/* ==========================================================================
   EECS 110 — Discover Computer Science
   One hand-written stylesheet. No frameworks, no CDN, no external fonts.
   Light theme. Left nav (subtle gray) against a white main column.
   ========================================================================== */

:root {
  /* Palette — subtle gray nav, white content, University of Michigan accents */
  --nav-bg:        #eef1f4;   /* subtle gray, clearly lighter than content */
  --nav-border:    #d5dbe1;
  --content-bg:    #ffffff;
  --page-bg:       #eef1f4;

  --text:          #1c2733;   /* near-black, high contrast on white */
  --text-muted:    #55606b;
  --heading:       #00274c;   /* Michigan blue */
  --accent:        #00539c;   /* link blue (accessible on white) */
  --accent-dark:   #003d75;
  --maize:         #ffcb05;   /* used only as an active-state marker, not text */

  --card-border:   #dde2e8;
  --card-shadow:   0 1px 3px rgba(16, 33, 50, 0.08);

  --maxw:          860px;     /* readable measure for the content column */
  --nav-w:         248px;

  --radius:        10px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica,
          Arial, sans-serif;
}

/* --- base ---------------------------------------------------------------- */

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

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

body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.6;
  color: var(--text);
  background: var(--page-bg);
}

a { color: var(--accent); text-decoration: none; }
a:hover, a:focus { color: var(--accent-dark); text-decoration: underline; }

img { max-width: 100%; height: auto; }

h1, h2, h3 { color: var(--heading); line-height: 1.25; }
h1 { font-size: 1.9rem; margin: 0 0 0.4em; }
h2 { font-size: 1.4rem; margin: 1.8em 0 0.6em; }
h3 { font-size: 1.15rem; margin: 1.4em 0 0.4em; }

/* Keyboard-only skip link */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--heading);
  color: #fff;
  padding: 0.6em 1em;
  z-index: 100;
}
.skip-link:focus { left: 0; }

/* Visible focus outline for keyboard users */
a:focus-visible, :focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
}

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

.layout {
  display: flex;
  align-items: stretch;
  min-height: 100vh;
}

.content-col {
  flex: 1 1 auto;
  min-width: 0;                 /* let the column shrink instead of overflow */
  display: flex;
  flex-direction: column;
  background: var(--content-bg);
}

.site-main {
  flex: 1 0 auto;
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 2.2rem 2rem 2.5rem;
}

/* --- left navigation ----------------------------------------------------- */

.site-nav {
  flex: 0 0 var(--nav-w);
  background: var(--nav-bg);
  border-right: 1px solid var(--nav-border);
  padding: 1.6rem 1.25rem;
  position: sticky;
  top: 0;
  align-self: flex-start;
  height: 100vh;
  overflow-y: auto;
}

.nav-logo { display: inline-block; margin-bottom: 0.75rem; }

.nav-title {
  display: block;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--heading);
  letter-spacing: 0.01em;
}
.nav-title:hover, .nav-title:focus { text-decoration: none; }

.nav-subtitle {
  margin: 0.15rem 0 1.4rem;
  font-size: 0.98rem;
  color: var(--text-muted);
}

.nav-links {
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-links li { margin: 0; }

.nav-links a {
  display: block;
  padding: 0.6rem 0.75rem;
  margin: 0.15rem 0;
  border-radius: 8px;
  border-left: 4px solid transparent;
  color: var(--text);
  font-size: 1.05rem;          /* comfortably sized nav font */
  font-weight: 500;
}
.nav-links a:hover, .nav-links a:focus {
  background: #e2e7ee;
  text-decoration: none;
}
.nav-links a[aria-current="page"] {
  background: #e2e7ee;
  border-left-color: var(--maize);
  color: var(--heading);
  font-weight: 700;
}

/* --- home banner + header ------------------------------------------------ */

.banner {
  margin: -2.2rem -2rem 1.5rem;   /* bleed to the edges of the content column */
}
.banner img {
  display: block;
  width: 100%;
  height: 180px;                  /* slim */
  object-fit: cover;
}

.page-header { margin-bottom: 0.5rem; }
.page-header .tagline {
  font-size: 1.2rem;
  color: var(--text-muted);
  margin-top: 0.2rem;
}

/* Small meta line (term · meeting time · location) */
.course-meta {
  font-size: 0.98rem;
  color: var(--text-muted);
  margin: 0.4rem 0 0;
}
.course-meta span + span::before { content: " · "; }

/* --- generic content bits ------------------------------------------------ */

.lead { font-size: 1.1rem; }

hr {
  border: 0;
  border-top: 1px solid var(--card-border);
  margin: 2rem 0;
}

/* Weekly-rhythm "at a glance" list */
.rhythm {
  list-style: none;
  padding: 0;
  margin: 0.5rem 0 0;
  display: grid;
  gap: 0.5rem;
}
.rhythm li {
  background: var(--nav-bg);
  border: 1px solid var(--card-border);
  border-radius: 8px;
  padding: 0.7rem 1rem;
}

/* --- cards (staff, links, resources) ------------------------------------- */

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 1rem;
  margin: 1rem 0;
  padding: 0;
  list-style: none;
}

.card {
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  padding: 1.1rem 1.2rem;
  background: #fff;
}
.card h3 { margin: 0 0 0.3rem; }
.card p  { margin: 0.3rem 0 0; }
.card .note { color: var(--text-muted); font-size: 0.95rem; }
.card .todo { color: var(--text-muted); font-style: italic; }

/* Link cards show the URL state clearly */
.link-card .pending {
  color: var(--text-muted);
  font-style: italic;
  font-size: 0.95rem;
}

/* --- staff: full-width two-column cards ---------------------------------- */

.staff-list {
  list-style: none;
  margin: 1.3rem 0;
  padding: 0;
  display: grid;
  gap: 1.3rem;
}

.staff-card {
  display: flex;
  gap: 1.6rem;
  padding: 1.5rem 1.6rem;
  text-align: left;
}

/* Left column: photo, meta lines, emoji row — centered within a fixed track. */
.staff-card__aside {
  flex: 0 0 180px;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}
.staff-card__main { flex: 1 1 auto; min-width: 0; }

.staff-photo {
  width: 120px;
  height: 120px;
  object-fit: cover;
  border-radius: 50%;
  margin: 0 0 0.7rem;
  display: block;
  background: var(--nav-bg);
}
/* Shown instead of a photo when a card has none: a neutral initial avatar. */
.staff-photo--placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.6rem;
  font-weight: 700;
  color: #8a96a3;
  background: var(--nav-bg);
  border: 1px solid var(--card-border);
  text-transform: uppercase;
}

/* Three lighter-gray meta lines under the photo */
.staff-meta {
  list-style: none;
  margin: 0.1rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.25rem;
  font-size: 0.9rem;
  color: var(--text-muted);
  word-break: break-word;
}

/* Emoji reveal row */
.staff-reveals {
  list-style: none;
  margin: 0.85rem 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.4rem;
}
.staff-reveals li { margin: 0; }

/* Each reveal is a focusable button; its text shows on hover/focus (CSS tip)
   and is always available to screen readers via aria-label on the button. */
.reveal {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  padding: 0;
  font-size: 1.25rem;
  line-height: 1;
  background: #fff;
  border: 1px solid var(--card-border);
  border-radius: 9px;
  cursor: pointer;
}
.reveal:hover, .reveal:focus-visible {
  background: var(--nav-bg);
  border-color: var(--accent);
}
.reveal__tip {
  position: absolute;
  bottom: calc(100% + 9px);
  left: 50%;
  transform: translateX(-50%);
  width: max-content;
  max-width: min(240px, 72vw);
  padding: 0.5rem 0.7rem;
  background: var(--heading);
  color: #fff;
  font-size: 0.85rem;
  line-height: 1.35;
  text-align: left;
  border-radius: 8px;
  box-shadow: 0 4px 14px rgba(16, 33, 50, 0.28);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.12s ease;
  pointer-events: none;
  z-index: 20;
}
/* Little downward caret under the tip */
.reveal__tip::after {
  content: "";
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  border: 6px solid transparent;
  border-top-color: var(--heading);
}
.reveal:hover .reveal__tip,
.reveal:focus .reveal__tip,
.reveal:focus-within .reveal__tip {
  opacity: 1;
  visibility: visible;
}

/* Name / role badge / bio (right column) */
.staff-card__name { margin: 0; font-size: 1.4rem; }
.staff-card .role {
  display: inline-block;
  margin: 0.35rem 0 0.7rem;
  padding: 0.2rem 0.65rem;
  background: var(--nav-bg);
  border: 1px solid var(--card-border);
  border-radius: 999px;
  color: var(--accent);
  font-weight: 600;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.staff-card .blurb { color: var(--text); }
.staff-card .blurb p { margin: 0.7rem 0; }
.staff-card .blurb p:first-child { margin-top: 0; }
.staff-card .blurb p:last-child { margin-bottom: 0; }

/* --- home: syllabus call-out card ---------------------------------------- */

.syllabus-card {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  margin: 1.4rem 0;
  padding: 1.05rem 1.2rem;
  background: #f6fafd;
  border: 1px solid var(--card-border);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
}
.syllabus-card__title { font-size: 1.1rem; font-weight: 700; color: var(--heading); }
.syllabus-card__note { color: var(--text-muted); font-size: 0.95rem; }
.syllabus-card--pending .syllabus-card__note { font-style: italic; }

/* Past-syllabi disclosure — reuses the FAQ +/– summary marker for consistency. */
.syllabus-past { margin-top: 0.6rem; }
.syllabus-past > summary {
  display: inline-flex;
  gap: 0.5rem;
  align-items: center;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--accent);
  cursor: pointer;
  list-style: none;
}
.syllabus-past > summary::-webkit-details-marker { display: none; }
.syllabus-past > summary::before {
  content: "+";
  font-weight: 700;
  color: var(--accent);
}
.syllabus-past[open] > summary::before { content: "\2013"; }
.syllabus-btns {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.7rem;
}
.syllabus-btn {
  display: inline-block;
  padding: 0.35rem 0.8rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent);
  background: #fff;
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
}
.syllabus-btn:hover, .syllabus-btn:focus {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  text-decoration: none;
}

/* --- schedule: weekly calendar ------------------------------------------- */

/* Three calendar categories, each a light background + darker left border + dark
   ink (all high-contrast, none red). Green = Class, blue = Office hours,
   amber = Deadline. The left border + printed category word carry the meaning
   too, so color is never the only signal. */
.pill--class        { --pill-bg: #daf0e4; --pill-line: #1c8f5a; --pill-ink: #0d5233; }
.pill--office_hours { --pill-bg: #dbe7f3; --pill-line: #00539c; --pill-ink: #00274c; }
.pill--deadline     { --pill-bg: #fbeecb; --pill-line: #b07d06; --pill-ink: #664700; }

.cal-legend {
  list-style: none;
  margin: 1.1rem 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.1rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}
.cal-legend li { display: flex; align-items: center; gap: 0.4rem; }
.pill-swatch {
  width: 14px;
  height: 14px;
  border-radius: 4px;
  background: var(--pill-bg);
  border-left: 4px solid var(--pill-line);
}

.cal-grid {
  list-style: none;
  margin: 1.2rem 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.8rem;
}
.cal-day { display: flex; flex-direction: column; padding: 0.85rem 0.85rem 1rem; }
.cal-day__name {
  margin: 0 0 0.6rem;
  padding-bottom: 0.4rem;
  font-size: 1rem;
  border-bottom: 1px solid var(--card-border);
}
.cal-events { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.5rem; }

.cal-pill {
  display: flex;
  flex-direction: column;
  padding: 0.45rem 0.6rem;
  background: var(--pill-bg);
  color: var(--pill-ink);
  border-left: 4px solid var(--pill-line);
  border-radius: 6px;
}
.cal-pill__time { font-size: 0.8rem; font-weight: 600; }
.cal-pill__label { font-weight: 600; }
.cal-pill__type {
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  opacity: 0.75;
}

.cal-note { margin-top: 1.4rem; }

/* --- FAQ accordions ------------------------------------------------------ */

.faq { display: grid; gap: 0.6rem; margin: 1.3rem 0; }
.faq-item {
  background: #fff;
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  overflow: hidden;
}
.faq-item > summary {
  display: flex;
  gap: 0.6rem;
  align-items: flex-start;
  padding: 0.9rem 1.1rem;
  font-weight: 600;
  color: var(--heading);
  cursor: pointer;
  list-style: none;
}
.faq-item > summary::-webkit-details-marker { display: none; }
.faq-item > summary::before {
  content: "+";
  flex: 0 0 auto;
  font-weight: 700;
  color: var(--accent);
}
.faq-item[open] > summary::before { content: "\2013"; }
.faq-item > summary:hover { background: var(--nav-bg); }
.faq-answer { padding: 0.1rem 1.1rem 1.05rem 2.35rem; }
.faq-answer > :first-child { margin-top: 0; }
.faq-answer > :last-child { margin-bottom: 0; }

/* --- academic-integrity policy page -------------------------------------- */

.policy > :first-child { margin-top: 0; }

/* --- home: grading table ------------------------------------------------- */

.table-wrap { overflow-x: auto; margin: 1rem 0; }
.table-wrap table {
  border-collapse: collapse;
  width: 100%;
  min-width: 34rem;              /* scrolls inside .table-wrap on a phone */
  font-size: 0.96rem;
}
.table-wrap th, .table-wrap td {
  border: 1px solid var(--card-border);
  padding: 0.55rem 0.7rem;
  text-align: left;
  vertical-align: top;
}
.table-wrap thead th { background: var(--nav-bg); color: var(--heading); }
.table-wrap th:nth-child(2), .table-wrap td:nth-child(2) {
  text-align: right;
  white-space: nowrap;
}

/* --- resources: filterable Python directory ------------------------------ */

.pyres { margin: 1.2rem 0; }

.pyres-filters { display: grid; gap: 1rem; margin-bottom: 1rem; }

.pyres-search label {
  display: block;
  font-weight: 600;
  font-size: 0.92rem;
  margin-bottom: 0.3rem;
  color: var(--heading);
}
.pyres-search input {
  width: 100%;
  padding: 0.5rem 0.7rem;
  border: 1px solid var(--card-border);
  border-radius: 8px;
  font: inherit;
  background: #fff;
}

.pyres-facet {
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 0.6rem 0.9rem 0.8rem;
}
.pyres-facet legend {
  font-weight: 600;
  font-size: 0.92rem;
  color: var(--heading);
  padding: 0 0.3rem;
}
.pyres-facet label {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin: 0.25rem 0.9rem 0.25rem 0;
  font-size: 0.9rem;
}
.pyres-facet input { flex: 0 0 auto; }

#pyres-clear {
  justify-self: start;
  padding: 0.45rem 0.9rem;
  background: #fff;
  border: 1px solid var(--card-border);
  border-radius: 8px;
  font: inherit;
  color: var(--accent);
  font-weight: 600;
  cursor: pointer;
}
#pyres-clear:hover, #pyres-clear:focus { background: var(--nav-bg); }

.pyres-count { color: var(--text-muted); font-size: 0.9rem; margin: 0 0 1rem; }

.pyres-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.7rem; }
.pyres-card {
  background: #fff;
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  padding: 0.8rem 1rem;
}
.pyres-card[hidden] { display: none; }
.pyres-card__title { font-weight: 600; }
.pyres-card__tags {
  margin: 0.45rem 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  align-items: center;
}
.pyres-badge {
  background: var(--heading);
  color: #fff;
  border-radius: 999px;
  padding: 0.12rem 0.6rem;
  font-size: 0.72rem;
  font-weight: 600;
}
.pyres-tag {
  background: var(--nav-bg);
  border: 1px solid var(--card-border);
  color: var(--text-muted);
  border-radius: 999px;
  padding: 0.12rem 0.6rem;
  font-size: 0.72rem;
}
.pyres-empty { color: var(--text-muted); font-style: italic; }

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

.site-footer {
  flex-shrink: 0;
  border-top: 1px solid var(--card-border);
  padding: 1.4rem 2rem;
  max-width: var(--maxw);
  width: 100%;
  margin: 0 auto;
  color: var(--text-muted);
  font-size: 0.9rem;
}
.site-footer p { margin: 0.3rem 0; }
.footer-copy { font-weight: 600; color: var(--text); }

/* --- responsive: stack the nav on top on narrow screens ------------------ */

@media (max-width: 720px) {
  .layout { flex-direction: column; }

  .site-nav {
    flex-basis: auto;
    width: 100%;
    height: auto;
    position: static;
    border-right: 0;
    border-bottom: 1px solid var(--nav-border);
    padding: 1rem 1.1rem;
  }
  .nav-subtitle { margin-bottom: 0.8rem; }
  .nav-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem;
  }
  .nav-links a { border-left: 0; border-bottom: 4px solid transparent; }
  .nav-links a[aria-current="page"] {
    border-left: 0;
    border-bottom-color: var(--maize);
  }

  .site-main { padding: 1.5rem 1.1rem 2rem; }
  .banner { margin: -1.5rem -1.1rem 1.2rem; }
  .banner img { height: 130px; }
  .site-footer { padding: 1.2rem 1.1rem; }

  /* Calendar: stack the five day-columns vertically. */
  .cal-grid { grid-template-columns: 1fr; }

  /* Staff: stack the two columns (photo/meta/emoji on top, name/bio below). */
  .staff-card { flex-direction: column; gap: 1rem; }
  .staff-card__aside { flex-basis: auto; }
}