/* External stylesheet for Lab 3 */

body {
  background-color: #f5f5f5;
  color: #222;
  font-family: Arial, sans-serif;
}

h1 {
  color: navy;
}

section {
  background-color: white;
}

/* Lab 3 stylesheet */
/* comment example */

:root {
  --main-text: #1f2937;
  --card-bg: #ffffff;
  --accent: rgb(59, 130, 246);
  --soft-bg: hsl(210, 40%, 96%);
  --highlight: orange;
  --fallback-demo: var(--undefined-color, #6b7280);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background-color: var(--soft-bg);
  color: var(--main-text, black);
  font-family: Arial, sans-serif;
}

header {
  background-color: #dbeafe;
  color: navy;
  text-align: center;
  padding: 16px 12px;
}

h1,
h2 {
  text-decoration: underline;
}

main {
  width: 90%;
  max-width: 960px;
  min-width: 320px;
  margin: auto;
}

section.card {
  background-color: var(--card-bg);
  color: var(--fallback-demo);
  border-style: solid;
  border-color: #cbd5e1;
  border-width: 2px;
  border-radius: 12px;
  margin: 16px 0 20px 0;
  padding: 16px 20px 16px 20px;
  padding-bottom: 24px;
}

nav {
  background-color: rgba(30, 41, 59, 0.9);
  padding: 10px;
  text-align: center;
}

nav a {
  color: white;
  text-decoration: none;
  margin: 0 8px;
  display: inline-block;
}

nav a:hover {
  color: var(--highlight);
}

nav a:active {
  color: #f87171;
}

p {
  line-height: 1.6;
}

.highlight {
  color: hsl(340, 82%, 52%);
  background-color: #fef3c7;
}

#important-note {
  background-color: rgb(220, 252, 231);
}

input[type="text"] {
  border: 1px solid #94a3b8;
  padding: 8px;
}

section p {
  text-align: left;
}

section > ul {
  background-color: #f8fafc;
}

h2 + p {
  font-style: italic;
}

h2 ~ ul {
  border-left: 4px solid #93c5fd;
  padding-left: 1rem;
}

footer {
  background-color: color-mix(in srgb, white 70%, skyblue 30%);
  text-align: center;
  padding: 1rem;
}

.color-wide {
  color: color(display-p3 0.2 0.4 0.8 / 1);
}

/* display examples */
.hidden-note {
  display: none;
}

.inline-tag {
  display: inline;
}

.inline-block-box {
  display: inline-block;
  width: 120px;
  height: 40px;
  background-color: #e0e7ff;
  text-align: center;
  padding-top: 10px;
}

.block-box {
  display: block;
  width: 100%;
}

/* position examples */
.relative-box {
  position: relative;
  left: 0.5rem;
}

.sticky-title {
  position: sticky;
  top: 0;
  background-color: white;
}

.fixed-help {
  position: fixed;
  right: 16px;
  bottom: 16px;
  background-color: #2563eb;
  color: white;
  padding: 10px 12px;
  border-radius: 999px;
}

/* flexbox */
.flex-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  flex-direction: row;
}

.flex-item {
  background-color: #e2e8f0;
  padding: 1rem;
  width: 10rem;
}

/* grid */
.grid-container {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 12px;
  place-items: stretch;
  grid-template-rows: auto;
}

.grid-item {
  background-color: #d1fae5;
  padding: 1rem;
}

/* :has() selector */
form:has(input:focus) {
  background-color: #eff6ff;
  border: 2px solid #60a5fa;
}

/* nested selector */
.info-box {
  background-color: #f1f5f9;
  padding: 1rem;

  & h3 {
    color: #0f172a;
    margin-bottom: 0.5rem;
  }

  & p {
    margin-top: 0;
  }
}

/* relative + absolute units */
.units-demo {
  font-size: 1.2rem;
  margin-top: 2em;
  width: 80%;
  border-width: 2px;
}

.absolute-demo {
  width: 200px;
  height: 120px;
  margin-left: 10mm;
  padding-top: 12pt;
  background-color: #fde68a;
}

/* media query */
@media (max-width: 768px) {
  body {
    font-size: 0.95rem;
  }

  .grid-container {
    grid-template-columns: 1fr;
  }

  .flex-container {
    flex-direction: column;
    align-items: stretch;
  }

  nav a {
    display: block;
    margin: 8px 0;
  }
}