/* 전체 애플리케이션 레이아웃 */
.app {
    display: flex;
    flex-direction: column;
    height: 100vh;
}

/* 상단 헤더 */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #2c3e50;
    color: white;
    padding: 10px 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    height: 60px;
    min-height: 60px;
}

.header-left {
    display: flex;
    align-items: center;
}

.header-title {
    font-size: 24px;
    margin: 0;
    font-weight: bold;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 15px;
}

.user-info {
    font-size: 16px;
    font-weight: 500;
    color: #ecf0f1;
}

.logout-btn, .login-btn {
    background-color: #e74c3c;
    color: white;
    padding: 6px 12px;
    text-decoration: none;
    border-radius: 4px;
    font-size: 14px;
    transition: background-color 0.2s;
}

.logout-btn:hover, .login-btn:hover {
    background-color: #c0392b;
    color: white;
    text-decoration: none;
}

.login-btn {
    background-color: #3498db;
}

.login-btn:hover {
    background-color: #2980b9;
}

/* 플래시 메시지 */
.flash-message {
    background-color: #27ae60;
    color: white;
    padding: 12px 20px;
    text-align: center;
    font-size: 14px;
    font-weight: 500;
    border-bottom: 2px solid rgba(0,0,0,0.1);
    animation: slideDown 0.3s ease-out;
}

@keyframes slideDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* 메인 컨테이너 (헤더 아래 영역) */
.main-container {
    display: flex;
    flex: 1;
    height: calc(100vh - 60px);
}

/* 사이드바 */
.sidebar {
    width: 250px;
    background-color: #34495e;
    color: white;
    padding: 20px;
    overflow-y: auto;
    max-height: 100%;
}

/* 컨텐츠 영역 */
.content {
    flex: 1;
    padding: 20px;
    background-color: #f5f6fa;
    overflow-y: auto;
}

/* 메뉴 스타일 */
.menu-group {
    margin-bottom: 20px;
}

.menu-group-title {
    font-weight: bold;
    margin-bottom: 8px;
    font-size: 18px;
    color: #ecf0f1;
    cursor: pointer;
    outline: none;
    user-select: none;
    transition: background 0.2s;
    padding: 6px 8px;
    border-radius: 4px;
}

.menu-group-title:hover, .menu-group-title:focus {
    background: #2c3e50;
}

.menu-group-children {
    margin-left: 10px;
    display: none;
    transition: max-height 0.2s;
}

.menu-group-children.open {
    display: block;
}

.sidebar nav a,
.menu-link {
    display: block;
    padding: 8px 12px;
    color: white;
    text-decoration: none;
    margin-bottom: 4px;
    border-radius: 5px;
    font-size: 15px;
    transition: background 0.2s;
}

.sidebar nav a:hover,
.menu-link:hover {
    background-color: #2c3e50;
}

.menu-link.active {
    background-color: #3498db;
}