body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: #f3f6fb;
}

.hidden {
    display: none;
}

/* LOGIN */
.login-screen {
    display: flex;
    height: 100vh;
    justify-content: center;
    align-items: center;
}

.login-box {
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 0 15px rgba(0,0,0,0.1);
    width: 250px;
}

.login-box input {
    width: 100%;
    margin-bottom: 10px;
    padding: 10px;
}

.login-box button {
    width: 100%;
    padding: 10px;
    background: #4a90e2;
    color: white;
    border: none;
    cursor: pointer;
}

/* APP */
header {
    display: flex;
    justify-content: space-between;
    padding: 15px;
    background: #4a90e2;
    color: white;
}

.container {
    display: flex;
}

aside {
    width: 200px;
    background: #fff;
    padding: 10px;
}

aside button {
    width: 100%;
    margin-bottom: 10px;
    padding: 10px;
}

main {
    flex: 1;
    padding: 20px;
}

.file {
    background: white;
    padding: 15px;
    margin-bottom: 10px;
    cursor: pointer;
    border-radius: 5px;
    transition: 0.2s;
}

.file:hover {
    background: #e6f0ff;
}