/* ---------------------------------------------------------
   GLOBAL
--------------------------------------------------------- */

body {
  margin: 0;
  padding: 40px;
  font-family: system-ui, sans-serif;
  background: #fdfdfd;
  display: flex;
  justify-content: center;
}

.container {
  max-width: 800px;
  width: 100%;
  position: relative;
}

/* ---------------------------------------------------------
   RESPONSIVE RENDERER VARIABLES
--------------------------------------------------------- */

:root {
  --number-height: max(7vw, 50px);
  --symbol-height: calc(var(--number-height) / 2);

  --facts-number-height: calc(var(--number-height) / 3);
  --facts-symbol-height: calc(var(--facts-number-height) / 2);
}

/* ---------------------------------------------------------
   FLEXIBLE TOP BAR
--------------------------------------------------------- */

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}

.top-left {
  display: flex;
  align-items: center;
}

#settings-form {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

#settings-form label {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 8px;
  border: 1px solid #ccc;
  border-radius: 6px;
  background: #fafafa;
  font-size: 0.9rem;
}

#settings-form input[type="number"] {
  width: 50px;
  padding: 2px 4px;
  font-size: 1rem;
  text-align: center;
}

#settings-form button {
  padding: 6px 12px;
  font-size: 1rem;
  cursor: pointer;
}

.top-right {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-left: auto;
  flex-wrap: nowrap;
}

.trial-box {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 60px;
  font-weight: 600;
  font-size: 1.1rem;
}

.home-link {
  display: flex;
  align-items: center;
}

.home-icon {
  width: 32px;
  opacity: 0.9;
  transition: opacity 0.2s;
}

.home-icon:hover {
  opacity: 1;
}

/* ---------------------------------------------------------
   SOUND TOGGLE
--------------------------------------------------------- */

.sound-toggle {
  display: flex;
  align-items: center;
  cursor: pointer;
  padding: 4px 8px;
  border: 1px solid #ccc;
  border-radius: 6px;
  background: #fafafa;
}

.sound-wrapper {
  position: relative;
  display: inline-block;
}

.sound-icon {
  width: 28px;
  height: auto;
}

.sound-wrapper::after {
  content: "";
  position: absolute;
  top: 8px;
  left: 0px;
  width: 30px;
  height: 3px;
  background: red;
  border-radius: 2px;
  transform: rotate(45deg);
  opacity: 0;
  transition: opacity 0.2s;
}

.sound-toggle input:not(:checked) ~ .sound-wrapper::after {
  opacity: 1;
}

/* ---------------------------------------------------------
   RENDERER WRAPPERS
--------------------------------------------------------- */

/* Only problem + solution are card-like boxes */
#problem-wrapper,
#solution-wrapper {
  width: 100%;
  margin-bottom: 20px;
  padding: 12px;
  border-radius: 16px;
  box-shadow: 0 8px 16px rgba(0,0,0,0.12);
  background: white;
}

/* Facts wrapper is just a plain container */
#facts-wrapper {
  width: 100%;
  margin: 0;
  margin-top: 20px;
  padding: 0;
  background: transparent;
  box-shadow: none;
  border-radius: 0;
}

.hidden {
  display: none;
}

/* ---------------------------------------------------------
   RENDERER ROWS
--------------------------------------------------------- */

.render-row {
  display: flex;
  flex-wrap: nowrap;
  align-items: center;
  justify-content: center;
  gap: 2vw;
}

.fact-row {
  display: flex;
  flex-wrap: nowrap;
  align-items: center;
  justify-content: center;
  gap: 1.2vw;
}

.render-row img,
.fact-row img {
  display: inline-block;
  height: auto;
  max-height: 100%;
}

/* ---------------------------------------------------------
   OUTER CONTAINERS
--------------------------------------------------------- */

#problem,
#solution {
  display: flex;
  justify-content: center;
  align-items: center;
}

/* Facts container stays vertical */
#facts {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

/* Smooth scaling animation */
img {
  transition: height 0.3s ease;
}

/* ---------------------------------------------------------
   CORRECT / WRONG COLOURING
--------------------------------------------------------- */

.solution-correct {
  background-color: #d4ffd4;
}

.solution-wrong {
  background-color: #ffd4d4;
}

/* ---------------------------------------------------------
   ANSWER AREA
--------------------------------------------------------- */

.answer-section {
  margin-top: 20px;
}

.answer-row {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 12px;
}

#answer-input {
  font-size: 2rem;
  padding: 6px 12px;
  width: 90px;
  text-align: center;
  border-radius: 8px;
  border: 2px solid #ccc;
}

#ok-button {
  font-size: 1.8rem;
  padding: 6px 14px;
  border-radius: 8px;
  border: none;
  background: #e0e0e0;
  cursor: pointer;
}

#ok-button:hover {
  background: #d5d5d5;
}

.next-btn {
  font-size: 1.8rem;
  padding: 6px 50px;
  border-radius: 10px;
  border: none;
  cursor: pointer;
  background: #ffd966;
  color: #333;
  transition: background 0.2s;
}

.next-btn:hover {
  background: #ffcc33;
}

/* ---------------------------------------------------------
   MEDIA QUERIES
--------------------------------------------------------- */

@media (max-width: 600px) {
  .topbar {
    flex-direction: column;
    align-items: stretch;
  }

  .top-left,
  .top-right {
    justify-content: center;
  }

  #answer-input {
    font-size: 1.5rem;
    width: 70px;
  }

  .next-btn {
    padding: 6px 20px;
    font-size: 1.5rem;
  }
}

@media (max-width: 500px) {
  :root {
    --number-height: max(7vw, 50px);
    --symbol-height: calc(var(--number-height) / 2);
    --facts-number-height: calc(var(--number-height) / 3);
    --facts-symbol-height: calc(var(--facts-number-height) / 2);
  }
}