:root {
  /* Palette */
  --p123-orange: #F68D2C;
  --p123-orange-700: #CF6F13;
  --p123-lightblue: #4A90BF;
  --p123-lightblue-700: #2F6F99;
  --p123-pink: #F92A82;
  --p123-pink-700: #CC1866;
  --p123-darkblue: #323C94;
  --p123-darkblue-800: #222A6F;
  --p123-white: #FFFFFF;

  /* Neutrals & surfaces */
  --p123-ink: #1F2937;
  --p123-muted: #6B7280;
  --p123-paper: #F7FAFC;

  /* Radii & effects */
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --shadow-card: 0 4px 14px rgba(0,0,0,0.08);
  --ring: 0 0 0 4px rgba(74,144,191,.35); /* visible focus ring */
}

/* Global base (keeps navbar untouched) */
body {
  background: linear-gradient(180deg, rgba(74,144,191,.06), rgba(255,255,255,.95) 40%), var(--p123-white);
  color: var(--p123-ink);
  letter-spacing: .1px;
}

/* Page title (scoped to page container to avoid navbar) */
.container .text-center h1 {
  font-weight: 800;
  letter-spacing: .2px;
  color: var(--p123-darkblue);
  margin: 1rem 0 1.25rem;
}

/* Accordion shell */
#accordionExercises {
  margin-top: .5rem;
}
#accordionExercises .card {
  border: 0;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  overflow: hidden;
}
#accordionExercises .card + .card {
  margin-top: .5rem;
}
#accordionExercises .card-header {
  border: 0;
  padding: 0;
}
#accordionExercises .card-header .btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  text-align: left;
  text-decoration: none !important;
  padding: 0.875rem 1rem;
  min-height: 56px; /* >=44px tap target */
  font-weight: 700;
  letter-spacing: .2px;
  border-radius: 0;
  outline: none;
  white-space: normal; /* replaces previous inline style */
}
#accordionExercises .card-header .btn .fa {
  transition: transform .25s ease;
}
#accordionExercises .card-header .btn[aria-expanded="true"] .fa-angle-down {
  transform: rotate(180deg);
}
@media (prefers-reduced-motion: reduce) {
  #accordionExercises .card-header .btn .fa { transition: none; }
}

/* Section header themes (ratio emphasis: orange > lightblue > pink > darkblue/white accents) */
#accordionExercises .lightpurple-card .btn {
  color: var(--p123-white);
  background-color: var(--p123-darkblue);
}

#accordionExercises .deeppurple-card .btn {
  color: var(--p123-white);
  background-color: var(--p123-orange);
}
#accordionExercises .lightpurple-card .btn:hover,
#accordionExercises .deeppurple-card .btn:hover {
  filter: brightness(1.03);
}
#accordionExercises .lightpurple-card .btn:focus,
#accordionExercises .deeppurple-card .btn:focus {
  box-shadow: var(--ring);
}

/* Collapse bodies */  
#accordionExercises .collapse { background: transparent; }
#accordionExercises .card-body {
  background: var(--p123-paper);
  padding: 1rem;
}
#accordionExercises .unset-color { color: inherit; }

/* Inner topic cards */
#accordionExercises .row > [class^="col-"] .card {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}
#accordionExercises .card .card .card-header {
  background: transparent;
  padding: .75rem 1rem .5rem;
  border-bottom: 0;
}
#accordionExercises .card .card .card-body {
  background: transparent;
  padding: .5rem 1rem 1rem;
}

#accordionExercises h4.std5,
#accordionExercises h4.std3,
#accordionExercises h4.std1 {
  display: inline-block;
  margin: 0;
  padding: .4rem .6rem;
  border-radius: 999px;
  font-size: 1rem;
  font-weight: 800;
  color: var(--p123-white);
  letter-spacing: .3px;
  box-shadow: 0 2px 6px rgba(0,0,0,.08);
}       
#accordionExercises h4.std5 { /* primary weight */
  background-image: linear-gradient(135deg, var(--p123-orange), var(--p123-orange-700));
}
#accordionExercises h4.std3 { /* secondary weight */
  background-image: linear-gradient(135deg, var(--p123-lightblue), var(--p123-lightblue-700));
}
#accordionExercises h4.std1 { 
  background-image: linear-gradient(135deg, var(--p123-pink), var(--p123-pink-700));
}

/* Menus/lists */
#accordionExercises .card-body ul {
  margin: 0;
  padding-left: 0;
}
#accordionExercises .card-body li + li { margin-top: .5rem; }
#accordionExercises .card-body a {
  display: block;
  background: var(--p123-white);
  border: 2px solid rgba(74,144,191,.15);
  border-left-width: 6px;
  border-left-color: var(--p123-lightblue);
  border-radius: var(--radius-md);
  padding: .75rem 1rem;
  line-height: 1.3;
  min-height: 44px;
  font-weight: 600;
  letter-spacing: .15px;
  color: var(--p123-darkblue);
  box-shadow: 0 2px 8px rgba(0,0,0,.04);
}
#accordionExercises .card-body a:hover {
  text-decoration: none;
  background: linear-gradient(0deg, rgba(246,141,44,.08), rgba(246,141,44,0));
  border-left-color: var(--p123-orange);
}
#accordionExercises .card-body a:focus {
  outline: 0;
  box-shadow: var(--ring);
}
#accordionExercises .card-body a:active { transform: translateY(1px); }
@media (prefers-reduced-motion: reduce) {
  #accordionExercises .card-body a:active { transform: none; }
}

/* Optional: friendly menu variant */
#accordionExercises .fp-menu a {
  border-left-width: 8px;
}
#accordionExercises .fp-menu li:nth-child(odd) a { border-left-color: var(--p123-lightblue); }
#accordionExercises .fp-menu li:nth-child(even) a { border-left-color: var(--p123-orange); }

/* Focus visibility (scoped) */
#accordionExercises a:focus-visible,
#accordionExercises .btn:focus-visible {
  outline: none;
  box-shadow: var(--ring);
}

/* Mobile tweaks */
@media (max-width: 767.98px) {
  .container .text-center h1 { font-size: 1.5rem; }
  #accordionExercises .card-header .btn {
    padding: 1rem 1rem;
    min-height: 56px;
  }
  #accordionExercises .card-body a {
    padding: .875rem 1rem;
    font-size: 1rem;
  }
  #accordionExercises .card .card .card-body {
    padding-left: .5rem;
    padding-right: .5rem;
  }
}

/* Respect reduced motion */
@media (prefers-reduced-motion: reduce) {
  #accordionExercises * {
    transition: none !important;
    animation: none !important;
  }
}