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

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --bg-color: #f3f4f6;
    --card-bg: #ffffff;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 40px;
    padding: 40px 0;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-radius: 16px;
}

h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
}

.subtitle {
    font-size: 1.1em;
    opacity: 0.9;
}

h2 {
    font-size: 1.5em;
    margin-bottom: 20px;
    color: var(--text-primary);
}

h3 {
    font-size: 1.2em;
    margin-bottom: 15px;
    color: var(--text-primary);
}

.main-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

section {
    background: var(--card-bg);
    padding: 30px;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

/* アップロードエリア */
.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    padding: 40px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    background: #fafafa;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background: #f0f7ff;
}

.upload-area.dragover {
    border-color: var(--primary-color);
    background: #e0f2fe;
}

#fileInput {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    opacity: 0;
    cursor: pointer;
}

.upload-icon {
    font-size: 3em;
    display: block;
    margin-bottom: 10px;
}

.upload-prompt p {
    color: var(--text-secondary);
    margin: 5px 0;
}

.file-types {
    font-size: 0.9em;
    margin-top: 10px;
}

/* ファイルリスト */
.file-list {
    margin-top: 20px;
    max-height: 300px;
    overflow-y: auto;
}

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px;
    margin-bottom: 8px;
    background: #f9fafb;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.file-info {
    display: flex;
    align-items: center;
    gap: 10px;
    flex: 1;
}

.file-icon {
    font-size: 1.5em;
}

.file-details {
    flex: 1;
}

.file-name {
    font-weight: 500;
    color: var(--text-primary);
    word-break: break-word;
}

.file-size {
    font-size: 0.9em;
    color: var(--text-secondary);
}

.remove-btn {
    background: var(--danger-color);
    color: white;
    border: none;
    padding: 6px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9em;
}

.remove-btn:hover {
    background: #dc2626;
}

/* 合計情報 */
.total-info {
    margin-top: 30px;
    padding: 20px;
    background: linear-gradient(135deg, #f0f9ff, #e0f2fe);
    border-radius: 12px;
    text-align: center;
}

.total-size {
    font-size: 2em;
    font-weight: bold;
    color: var(--primary-color);
    margin: 10px 0;
}

.file-count {
    color: var(--text-secondary);
}

/* 計算ツール */
.calc-tool {
    margin-bottom: 30px;
    padding: 20px;
    background: #f9fafb;
    border-radius: 8px;
}

.calc-form {
    display: grid;
    gap: 15px;
}

.form-group {
    display: grid;
    gap: 5px;
}

label {
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.95em;
}

input[type="number"],
select {
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 1em;
    transition: border-color 0.3s;
}

input[type="number"]:focus,
select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.calc-btn,
button {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 6px;
    font-size: 1em;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.3s;
}

.calc-btn:hover,
button:hover {
    background: var(--primary-hover);
}

.calc-result {
    margin-top: 15px;
    padding: 15px;
    background: white;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    display: none;
}

.calc-result.show {
    display: block;
}

/* ストレージ管理 */
.storage-input {
    margin-bottom: 20px;
}

.storage-form {
    display: flex;
    gap: 10px;
    margin-top: 10px;
}

.storage-form input {
    flex: 1;
}

.storage-form select {
    width: 80px;
}

.storage-visual {
    margin: 20px 0;
}

.storage-bar {
    height: 30px;
    background: #e5e7eb;
    border-radius: 15px;
    overflow: hidden;
    position: relative;
}

.storage-used {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    width: 0%;
    transition: width 0.5s ease;
}

.storage-info {
    display: flex;
    justify-content: space-between;
    margin-top: 10px;
    font-size: 0.9em;
}

.used {
    color: var(--primary-color);
}

.available {
    color: var(--secondary-color);
}

.percentage {
    font-weight: bold;
}

.storage-breakdown {
    margin-top: 30px;
}

#breakdownChart {
    max-height: 250px;
}

/* 変換ツール */
.converter {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.converter input {
    flex: 1;
    min-width: 120px;
}

.converter select {
    width: 100px;
}

.arrow {
    font-size: 1.2em;
    color: var(--text-secondary);
}

.convert-result {
    margin-top: 15px;
    padding: 15px;
    background: #f0f9ff;
    border-radius: 8px;
    text-align: center;
    font-size: 1.1em;
    font-weight: 500;
    color: var(--primary-color);
    display: none;
}

.convert-result.show {
    display: block;
}

/* クイックリファレンス */
.quick-reference {
    margin-top: 30px;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 15px;
}

th, td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

th {
    background: #f9fafb;
    font-weight: 600;
}

/* ガイドライン */
.guidelines {
    background: var(--card-bg);
    padding: 30px;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.guideline-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.guideline-card {
    padding: 20px;
    background: #f9fafb;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.guideline-card h3 {
    margin-bottom: 15px;
    font-size: 1.1em;
}

.guideline-card ul {
    list-style: none;
}

.guideline-card li {
    padding: 5px 0;
    color: var(--text-secondary);
    font-size: 0.95em;
}

/* レスポンシブ */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }

    header {
        padding: 30px 20px;
    }

    h1 {
        font-size: 2em;
    }

    .main-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    section {
        padding: 20px;
    }

    .converter {
        flex-direction: column;
    }

    .converter input,
    .converter select {
        width: 100%;
    }

    .arrow {
        transform: rotate(90deg);
    }

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

/* アニメーション */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.file-item {
    animation: fadeIn 0.3s ease;
}

/* スクロールバー */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: #888;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #555;
}