add validate email and fix style code

app/assets/stylesheets/custom.scss

 @import "bootstrap";
-@import "flash";
+@import "colors";
 @import url('https://fonts.googleapis.com/css2?family=Roboto:wght@100;300;400;500;700&display=swap');
 
 #logo {
@@ -161,23 +161,16 @@ footer {
   }
 }
 
-.alert-error,  .alert-alert {
+.alert-error, .alert-alert {
   background-color: $background-error-alert-color;
   border-color: $border-error-alert-color;
   color: $error-alert-color;
   text-align: left;
 }
 
-.alert-success {
+.alert-success, .alert-notice {
   background-color: $background-success-notice-color;
   border-color: $border-success-notice-color;
   color: $success-notice-color;
   text-align: left;
-}
-
-.alert-notice {
-  background-color: $background-success-notice-color;
-  border-color: $border-success-notice-color;
-  color: $success-notice-color;
-  text-align: left;
-}
+}
\ No newline at end of file

app/models/user.rb

@@ -6,8 +6,9 @@ class User < ApplicationRecord
   devise :database_authenticatable, :registerable,
          :recoverable, :rememberable, :validatable,
          :confirmable
+  VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i
   validates :name, length: { maximum: 200 }
-  validates :email, length: { maximum: 200 }, uniqueness: true
+  validates :email, length: { maximum: 200 }, uniqueness: true, format: { with: VALID_EMAIL_REGEX }
   validates :cv, content_type: { in: 'application/pdf', message: 'must be a valid pdf format' },
                  size: { less_than: 5.megabytes, message: 'should be less than 5MB' }
 end
\ No newline at end of file

app/views/users/registrations/new.html.slim

@@ -9,11 +9,11 @@ h2.p-3.text-center
           .field
             = f.label :name, "Full Name"
             br
-            = f.text_field :name, required: true, length: { maximum: 200 }, class: 'form-control'
+            = f.text_field :name, required: true, autofocus: true, length: { maximum: 200 }, class: 'form-control'
           .field
             = f.label :email
             br
-            = f.email_field :email, required: true, length: { maximum: 200 }, autofocus: true, autocomplete: "email", class: 'form-control'
+            = f.email_field :email, required: true, length: { maximum: 200 }, autocomplete: "email", class: 'form-control'
           .field
             = f.label :password
             - if @minimum_password_length

app/views/users/show.html.slim

@@ -8,11 +8,11 @@ h2.p-3.text-center
           .field
             = f.label :email
             br
-            = f.email_field :email, required: true, autofocus: true, autocomplete: "email", class: 'form-control'
+            = f.email_field :email, disabled: true, class: 'form-control'
           .field
             = f.label :name, "Full Name"
             br
-            = f.text_field :name, required: true, length: { maximum: 200 }, class: 'form-control'
+            = f.text_field :name, disabled: true, class: 'form-control'
           .field
             -if @user.cv.attached?
               = f.label :cv, "CV"