/* ========== Base / Reset ========== */
* { box-sizing: border-box; }
html, body { height: 100%; }
body, h1, h2, h3, p, ul, li { margin: 0; padding: 0; }

body {
  font-family: Arial, Helvetica, sans-serif;
  background: #f9fafb;
  color: #111827;
  line-height: 1.6;
}

.container {
  width: 90%;
  max-width: 1000px;
  margin: 0 auto;
}

/* ========== Header & Navigation ========== */
header {
  background: #0b5bd3;
  color: #fff;
  padding: 16px 0;
}
header h1 { font-size: 1.9rem; }
header .subtitle { margin-top: 4px; color: #dbeafe; font-size: 0.95rem; }

/* Primary nav (desktop default) */
.site-nav { margin-top: 12px; }
.site-nav .menu {
  display: flex;
  gap: 16px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.site-nav .menu > li { position: relative; }

.site-nav a,
.site-nav .dropdown-toggle {
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  padding: 6px 10px;
  display: inline-block;
  border: 0;
  background: transparent;
  cursor: pointer;
}
.site-nav a:visited { color: #fff; }
.site-nav a:hover,
.site-nav a:focus-visible,
.site-nav .dropdown-toggle:hover,
.site-nav .dropdown-toggle:focus-visible { text-decoration: underline; }

.site-nav a.active {
  background: rgba(255,255,255,0.18);
  border-radius: 6px;
}

/* Dropdown panel */
.site-nav .dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 240px;
  list-style: none;
  margin: 6px 0 0 0;
  padding: 6px 0;
  background: #ffffff;
  color: #111827;
  border: 1px solid #e5e7eb;
  border-radius: 10px;
  box-shadow: 0 10px 30px rgba(0,0,0,.15);
  display: none;
  z-index: 1000;
}

/* Show dropdown (desktop hover) and when opened via JS */
.site-nav .dropdown.open .dropdown-menu,
.site-nav .dropdown:hover .dropdown-menu { display: block; }

.site-nav .dropdown-menu a {
  display: block;
  padding: 8px 12px;
  color: #111827;
  text-decoration: none;
  white-space: nowrap;
}
.site-nav .dropdown-menu a:visited { color: #111827; }
.site-nav .dropdown-menu a:hover,
.site-nav .dropdown-menu a:focus-visible { background: #f1f5f9; }

/* ========== Mobile nav toggle (hamburger) ========== */
.navbar {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 10px;
}

.nav-toggle {
  display: none;             /* hidden on desktop */
  background: transparent;
  border: 2px solid #dbeafe;
  color: #fff;
  padding: 6px 10px;
  border-radius: 8px;
  font-weight: 700;
  cursor: pointer;
}

/* ========== Main ========== */
main { padding: 24px 0; }
h2 { margin-bottom: 8px; }
p { margin: 8px 0 16px; }

.assignment-list {
  list-style: decimal;
  padding-left: 18px;
}
.assignment-list li { margin: 14px 0; }
.assignment-list .desc { color: #475569; font-size: 0.95rem; }

/* Buttons */
a.button {
  display: inline-block;
  padding: 8px 12px;
  background: #2563eb;
  color: #fff !important;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 600;
}
a.button:hover { background: #1e40af; }

/* Responsive utility for images */
img.responsive { max-width: 100%; height: auto; display: block; }

/* ========== Footer ========== */
footer {
  background: #0b5bd3;
  color: #fff;
  text-align: center;
  padding: 14px 0;
  margin-top: 24px;
}
footer a { color: #dbeafe; text-decoration: underline; }

/* ========== Mobile styles (≤ 768px) ========== */
@media (max-width: 768px) {
  /* Show the hamburger; collapse the menu into a vertical panel */
  .nav-toggle { display: inline-block; }

  .site-nav .menu {
    display: none;                /* hidden until toggled open */
    flex-direction: column;
    gap: 8px;
    background: #0a4ec1;
    padding: 10px;
    border-radius: 10px;
    margin-top: 8px;
  }
  .site-nav.open .menu { display: flex; }

  /* Make dropdown menus “static” blocks inside the vertical panel */
  .site-nav .dropdown-menu {
    position: static;
    min-width: 0;
    margin: 4px 0 0 0;
    padding: 4px 0;
    border: 1px solid rgba(255,255,255,.25);
    background: #ffffff;
    box-shadow: none;
    border-radius: 8px;
  }
  /* Only show a dropdown when its parent has .open */
  .site-nav .dropdown:not(.open) .dropdown-menu { display: none; }

  /* Make the resource toggle button stand out a bit */
  .site-nav .dropdown-toggle {
    background: rgba(255,255,255,.15);
    border-radius: 6px;
  }
}