<!--  
View the step by step video tutorial on how to create this login form with only css(sass) and html

https://youtu.be/dok2xAaheWk
-->

<div class="wrapper">
        <div class="container">
            <div class="tabs">
                <!-- Sign In -->
                <input type="radio" class="tabs__button" name="signForm" id="signIn" checked />
                <label class="tabs__text" for="signIn">Sign In</label>
                <div class="tabs__content">
                    <h1>Welcome back!</h1>
                    <p>Get back on your track</p>
                    <form class="form">
                        <div class="input-group">
                            <input class="input-group__input" type="text" placeholder="&nbsp;" name="username" id="username" autocomplete="off" required />
                            <label class="input-group__label" for="username">Username</label>
                        </div>
                        <div class="input-group">
                            <input class="input-group__input" type="password" name="password" placeholder="&nbsp;" id="password" required />
                            <label class="input-group__label" for="password">Password</label>
                        </div>
                        <!-- Normally I would create a grid system or use an existing to cater this issue -->
                        <div class="flex-space-between">
                            <label class="flex-align-center"><input type="checkbox" /> Remember Me</label>
                            <p><a href="#">Forgot Password?</a></p>
                        </div>
                        <button type="submit">Submit</button>
                    </form>
                </div>

                <!-- Sign Up -->
                <input type="radio" class="tabs__button" name="signForm" id="signUp" />
                <label class="tabs__text" for="signUp">Sign Up</label>
                <div class="tabs__content">
                    <h1>New Account</h1>
                    <p>Start your journey now</p>
                    <form class="form">
                        <div class="input-group">
                            <input class="input-group__input" type="email" placeholder="&nbsp;" name="username" id="username" autocomplete="off" required />
                            <label class="input-group__label" for="email">Email</label>
                        </div>
                        <div class="input-group">
                            <input class="input-group__input" type="password" name="password" placeholder="&nbsp;" id="password" required />
                            <label class="input-group__label" for="password">Password</label>
                        </div> 
                        <p><small>By submitting this form, you confirm you have read and agreed to the <a href="#">Terms and Conditions.</a></small></p>
                        <button type="submit">Submit</button>
                    </form>
                </div>
            </div>
        </div>
    </div>

@import url('https://fonts.googleapis.com/css2?family=Lato:wght@400;700&display=swap');

// Color
$gray: #999999;
$dark-gray: #333333;
$blue: #0086e4;

$primary-color: $blue;
$border-color: #dddddd;

// Font
$primary-font: 'Lato', sans-serif;

// Typography
$body-font-family: $primary-font;
$body-font-size: 14px;
$body-color: $dark-gray;

// Input
$input-height: 40px;

// Button
$button-height: $input-height;

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font: {
    family: $body-font-family;
    size: $body-font-size;
  }
  color: $body-color;
}

h1,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 10px;
  + p {
    color: $gray;
    margin-bottom: 30px;
  }
}

p {
  margin-bottom: 20px; 
}

a {
  color: $primary-color;
  text-decoration: none;
}

input[type="checkbox"] {
  margin: 0;
  padding: 0;
  height: 17px;
}

.wrapper {
  min-height: 100vh;
  display: grid;
  place-items: center;
  // display: flex;
  // align-items: center;
  // justify-content: center;
  background: rgb(150,0,150);
  background: linear-gradient(225deg, rgba(150,0,150,1) 0%, rgba(107,36,205,1) 50%, rgba(0,104,255,1) 100%);
}

.container {
  width: 100%;
  height: auto;
  max-width: 400px;
  min-width: 320px;
  background-color: white;
}


// Util
// You can create a different file to store all utilities classes
.flex-space-between {
  display: flex;
  justify-content: space-between;
}

.flex-align-center {
  display: flex;
  justify-content: center;
  gap: 5px;
}

button {
    cursor: pointer;
    background-color: $primary-color;
    color: white;
    border: none;
    font-weight: bold;
    text-transform: uppercase;
    border-radius: 6px;
    letter-spacing: 1px;
    width: 100%;
    height: $button-height;
    transition: 300ms background-color ease-in-out;
    &:hover {
        background-color: lighten($primary-color, 10%);
    }
}

.input-group {
    margin-bottom: 20px;
    position: relative;
    &__label {
        display: block;
        position: absolute;
        top: 0;
        // to keep the position center
        line-height: $input-height;
        color: #aaa;
        left: 5px;
        padding: 0 5px;
        transition: line-height 200ms ease-in-out,
            font-size 200ms ease-in-out, 
            top 200ms ease-in-out;
        // firefox fix
        pointer-events: none;
    }
    &__input {
        width: 100%;
        height: $input-height;
        border: 1px solid $border-color;
        border-radius: 3px;
        padding: 0 10px;
        // there must a required prop in input
        // &:valid,
        // need to add placeholder
        &:not(:placeholder-shown),
        &:focus {
            + label {
                background-color: white;
                line-height: 10px;
                opacity: 1;
                font-size: 10px;
                top: -5px;
            }
        }
        &:focus {
            outline: none;
            border: 1px solid $primary-color;
            + label {
                color: $primary-color;
            }
        }
    }
}

.tabs {
    $parent: &;
    display: flex;
    flex-flow: row wrap;
    &__text {
        flex: 1;
        margin: 0;
        cursor: pointer;
        padding: 20px 30px;
        font-size: 1.2em;
        opacity: 0.5;
        background-color: #eeeeee;
        border-top: 3px solid #eeeeee;
        transition: border-top 300ms ease-out;
        transform-origin: top;
        text-transform: uppercase;
        font-weight: bold;
        text-align: center;
    }
    &__content {
        display: none;
        flex: 1 1 100%;
        order: 99;
        padding: 40px 30px 30px 30px;
    }
    &__button {
        visibility: hidden;
        height: 0;
        margin: 0;
        position: absolute;
        &:checked {
            + #{$parent}__text {
                // order: -1;
                color: $primary-color;
                opacity: 1;
                background-color: white;
                border-top: 3px solid $primary-color;
            }
            + #{$parent}__text + #{$parent}__content {
                display: block;
            }
        }
    }
}