Enumerando casos (Caso 1, Caso 2, etc.) dentro de problemas

Question

Sou iniciante em látex e queria saber como enumerar casos. Tentei usar \begin{case}, mas a numeração está errada. Se eu tivesse vários problemas envolvendo casos, a numeração não reinicia após cada problema, mas continua como se nada tivesse acontecido. Como faço para que isso pare. Além disso, quando falo sobre casos, quero dizer Caso 1 e Caso 2

Também estou usando todos esses pacotes que encontrei no sharelatex:

\documentclass[28pt]{article}

\usepackage{fancyhdr}
\usepackage[includeheadfoot,margin=1.0cm]{geometry} 
\usepackage{amsmath,amsthm,amssymb}
\usepackage{enumitem}
\usepackage{mathtools}
\usepackage{framed}
\usepackage{chessfss} %chess figure for HW #2
\usepackage[english]{babel} %table for problem A.43
\usepackage{multirow} %table for problem A.43 %\usepackage[table]{xcolor} color certain blocks in a table %\usepackage[pass,showframe]{geometry}  just to show the margins \usepackage[makeroom]{cancel} \usepackage{array}  %BETWEEN TWO 2-DIGIT NUMBERS

\newcommand{\N}{\mathbb{N}} \newcommand{\Z}{\mathbb{Z}} \newcommand{\thedate}{\today}

\newtheoremstyle{case}{}{}{}{}{}{:}{ }{} \theoremstyle{case} \newtheorem{case}{Case}


\newenvironment{theorem}[2][Theorem]{\begin{trivlist}  \item[\hskip \labelsep {\bfseries #1}\hskip \labelsep {\bfseries
#2.}]}{\end{trivlist}} \newenvironment{lemma}[2][Lemma]{\begin{trivlist} \item[\hskip \labelsep {\bfseries #1}\hskip \labelsep {\bfseries
#2.}]}{\end{trivlist}} \newenvironment{exercise}[2][Exercise]{\begin{trivlist} \item[\hskip \labelsep {\bfseries #1}\hskip \labelsep {\bfseries
#2.}]}{\end{trivlist}} \newenvironment{problem}[2][Problem]{\begin{trivlist} \item[\hskip \labelsep {\bfseries #1}\hskip \labelsep {\bfseries
#2.}]}{\end{trivlist}} \newenvironment{question}[2][Question]{\begin{trivlist} \item[\hskip \labelsep {\bfseries #1}\hskip \labelsep {\bfseries
#2.}]}{\end{trivlist}} \newenvironment{corollary}[2][Corollary]{\begin{trivlist}
\item[\hskip \labelsep {\bfseries #1}\hskip \labelsep {\bfseries #2.}]}{\end{trivlist}}