:root {
  --bg: var(--tg-theme-bg-color, #ffffff);
  --secondary-bg: var(--tg-theme-secondary-bg-color, #f7f7f7);
  --text: var(--tg-theme-text-color, #3c3c3c);
  --hint: var(--tg-theme-hint-color, #777777);
  --section-bg: var(--tg-theme-section-bg-color, #ffffff);

  /* Duolingo-style brand palette */
  --duo-green: #58cc02;
  --duo-green-shadow: #58a700;
  --duo-blue: #1cb0f6;
  --duo-blue-shadow: #1899d6;
  --duo-red: #ff4b4b;
  --duo-red-shadow: #ea2b2b;
  --duo-yellow: #ffc800;
  --duo-gray-border: #e5e5e5;
  --duo-gray-shadow: #d6d6d6;

  --link: var(--duo-blue);
  --button: var(--duo-green);
  --button-text: #ffffff;
  --green: var(--duo-green);
  --red: var(--duo-red);
  --radius: 16px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  -webkit-tap-highlight-color: transparent;
}

#app {
  min-height: var(--tg-vh, 100vh);
  padding-bottom: 96px;
}

.screen {
  padding: 16px;
  animation: fade-in 0.15s ease-out;
}

@keyframes fade-in {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

.loading-screen {
  display: flex;
  align-items: center;
  justify-content: center;
  height: var(--tg-vh, 100vh);
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--secondary-bg);
  border-top-color: var(--duo-green);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

h1 {
  font-size: 22px;
  font-weight: 800;
  margin: 4px 0 4px;
}

h2 {
  font-size: 18px;
  font-weight: 700;
  margin: 0 0 12px;
}

.subtitle {
  color: var(--hint);
  font-size: 14px;
  margin: 0 0 16px;
}

.field {
  margin-bottom: 14px;
}

.field label {
  display: block;
  font-size: 13px;
  color: var(--hint);
  margin-bottom: 6px;
  font-weight: 700;
}

.field input, .field select {
  width: 100%;
  padding: 12px 14px;
  border-radius: 12px;
  border: 2px solid var(--duo-gray-border);
  background: var(--secondary-bg);
  color: var(--text);
  font-size: 16px;
}

.field input:focus, .field select:focus {
  outline: none;
  border-color: var(--duo-blue);
}

.card {
  background: var(--section-bg);
  border: 2px solid var(--duo-gray-border);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 10px;
}

.card.tappable {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  cursor: pointer;
}

.card.tappable:active {
  background: var(--secondary-bg);
}

.card-title {
  font-weight: 700;
  font-size: 15px;
  margin-bottom: 2px;
}

.card-meta {
  font-size: 13px;
  color: var(--hint);
}

.badge {
  font-size: 12px;
  font-weight: 800;
  padding: 3px 9px;
  border-radius: 20px;
  background: var(--secondary-bg);
  color: var(--hint);
  white-space: nowrap;
}

.badge.done {
  background: rgba(88, 204, 2, 0.15);
  color: var(--duo-green-shadow);
}

.badge.elective {
  background: rgba(28, 176, 246, 0.12);
  color: var(--duo-blue-shadow);
}

.section-label {
  font-size: 13px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--hint);
  margin: 20px 0 8px;
}

.lesson-card {
  background: var(--section-bg);
  border-radius: var(--radius);
  padding: 18px;
  margin-bottom: 12px;
  font-size: 16px;
  line-height: 1.5;
  border-left: 4px solid var(--duo-blue);
}

.lesson-card-number {
  font-size: 12px;
  font-weight: 800;
  color: var(--duo-blue);
  margin-bottom: 6px;
}

.quiz-progress {
  display: flex;
  gap: 4px;
  margin-bottom: 18px;
}

.quiz-progress-dot {
  flex: 1;
  height: 8px;
  border-radius: 4px;
  background: var(--duo-gray-border);
}

.quiz-progress-dot.done {
  background: var(--duo-green);
}

.question-text {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 18px;
  line-height: 1.4;
}

.option {
  display: block;
  width: 100%;
  text-align: left;
  padding: 14px 16px;
  border-radius: 14px;
  border: 2px solid var(--duo-gray-border);
  background: var(--section-bg);
  color: var(--text);
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 10px;
  cursor: pointer;
  box-shadow: 0 3px 0 var(--duo-gray-shadow);
  transition: transform 0.05s ease-out, box-shadow 0.05s ease-out;
}

.option:active:not(:disabled) {
  transform: translateY(2px);
  box-shadow: 0 1px 0 var(--duo-gray-shadow);
}

.option.selected {
  border-color: var(--duo-blue);
  background: rgba(28, 176, 246, 0.1);
  box-shadow: 0 3px 0 var(--duo-blue-shadow);
}

.option.correct {
  border-color: var(--duo-green);
  background: rgba(88, 204, 2, 0.12);
  color: var(--duo-green-shadow);
  box-shadow: 0 3px 0 var(--duo-green-shadow);
}

.option.incorrect {
  border-color: var(--duo-red);
  background: rgba(255, 75, 75, 0.12);
  color: var(--duo-red-shadow);
  box-shadow: 0 3px 0 var(--duo-red-shadow);
}

.option:disabled {
  cursor: default;
}

.option:disabled:not(.correct):not(.incorrect) {
  opacity: 0.45;
  box-shadow: 0 3px 0 var(--duo-gray-shadow);
}

/* Image-based answer options: a 2x2 grid of picture cards instead of text rows */
.option-images {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 10px;
}

.option-image-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 10px;
  border-radius: 14px;
  border: 2px solid var(--duo-gray-border);
  background: var(--section-bg);
  cursor: pointer;
  box-shadow: 0 3px 0 var(--duo-gray-shadow);
  transition: transform 0.05s ease-out, box-shadow 0.05s ease-out;
}

.option-image-card:active:not(.locked) {
  transform: translateY(2px);
  box-shadow: 0 1px 0 var(--duo-gray-shadow);
}

.option-image-card img {
  width: 100%;
  height: auto;
  border-radius: 8px;
  margin-bottom: 6px;
  background: var(--secondary-bg);
}

.option-image-card .caption {
  font-size: 13px;
  font-weight: 700;
  text-align: center;
  color: var(--text);
}

.option-image-card.selected {
  border-color: var(--duo-blue);
  box-shadow: 0 3px 0 var(--duo-blue-shadow);
}

.option-image-card.correct {
  border-color: var(--duo-green);
  background: rgba(88, 204, 2, 0.12);
  box-shadow: 0 3px 0 var(--duo-green-shadow);
}

.option-image-card.incorrect {
  border-color: var(--duo-red);
  background: rgba(255, 75, 75, 0.12);
  box-shadow: 0 3px 0 var(--duo-red-shadow);
}

.option-image-card.dimmed {
  opacity: 0.45;
}

.question-image {
  display: block;
  width: 100%;
  max-width: 420px;
  margin: 0 auto 16px;
  border-radius: 12px;
  background: var(--secondary-bg);
  border: 2px solid var(--duo-gray-border);
}

.explanation {
  margin-top: 10px;
  padding: 12px 14px;
  border-radius: 12px;
  background: var(--secondary-bg);
  font-size: 14px;
  color: var(--text);
  font-weight: 600;
  border: 2px solid var(--duo-gray-border);
}

.result-wrap {
  position: relative;
  overflow: hidden;
  min-height: 60vh;
}

.confetti {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 2;
}

.result-hero {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 20px 0 8px;
  animation: result-pop 0.6s cubic-bezier(0.2, 0.9, 0.3, 1.3) both;
}

@keyframes result-pop {
  from { transform: scale(0.85); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

.result-ring {
  position: relative;
  width: 150px;
  height: 150px;
  margin: 0 auto 12px;
}

.result-ring svg { transform: rotate(-90deg); }

.ring-bg {
  fill: none;
  stroke: var(--duo-gray-border);
  stroke-width: 12;
}

.ring-fg {
  fill: none;
  stroke-width: 12;
  stroke-linecap: round;
  transition: stroke-dashoffset 1.2s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.tier-great .ring-fg { stroke: var(--duo-green); }
.tier-good .ring-fg { stroke: var(--duo-blue); }
.tier-low .ring-fg { stroke: var(--duo-yellow); }

.ring-label {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.ring-pct {
  font-size: 36px;
  font-weight: 800;
  color: var(--text);
}

.result-title {
  font-size: 24px;
  font-weight: 800;
  margin: 6px 16px 8px;
  color: var(--text);
}

.tier-great .result-title { color: var(--duo-green-shadow); }
.tier-good .result-title { color: var(--duo-blue-shadow); }

.result-msg {
  color: var(--hint);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.45;
  margin: 0 20px 18px;
}

.result-stats {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 18px;
}

.stat-pill {
  min-width: 96px;
  padding: 10px 14px;
  border-radius: 14px;
  border: 2px solid var(--duo-gray-border);
  background: var(--section-bg);
  display: flex;
  flex-direction: column;
  align-items: center;
  animation: result-pop 0.5s 0.35s cubic-bezier(0.2, 0.9, 0.3, 1.3) both;
}

.stat-pill.ok { border-color: var(--duo-green); }
.stat-pill.ko { border-color: var(--duo-red); }
.stat-pill.ok .stat-num { color: var(--duo-green); }
.stat-pill.ko .stat-num { color: var(--duo-red); }

.stat-num { font-size: 22px; font-weight: 800; }
.stat-lbl { font-size: 12px; font-weight: 700; color: var(--hint); text-transform: uppercase; letter-spacing: 0.04em; }

/* legacy classes kept for safety */
.result-score { font-size: 48px; font-weight: 800; }
.result-score.good { color: var(--duo-green); }
.result-score.bad { color: var(--duo-red); }
.result-sub { color: var(--hint); font-size: 14px; margin-top: 4px; font-weight: 600; }

.top-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.brand-row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-logo {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  object-fit: cover;
  flex-shrink: 0;
}

.brand-logo.small {
  width: 28px;
  height: 28px;
  border-radius: 8px;
}

.brand-name {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--duo-green);
}

.profile-link {
  font-size: 13px;
  color: var(--duo-blue);
  cursor: pointer;
  font-weight: 800;
}

.stat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 14px;
}

.stat-box {
  background: var(--section-bg);
  border: 2px solid var(--duo-gray-border);
  border-radius: var(--radius);
  padding: 14px;
  text-align: center;
}

.stat-box .num {
  font-size: 24px;
  font-weight: 800;
  color: var(--duo-green);
}

.stat-box .label {
  font-size: 12px;
  color: var(--hint);
  margin-top: 2px;
  font-weight: 600;
}

.empty-state {
  text-align: center;
  color: var(--hint);
  padding: 40px 20px;
  font-size: 14px;
}

.debug-banner {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--duo-yellow);
  color: #3c3c3c;
  font-size: 11px;
  text-align: center;
  padding: 3px;
  z-index: 999;
}

/* Duolingo-style chunky 3D action bar button */
.action-bar {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 12px 16px calc(12px + env(safe-area-inset-bottom));
  background: var(--bg);
  border-top: 2px solid var(--duo-gray-border);
  z-index: 10;
}

.btn-primary {
  display: block;
  width: 100%;
  margin: 0;
  padding: 16px;
  border: none;
  border-radius: 16px;
  background: var(--duo-green);
  color: #ffffff;
  font-size: 15px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  text-align: center;
  cursor: pointer;
  box-shadow: 0 4px 0 var(--duo-green-shadow);
  transition: transform 0.05s ease-out, box-shadow 0.05s ease-out;
}

.btn-primary:active:not(:disabled) {
  transform: translateY(3px);
  box-shadow: 0 1px 0 var(--duo-green-shadow);
}

.btn-primary:disabled {
  background: var(--duo-gray-border);
  box-shadow: 0 4px 0 var(--duo-gray-shadow);
  color: #a6a6a6;
  cursor: default;
}