/* ===== Simple color scheme: change these and the whole page updates ===== */
:root {
  --bg: #f5f6f7;        /* page background */
  --card: #ffffff;      /* box background */
  --text: #222222;      /* main text */
  --muted: #6b7075;     /* secondary text */
  --accent: #2f5d62;    /* header, links, hover */
  --border: #d9dcde;    /* box borders */
}

body {
  margin: 0;
  padding: 0 0 70px; /* room so the footer never covers content */
  font-family: Arial, sans-serif;
  background-color: var(--bg);
  color: var(--text);
}

/* Header + nav */
.sticky-header {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  padding: 10px 20px;
  background-color: var(--accent);
  color: #fff;
}

.sticky-header h1 {
  margin: 0;
  font-size: 18px;
}

nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

nav li {
  display: inline;
  margin-left: 20px;
}

nav a,
nav a:visited {
  color: #fff;
  text-decoration: none;
  font-weight: bold;
  font-size: 14px;
}

nav a:hover {
  text-decoration: underline;
}

/* Intro text */
.intro {
  max-width: 720px;
  margin: 30px auto 10px;
  padding: 0 20px;
}

.intro h2 {
  font-size: 20px;
  margin-bottom: 10px;
}

p {
  font-size: 14px;
  line-height: 1.5;
}

/* Assignment boxes */
.box-container {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  max-width: 1000px;
  margin: 20px auto;
  padding: 0 10px;
}

.box {
  width: 200px;
  min-height: 130px;
  background-color: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.08);
  padding: 20px;
  margin: 10px;
  text-align: center;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.box:hover {
  border-color: var(--accent);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.box h2 {
  margin: 0 0 8px;
  font-size: 16px;
}

.box p {
  margin: 0 0 12px;
  color: var(--muted);
}

/* Links */
a:link {
  color: var(--accent);
  text-decoration: none;
}

a:visited {
  color: var(--muted);
}

a:hover {
  text-decoration: underline;
}

.box a {
  font-weight: bold;
  font-size: 14px;
}

/* Footer */
footer {
  position: fixed;
  left: 0;
  bottom: 0;
  width: 100%;
  padding: 10px 0;
  text-align: center;
  font-size: 13px;
  color: var(--muted);
  background-color: var(--card);
  border-top: 1px solid var(--border);
}