styles.css

:root {
  --color-primary: #1536f1;
  --color-secondary: #d0e90d;
  --color-tertiary: #ddd;
}

* {
  box-sizing: border-box;
  font-family: Roboto, Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue",
    sans-serif;
}

html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
}

p {
  line-height: 1.5;
}

a {
  text-decoration: none;
  color: var(--color-primary);
}

img {
  max-width: 100%;
  border-radius: 1rem;
}

hr {
  border: 0;
  border-bottom: 1px solid var(--color-tertiary);
}

/* nav */
nav {
  background-color: #fff;
  border-bottom: 1px solid #e0e0e0;
  height: 60px;
  position: sticky;
  top: 0;
  width: 100%;
  z-index: 999999999999999999999999;
  margin-bottom: 2rem;
}

nav .nav-wrapper {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 100%;
  margin: 0 auto;
  max-width: 1200px;
  padding: 0 20px;
}

nav .nav-wrapper .brand-logo {
  width: auto;
}

/* container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* card */
.card {
  background-color: #fff;
  border-radius: 1rem;
  box-shadow: 0 1px 0.25rem 0 rgba(0, 0, 0, 0.25);
  margin: 0 0 1rem;
  padding: 1rem;
}

/* card header */
.card-header {
  align-items: center;
  display: flex;
  justify-content: space-between;
}

/* card title */
.card-title {
  font-size: 1.25rem;
  font-weight: 400;
  margin: 0;
  margin-bottom: 1rem;
}

/* card body */
.card-body {
  padding: 1rem 0;
}

/* card text */
.card-text {
  font-size: 1rem;
  font-weight: 400;
  margin: 0;
  line-height: 1.5;
}

#output-container {
  background-color: rgb(115, 115, 115);
  border-radius: 1rem;
  margin: 1.25rem 0 0 0;
  padding: 1.25rem;
  display: none;
  color: #f1f1f1;
}

.output-email-container {
  font-size: 1.25rem;
  margin: 0;
  display: flex;
  justify-content: space-between;
  font-weight: 700;
}

.hidden {
  display: none !important;
}

.text-small {
  font-size: 0.875rem;
}

.text-muted {
  color: #757575;
}

/* form */
.form {
  display: flex;
  flex-direction: column;
}

/* form group */
.form-group {
  margin-bottom: 1rem;
}

/* form label */
.form-group label {
  font-size: 0.875rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  display: block;
}

/* form input */
.form-group input {
  border: 1px solid #ccc;
  border-radius: 999rem;
  font-size: 0.875rem;
  padding: 0.75rem;
  width: 100%;
}

.form-group input:focus {
  border-color: var(--color-primary);
  outline: none;
}

.form-group input::placeholder {
  color: #ccc;
}

.form-group .input-error-message {
  color: #f44336;
  font-size: 0.75rem;
  margin-top: 0.25rem;
}

/* button linear gradient */
.btn {
  background: linear-gradient(
    to right bottom,
    var(--color-primary),
    var(--color-secondary)
  );
  border: none;
  border-radius: 999rem;
  color: #fff;
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 700;
  padding: 0.5rem 1rem;
  text-transform: uppercase;
}

/* button hover */
.btn:hover {
  background: linear-gradient(
    to right bottom,
    var(--color-secondary),
    var(--color-primary)
  );
}

/* button disabled */
.btn:disabled {
  background: #ccc;
  cursor: not-allowed;
}

/* button block */
.btn-block {
  display: block;
  width: 100%;
}

.btn-link {
  background: none;
  color: var(--color-secondary);
  font-size: 0.875rem;
  font-weight: 700;
  padding: 0;
  text-transform: none;
  border: none;
  outline: none;
  cursor: pointer;
}

.btn-link:hover {
  color: var(--color-secondary);
}

.btn-link:disabled {
  color: #ccc;
  cursor: not-allowed;
}

.btn-link:focus {
  outline: none;
}

.m-0 {
  margin: 0;
}

/* margins */
.m-1 {
  margin: 1rem;
}

.m-2 {
  margin: 2rem;
}

.mr-1 {
  margin-right: 1rem;
}

.mr-2 {
  margin-right: 2rem;
}

.mb-1 {
  margin-bottom: 1rem;
}

.mb-2 {
  margin-bottom: 2rem;
}

.mt-1 {
  margin-top: 1rem;
}

.mt-2 {
  margin-top: 2rem;
}

/* padding */
.p-1 {
  padding: 1rem;
}

.p-2 {
  padding: 2rem;
}

/* text align */
.text-center {
  text-align: center;
}

.text-end {
  text-align: right;
}

/* text color */
.text-primary {
  color: var(--color-primary);
}

.text-secondary {
  color: var(--color-secondary);
}

/* text transform */
.text-uppercase {
  text-transform: uppercase;
}

/* text weight */
.font-weight-bold {
  font-weight: 700;
}

/*  snackbar */
.snackbar {
  background-color: #333;
  border-radius: 0.25rem;
  bottom: 2.75rem;
  color: #fff;
  font-size: 0.875rem;
  left: 50%;
  max-width: 568px;
  min-width: 288px;
  padding: 16px;
  position: fixed;
  transform: translateX(-50%);
  visibility: hidden;
  z-index: 1000;
}

.snackbar-text {
  margin: 0;
}

.snackbar.show {
  visibility: visible;
  -webkit-animation: fadein 0.5s, fadeout 0.5s 2.5s;
  animation: fadein 0.5s, fadeout 0.5s 2.5s;
}

/* action */
.snackbar-action {
  background: none;
  border: none;
  color: #fff;
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 700;
  padding: 0;
  text-transform: uppercase;
}

/*  flex snackbar if there is an action */
.snackbar.action {
  align-items: center;
  display: flex;
  justify-content: space-between;
}

.snackbar.action .snackbar-text {
  margin-right: 1rem;
  flex: 1;
}

@-webkit-keyframes fadein {
  from {
    bottom: 0;
    opacity: 0;
  }
  to {
    bottom: 2.75rem;
    opacity: 1;
  }
}

@keyframes fadein {
  from {
    bottom: 0;
    opacity: 0;
  }
  to {
    bottom: 2.75rem;
    opacity: 1;
  }
}

@-webkit-keyframes fadeout {
  from {
    bottom: 2.75rem;
    opacity: 1;
  }
  to {
    bottom: 0;
    opacity: 0;
  }
}

@keyframes fadeout {
  from {
    bottom: 2.75rem;
    opacity: 1;
  }
  to {
    bottom: 0;
    opacity: 0;
  }
}

/* blockquotes */
blockquote {
  border-left: 5px solid #ccc;
  margin: 1.5rem 10px;
  padding: 0 1rem;
  line-height: 1.5;
  font-style: italic;
  font-size: 0.85rem;
  color: #757575;
}

blockquote footer {
  font-size: 0.875rem;
  font-weight: 700;
  margin-top: 0.5rem;
  text-align: right;
}

blockquote footer::before {
  content: "— ";
}

/* banner  fixed in the bottom of the page */
.bottom-banner {
  background-color: rgb(200, 200, 200);
  bottom: 0;
  box-shadow: 0 0px 0.25rem 0 rgba(0, 0, 0, 0.2);
  left: 0;
  padding: 0.5rem 1rem;
  position: sticky;
  width: 100%;
  z-index: 99999999999999999999999;
}

.bottom-banner p {
  margin: 0;
  font-size: small;
}

.hashtag {
  color: var(--color-primary);
  font-weight: 700;
  text-decoration: none;
}

.duck-splash {
  display: none;
}

/*  grid using flexbox */
.grid {
  display: flex;
  flex-wrap: wrap;
  margin: 0 -1rem;
}

.grid-item {
  flex: 1 0 50%;
  padding: 0 1rem;
}

@media (min-width: 768px) {
  .grid-item {
    flex: 1 0 33.333333%;
  }

  .duck-splash {
    display: block;
  }
}

@media (min-width: 992px) {
  .grid-item {
    flex: 1 0 25%;
  }
}

@media (min-width: 1200px) {
  .grid-item {
    flex: 1 0 20%;
  }
}