@import url("https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@500;700&family=Manrope:wght@400;600;700&display=swap");

:root {
  --bg: #f8fafc;
  --ink: #13233f;
  --muted: #5f6b84;
  --good: #16a34a;
  --bad: #dc2626;
  --brand: #0ea5e9;
  --accent: #ff6b35;
  --surface: rgba(255, 255, 255, 0.82);
  --border: rgba(19, 35, 63, 0.12);
  --shadow: 0 18px 44px rgba(19, 35, 63, 0.15);
  --green-glow: rgba(34, 197, 94, 0.24);
}

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

body {
  position: relative;
  overflow-x: hidden;
  font-family: "Manrope", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 12% 10%, rgba(14, 165, 233, 0.2), transparent 34%),
    radial-gradient(circle at 90% 6%, rgba(255, 107, 53, 0.2), transparent 30%),
    var(--bg);
  min-height: 100vh;
}

body::before {
  content: "";
  position: fixed;
  inset: auto auto -140px -120px;
  width: 280px;
  height: 280px;
  background: radial-gradient(circle, var(--green-glow), transparent 65%);
  z-index: -1;
  animation: floatBlob 7s ease-in-out infinite alternate;
}

.navbar {
  width: min(1100px, 92%);
  margin: 18px auto 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 14px 18px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(8px);
  box-shadow: var(--shadow);
}

.logo {
  display: flex;
  align-items: center;
}

.logo img {
  height: 34px;
  width: auto;
  display: block;
}

nav {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.navbar a {
  padding: 6px 10px;
  border-radius: 10px;
  text-decoration: none;
  color: var(--ink);
  font-weight: 600;
  transition: color 0.2s ease, background-color 0.2s ease;
}

.navbar a:hover {
  color: var(--accent);
  background: rgba(255, 107, 53, 0.12);
}

.quiz-section {
  width: min(1100px, 92%);
  margin: 26px auto;
  display: flex;
  justify-content: center;
  padding-bottom: 84px;
}

.quiz-container {
  width: min(640px, 100%);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 22px;
  padding: clamp(20px, 4vw, 34px);
  padding-bottom: 140px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
  animation: rise 0.45s ease;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.quiz-container:hover {
  transform: none;
  box-shadow: 0 24px 48px rgba(19, 35, 63, 0.18);
}

.quiz-container h2 {
  position: relative;
  font-family: "Space Grotesk", sans-serif;
  text-align: center;
  margin-bottom: 18px;
  font-size: clamp(1.45rem, 2.6vw, 2rem);
}

.quiz-container h2::after {
  content: "";
  display: block;
  width: 78px;
  height: 4px;
  margin: 10px auto 0;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--brand), var(--accent));
}


.level-picker {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  margin-bottom: 12px;
}

.level-btn {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 8px 10px;
  font-family: "Space Grotesk", sans-serif;
  font-weight: 700;
  background: #fff;
  color: var(--ink);
  cursor: pointer;
  transition: transform 0.15s ease, background-color 0.15s ease, color 0.15s ease;
}

.level-btn:hover {
  transform: translateY(-1px);
}

.level-btn:disabled {
  opacity: 1;
  cursor: not-allowed;
  transform: none;
  background: transparent;
  color: rgba(19, 35, 63, 0.5);
  border-color: rgba(19, 35, 63, 0.2);
}

.level-btn:disabled:hover {
  transform: none;
  filter: none;
}

.level-btn.active {
  color: #fff;
  background: linear-gradient(120deg, var(--brand), #0284c7);
  border-color: transparent;
}

.level-meta {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--muted);
  margin-bottom: 12px;
}

#question {
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  font-weight: 700;
  margin-bottom: 16px;
}

#answers {
  display: grid;
  gap: 24px;
}

#answers button {
  position: relative;
  overflow: hidden;
  width: 100%;
  border: 1px solid transparent;
  border-radius: 12px;
  padding: 12px 14px;
  font-size: 1rem;
  font-weight: 700;
  font-family: "Manrope", sans-serif;
  cursor: pointer;
  color: #fff;
  background: linear-gradient(120deg, var(--brand), #0284c7);
  transition: transform 0.18s ease, filter 0.18s ease;
}

#answers button::after {
  content: "";
  position: absolute;
  top: -120%;
  left: -30%;
  width: 24%;
  height: 320%;
  background: rgba(255, 255, 255, 0.22);
  transform: rotate(18deg);
  transition: left 0.45s ease;
}

#answers button:hover:not(:disabled) {
  transform: translateY(-2px);
  filter: brightness(1.05);
}

#answers button:hover:not(:disabled)::after {
  left: 115%;
}

#answers button:disabled {
  opacity: 0.95;
  cursor: not-allowed;
}

#explanation {
  margin-top: 16px;
  margin-bottom: 12px;
  min-height: 0;
  max-height: 32vh;
  overflow-y: auto;
  padding-right: 6px;
  border-radius: 14px;
  padding: 0;
  background: transparent;
  border: none;
  color: var(--ink);
  line-height: 1.45;
}

.feedback-box {
  padding: 14px 16px;
  border-radius: 14px;
  border: 1px solid transparent;
  box-shadow: 0 10px 20px rgba(19, 35, 63, 0.08);
  animation: feedbackFade 0.25s ease-out;
}

.feedback-title {
  display: inline-block;
  margin-bottom: 8px;
  padding: 5px 10px;
  border-radius: 999px;
  font-family: "Space Grotesk", sans-serif;
  font-weight: 700;
  font-size: 0.82rem;
  letter-spacing: 0.2px;
}

.feedback-box p + p {
  margin-top: 6px;
}

.feedback-correct {
  background: linear-gradient(120deg, rgba(22, 163, 74, 0.14), rgba(74, 222, 128, 0.14));
  border-color: rgba(22, 163, 74, 0.4);
}

.feedback-correct .feedback-title {
  background: rgba(22, 163, 74, 0.2);
  color: #166534;
}

.feedback-wrong {
  background: linear-gradient(120deg, rgba(220, 38, 38, 0.12), rgba(251, 113, 133, 0.12));
  border-color: rgba(220, 38, 38, 0.35);
}

.feedback-wrong .feedback-title {
  background: rgba(220, 38, 38, 0.18);
  color: #991b1b;
}

@keyframes feedbackFade {
  from {
    opacity: 0;
    transform: translateY(6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

#nextBtn {
  display: none;
  margin-top: 0;
  position: fixed !important;
  left: 12px !important;
  right: 12px !important;
  bottom: 16px !important;
  z-index: 3000;
  width: auto;
  max-width: 460px;
  margin-left: auto;
  margin-right: auto;
  overflow: hidden;
  border: none;
  border-radius: 999px;
  padding: 11px 26px;
  font-family: "Space Grotesk", sans-serif;
  font-size: 0.98rem;
  font-weight: 700;
  cursor: pointer;
  color: #fff;
  background: linear-gradient(120deg, var(--accent), #ff8f5c);
  box-shadow: 0 10px 20px rgba(255, 107, 53, 0.28);
  transition: transform 0.2s ease, filter 0.2s ease;
}

#nextBtn::after {
  content: "";
  position: absolute;
  top: -120%;
  left: -30%;
  width: 24%;
  height: 320%;
  background: rgba(255, 255, 255, 0.24);
  transform: rotate(18deg);
  transition: left 0.45s ease;
}

#nextBtn:hover {
  transform: translateY(-2px) !important;
  filter: brightness(1.05);
}

#nextBtn:hover::after {
  left: 115%;
}

#result {
  margin-top: 16px;
  text-align: center;
}

#result h3 {
  font-family: "Space Grotesk", sans-serif;
}

#result button {
  margin-top: 14px;
  border: none;
  border-radius: 999px;
  padding: 10px 24px;
  font-weight: 700;
  cursor: pointer;
  color: #fff;
  background: linear-gradient(120deg, #2563eb, #0ea5e9);
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@keyframes floatBlob {
  from {
    transform: translateY(0);
  }
  to {
    transform: translateY(-16px);
  }
}

@media (max-width: 1024px), (pointer: coarse) {
  .navbar {
    flex-direction: column;
    align-items: flex-start;
  }

  nav {
    gap: 10px 14px;
  }

}

@media (max-width: 600px) {
  .navbar {
    width: 94%;
    padding: 12px;
    border-radius: 12px;
  }

  .logo img {
    height: 30px;
  }

  nav {
    width: 100%;
    gap: 8px;
  }

  .navbar a {
    font-size: 0.92rem;
    padding: 6px 8px;
  }

  .quiz-section {
    width: 94%;
    margin-top: 18px;
  }

  .quiz-container {
    border-radius: 16px;
    padding: 16px 16px 240px;
  }

  #question {
    font-size: 1rem;
  }

  #answers {
    gap: 14px;
  }

  #answers button {
    padding: 11px 12px;
    font-size: 0.95rem;
  }

  .feedback-box {
    padding: 12px;
  }

  .level-picker {
    gap: 8px;
  }

  .level-btn {
    padding: 8px 6px;
    font-size: 0.9rem;
  }

  #explanation {
    max-height: 30vh;
  }

  #nextBtn,
  #result button {
    width: 100%;
  }

  #nextBtn {
    max-width: 360px;
    bottom: calc(env(safe-area-inset-bottom, 0px) + 16px) !important;
  }

  #nextBtn:hover {
    transform: translateY(-2px);
  }
}