CSS Булки (style.css)

@import url('https://fonts.googleapis.com/css2?family=Underdog&display=swap');
html {
font-size: 10px;
font-family: 'Underdog', cursive;
background-color: white;
}
button {
     background-color: transparent;
     border: none;
}
h1 {
     font-size: 100px;
     margin-bottom: 5px;
     margin-top: 5px;
     color: #6e1700;
}
h2 {
     font-size: 70px;
     margin-bottom: 5px;
     margin-top: 5px;
     color: #6e1700;
}
h3 {
     font-size: 20px;
     margin-bottom: 5px;
     margin-top: 5px;
     color: #6e1700;
}
h4 {
     font-size: 20px;
     margin-bottom: 5px;
     margin-top: 5px;
     color: #6e1700;
}
p {
     font-size: 15px;
     margin-bottom: 5px;
     margin-top: 5px;
     color: #6e1700;
}

.page{
    width: 100%;
    height: 100vh;
    display: flex;
    align-items: center;
}

.container-main {
     display: flex;
     flex-direction: column;
     justify-content: center;
     align-items: center;
     width: 800px;
     height: 900px;
     margin: 0 auto;
    box-shadow: 0 14px 28px gray, 0 10px 10px gray;
}
#container {
  display: flex;
  flex-direction: column;
  justify-content: center;
  width: 100%;
}
#container-shop {
    flex: 1;
    background-color: #ecc6a5;
    width: 100%;
    margin-bottom: 20px;
}
#container-upgrade {
  display: flex;
  justify-content: center;
  width: 100%;
}
#container-upgrade div {
    display: inline-block;
  padding: 10px;
  border: 5px solid #ecc6a5;
}

#container div {
  padding: 10px 0;
  border: none;
}
#box1 {
    flex: 1;
    background-color: #f7e7dc;
    text-align: center;
    width: 100%;
}

#container-box3 {
    flex: 1;
    display: inline-block;
    background-color: #fdfaf4;
    text-align: center;
    width: 100%;
    width: 800px;
}
#box3-1 {
    display: inline-block;
    flex: 1;
    background-color: #fdfaf4;
    width: 100%;
}
#box4 {
    flex: 1;
    background-color: #f7e7dc;
    text-align: center;
    width: 300px;
    margin: 0 auto;
}
#box5 {
    flex: 1;
    background-color: #f7e7dc;
    text-align: center;
}

#box5-1-1 {
    flex: 1;
    background-color: #f4e0cb;
    justify-content: center;
}
#box5-1-2 {
    flex: 1;
    background-color: #de9f68;
    flex-basis: 50%;
}
#box5-1-3 {
    flex: 1;
    background-color: #d1884d;
    text-align:center;
}
#box6 {
    flex: 1;
    background-color: #de9f68;
    text-align:center;
    width: 100%;
}