/* リセットと基本スタイル */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #0052cc;
    --primary-hover: #0747a6;
    --secondary-color: #42526e;
    --background-color: #f4f5f7;
    --surface-color: #ffffff;
    --border-color: #dfe1e6;
    --text-primary: #172b4d;
    --text-secondary: #6b778c;
    --success-color: #00875a;
    --warning-color: #ff991f;
    --error-color: #de350b;
    --working-hours-bg: #e3fcef;
    --working-hours-border: #00875a;
    --outside-hours-bg: #ffebe6;
    --outside-hours-border: #ff5630;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
    --radius: 4px;
    --radius-lg: 8px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Noto Sans', 'Ubuntu', 'Droid Sans', 'Helvetica Neue', sans-serif;
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ヘッダー */
header {
    padding: 48px 0 32px;
    text-align: center;
    position: relative;
}

h1 {
    font-size: 32px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
    letter-spacing: -0.5px;
}

.subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.language-selector {
    position: absolute;
    top: 24px;
    right: 0;
}

.language-selector select {
    padding: 8px 32px 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background-color: var(--surface-color);
    color: var(--text-primary);
    font-size: 14px;
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%236b778c' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 8px center;
    background-size: 16px;
}

.language-selector select:hover {
    border-color: var(--primary-color);
}

/* メインコンテンツ */
main {
    flex: 1;
    padding-bottom: 48px;
}

section {
    background: var(--surface-color);
    border-radius: var(--radius-lg);
    padding: 32px;
    margin-bottom: 24px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

h2 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 24px;
    color: var(--text-primary);
}

/* フォーム要素 */
.form-group {
    margin-bottom: 20px;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 20px;
}

label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
    font-size: 14px;
}

input[type="text"],
input[type="date"],
input[type="time"],
select {
    width: 100%;
    padding: 10px 12px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 14px;
    color: var(--text-primary);
    background-color: var(--surface-color);
    transition: all 0.2s ease;
}

input[type="text"]:focus,
input[type="date"]:focus,
input[type="time"]:focus,
select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(0, 82, 204, 0.1);
}

/* タイムゾーン選択 */
.quick-select {
    display: flex;
    gap: 12px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.quick-btn {
    padding: 8px 16px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background: var(--surface-color);
    color: var(--text-primary);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.quick-btn:hover {
    background-color: var(--background-color);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.timezone-search {
    margin-bottom: 20px;
}

.timezone-search input {
    width: 100%;
    padding: 10px 12px;
    padding-left: 40px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 14px;
    background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%236b778c' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3ccircle cx='11' cy='11' r='8'%3e%3c/circle%3e%3cpath d='m21 21-4.35-4.35'%3e%3c/path%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: 12px center;
    background-size: 20px;
}

.timezone-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 12px;
    max-height: 300px;
    overflow-y: auto;
    padding: 4px;
}

.timezone-checkbox {
    display: flex;
    align-items: center;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    cursor: pointer;
    transition: all 0.2s ease;
}

.timezone-checkbox:hover {
    background-color: var(--background-color);
    border-color: var(--primary-color);
}

.timezone-checkbox input[type="checkbox"] {
    margin-right: 12px;
    width: 16px;
    height: 16px;
    cursor: pointer;
}

.timezone-checkbox span {
    flex: 1;
    font-size: 14px;
}

/* 結果セクション */
.meeting-info {
    background-color: var(--background-color);
    padding: 20px;
    border-radius: var(--radius);
    margin-bottom: 24px;
    text-align: center;
}

.meeting-info h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.meeting-info p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 4px;
}

.timezone-results {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 16px;
    margin-bottom: 24px;
}

.timezone-card {
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 20px;
    background-color: var(--surface-color);
    transition: all 0.2s ease;
}

.timezone-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.timezone-name {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
    font-size: 16px;
}

.timezone-time {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 4px;
    display: flex;
    align-items: baseline;
    gap: 8px;
}

.timezone-time.working-hours {
    color: var(--success-color);
}

.timezone-time.outside-hours {
    color: var(--warning-color);
}

.day-indicator {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
}

.timezone-date {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 8px;
}

.timezone-status {
    font-size: 12px;
    font-weight: 500;
    padding: 4px 8px;
    border-radius: var(--radius);
    display: inline-block;
}

.working-hours .timezone-status {
    background-color: var(--working-hours-bg);
    color: var(--working-hours-border);
    border: 1px solid var(--working-hours-border);
}

.outside-hours .timezone-status {
    background-color: var(--outside-hours-bg);
    color: var(--outside-hours-border);
    border: 1px solid var(--outside-hours-border);
}

/* アクションボタン */
.share-section {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}

.action-btn {
    padding: 12px 24px;
    border: none;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    background-color: var(--primary-color);
    color: white;
}

.action-btn:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.action-btn:active {
    transform: translateY(0);
}

/* フッター */
footer {
    padding: 32px 0;
    text-align: center;
    border-top: 1px solid var(--border-color);
}

footer p {
    color: var(--text-secondary);
    font-size: 14px;
}

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

.timezone-list::-webkit-scrollbar-track {
    background: var(--background-color);
    border-radius: var(--radius);
}

.timezone-list::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: var(--radius);
}

.timezone-list::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* レスポンシブデザイン */
@media (max-width: 768px) {
    .container {
        padding: 0 16px;
    }
    
    header {
        padding: 32px 0 24px;
    }
    
    h1 {
        font-size: 24px;
    }
    
    .subtitle {
        font-size: 16px;
    }
    
    .language-selector {
        position: static;
        margin-top: 16px;
    }
    
    section {
        padding: 20px;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .timezone-results {
        grid-template-columns: 1fr;
    }
    
    .quick-select {
        justify-content: center;
    }
    
    .share-section {
        flex-direction: column;
    }
    
    .action-btn {
        width: 100%;
    }
}

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

.timezone-card {
    animation: fadeIn 0.3s ease-out;
}

/* アクセシビリティ */
:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* 印刷対応 */
@media print {
    body {
        background: white;
    }
    
    .language-selector,
    .quick-select,
    .timezone-search,
    .timezone-list,
    .share-section,
    footer {
        display: none;
    }
    
    section {
        box-shadow: none;
        border: 1px solid #ddd;
    }
}