:root {
    --primary-color: #FF6B6B;
    --secondary-color: #4ECDC4;
    --accent-color: #FFE66D;
    --text-color: #2C3E50;
    --bg-color: #F8F9FA;
    --card-bg: #FFFFFF;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ヘッダー */
header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 2rem 0;
    text-align: center;
    box-shadow: var(--shadow);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.tagline {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* メインコンテンツ */
main {
    padding: 2rem 0;
}

section {
    background: var(--card-bg);
    padding: 2rem;
    margin-bottom: 2rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
}

section h2 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.8rem;
    border-bottom: 2px solid var(--accent-color);
    padding-bottom: 0.5rem;
}

/* フォーム */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-color);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #E0E0E0;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--secondary-color);
}

.reminder-options {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.reminder-options label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: normal;
}

/* ボタン */
.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    font-size: 1.1rem;
    border-radius: 30px;
    cursor: pointer;
    transition: transform 0.3s, box-shadow 0.3s;
    font-weight: 600;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.filter-buttons {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.filter-btn {
    background: #E0E0E0;
    border: none;
    padding: 0.5rem 1.5rem;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s;
    font-weight: 500;
}

.filter-btn.active,
.filter-btn:hover {
    background: var(--secondary-color);
    color: white;
}

/* 誕生日カード */
.birthday-list {
    display: grid;
    gap: 1rem;
}

.birthday-card {
    background: #F5F5F5;
    padding: 1.5rem;
    border-radius: 10px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.3s;
}

.birthday-card:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow);
}

.birthday-info h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.birthday-date {
    font-weight: 600;
    color: var(--text-color);
}

.birthday-relation {
    display: inline-block;
    background: var(--accent-color);
    padding: 0.2rem 0.8rem;
    border-radius: 15px;
    font-size: 0.9rem;
    margin-top: 0.5rem;
}

.birthday-notes {
    color: #666;
    font-style: italic;
    margin-top: 0.5rem;
}

.next-birthday {
    color: var(--secondary-color);
    font-weight: 500;
    margin-top: 0.5rem;
}

.birthday-actions {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.birthday-actions button {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 0.9rem;
}

.btn-gift {
    background: var(--accent-color);
    color: var(--text-color);
}

.btn-message {
    background: var(--secondary-color);
    color: white;
}

.btn-delete {
    background: #E57373;
    color: white;
}

.birthday-actions button:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow);
}

/* 今月の誕生日 */
.upcoming-card {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: linear-gradient(135deg, #FFE5E5, #E5F5FF);
    border-radius: 10px;
    margin-bottom: 0.5rem;
}

.upcoming-date {
    font-size: 2rem;
    font-weight: bold;
    color: var(--primary-color);
    min-width: 80px;
    text-align: center;
}

.upcoming-info h4 {
    color: var(--text-color);
    margin-bottom: 0.2rem;
}

/* ギフト提案 */
.gift-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.gift-card {
    background: #F9F9F9;
    padding: 1.5rem;
    border-radius: 10px;
    text-align: center;
    transition: all 0.3s;
}

.gift-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
}

.gift-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.gift-card h4 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.gift-price {
    color: var(--secondary-color);
    font-weight: bold;
    margin-top: 0.5rem;
}

/* メッセージテンプレート */
.message-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.message-card {
    background: #F9F9F9;
    padding: 1.5rem;
    border-radius: 10px;
}

.message-card h4 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.message-card button {
    background: var(--secondary-color);
    color: white;
    border: none;
    padding: 0.5rem 1.5rem;
    border-radius: 20px;
    cursor: pointer;
    margin-top: 1rem;
    transition: all 0.3s;
}

.message-card button:hover {
    transform: scale(1.05);
}

/* 通知 */
.notification {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--primary-color);
    color: white;
    padding: 1rem 2rem;
    border-radius: 10px;
    box-shadow: var(--shadow-hover);
    transform: translateY(100px);
    opacity: 0;
    transition: all 0.3s;
}

.notification.show {
    transform: translateY(0);
    opacity: 1;
}

/* 空メッセージ */
.empty-message {
    text-align: center;
    color: #999;
    padding: 2rem;
    font-style: italic;
}

/* フッター */
footer {
    background: #2C3E50;
    color: white;
    text-align: center;
    padding: 1.5rem 0;
    margin-top: 3rem;
}

/* レスポンシブ */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }
    
    .birthday-card {
        flex-direction: column;
        align-items: stretch;
    }
    
    .birthday-actions {
        margin-top: 1rem;
        justify-content: center;
    }
    
    .gift-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    }
    
    .message-grid {
        grid-template-columns: 1fr;
    }
    
    .upcoming-card {
        flex-direction: column;
        text-align: center;
    }
}