@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,700;9..144,900&family=Space+Grotesk:wght@400;600;700&family=Bebas+Neue&family=Space+Mono:wght@400;700&display=swap');

:root {
  --bg-1: #0f172a;
  --bg-2: #111827;
  --bg-3: #0b1020;
  --panel: rgba(17, 24, 39, 0.78);
  --text: #e5e7eb;
  --muted: #94a3b8;
  --accent: #34d399;
  --accent-2: #60a5fa;
  --danger: #f87171;
  --gold: #fbbf24;
  --headline: #f8fafc;
  --shadow: 0 20px 50px rgba(5, 8, 20, 0.4);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: 'Space Grotesk', system-ui, sans-serif;
  color: var(--text);
  background: radial-gradient(circle at top, #14203a, var(--bg-1) 45%, var(--bg-3) 100%);
  min-height: 100vh;
  height: 100vh;
  overflow: hidden;
}

#bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  overflow: hidden;
  pointer-events: none;
}

#bg::before,
#bg::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  width: 220px;
  filter: blur(12px);
  opacity: 0.8;
  mix-blend-mode: screen;
  animation: edgePulse 4s ease-in-out infinite;
}

#bg::before {
  left: -80px;
  background: linear-gradient(180deg, rgba(52, 211, 153, 0.75), transparent 55%);
}

#bg::after {
  right: -80px;
  background: linear-gradient(180deg, rgba(96, 165, 250, 0.75), transparent 55%);
  animation-delay: -2s;
}

.orb {
  position: absolute;
  width: 480px;
  height: 480px;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.35;
  animation: float 14s ease-in-out infinite;
}

.orb-a { background: var(--accent); top: -120px; left: -120px; }
.orb-b { background: var(--accent-2); bottom: -160px; right: -120px; animation-delay: -6s; }

.grid {
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(148, 163, 184, 0.08) 1px, transparent 1px),
                    linear-gradient(90deg, rgba(148, 163, 184, 0.08) 1px, transparent 1px);
  background-size: 40px 40px;
  opacity: 0.35;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(20px); }
}

@keyframes edgePulse {
  0%, 100% { transform: translateY(0) translateX(0) scaleY(1); opacity: 0.55; }
  50% { transform: translateY(26px) translateX(12px) scaleY(1.12); opacity: 0.95; }
}

#app {
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px 20px 24px;
  height: 100vh;
  display: flex;
  flex-direction: column;
  gap: 16px;
  position: relative;
  z-index: 1;
}

.top {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  align-items: center;
  justify-content: space-between;
}

.brand h1 {
  font-family: 'Bebas Neue', 'Fraunces', serif;
  font-size: clamp(2.6rem, 5vw, 3.8rem);
  letter-spacing: 0.04em;
  color: var(--headline);
  margin: 0 0 6px;
  text-transform: uppercase;
}

.byline {
  margin: 0;
  font-family: 'Space Mono', monospace;
  color: var(--accent-2);
  font-size: clamp(1rem, 2vw, 1.15rem);
  letter-spacing: 0.08em;
}

.mode-toggle {
  display: inline-flex;
  background: rgba(15, 23, 42, 0.6);
  border-radius: 999px;
  padding: 6px;
  gap: 6px;
}

.mode-btn {
  border: 0;
  padding: 10px 18px;
  border-radius: 999px;
  background: transparent;
  color: var(--text);
  cursor: pointer;
  font-weight: 600;
}

.mode-btn.active {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #0b1020;
}

.panel {
  background: var(--panel);
  border: 1px solid rgba(148, 163, 184, 0.2);
  border-radius: 20px;
  padding: 20px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
}

.controls {
  position: sticky;
  top: 0;
  z-index: 2;
}

.top {
  position: sticky;
  top: 0;
  z-index: 3;
}

.content-scroll {
  overflow-y: auto;
  padding-right: 6px;
  flex: 1;
}

.content-scroll::-webkit-scrollbar {
  width: 8px;
}

.content-scroll::-webkit-scrollbar-thumb {
  background: rgba(148, 163, 184, 0.35);
  border-radius: 999px;
}

@media (max-width: 900px) {
  body {
    height: auto;
    overflow: auto;
  }

  #app {
    height: auto;
  }

  .top,
  .controls {
    position: static;
  }

  .content-scroll {
    overflow: visible;
    padding-right: 0;
  }
}

.panel-header h2 {
  margin: 0 0 6px;
  font-size: 1.2rem;
}

.panel-header p {
  margin: 0;
  color: var(--muted);
}

.controls .row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.field {
  display: flex;
  flex-direction: column;
  min-width: 160px;
  flex: 1;
}

label {
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 8px;
}

select, input {
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid rgba(148, 163, 184, 0.35);
  color: var(--text);
  padding: 10px 12px;
  border-radius: 12px;
  font-size: 0.95rem;
}

button {
  border: 0;
  cursor: pointer;
  font-weight: 600;
  border-radius: 12px;
  padding: 12px 18px;
}

.primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #0b1020;
}

.ghost {
  background: transparent;
  border: 1px solid rgba(148, 163, 184, 0.4);
  color: var(--text);
}

.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 12px;
  margin-top: 16px;
}

.stat {
  background: rgba(15, 23, 42, 0.6);
  border-radius: 16px;
  padding: 12px;
}

.stat-label {
  display: block;
  font-size: 0.8rem;
  color: var(--muted);
}

.stat-value {
  font-size: 1.4rem;
  font-weight: 700;
}

.question-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 14px;
}

.learn-search {
  margin: 14px 0 6px;
}

.learn-search input {
  width: 100%;
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid rgba(148, 163, 184, 0.35);
  color: var(--text);
  padding: 12px 14px;
  border-radius: 12px;
  font-size: 0.95rem;
}

.question-card {
  background: rgba(15, 23, 42, 0.85);
  border: 1px solid rgba(148, 163, 184, 0.18);
  padding: 16px;
  border-radius: 16px;
}

.question-card h3 {
  margin: 0 0 10px;
  font-size: 1rem;
}

.option {
  padding: 6px 8px;
  border-radius: 10px;
  margin-bottom: 6px;
  background: rgba(148, 163, 184, 0.08);
}

.option.correct { color: #052e16; background: rgba(34, 197, 94, 0.8); font-weight: 700; }

.option.wrong { color: #3f0a0a; background: rgba(239, 68, 68, 0.85); font-weight: 700; }

.test-card {
  background: rgba(15, 23, 42, 0.85);
  border-radius: 20px;
  padding: 20px;
  border: 1px solid rgba(148, 163, 184, 0.2);
}

.test-card h3 {
  margin: 0 0 14px;
}

.answer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 10px;
}

.answer-btn {
  background: rgba(148, 163, 184, 0.12);
  border: 1px solid rgba(148, 163, 184, 0.2);
  color: var(--text);
  padding: 12px 14px;
  border-radius: 14px;
  cursor: pointer;
  text-align: left;
  transition: transform 0.2s ease, background 0.2s ease;
}

.answer-btn:hover { transform: translateY(-2px); background: rgba(56, 189, 248, 0.2); }

.answer-btn.correct { background: rgba(34, 197, 94, 0.85); color: #052e16; font-weight: 700; }

.answer-btn.wrong { background: rgba(239, 68, 68, 0.85); color: #3f0a0a; font-weight: 700; }

.confetti {
  position: fixed;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
  z-index: 999;
}

.confetti-piece {
  position: absolute;
  width: 8px;
  height: 12px;
  opacity: 0.9;
  border-radius: 2px;
  animation: confettiFall 900ms ease-out forwards;
}

@keyframes confettiFall {
  0% { transform: translate(var(--x), var(--y)) rotate(0deg); opacity: 1; }
  100% { transform: translate(calc(var(--x) + var(--dx)), calc(var(--y) + 220px)) rotate(360deg); opacity: 0; }
}

.test-actions { display: flex; gap: 12px; margin-top: 14px; }

.history-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 12px;
}

.history-card {
  border-radius: 16px;
  padding: 14px;
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid rgba(148, 163, 184, 0.2);
}

.history-card.correct { border-color: rgba(34, 197, 94, 0.7); }
.history-card.wrong { border-color: rgba(239, 68, 68, 0.7); }

.hidden { display: none; }

@media (max-width: 720px) {
  .test-actions { flex-direction: column; }
  .mode-toggle { width: 100%; justify-content: center; }
}