index.css

* {
    margin: 0;
    padding: 0;
}

a {
    text-decoration: none;
}

ul {
    list-style: none;
}

body {
    background-color: #E6E6FA;
    background-size: cover;
    width: 100vw;
    height: 100vh;
}


header {
    height: 60px;
    background-color: rgba(64, 52, 80, 0.4);
    display: flex;
    justify-content: space-between;
    padding: 20px 80px 20px 40px;
}

header div {
    position: relative;
    left: 80px;
}

header div span {
    width: 700px;
    position: absolute;
    font-size: 40px;
    font-weight: 700;
    cursor: pointer;
}

header nav a {
    height: 40px;
    color: #f0f8ff;
    display: flex;
    justify-content: end;
    align-items: center;
    cursor: pointer;
    transition: 0.2s;
}

header nav a:hover {
    color: #574266;
    filter: brightness(120%);
}

#mainBox {
    display: flex;
    justify-content: center;
}

#mainBox li {
    width: 800px;
    height: 100px;
    border-radius: 15px;
    margin: 30px;
    display: flex;
    align-items: center;
    position: relative;
    border: 1px solid #50187382;
}

#mainBox li:hover {
    filter: brightness(110%);
    transform: scale(1.05);
    transition: 0.15s;
    color: #50187382;
}

.info {
    height: 80px;
    width: 240px;
    font-size: 24px;
    display: flex;
    justify-content: flex-start;
    align-items: center;
    position: absolute;
    left: 20px;
    border-right: 2px double #50187382;
}

.info img {
    width: 60px;
    height: 60px;
    border: 2px #deb887dc solid;
    border-radius: 100%;
    transition: 0.2s;
    margin-right: 20px;
}

.info h3 {
    font-size: 20px;
    color: #50187382;
}

.info .time {
    font-size: 12px;
    font-weight: 55s0;
    color: #50187382;
}

.cont {
    position: absolute;
    left: 280px;
    right: 20px;
    text-indent: 2em;
    font-size: 14px;
}

.footer {
    height: 200px;
    display: flex;
    justify-content: space-evenly;
    align-items: center;
    background-color: rgba(0, 0, 0, 1);
}

.cue {
    color: #f0f8ff;
    font-size: 30px;
    font-weight: 100;
    display: flex;
    flex-direction: column;
}

textarea {
    width: 560px;
    height: 140px;
    font-size: 16px;
    font-family: Microsoft YaHei;
    text-indent: 2em;
    padding: 10px;
    box-sizing: border-box;
}

textarea:focus {
    outline-color: #50187382;
}

#sendBtn {
    color: #f0f8ff;
    background-color: black;
    border: none;
    cursor: pointer;
}

.deleteBtn {
    color: #f0f8ff;
    background-color: rgb(181, 158, 195);
    border: none;
    border-radius: 5px;
}