/* ---- Tokens ---------------------------------------------------------- */

:root {
  --ink: #212529;
  --muted: #6c757d;
  --surface: #FFFFFF;
  --blue: #0d6efd;
  --info: #17a2b8;
  --red: #dc3545;
  --yellow: #ffc107;
  --green: #198754;

  --radius: 0.5rem;
  --radius-lg: 1rem;
  --shadow-sm: 0 2px 6px rgba(0, 0, 0, 0.06);
  --shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.1);
  --shadow-hover: 0 0.75rem 1.5rem rgba(0, 0, 0, 0.14);
}

/* ---- Base / typography ------------------------------------------------ */

body {
  background-color: #74EBD5;
  background-image: linear-gradient(135deg, #74EBD5 0%, #9FACE6 100%);
  background-attachment: fixed;
  min-height: 100vh;
  color: var(--ink);
}

h1, h2, h3, h4, h5, h6, .h1, .h2, .h3, .h4, .h5, .h6,
.display-4, .lead, .card-title {
  color: var(--ink);
}

a {
  color: var(--blue);
}
a:hover {
  color: #0a58ca;
}

body > .container .text-muted,
body > .container-fluid .text-muted {
  color: var(--ink);
  font-weight: 500;
}

.mono {
  font-family: ui-monospace, "SFMono-Regular", monospace;
}

/* ---- Navbar ------------------------------------------------------------ */

.navbar.bg-dark {
  background-color: rgba(255, 255, 255, 0.9) !important;
  box-shadow: var(--shadow-sm);
}
.navbar-dark .navbar-brand,
.navbar-dark .navbar-brand:hover,
.navbar-dark .navbar-brand:focus {
  color: var(--ink);
  font-weight: 600;
}
.navbar-dark .navbar-nav .nav-link {
  color: var(--muted);
}
.navbar-dark .navbar-nav .nav-link:hover {
  color: var(--ink);
}
.navbar-dark .navbar-text {
  color: var(--muted);
  font-size: 0.85rem;
}
.navbar-dark .btn-outline-light {
  border-color: var(--muted);
  color: var(--muted);
}
.navbar-dark .btn-outline-light:hover {
  background-color: var(--ink);
  border-color: var(--ink);
  color: #fff;
}

main.container {
  max-width: 900px;
}

/* ---- Buttons ------------------------------------------------------------ */

.btn {
  border-radius: var(--radius);
  font-weight: 500;
  transition: transform 0.08s ease, box-shadow 0.08s ease;
}
.btn:hover:not(:disabled), .btn:focus:not(:disabled) {
  box-shadow: var(--shadow-sm);
}

.btn-outline-primary {
  color: var(--info);
  border-color: var(--info);
}
.btn-outline-primary:hover, .btn-outline-primary:focus {
  background-color: var(--info);
  border-color: var(--info);
  color: #fff;
}

.choice-btn {
  font-size: 1.1rem;
  text-align: left;
  margin-bottom: 0.5rem;
  border-radius: var(--radius);
}

/* ---- Cards / panels ------------------------------------------------------ */

.card {
  border: 1px solid #dee2e6;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  background-color: var(--surface);
  overflow: hidden;
}
.card.h-100:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.panel-blue, .panel-yellow {
  border: none;
}
.panel-blue h2, .panel-blue p, .panel-yellow h2, .panel-yellow p {
  color: var(--ink);
}
.panel-blue .text-muted, .panel-yellow .text-muted {
  color: rgba(33, 37, 41, 0.65) !important;
}

.panel-blue {
  background-color: #cfe2ff;
  border-left: 4px solid var(--blue);
}

.panel-yellow {
  background-color: #fff3cd;
  border-left: 4px solid var(--yellow);
}

/* ---- Badges -------------------------------------------------------------- */

.badge {
  border-radius: 50rem;
  font-weight: 500;
  padding: 0.4em 0.7em;
}

.badge-success {
  background-color: #d1e7dd;
  color: #0f5132;
}
.badge-warning {
  background-color: #fde2e1;
  color: #842029;
}
.badge-secondary {
  background-color: #e9ecef;
  color: var(--muted);
}

/* ---- Block meter (signature component) ----------------------------------- */

.meter {
  display: inline-flex;
  gap: 3px;
  vertical-align: middle;
}
.meter-segment {
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 50%;
  background-color: #e9ecef;
  flex: none;
}
.meter-segment--filled {
  background-color: var(--green);
}
.meter--sm .meter-segment {
  width: 0.4rem;
  height: 0.4rem;
}
.meter--lg .meter-segment {
  width: 0.7rem;
  height: 0.7rem;
}

/* ---- Session / exercise runner -------------------------------------------- */

.progress {
  height: 8px;
  border-radius: 50rem;
  background-color: rgba(255, 255, 255, 0.5);
  overflow: hidden;
}
#session-progress {
  background-color: var(--info) !important;
  transition: width 0.2s ease;
}

#exercise.card {
  box-shadow: var(--shadow);
  border-radius: var(--radius-lg);
}
#exercise .card-body {
  padding: 2.5rem 2rem;
}

#exercise-instruction {
  font-size: 0.8rem;
  color: var(--muted);
}

#exercise-prompt {
  font-weight: 600;
  word-break: break-word;
}

#feedback-example {
  font-style: italic;
}

.choice-key {
  display: inline-block;
  min-width: 1.4em;
  padding: 0.05em 0.5em;
  font-size: 0.8rem;
  color: var(--muted);
  background-color: #f1f3f5;
  border-radius: 50rem;
}

#typing-input.form-control {
  border-radius: var(--radius);
  font-size: 1.25rem;
}
#typing-input.form-control:focus {
  border-color: var(--info);
  box-shadow: 0 0 0 0.2rem rgba(23, 162, 184, 0.25);
}

#feedback-verdict {
  display: inline-block;
  font-weight: 600;
  padding: 0.35rem 1rem;
  border-radius: 50rem;
}
#feedback-verdict.text-success {
  background-color: #d1e7dd !important;
  color: #0f5132 !important;
}
#feedback-verdict.text-danger {
  background-color: #fde2e1 !important;
  color: #842029 !important;
}

#feedback-your-answer.text-danger {
  text-decoration: line-through;
}

.spinner-border.text-primary {
  color: var(--info) !important;
}

/* ---- Reorder tiles (grammar) ---------------------------------------------- */

#reorder-answer, #reorder-bank {
  border: 1px solid #dee2e6;
  border-radius: var(--radius);
  background-color: #f8f9fa;
}
.reorder-bank-tile, .reorder-picked {
  border-radius: 50rem;
  font-weight: 500;
}
.reorder-picked {
  background-color: var(--info);
  color: #fff;
  border-color: var(--info);
}

/* ---- Chunk fill-in-the-blank ------------------------------------------ */

.chunk-fill-text {
  line-height: 2.75rem;
}
.chunk-blank-input {
  width: 8rem;
  display: inline-block;
  border-radius: var(--radius);
  text-align: center;
  vertical-align: baseline;
}
.chunk-blank-input:focus {
  border-color: var(--info);
  box-shadow: 0 0 0 0.2rem rgba(23, 162, 184, 0.25);
}

/* ---- Grammar explanation content ------------------------------------------ */

.explanation-content {
  line-height: 1.65;
}
.explanation-content h1, .explanation-content h2, .explanation-content h3 {
  border-bottom: 2px solid #dee2e6;
  padding-bottom: 0.25rem;
  margin-top: 1.5rem;
}
.explanation-content p {
  margin-bottom: 1rem;
}
.explanation-content ul, .explanation-content ol {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}
.explanation-content em {
  color: var(--blue);
  font-style: italic;
}
.explanation-content table.table-bordered th,
.explanation-content table.table-bordered td {
  border: 1px solid #ced4da;
  padding: 0.5rem 0.75rem;
}
.explanation-content table.table-bordered tbody td,
.explanation-content table.table-bordered tbody th {
  color: var(--ink);
}
.explanation-content table thead th {
  background-color: #495057;
  color: #fff;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.explanation-content table tbody tr:nth-child(even) {
  background-color: #f1f3f5;
}

/* ---- Lists ----------------------------------------------------------------- */

.list-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.list-group-item {
  border: 1px solid #dee2e6;
  border-radius: var(--radius) !important;
  margin-bottom: 0;
}
.lesson-ordinal {
  color: var(--info);
  font-weight: 600;
}

/* ---- Login page -------------------------------------------------------------- */

.login-card {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.login-card::before {
  content: "";
  display: block;
  height: 8px;
  background: linear-gradient(90deg, #74EBD5 0%, #9FACE6 100%);
}
.form-control {
  border-radius: var(--radius);
}
.form-control:focus {
  border-color: var(--info);
  box-shadow: 0 0 0 0.2rem rgba(23, 162, 184, 0.25);
}
.alert-danger {
  border: none;
  border-radius: var(--radius);
  background-color: #fde2e1;
  color: #842029;
}