:root {
  --forest: #1a3a2a;
  --forest-mid: #2d5a3d;
  --forest-light: #4a8c5c;
  --moss: #7ab648;
  --leaf: #a8d672;
  --bark: #8b5e3c;
  --cream: #f7f3ec;
  --cream-dark: #ede7db;
  --ink: #1c2b1e;
  --ink-mid: #3a4a3c;
  --ink-light: #6b7d6d;
  --red: #c0392b;
  --red-soft: #fde8e6;
  --green-soft: #e6f5ea;
  --white: #ffffff;
  --shadow: 0 4px 24px rgba(26,58,42,0.10);
  --shadow-lg: 0 12px 48px rgba(26,58,42,0.18);
  --radius: 16px;
  --radius-sm: 10px;
  --topbar-h: 56px;
  --progressbar-h: 4px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'DM Sans', sans-serif;
  background: var(--cream);
  color: var(--ink);
  min-height: 100vh;
  overflow-x: hidden;
}

/* ===== SCREENS ===== */
.screen { display: none; min-height: 100vh; }
.screen.active { display: block; }

/* ===== HOME SCREEN ===== */
#home-screen { position: relative; background: var(--forest); }

.home-bg {
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse at 20% 50%, rgba(74,140,92,0.25) 0%, transparent 60%),
    radial-gradient(ellipse at 80% 20%, rgba(168,214,114,0.15) 0%, transparent 50%),
    radial-gradient(ellipse at 60% 80%, rgba(45,90,61,0.4) 0%, transparent 50%),
    var(--forest);
  z-index: 0;
}

.home-header {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 64px 24px 40px;
}

.leaf-icon {
  font-size: 48px;
  display: block;
  margin-bottom: 16px;
  animation: sway 3s ease-in-out infinite;
}

@keyframes sway {
  0%, 100% { transform: rotate(-5deg); }
  50% { transform: rotate(5deg); }
}

.home-header h1 {
  font-family: 'Playfair Display', serif;
  font-size: clamp(32px, 6vw, 56px);
  font-weight: 900;
  color: var(--leaf);
  letter-spacing: -1px;
  line-height: 1.1;
}

.subtitle {
  color: rgba(255,255,255,0.55);
  font-size: 14px;
  font-weight: 400;
  margin-top: 10px;
  letter-spacing: 0.5px;
}

.week-selector-container {
  position: relative;
  z-index: 1;
  max-width: 720px;
  margin: 0 auto;
  padding: 0 20px 60px;
}

.selector-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.selector-header h2 {
  font-family: 'Playfair Display', serif;
  font-size: 20px;
  color: var(--cream);
  font-weight: 700;
}

.select-actions { display: flex; gap: 8px; align-items: center; color: rgba(255,255,255,0.4); font-size: 13px; }

.text-btn {
  background: none;
  border: none;
  color: var(--moss);
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  font-size: 13px;
  font-weight: 500;
  padding: 2px 0;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.week-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  gap: 10px;
  margin-bottom: 36px;
}

.week-card {
  background: rgba(255,255,255,0.06);
  border: 1.5px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-sm);
  padding: 14px 10px;
  cursor: pointer;
  text-align: center;
  transition: all 0.2s ease;
  user-select: none;
}

.week-card:hover {
  background: rgba(122,182,72,0.15);
  border-color: var(--moss);
  transform: translateY(-2px);
}

.week-card.selected {
  background: rgba(122,182,72,0.2);
  border-color: var(--moss);
  box-shadow: 0 0 0 1px var(--moss);
}

.week-card input[type="checkbox"] { display: none; }

.week-num {
  font-family: 'Playfair Display', serif;
  font-size: 22px;
  font-weight: 700;
  color: var(--white);
  line-height: 1;
}

.week-card.selected .week-num { color: var(--leaf); }

.week-label {
  font-size: 11px;
  color: rgba(255,255,255,0.45);
  margin-top: 4px;
  font-weight: 500;
  letter-spacing: 0.3px;
}

.week-card.selected .week-label { color: var(--moss); }

.week-check {
  font-size: 14px;
  margin-top: 6px;
  opacity: 0;
  transition: opacity 0.2s;
}
.week-card.selected .week-check { opacity: 1; }

.mode-buttons {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.mode-btn {
  background: rgba(255,255,255,0.05);
  border: 1.5px solid rgba(255,255,255,0.12);
  border-radius: var(--radius);
  padding: 24px 16px;
  cursor: pointer;
  text-align: center;
  transition: all 0.25s ease;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  font-family: 'DM Sans', sans-serif;
}

.mode-btn:hover { transform: translateY(-3px); box-shadow: 0 12px 32px rgba(0,0,0,0.3); }
.study-btn:hover { background: rgba(122,182,72,0.2); border-color: var(--moss); }
.test-btn:hover { background: rgba(139,94,60,0.3); border-color: var(--bark); }

.mode-icon { font-size: 28px; }
.mode-label { font-size: 16px; font-weight: 600; color: var(--white); }
.mode-desc { font-size: 12px; color: rgba(255,255,255,0.45); }

/* ===== QUIZ SCREEN ===== */
#quiz-screen {
  background: var(--cream);
  display: flex;
  flex-direction: column;
}

/* Sticky topbar */
.quiz-topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--forest);
  height: var(--topbar-h);
  padding: 0 16px;
  display: flex;
  align-items: center;
  gap: 10px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.25);
}

.back-btn {
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.15);
  color: var(--cream);
  padding: 7px 14px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 13px;
  font-family: 'DM Sans', sans-serif;
  font-weight: 500;
  transition: background 0.2s;
  white-space: nowrap;
  flex-shrink: 0;
}
.back-btn:hover { background: rgba(255,255,255,0.16); }

.quiz-meta {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  flex: 1;
  justify-content: center;
}

.mode-badge, .week-badge, .q-count-badge {
  font-size: 11px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 20px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  white-space: nowrap;
}

#mode-badge  { background: var(--moss); color: var(--forest); }
#week-badge  { background: rgba(255,255,255,0.12); color: rgba(255,255,255,0.7); }
#q-count-badge { background: rgba(255,255,255,0.08); color: rgba(255,255,255,0.55); }

.answered-counter {
  font-size: 13px;
  color: var(--leaf);
  font-weight: 600;
  white-space: nowrap;
  flex-shrink: 0;
  min-width: 64px;
  text-align: right;
}

/* Progress bar */
.progress-bar-wrap {
  height: var(--progressbar-h);
  background: rgba(26,58,42,0.1);
  flex-shrink: 0;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--forest-light), var(--moss));
  transition: width 0.5s ease;
  border-radius: 0 2px 2px 0;
}

/* Scrollable body */
.questions-scroll-body {
  flex: 1;
  padding: 28px 16px 60px;
  max-width: 720px;
  margin: 0 auto;
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* ===== QUESTION CARD ===== */
.question-card {
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px 28px 24px;
  transition: box-shadow 0.2s;
  scroll-margin-top: calc(var(--topbar-h) + var(--progressbar-h) + 12px);
}

.question-card:hover {
  box-shadow: 0 6px 32px rgba(26,58,42,0.13);
}

.qcard-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
}

.question-number {
  font-size: 11px;
  font-weight: 700;
  color: var(--ink-light);
  letter-spacing: 1px;
  text-transform: uppercase;
  flex: 1;
}

.week-tag {
  font-size: 10px;
  font-weight: 600;
  color: var(--forest-light);
  background: rgba(74,140,92,0.1);
  border-radius: 12px;
  padding: 3px 9px;
  letter-spacing: 0.4px;
}

.answered-badge {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.5px;
  padding: 3px 9px;
  border-radius: 12px;
  display: none;
}

.answered-badge.show-correct { display: inline-block; background: var(--green-soft); color: var(--forest-light); }
.answered-badge.show-wrong   { display: inline-block; background: var(--red-soft); color: var(--red); }
.answered-badge.show-selected { display: inline-block; background: rgba(139,94,60,0.1); color: var(--bark); }

.question-text {
  font-family: 'Playfair Display', serif;
  font-size: clamp(16px, 2.4vw, 20px);
  font-weight: 700;
  color: var(--ink);
  line-height: 1.55;
  margin-bottom: 22px;
}

.options-grid {
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.option-btn {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 13px 16px;
  background: var(--cream);
  border: 2px solid var(--cream-dark);
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-align: left;
  font-family: 'DM Sans', sans-serif;
  font-size: 14.5px;
  color: var(--ink);
  transition: border-color 0.15s, background 0.15s, transform 0.15s;
  line-height: 1.5;
  width: 100%;
}

.option-btn:hover:not(:disabled) {
  border-color: var(--forest-light);
  background: rgba(74,140,92,0.07);
  transform: translateX(3px);
}

.option-letter {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  min-width: 26px;
  background: var(--cream-dark);
  border-radius: 50%;
  font-size: 12px;
  font-weight: 700;
  color: var(--ink-mid);
  transition: background 0.15s, color 0.15s;
}

/* Study mode: answered states */
.option-btn.correct {
  background: var(--green-soft);
  border-color: var(--forest-light);
  color: var(--forest);
}
.option-btn.correct .option-letter { background: var(--forest-light); color: white; }

.option-btn.wrong {
  background: var(--red-soft);
  border-color: var(--red);
  color: var(--red);
}
.option-btn.wrong .option-letter { background: var(--red); color: white; }

/* Test mode: selected */
.option-btn.selected-test {
  border-color: var(--bark);
  background: rgba(139,94,60,0.08);
}
.option-btn.selected-test .option-letter { background: var(--bark); color: white; }

/* Test review: after submit */
.option-btn.review-correct {
  background: var(--green-soft);
  border-color: var(--forest-light);
  color: var(--forest);
}
.option-btn.review-correct .option-letter { background: var(--forest-light); color: white; }

.option-btn.review-wrong {
  background: var(--red-soft);
  border-color: var(--red);
  color: var(--red);
}
.option-btn.review-wrong .option-letter { background: var(--red); color: white; }

.option-btn:disabled { cursor: default; }

/* Explanation box */
.explanation-box {
  margin-top: 18px;
  padding: 16px 18px;
  background: linear-gradient(135deg, rgba(26,58,42,0.04) 0%, rgba(122,182,72,0.06) 100%);
  border-left: 4px solid var(--moss);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  animation: fadeUp 0.35s ease;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

.explanation-box .exp-label {
  font-size: 11px;
  font-weight: 700;
  color: var(--forest-light);
  letter-spacing: 0.8px;
  text-transform: uppercase;
  margin-bottom: 7px;
}

.explanation-box p {
  font-size: 13.5px;
  color: var(--ink-mid);
  line-height: 1.65;
}

/* ===== SUBMIT AREA (Test mode) ===== */
#submit-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 20px 0 40px;
}

.big-submit-btn {
  background: var(--forest);
  color: var(--leaf);
  border: none;
  padding: 16px 48px;
  border-radius: var(--radius);
  font-family: 'Playfair Display', serif;
  font-size: 18px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s;
  box-shadow: 0 6px 24px rgba(26,58,42,0.25);
  letter-spacing: 0.3px;
}

.big-submit-btn:hover {
  background: var(--forest-mid);
  transform: translateY(-2px);
  box-shadow: 0 10px 32px rgba(26,58,42,0.3);
}

.submit-hint {
  font-size: 13px;
  color: var(--ink-light);
}

/* ===== RESULTS SCREEN ===== */
#results-screen { background: var(--cream); }

.results-header {
  background: var(--forest);
  padding: 48px 24px 36px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.results-header::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 50% 100%, rgba(122,182,72,0.2) 0%, transparent 70%);
}

.score-ring {
  position: relative;
  width: 140px;
  height: 140px;
  margin: 0 auto 24px;
}

.ring-svg { width: 140px; height: 140px; transform: rotate(-90deg); }

.ring-bg {
  fill: none;
  stroke: rgba(255,255,255,0.08);
  stroke-width: 10;
}

.ring-fill {
  fill: none;
  stroke: var(--moss);
  stroke-width: 10;
  stroke-linecap: round;
  stroke-dasharray: 327;
  stroke-dashoffset: 327;
  transition: stroke-dashoffset 1.2s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.score-text {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.score-num {
  font-family: 'Playfair Display', serif;
  font-size: 30px;
  font-weight: 900;
  color: var(--white);
  line-height: 1;
}

.score-label {
  font-size: 11px;
  color: rgba(255,255,255,0.5);
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-top: 4px;
}

.result-stats {
  display: flex;
  gap: 10px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 24px;
  position: relative;
}

.stat-pill {
  padding: 8px 18px;
  border-radius: 20px;
  font-size: 14px;
  font-weight: 600;
}

.correct-pill { background: rgba(122,182,72,0.2); color: var(--leaf); }
.wrong-pill   { background: rgba(192,57,43,0.2); color: #e74c3c; }
.pct-pill     { background: rgba(255,255,255,0.1); color: rgba(255,255,255,0.8); }

.result-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  position: relative;
}

.restart-btn {
  background: var(--moss);
  color: var(--forest);
  border: none;
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  font-family: 'DM Sans', sans-serif;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s;
}
.restart-btn:hover { background: var(--leaf); transform: translateY(-2px); }

.review-toggle-btn {
  background: rgba(255,255,255,0.1);
  color: rgba(255,255,255,0.85);
  border: 1px solid rgba(255,255,255,0.2);
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  font-family: 'DM Sans', sans-serif;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}
.review-toggle-btn:hover { background: rgba(255,255,255,0.18); }

/* Review section */
.review-section {
  max-width: 720px;
  margin: 0 auto;
  padding: 36px 16px 60px;
}

.review-title {
  font-family: 'Playfair Display', serif;
  font-size: 26px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 20px;
}

.review-item {
  background: var(--white);
  border-radius: var(--radius);
  padding: 22px;
  margin-bottom: 14px;
  box-shadow: var(--shadow);
  border-left: 5px solid var(--cream-dark);
}

.review-item.review-correct { border-left-color: var(--forest-light); }
.review-item.review-wrong   { border-left-color: var(--red); }

.review-q-num {
  font-size: 11px;
  font-weight: 700;
  color: var(--ink-light);
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.review-q-text {
  font-family: 'Playfair Display', serif;
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 12px;
  line-height: 1.5;
}

.review-answers {
  display: flex;
  flex-direction: column;
  gap: 5px;
  margin-bottom: 12px;
}

.review-answer-row {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 13px;
  line-height: 1.5;
}

.review-answer-label { font-weight: 700; min-width: 96px; color: var(--ink-light); }
.review-answer-val   { color: var(--ink-mid); }
.review-answer-val.is-correct { color: var(--forest-light); font-weight: 600; }
.review-answer-val.is-wrong   { color: var(--red); font-weight: 600; }

.review-exp {
  font-size: 13px;
  color: var(--ink-mid);
  line-height: 1.65;
  padding: 10px 13px;
  background: var(--cream);
  border-radius: 8px;
}

.review-exp strong {
  color: var(--forest-mid);
  font-size: 10.5px;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  display: block;
  margin-bottom: 5px;
}

/* Scroll-to-top fab */
.fab-top {
  position: fixed;
  bottom: 24px;
  right: 20px;
  width: 44px;
  height: 44px;
  background: var(--forest);
  color: var(--leaf);
  border: none;
  border-radius: 50%;
  font-size: 18px;
  cursor: pointer;
  box-shadow: 0 4px 16px rgba(0,0,0,0.25);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 200;
  transition: opacity 0.2s, transform 0.2s;
}
.fab-top:hover { transform: translateY(-2px); }
.fab-top.visible { display: flex; }

/* ===== RESPONSIVE ===== */
@media (max-width: 520px) {
  .question-card { padding: 20px 16px 18px; }
  .mode-buttons  { grid-template-columns: 1fr; }
  .week-grid     { grid-template-columns: repeat(4, 1fr); }
  .quiz-meta     { gap: 4px; }
  .big-submit-btn { font-size: 16px; padding: 14px 36px; }
}

@media (max-width: 360px) {
  .week-grid { grid-template-columns: repeat(3, 1fr); }
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--cream-dark); }
::-webkit-scrollbar-thumb { background: var(--forest-light); border-radius: 3px; }