/* DATA 3301 course site
   Colors, type, and link treatment mirror www.frank.computer */

:root {
  --navy: #1e3369;
  --navy-mid: #355ab8;
  --ink: #414141;
  --link: #174b3f;
  --mint: #aadbcf;
  --muted: #565656;
  --rule: #c1c1c1;
  --border: #ddd;
  --shade: #f7f8fa;
  --warn: #5b1936;
  --warn-rule: #e7b3cb;
  --gutter: 32px;
}

html,
body {
  width: 100%;
  min-height: 100vh;
  scroll-behavior: smooth;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: "Montserrat", Verdana, -apple-system, BlinkMacSystemFont,
    "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.64;
  color: var(--ink);
  background-color: #fff;
  text-rendering: optimizeLegibility;
  -moz-osx-font-smoothing: grayscale;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "kern" 1;
  box-sizing: border-box;
  margin: 0;
  display: flex;
  flex-direction: column;
}

body,
h1, h2, h3, h4, h5, h6,
p, blockquote, pre, hr, dl, dd, ol, ul, figure {
  margin: 0;
  padding: 0;
}

h1, h2, h3, h4, h5, h6,
p, blockquote, pre, ul, ol, dl, figure, table {
  margin-bottom: 16px;
}

ul, ol {
  margin-left: 32px;
}

strong, b {
  font-weight: 600;
}

/* ---------- links ---------- */

a {
  color: var(--link);
  text-decoration: none;
  background-image: linear-gradient(transparent 85%, var(--mint) 15%);
  background-size: 100% 100%;
  background-repeat: no-repeat;
  background-position: top center;
}

a:hover,
a:focus {
  background-image: linear-gradient(transparent 85%, var(--link) 15%);
  background-size: 100% 110%;
  transition: background-size 0.15s ease-in-out,
    background-image 0.15s ease-in-out;
}

a:focus-visible {
  outline: 3px solid var(--navy-mid);
  outline-offset: 2px;
}

/* ---------- headings ---------- */

h1, h2, h3, h4, h5, h6 {
  margin-top: 1.2rem;
  margin-bottom: 0.6rem;
  color: var(--navy);
  font-weight: 600;
}

h1 {
  font-weight: 900;
  font-size: 2.6rem;
  line-height: 1.15;
  margin-top: 0;
  margin-bottom: 0.4rem;
}

h1 .term {
  display: block;
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--muted);
  letter-spacing: 0.02em;
  margin-top: 0.4rem;
}

h2 {
  font-size: 1.75rem;
  border-bottom: 1px solid var(--rule);
  margin-top: 2.5rem;
  font-weight: 800;
}

h3 {
  font-size: 1.3rem;
  margin-top: 1.8rem;
}

/* ---------- layout ---------- */

.container {
  max-width: 864px;
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.container-wide {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.page-content {
  padding-bottom: 3rem;
  flex: 1 1 auto;
}

@media screen and (max-width: 600px) {
  .container,
  .container-wide {
    padding: 0 16px;
  }
}

/* ---------- header / nav ---------- */

.page-header {
  border-top: 6px solid var(--navy);
  padding-top: 6px;
  margin-bottom: 40px;
}

nav {
  display: flex;
  align-items: center;
  flex-flow: row wrap;
  line-height: 36px;
  justify-content: flex-start;
}

nav .site-title-wrapper {
  margin-right: auto;
}

nav a {
  position: relative;
  color: #333;
  padding: 12px 0.3rem 0 0.3rem;
  margin: 0 0.3rem;
  font-weight: 600;
  opacity: 0.75;
  border-bottom: 2px solid transparent;
  transition: opacity 0.25s ease-in-out;
  background-image: linear-gradient(transparent 80%, var(--mint) 20%);
}

nav a:hover,
nav a:focus {
  background-image: linear-gradient(transparent 90%, var(--mint) 10%);
  background-size: 100% 90%;
  padding-bottom: 0.35rem;
  opacity: 1;
}

nav .site-title {
  font-weight: 900;
  font-size: 1.15rem;
  color: var(--navy);
  opacity: 1;
  margin-left: 0;
  padding-left: 0;
}

@media screen and (max-width: 700px) {
  nav {
    justify-content: flex-start;
  }
  nav .site-title-wrapper {
    flex: 0 1 100%;
  }
  nav a {
    margin: 0 5px;
  }
}

/* ---------- intro block ---------- */

.lead {
  font-size: 1.15rem;
}

.facts {
  list-style: none;
  margin: 0 0 1.5rem 0;
  padding: 0;
}

.facts li {
  margin-bottom: 0.2rem;
}

.facts .label {
  display: inline-block;
  min-width: 7.5rem;
  font-weight: 600;
  color: var(--navy);
}

/* ---------- callouts ---------- */

.note {
  color: var(--navy);
  border-left: 4px solid var(--mint);
  background: var(--shade);
  padding: 12px 16px;
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
}

.note > :last-child {
  margin-bottom: 0;
}

.note.warning {
  color: var(--warn);
  border-left-color: var(--warn-rule);
  background: #fdf6f9;
}

.tbd {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  background: #f1f2f5;
  border: 1px solid #dcdee5;
  border-radius: 3px;
  padding: 0 0.4rem;
  vertical-align: 0.08em;
  white-space: nowrap;
}

/* one-off placeholders in prose stay emphasized; repeated ones in tables recede */
td .tbd,
th .tbd {
  background: transparent;
  border-color: transparent;
  padding: 0;
  font-weight: 400;
}

/* ---------- tables ---------- */

.table-scroll {
  overflow-x: auto;
  margin-bottom: 1.5rem;
  border: 1px solid var(--border);
  border-radius: 3px;
}

.table-scroll:focus-visible {
  outline: 3px solid var(--navy-mid);
  outline-offset: 2px;
}

table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.9rem;
  margin-bottom: 0;
}

caption {
  text-align: left;
  font-size: 0.85rem;
  color: var(--muted);
  padding: 0 0 0.5rem 0;
}

th,
td {
  text-align: left;
  vertical-align: top;
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
}

thead th {
  background: var(--navy);
  color: #fff;
  font-weight: 600;
  border-bottom: none;
  white-space: nowrap;
}

tbody tr:nth-child(even) {
  background: var(--shade);
}

tbody tr:last-child td {
  border-bottom: none;
}

tbody th {
  font-weight: 600;
  color: var(--navy);
  white-space: nowrap;
}

td a,
th a {
  white-space: nowrap;
}

/* schedule-specific */

.schedule thead th[colspan] {
  text-align: center;
  border-left: 1px solid rgba(255, 255, 255, 0.25);
  border-right: 1px solid rgba(255, 255, 255, 0.25);
}

.schedule thead tr:last-child th {
  background: var(--navy-mid);
  font-weight: 400;
  font-size: 0.8rem;
}


.schedule td:empty::after {
  content: "\2013";
  color: #c8c8c8;
}

.schedule .date {
  color: var(--muted);
  white-space: nowrap;
}

.schedule tr.milestone {
  background: #eef2fb !important;
}

.schedule tr.milestone td {
  color: var(--navy);
  font-weight: 600;
}

.schedule tr.milestone td:empty::after {
  content: "";
}

/* ---------- footer ---------- */

footer {
  padding: 32px 0;
  font-size: 0.9rem;
  background-color: var(--navy);
  color: #e6e6e6;
}

footer a {
  color: #fff;
  background-image: linear-gradient(transparent 87%, var(--mint) 13%);
}

footer a:hover,
footer a:focus {
  background-image: linear-gradient(transparent 92%, var(--mint) 8%);
}

footer .container {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
}

footer .footer-col {
  padding: 16px 0;
}

footer .footer-col.wide {
  width: 420px;
}

@media screen and (max-width: 800px) {
  footer .footer-col.wide {
    flex: 1 100%;
  }
}

/* ---------- utility ---------- */

.skip-link {
  position: absolute;
  left: -9999px;
  background: #fff;
  color: var(--navy);
  padding: 10px 16px;
  font-weight: 600;
  z-index: 10;
}

.skip-link:focus {
  left: 8px;
  top: 8px;
}

/* Visually hidden, still announced by screen readers. Modern clip-path
   approach; the :not() guard lets a focusable child reveal itself. */
.visually-hidden:not(:focus):not(:active) {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

@media print {
  .no-print { display: none !important; }
  body { margin: 0; }
  .table-scroll { border: none; overflow: visible; }
}