@import url("https://fonts.googleapis.com/css2?family=Epilogue:ital,wght@0,100..900;1,100..900&display=swap");

:root {
  /* Base (light mode) colors */
  --bg-h: 0;
  --bg-s: 0%;
  --bg-l: 95%;

  --primary-h: 0;
  --primary-s: 0%;
  --primary-l: 0%;

  --text-h: var(--primary-h);
  --text-s: var(--primary-s);
  --text-l: var(--primary-l);

  --danger-h: 0;
  --danger-s: 60%;
  --danger-l: 60%;

  /* Derived colors */
  --bg: hsl(var(--bg-h) var(--bg-s) var(--bg-l));
  --bg-dark: hsl(var(--bg-h) var(--bg-s) calc(var(--bg-l) - 10%));
  --bg-light: hsl(var(--bg-h) var(--bg-s) calc(var(--bg-l) + 5%));

  --primary: hsl(var(--primary-h) var(--primary-s) var(--primary-l));
  --text: hsl(var(--text-h) var(--text-s) var(--text-l));

  --button-high: hsl(
    var(--primary-h) var(--primary-s) calc(var(--primary-l) + 20%)
  );
  --button-mid: hsl(
    var(--primary-h) var(--primary-s) calc(var(--primary-l) + 15%)
  );
  --button-low: hsl(
    var(--primary-h) var(--primary-s) calc(var(--primary-l) + 10%)
  );

  --button-secondary-high: hsl(var(--bg-h) var(--bg-s) calc(var(--bg-l) - 0%));
  --button-secondary-mid: hsl(var(--bg-h) var(--bg-s) calc(var(--bg-l) - 2%));
  --button-secondary-low: hsl(var(--bg-h) var(--bg-s) calc(var(--bg-l) - 4%));

  --button-danger-high: hsl(var(--danger-h) var(--danger-s) var(--danger-l));
  --button-danger-mid: hsl(
    var(--danger-h) var(--danger-s) calc(var(--danger-l) - 5%)
  );
  --button-danger-low: hsl(
    var(--danger-h) var(--danger-s) calc(var(--danger-l) - 10%)
  );

  --text-muted: hsl(var(--text-h) var(--text-s) calc(var(--text-l) + 25%));
  --border: hsl(var(--primary-h) var(--primary-s) var(--primary-l));
  --shadow: hsl(var(--primary-h) var(--primary-s) var(--primary-l));
}

*,
*:before,
*:after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

.flex {
  display: flex;
}
.flex-row {
  flex-direction: row;
}
.flex-wrap {
  flex-wrap: wrap;
}
.flex-space-between {
  justify-content: space-between;
}

.gap-1 {
  gap: 1rem;
}

body {
  font-family: "Epilogue", "Courier New", monospace;
  font-optical-sizing: auto;
  font-size: 1rem;
  font-weight: 400;
  font-style: normal;

  line-height: 1.5;

  background-color: var(--bg-light);
  color: var(--text-muted);

  margin: 0 auto;
  padding-top: 0.7rem; /* works in conjuction with heading padding to control size when sticky activated */

  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  background-color: var(--bg-light);
  border-bottom: 3px solid var(--border);
  position: sticky;
  top: 0;
  padding: 0.3rem 1rem 0.3rem 1rem;
}
header .inner {
  max-width: 600px;
  margin: 0 auto;
  width: 100%;

  display: flex;
  flex-direction: row;
  justify-content: space-between;
  align-items: center;
}
header h1 {
  font-size: 1rem;
}
header h1 a:hover {
  border-bottom: none;
}
header nav {
  display: flex;
  flex-direction: row;
  gap: 1rem;
}

.main-background {
  background: var(--bg-dark);
  padding-top: 2rem;
}

main {
  max-width: 600px;
  margin: 0 auto;
  width: 100%;
  min-height: 90vh;
  padding: 0 1.5rem 2rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

footer {
  background-color: var(--bg);
  border-top: 3px solid var(--border);
  padding: 1rem 1rem 3rem 1rem;
}

/*
typography
*/
h1,
h2,
h3 {
  color: var(--text);
}
h1 {
  font-size: 2rem;
  text-transform: uppercase;
}
h2 {
  font-size: 1.5rem;
}
h3 {
  font-size: 1rem;
}

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

/*
Link
*/
a {
  text-decoration: none;
  font-weight: 600;
  color: var(--text-muted);
  border-bottom: 2px solid transparent; /*prevent hover from causing layout shift*/
}
a:hover {
  color: var(--text);
  border-bottom: 2px solid var(--text);
}
/* 
section (aka cards)
*/
section {
  background-color: var(--bg);
  border-radius: var(--radius);
  padding: 1rem 2rem 2rem 2rem;
  border: 3px solid var(--border);
  box-shadow: 8px 8px var(--shadow);
}

/*
buttons
*/
button,
input[type="submit"],
a.button {
  line-height: 1.5;
  text-align: center;

  border: 3px solid var(--border);
  padding: 0.5rem 1rem;
  font-size: 1rem;
  font-weight: 500;

  border-radius: var(--radius);
  box-shadow: 0.3rem 0.3rem var(--shadow);

  cursor: pointer;

  transition: box-shadow 0.05s ease-out, transform 0.05s ease-out;

  background-color: var(--button-high);
  color: var(--bg-light);
}

button.secondary,
input[type="submit"].secondary,
a.button.secondary {
  background-color: var(--button-secondary-high);
  color: var(--text);
}

button.danger,
input[type="submit"].danger,
a.button.danger {
  background-color: var(--button-danger-high);
  color: var(--text);
}

button:hover,
input[type="submit"]:hover,
a.button:hover {
  background-color: var(--button-mid);
  box-shadow: 0.15rem 0.15rem var(--shadow);
  transform: translate(0.1rem, 0.1rem);
}
button.secondary:hover,
input[type="submit"].secondary:hover,
a.button.secondary:hover {
  background-color: var(--button-secondary-mid);
}
button.danger:hover,
input[type="submit"].danger:hover,
a.button.danger:hover {
  background-color: var(--button-danger-mid);
}

button:active,
input[type="submit"]:active,
a.button:active {
  background-color: var(--button-low);
  box-shadow: none;
  transform: translate(0.2rem, 0.2rem);
}
button.secondary:active,
input[type="submit"].secondary:active,
a.button.secondary:active {
  background-color: var(--button-secondary-low);
}
button.danger:active,
input[type="submit"].danger:active,
a.button.danger:active {
  background-color: var(--button-danger-low);
}

/*
Lists
*/
ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  padding-left: 0 0.5rem;
}

li {
  font-size: 1.25rem;
  font-weight: 500;
}

li::before {
  content: url("data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIxMiIgaGVpZ2h0PSIxMiIgdmlld0JveD0iMCAwIDE2IDE2Ij48Y2lyY2xlIGN4PSI4IiBjeT0iOCIgcj0iOCIgZmlsbD0iYmxhY2siLz48L3N2Zz4=");
  display: inline-block;
  margin-right: 0.75rem;
  transform: translateY(-0.05rem);
}

li:last-child {
  border-bottom: none;
}

li a {
  color: var(--text);
}

/*
Forms
*/
form {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.form-group-label {
  display: flex;
  flex-direction: row;
  gap: 1rem;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  padding-right: 0.5rem;
}

label {
  font-weight: 600;
  color: var(--text);
}

input[type="text"],
input[type="password"],
input[type="email"],
textarea {
  font-family: inherit;
  font-size: 1rem;
  color: var(--text);
  background-color: var(--bg-light);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  box-shadow: 0.3rem 0.3rem var(--shadow);
  outline: none;
  transition: border-color 0.1s ease-out, box-shadow 0.1s ease-out;
}

input[type="text"]:focus,
input[type="password"]:focus,
input[type="email"]:focus,
textarea:focus {
  box-shadow: 0.2rem 0.2rem var(--shadow);
}

textarea {
  resize: none;
}

.error {
  font-size: 1.2rem;
  color: var(--button-danger-low);
  font-weight: 500;
}

.form-actions {
  display: flex;
  flex-direction: row;
  justify-content: end;
  gap: 2rem;
}

@media (max-width: 600px) {
  .form-actions {
    flex-direction: column;
    justify-content: center;
  }
}

/*
App specifics
*/
.no-items {
  color: var(--primary-500);
  text-align: center;
  padding: 3rem;
}

section h2 {
  font-size: 1rem;
}
section h2:first-of-type {
  margin-bottom: 1rem;
}
.section-subhead {
  display: flex;
  flex-direction: row;
  justify-content: space-between;
  margin-bottom: 1rem;
}
section .section-subhead h2 {
  margin-bottom: 0;
}

li {
  color: var(--text);
}

.history-action {
  padding: 1rem;
  display: flex;
  justify-content: center;
}

.versions {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.version {
  background-color: var(--bg-light);
}
.version .date {
  display: flex;
  flex-direction: row;
  justify-content: end;
  color: var(--text-muted);
  font-size: 0.8rem;
}
.version ul {
  margin-top: -0.25rem; /* share some of the vertical space with date */
}
.version li {
  font-size: 0.8rem;
}

.made-with {
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.made-with p {
  text-align: center;
}