/* -------------------------------------------------
   HKU Co-Learning KBot
   HKU Moodle-inspired student interface
-------------------------------------------------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

:root {
  --hku-teal: #008f7a;
  --hku-teal-dark: #006f62;
  --hku-teal-soft: #e7f5f1;
  --hku-navy: #273442;
  --hku-orange: #f04b2f;
  --page-bg: #f5f7f7;
  --surface: #ffffff;
  --border: #d8e3e0;
  --text: #263330;
  --muted: #65736f;
  --success: #16845b;
  --danger: #d6454f;
  --warning: #a36f00;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Inter', Arial, Helvetica, sans-serif;
  background: var(--page-bg);
  color: var(--text);
  line-height: 1.55;
  font-size: 15px;
}

button, input, select, textarea {
  font: inherit;
}

a {
  color: var(--hku-teal-dark);
}

.app-container,
.auth-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ---------- HKU / ECE masthead ---------- */
.main-header {
  background: var(--surface);
  border-bottom: 5px solid var(--hku-teal);
  padding: 0.75rem 2rem;
  min-height: 92px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1.5rem;
}

.auth-header {
  width: 100%;
}

.hku-brand {
  display: flex;
  align-items: center;
  gap: 1rem;
  min-width: 0;
}

.brand-logos {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  min-width: 0;
}

.hku-crest {
  width: 54px;
  height: 62px;
  object-fit: cover;
  object-position: center;
  border-radius: 2px;
}

.logo-divider {
  width: 1px;
  height: 50px;
  background: var(--border);
  flex: 0 0 auto;
}

.ece-logo {
  width: 250px;
  height: 76px;
  object-fit: contain;
  object-position: left center;
  background: #fff;
}

.brand-copy {
  display: flex;
  flex-direction: column;
  border-left: 1px solid var(--border);
  padding-left: 1rem;
  min-width: 220px;
}

.brand-kicker {
  color: var(--muted);
  text-transform: uppercase;
  font-size: 0.67rem;
  font-weight: 600;
  letter-spacing: 0.09em;
}

.brand-name {
  color: var(--hku-navy);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  white-space: nowrap;
}

.header-info {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  justify-content: flex-end;
  flex-wrap: wrap;
}

.header-info > div,
.header-link,
.icon-btn {
  border: 1px solid var(--border);
  background: #f7faf9;
  color: var(--text);
  padding: 0.42rem 0.7rem;
  border-radius: 4px;
  font-size: 0.76rem;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  text-decoration: none;
}

.header-info i,
.header-link i {
  color: var(--hku-teal-dark);
}

.user-info {
  background: var(--hku-teal-soft) !important;
  color: var(--hku-teal-dark) !important;
}

.header-link:hover {
  background: var(--hku-teal-soft);
  border-color: #a9d7cd;
}

.icon-btn {
  cursor: pointer;
  min-width: 36px;
  justify-content: center;
}

.icon-btn:hover {
  background: #eef5f3;
}

/* ---------- Moodle-like page structure ---------- */
.quiz-main,
.history-main {
  max-width: 1180px;
  margin: 2rem auto;
  padding: 0 1.5rem;
  width: 100%;
  flex: 1;
}

.page-heading {
  background: #fff;
  border: 1px solid var(--border);
  border-left: 5px solid var(--hku-teal);
  padding: 1.25rem 1.5rem;
  margin-bottom: 1rem;
}

.page-eyebrow {
  color: var(--hku-teal-dark);
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.page-heading h1 {
  color: var(--hku-navy);
  font-size: 1.75rem;
  margin: 0.1rem 0 0.25rem;
}

.page-heading p {
  color: var(--muted);
  font-size: 0.9rem;
}

.quiz-card,
.history-card,
.auth-card,
.setup-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(39, 52, 66, 0.06);
}

.quiz-card {
  padding: 1.5rem;
}

/* ---------- Auth / setup ---------- */
.auth-page,
.setup-page {
  min-height: 100vh;
  background: var(--page-bg);
}

.auth-main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 3rem 1rem;
}

.auth-container,
.setup-container {
  width: 100%;
  max-width: 500px;
}

.auth-card,
.setup-card {
  padding: 2rem 2.1rem;
  text-align: left;
}

.section-marker {
  width: 54px;
  height: 5px;
  background: var(--hku-teal);
  margin-bottom: 1rem;
}

.auth-card h1,
.setup-card h2 {
  color: var(--hku-navy);
  font-size: 1.7rem;
  font-weight: 700;
  margin-bottom: 0.35rem;
}

.tagline {
  color: var(--muted);
  margin-bottom: 1.5rem;
  font-size: 0.9rem;
}

.field-label,
.select-group label {
  display: block;
  margin-bottom: 0.35rem;
  font-weight: 600;
  font-size: 0.82rem;
  color: #3d4c48;
}

.input-group,
.select-group {
  margin-bottom: 1rem;
}

.input-group {
  display: flex;
  align-items: center;
  background: #fff;
  border: 1px solid #bfcfca;
  border-radius: 4px;
  padding: 0 0.8rem;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.input-group i {
  color: var(--hku-teal-dark);
  font-size: 0.95rem;
}

.input-group input {
  background: transparent;
  border: none;
  padding: 0.78rem 0.65rem;
  width: 100%;
  font-size: 0.92rem;
  outline: none;
  color: var(--text);
}

.input-group:focus-within,
.custom-select:focus-within {
  border-color: var(--hku-teal);
  box-shadow: 0 0 0 3px rgba(0, 143, 122, 0.13);
}

.custom-select {
  position: relative;
  background: #fff;
  border: 1px solid #bfcfca;
  border-radius: 4px;
  padding: 0 0.8rem;
}

.custom-select select {
  width: 100%;
  background: transparent;
  border: none;
  padding: 0.78rem 0;
  color: var(--text);
  cursor: pointer;
  appearance: none;
  outline: none;
}

.custom-select i {
  position: absolute;
  right: 0.9rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--muted);
  pointer-events: none;
}

.btn-primary {
  background: var(--hku-teal);
  border: 1px solid var(--hku-teal);
  border-radius: 4px;
  padding: 0.72rem 1.25rem;
  font-weight: 600;
  font-size: 0.9rem;
  color: white;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.btn-primary:hover {
  background: var(--hku-teal-dark);
  border-color: var(--hku-teal-dark);
}

.btn-block {
  width: 100%;
}

.error-msg {
  background: #fff0f1;
  border-left: 4px solid var(--danger);
  color: #9f2f38;
  padding: 0.65rem 0.8rem;
  margin-top: 0.8rem;
  font-size: 0.82rem;
}

.demo-hint {
  margin-top: 1.1rem;
  padding: 0.7rem 0.8rem;
  background: #f7faf9;
  border: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.78rem;
}

/* ---------- Sequential flow ---------- */
.flow-steps {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  margin-bottom: 1.4rem;
  border: 1px solid var(--border);
  background: #f7faf9;
}

.flow-step {
  min-height: 56px;
  padding: 0.65rem 0.7rem;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--muted);
  display: flex;
  align-items: center;
  gap: 0.45rem;
  border-right: 1px solid var(--border);
}

.flow-step:last-child {
  border-right: none;
}

.flow-step.active {
  background: var(--hku-teal);
  color: #fff;
}

.flow-step.completed {
  background: var(--hku-teal-soft);
  color: var(--hku-teal-dark);
}

.flow-step-number {
  width: 1.5rem;
  height: 1.5rem;
  border-radius: 50%;
  border: 1px solid currentColor;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  flex: 0 0 auto;
}

.flow-note {
  color: var(--muted);
  font-size: 0.82rem;
  margin-bottom: 1rem;
}

/* ---------- Quiz content ---------- */
.topic-section {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 0.9rem;
  flex-wrap: wrap;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border);
}

.topic-section .input-group {
  flex: 1;
  min-width: 280px;
  margin-bottom: 0;
}

.status-message {
  background: #fff7df;
  border-left: 4px solid #d5a016;
  padding: 0.55rem 0.75rem;
  font-size: 0.8rem;
  margin: 0.6rem 0;
  color: #765900;
}

.bad-text {
  background: #fff0f1;
  color: #9f2f38;
  border-left-color: var(--danger);
}

.quiz-area {
  margin: 1.2rem 0;
}

.quiz-stem {
  font-size: 1.22rem;
  font-weight: 600;
  line-height: 1.5;
  margin-bottom: 1.2rem;
  color: var(--hku-navy);
}

.choice-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 0.7rem;
  margin: 1rem 0;
}

.choice-btn {
  border: 1px solid var(--border);
  border-left: 6px solid var(--option-accent, var(--hku-teal));
  border-radius: 4px;
  padding: 0.9rem 1rem;
  min-height: 58px;
  font-size: 0.9rem;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, transform 0.15s, box-shadow 0.15s;
  color: var(--hku-navy);
  background: var(--option-bg, #fff);
  box-shadow: 0 1px 2px rgba(39, 52, 66, 0.04);
}

/* HKU-inspired four-option palette:
   orange from the HKU/ECE identity, Moodle/HKU teal,
   ECE cyan-blue, and institutional navy. */
.choice-btn:nth-child(1) {
  --option-accent: #ef4b2f;
  --option-bg: #fff5f1;
}

.choice-btn:nth-child(2) {
  --option-accent: #008f7a;
  --option-bg: #edf8f5;
}

.choice-btn:nth-child(3) {
  --option-accent: #16a7c6;
  --option-bg: #eef9fc;
}

.choice-btn:nth-child(4) {
  --option-accent: #274d5b;
  --option-bg: #f0f5f6;
}

/* True / False specific colours */
body[data-quiz-type="true_false"] .choice-btn:nth-child(1) {
  --option-accent: #16845b;
  --option-bg: #eef8f3;
}

body[data-quiz-type="true_false"] .choice-btn:nth-child(2) {
  --option-accent: #d6454f;
  --option-bg: #fff2f3;
}

.choice-btn:hover {
  border-color: var(--option-accent, var(--hku-teal));
  background: color-mix(in srgb, var(--option-bg, #fff) 72%, var(--option-accent, var(--hku-teal)) 28%);
  transform: translateY(-1px);
  box-shadow: 0 4px 10px rgba(39, 52, 66, 0.10);
}

.choice-btn:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--option-accent, var(--hku-teal)) 28%, transparent);
  outline-offset: 2px;
}

.matching-container {
  display: flex;
  gap: 1.5rem;
  margin: 1rem 0;
  flex-wrap: wrap;
}

.matching-left,
.matching-right {
  flex: 1;
  min-width: 260px;
}

.matching-left h4,
.matching-right h4 {
  font-size: 0.88rem;
  font-weight: 700;
  margin-bottom: 0.8rem;
  color: var(--hku-navy);
  border-left: 4px solid var(--hku-teal);
  padding-left: 0.6rem;
}

.terms-list,
.definitions-list {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.term-card {
  background: #f7faf9;
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.72rem 0.85rem;
  font-weight: 500;
  font-size: 0.88rem;
  cursor: grab;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  user-select: none;
}

.term-card:active {
  cursor: grabbing;
}

.term-card.dragging {
  opacity: 0.45;
}

.term-card.matched {
  background: var(--hku-teal-soft);
  border-color: #9fd1c6;
  color: var(--hku-teal-dark);
  text-decoration: line-through;
  opacity: 0.78;
  cursor: default;
}

.definition-slot {
  background: #fff;
  border: 1px dashed #9eb7b0;
  border-radius: 4px;
  padding: 0.75rem;
}

.definition-slot.drag-over {
  border-color: var(--hku-teal);
  background: var(--hku-teal-soft);
}

.definition-text {
  font-weight: 500;
  margin-bottom: 0.4rem;
  font-size: 0.88rem;
  color: var(--text);
}

.matched-term {
  margin-top: 0.45rem;
  padding: 0.45rem 0.55rem;
  background: #f1f6f5;
  border-left: 3px solid var(--hku-teal);
  font-size: 0.8rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.matched-term span {
  font-weight: 600;
  color: var(--hku-navy);
}

.unmatch-btn {
  background: none;
  border: none;
  color: var(--danger);
  cursor: pointer;
  font-size: 0.72rem;
  padding: 0.2rem 0.35rem;
}

.unmatch-btn:hover {
  background: #fff0f1;
}

.matching-progress {
  margin: 0.8rem 0;
  font-size: 0.8rem;
  text-align: center;
  color: var(--muted);
}

#submitMatchBtn {
  width: 100%;
  margin-top: 0.8rem;
}

#fillBlankInput,
textarea {
  width: 100%;
  background: #fff;
  border: 1px solid #bfcfca;
  border-radius: 4px;
  padding: 0.8rem 0.9rem;
  font-size: 0.9rem;
  margin: 0.8rem 0;
  outline: none;
  font-family: inherit;
}

#fillBlankInput:focus,
textarea:focus {
  border-color: var(--hku-teal);
  box-shadow: 0 0 0 3px rgba(0, 143, 122, 0.13);
}

textarea {
  resize: vertical;
}

.feedback-area {
  margin: 0.8rem 0;
}

#feedback {
  background: #f7faf9;
  padding: 0.8rem 1rem;
  font-size: 0.88rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  border: 1px solid var(--border);
  border-left: 5px solid var(--hku-teal);
}

#feedback.good {
  border-left-color: var(--success);
  background: #eef8f3;
}

#feedback.bad {
  border-left-color: var(--danger);
  background: #fff2f3;
}

#feedback::before {
  font-family: 'Font Awesome 6 Free';
  font-weight: 900;
  font-size: 1.05rem;
}

#feedback.good::before {
  content: "\f00c";
  color: var(--success);
}

#feedback.bad::before {
  content: "\f00d";
  color: var(--danger);
}

.next-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 1.25rem;
}

.btn-outline {
  background: #fff;
  border: 1px solid var(--hku-teal);
  border-radius: 4px;
  padding: 0.55rem 1.1rem;
  font-weight: 600;
  font-size: 0.84rem;
  color: var(--hku-teal-dark);
  cursor: pointer;
}

.btn-outline:not(:disabled):hover {
  background: var(--hku-teal-soft);
}

.hint {
  font-size: 0.72rem;
  color: var(--muted);
}

.hidden {
  display: none;
}

/* ---------- Attempts / history ---------- */
.history-section {
  margin-top: 1.2rem;
  padding: 1rem;
  background: #f7faf9;
  border: 1px solid var(--border);
}

.history-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.8rem;
  margin-bottom: 0.8rem;
  flex-wrap: wrap;
}

.history-header h3 {
  font-size: 1rem;
  color: var(--hku-navy);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.history-count {
  font-size: 0.75rem;
  color: var(--muted);
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 0.25rem 0.55rem;
}

.history-item {
  background: #fff;
  padding: 0.9rem 1rem;
  margin-bottom: 0.7rem;
  border: 1px solid var(--border);
  border-left: 5px solid #96a7a2;
}

.history-item:last-child {
  margin-bottom: 0;
}

.history-good {
  border-left-color: var(--success);
}

.history-bad {
  border-left-color: var(--danger);
}

.history-item-top {
  display: flex;
  justify-content: space-between;
  gap: 0.8rem;
  flex-wrap: wrap;
  margin-bottom: 0.5rem;
  color: var(--hku-navy);
}

.history-line {
  font-size: 0.85rem;
  color: #44524f;
  margin-top: 0.35rem;
  line-height: 1.45;
}

.history-line strong {
  color: var(--hku-navy);
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--hku-navy);
  border-top: 5px solid var(--hku-teal);
  color: #fff;
  padding: 1.2rem 2rem;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  font-size: 0.78rem;
}

.site-footer span:last-child {
  color: #c8d5d2;
}

/* ---------- Responsive ---------- */
@media (max-width: 1050px) {
  .main-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .header-info {
    width: 100%;
    justify-content: flex-start;
  }

  .ece-logo {
    width: 220px;
  }
}

@media (max-width: 760px) {
  .main-header {
    padding: 0.7rem 1rem;
  }

  .hku-brand {
    width: 100%;
    align-items: flex-start;
    gap: 0.65rem;
  }

  .brand-logos {
    gap: 0.45rem;
  }

  .hku-crest {
    width: 40px;
    height: 50px;
  }

  .logo-divider {
    height: 40px;
  }

  .ece-logo {
    width: 160px;
    height: 55px;
  }

  .brand-copy {
    min-width: 0;
    padding-left: 0.65rem;
  }

  .brand-kicker {
    font-size: 0.56rem;
  }

  .brand-name {
    white-space: normal;
    font-size: 1rem;
    line-height: 1.2;
  }

  .header-info > div,
  .header-link,
  .icon-btn {
    font-size: 0.7rem;
  }

  .quiz-main,
  .history-main {
    margin: 1rem auto;
    padding: 0 0.75rem;
  }

  .page-heading,
  .quiz-card,
  .auth-card,
  .setup-card {
    padding: 1rem;
  }

  .flow-steps {
    grid-template-columns: 1fr;
  }

  .flow-step {
    border-right: none;
    border-bottom: 1px solid var(--border);
    min-height: 44px;
  }

  .flow-step:last-child {
    border-bottom: none;
  }

  .topic-section {
    flex-direction: column;
  }

  .topic-section .input-group {
    min-width: 0;
  }

  .topic-section .btn-primary {
    width: 100%;
  }

  .choice-grid {
    grid-template-columns: 1fr;
  }

  .site-footer {
    padding: 1rem;
    flex-direction: column;
  }
}


/* ---------- Quiz completion actions ---------- */
.completion-actions {
  display: flex;
  gap: 0.65rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}

.completion-actions a {
  min-height: 40px;
  padding: 0.6rem 0.9rem;
  border-radius: 4px;
  font-size: 0.82rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  text-decoration: none;
}

.completion-primary {
  background: var(--hku-teal);
  border: 1px solid var(--hku-teal);
  color: #fff;
}

.completion-primary:hover {
  background: var(--hku-teal-dark);
  border-color: var(--hku-teal-dark);
}

.completion-secondary {
  background: #fff;
  border: 1px solid #9fc8bf;
  color: var(--hku-teal-dark);
}

.completion-secondary:hover {
  background: var(--hku-teal-soft);
  border-color: var(--hku-teal);
}