@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:wght@700;900&family=DM+Sans:ital,opsz,wght@0,9..40,400;0,9..40,500;0,9..40,700;1,9..40,400&display=swap');

:root {
  --bg: #0f1a14;
  --panel: #162018;
  --panel2: #1c2a1f;
  --border: rgba(255,255,255,0.08);
  --ink: #e8f0e4;
  --muted: #7a9480;
  --accent: #4fc98a;
  --accent2: #d4a027;
  --danger: #e05c4b;
  --success: #4fc98a;
  --error: #e05c4b;
  --radius: 14px;
  --radius-sm: 8px;
  --shadow: 0 24px 60px rgba(0,0,0,0.5);
}

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

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

/* grain noise overlay */
.noise {
  position: fixed; inset: 0; pointer-events: none; z-index: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.04'/%3E%3C/svg%3E");
  opacity: 0.5;
}

.screen { position: relative; z-index: 1; }
.hidden { display: none !important; }

/* ─── HOME ─────────────────────────────────────────────── */
#homeScreen {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px 20px;
}

.home-inner {
  max-width: 640px;
  width: 100%;
  text-align: center;
}

.home-badge {
  display: inline-block;
  background: rgba(79,201,138,0.12);
  border: 1px solid rgba(79,201,138,0.3);
  color: var(--accent);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 5px 14px;
  border-radius: 999px;
  margin-bottom: 24px;
}

.home-title {
  font-family: 'Playfair Display', serif;
  font-size: clamp(4rem, 12vw, 7rem);
  font-weight: 900;
  line-height: 0.95;
  color: var(--ink);
  letter-spacing: -0.02em;
  margin-bottom: 18px;
}
.home-title span { color: var(--accent); }

.home-sub {
  color: var(--muted);
  font-size: 1rem;
  max-width: 400px;
  margin: 0 auto 40px;
  line-height: 1.55;
}

.mode-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin-bottom: 32px;
}

.mode-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 16px;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  transition: border-color 0.2s, transform 0.2s, box-shadow 0.2s;
  color: var(--ink);
  font-family: inherit;
  text-align: center;
}
.mode-card:hover {
  border-color: var(--accent);
  transform: translateY(-3px);
  box-shadow: 0 12px 32px rgba(79,201,138,0.12);
}
.mode-card[data-diff="hard"]:hover { border-color: var(--accent2); box-shadow: 0 12px 32px rgba(212,160,39,0.15); }
.mode-icon { font-size: 2rem; }
.mode-card strong { font-size: 1rem; font-weight: 700; }
.mode-card span { font-size: 0.78rem; color: var(--muted); }

.stats-row {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}
.stat-chip {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 8px 18px;
  font-size: 0.82rem;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
}
.stat-chip strong { color: var(--accent); font-weight: 700; }

/* ─── QUIZ ─────────────────────────────────────────────── */
#quizScreen {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px 20px;
}

.quiz-wrap {
  width: min(100%, 680px);
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 20px;
  box-shadow: var(--shadow);
  padding: clamp(24px, 4vw, 40px);
}

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

.back-btn {
  background: none;
  border: 1px solid var(--border);
  color: var(--muted);
  font-family: inherit;
  font-size: 0.82rem;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: color 0.2s, border-color 0.2s;
}
.back-btn:hover { color: var(--ink); border-color: rgba(255,255,255,0.2); }

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

.hud-chip {
  background: var(--panel2);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 7px 14px;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--muted);
}
.score-chip { color: var(--accent); }
.diff-chip { text-transform: uppercase; font-size: 0.7rem; letter-spacing: 0.1em; }

.timer-warn { border-color: rgba(212,160,39,0.5); color: var(--accent2) !important; }
.timer-danger { border-color: rgba(224,92,75,0.6); color: var(--error) !important; animation: pulse 0.5s infinite alternate; }
@keyframes pulse { to { opacity: 0.5; } }

.progress-track {
  height: 6px;
  background: rgba(255,255,255,0.06);
  border-radius: 999px;
  overflow: hidden;
  margin-bottom: 28px;
}
.progress-fill {
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  transition: width 0.4s ease;
  width: 0%;
}

.q-area { margin-bottom: 24px; }
.q-num {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
}
.q-text {
  font-family: 'Playfair Display', serif;
  font-size: clamp(1.3rem, 3.5vw, 1.9rem);
  font-weight: 700;
  line-height: 1.25;
  color: var(--ink);
}

.options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 18px;
}

.opt-btn {
  background: var(--panel2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--ink);
  font-family: inherit;
  font-size: 0.9rem;
  padding: 14px 16px;
  cursor: pointer;
  text-align: left;
  display: flex;
  align-items: center;
  gap: 12px;
  transition: border-color 0.18s, background 0.18s, transform 0.18s;
  line-height: 1.35;
}
.opt-btn:hover:not(:disabled) {
  border-color: var(--accent);
  background: rgba(79,201,138,0.07);
  transform: translateY(-1px);
}
.opt-letter {
  width: 26px;
  height: 26px;
  border-radius: 6px;
  background: rgba(255,255,255,0.06);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 700;
  flex-shrink: 0;
  color: var(--muted);
}
.opt-correct { border-color: var(--success) !important; background: rgba(79,201,138,0.12) !important; }
.opt-correct .opt-letter { background: var(--success); color: #000; }
.opt-wrong { border-color: var(--error) !important; background: rgba(224,92,75,0.1) !important; }
.opt-wrong .opt-letter { background: var(--error); color: #fff; }
.opt-btn:disabled { cursor: default; }

/* feedback */
.fb-box {
  border-radius: var(--radius-sm);
  padding: 16px 18px;
  display: flex;
  gap: 14px;
  align-items: flex-start;
  margin-bottom: 18px;
  border: 1px solid transparent;
}
.fb-correct { background: rgba(79,201,138,0.08); border-color: rgba(79,201,138,0.25); }
.fb-wrong { background: rgba(224,92,75,0.08); border-color: rgba(224,92,75,0.22); }
.fb-icon { font-size: 1.5rem; flex-shrink: 0; line-height: 1; }
.fb-verdict { font-weight: 700; font-size: 0.92rem; margin-bottom: 4px; }
.fb-correct .fb-verdict { color: var(--success); }
.fb-wrong .fb-verdict { color: var(--error); }
.fb-fact { font-size: 0.87rem; color: var(--muted); line-height: 1.5; }

.quiz-actions { display: flex; justify-content: flex-end; }
.btn-next {
  background: var(--accent);
  color: #0a1a10;
  font-family: inherit;
  font-weight: 700;
  font-size: 0.95rem;
  border: none;
  border-radius: var(--radius-sm);
  padding: 13px 28px;
  cursor: pointer;
  transition: background 0.18s, transform 0.18s;
}
.btn-next:hover { background: #3db075; transform: translateY(-1px); }

/* ─── RESULTS ────────────────────────────────────────────── */
#resultsScreen {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px 20px;
}

.results-wrap {
  width: min(100%, 680px);
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 20px;
  box-shadow: var(--shadow);
  padding: clamp(28px, 5vw, 48px);
}

.trophy { font-size: 3.5rem; margin-bottom: 12px; }
.eyebrow {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 8px;
}
.result-score {
  font-family: 'Playfair Display', serif;
  font-size: clamp(2.2rem, 7vw, 3.5rem);
  font-weight: 900;
  color: var(--ink);
  margin-bottom: 8px;
}
.result-msg { color: var(--muted); font-size: 0.95rem; line-height: 1.5; margin-bottom: 24px; }

.result-bar-wrap {
  height: 10px;
  background: rgba(255,255,255,0.06);
  border-radius: 999px;
  overflow: hidden;
  margin-bottom: 28px;
}
.result-bar-fill {
  height: 100%;
  border-radius: inherit;
  width: 0;
  transition: width 1s ease;
}

.review-grid {
  display: grid;
  gap: 8px;
  margin-bottom: 28px;
  max-height: 340px;
  overflow-y: auto;
  padding-right: 4px;
}
.review-grid::-webkit-scrollbar { width: 4px; }
.review-grid::-webkit-scrollbar-track { background: transparent; }
.review-grid::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.1); border-radius: 99px; }

.review-card {
  background: var(--panel2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  border-left: 4px solid transparent;
}
.rc-ok { border-left-color: var(--success); }
.rc-bad { border-left-color: var(--error); }
.rc-num { font-size: 0.7rem; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); margin-bottom: 4px; }
.rc-q { font-size: 0.88rem; color: var(--ink); margin-bottom: 6px; line-height: 1.4; }
.rc-detail { font-size: 0.8rem; }
.rc-ok-text { color: var(--success); }
.rc-bad-text { color: var(--error); }

.results-actions { display: flex; gap: 12px; justify-content: flex-end; }
.btn-primary {
  background: var(--accent);
  color: #0a1a10;
  font-family: inherit;
  font-weight: 700;
  border: none;
  border-radius: var(--radius-sm);
  padding: 13px 28px;
  cursor: pointer;
  font-size: 0.95rem;
  transition: background 0.18s;
}
.btn-primary:hover { background: #3db075; }
.btn-outline {
  background: transparent;
  color: var(--muted);
  font-family: inherit;
  font-weight: 600;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 13px 24px;
  cursor: pointer;
  font-size: 0.95rem;
  transition: border-color 0.18s, color 0.18s;
}
.btn-outline:hover { border-color: rgba(255,255,255,0.2); color: var(--ink); }

/* ─── RESPONSIVE ──────────────────────────────────────────── */
@media (max-width: 560px) {
  .mode-grid { grid-template-columns: 1fr; }
  .options { grid-template-columns: 1fr; }
  .quiz-header { flex-wrap: wrap; gap: 10px; }
  .hud { flex-wrap: wrap; }
  .results-actions { flex-direction: column-reverse; }
  .btn-primary, .btn-outline { width: 100%; text-align: center; }
  .home-title { font-size: 3.5rem; }
}