 1fr;
    gap: 4px;
}

.preset-button {
    background-color: white;
    border: 1px solid var(--primary-color);
    color: var(--primary-color);
    text-align: left;
    padding: 6px 8px;
    font-size: 0.75rem;
}

.preset-button:hover {
    background-color: var(--bg-color);
    color: var(--primary-color);
}

.note {
    font-size: 0.625rem;
    color: #666;
    margin-top: 4px;
}

@media (min-width: 640px) {
    .container {
        padding: 16px;
    }

    .header h1 {
        font-size: 1.75rem;
    }

    .results-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .button-group {
        flex-wrap: nowrap;
        gap: 8px;
    }

    .button-group button {
        min-width: 100px;
    }

    .preset-buttons {
        grid-template-columns: repeat(2, 1fr);
    }

    .input-row {
        gap: 8px;
    }

    .input-group label {
        font-size: 0.875rem;
    }

    .unit {
        font-size: 0.875rem;
    }

    .result-item label {
        font-size: 0.75rem;
    }

    .result-item span,
    .result-item input {
        font-size: 1rem;
    }

    .preset-button {
        font-size: 0.875rem;
    }

    .note {
        font-size: 0.75rem;
    }
}