body {
  font-family: sans-serif;
  background-color: #f4f4f4;
  margin: 0;
  padding: 2rem;
  text-align: center;
}

.screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 80vh;
}

.hidden {
  display: none;
}

h1, h2 {
  color: #333;
}

p {
  font-size: 1.2rem;
}

button {
  font-size: 1.2rem;
  padding: 0.6rem 1.5rem;
  margin-top: 1rem;
  background-color: #007bff;
  color: white;
  border: none;
  border-radius: 5px;
  cursor: pointer;
}

button:hover {
  background-color: #0056b3;
}

.test-header {
  display: flex;
  justify-content: space-between;
  width: 100%;
  max-width: 600px;
  font-size: 1.5rem;
  margin-bottom: 2rem;
}

#question-box {
  font-size: 3rem;
  margin: 1rem;
}

#answer-input {
  font-size: 2rem;
  padding: 0.5rem;
  width: 6rem;
  text-align: center;
}

#score-summary {
  font-size: 1.5rem;
  margin-bottom: 1rem;
}

#missed-questions {
  text-align: left;
  max-width: 600px;
  margin: 0 auto;
  font-size: 1.2rem;
}

.levels {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
}

.levels a {
  display: inline-block;
  width: 120px;
  height: 60px;
  line-height: 60px;
  margin: 0.5rem;
  color: white;
  text-decoration: none;
  font-size: 1.2rem;
  border-radius: 10px;
  transition: background-color 0.3s ease;
  text-align: center;
}

/*
.levels a.completed {
  background-color: #28a745 !important;
  color: white;
}

.levels a.completed:hover{
  background-color: #19682b !important;
  color: white;
}
*/

/* Category-specific colors */
/* Addition */
.addition-levels a {
  background-color: #007bff;
}
.addition-levels a:hover {
  background-color: #0056b3;
}
.addition-bg {
  background-color: #e0f0ff; 
}
.addition-bg #start-btn {
  background-color: #007bff;
  color: white;
}
.addition-bg #start-btn:hover {
  background-color: #0056b3;
}
.addition-bg .home-btn {
  background-color: #007bff;
  color: white;
}
.addition-bg .home-btn:hover {
  background-color: #0056b3;
}

/* Subtraction */
.subtraction-levels a {
  background-color: #dc3545;
}
.subtraction-levels a:hover {
  background-color: #a71d2a;
}
.subtraction-bg {
  background-color: #ffe6e6;
}
.subtraction-bg #start-btn {
  background-color: #dc3545;
  color: white;
}
.subtraction-bg #start-btn:hover {
  background-color: #a71d2a;
}
.subtraction-bg .home-btn {
  background-color: #dc3545;
  color: white;
}
.subtraction-bg .home-btn:hover {
  background-color: #a71d2a;
}

/* Multiplication */
.multiplication-levels a {
  background-color: #6f42c1;
}
.multiplication-levels a:hover {
  background-color: #5936a2;
}
.multiplication-bg {
  background-color: #f0e6ff;
}
.multiplication-bg #start-btn {
  background-color: #6f42c1;
  color: white;
}
.multiplication-bg #start-btn:hover {
  background-color: #5936a2;
}
.multiplication-bg .home-btn {
  background-color: #6f42c1;
  color: white;
}
.multiplication-bg .home-btn:hover {
  background-color: #5936a2;
}

/* Multiplication 2*/
.multiplication2-levels a {
  background-color: #2d835b;
}
.multiplication2-levels a:hover {
  background-color: #135536;
}
.multiplication2-bg {
  background-color: #e8f7ec;
}
.multiplication2-bg #start-btn {
  background-color: #2d835b;
  color: white;
}
.multiplication2-bg #start-btn:hover {
  background-color: #135536;
}
.multiplication2-bg .home-btn {
  background-color: #2d835b;
  color: white;
}
.multiplication2-bg .home-btn:hover {
  background-color: #135536;
}

/* Division */
.division-levels a {
  background-color: #ff7f07;
}
.division-levels a:hover {
  background-color: #c96202;
}
.division-bg {
  background-color: #fff3e0;
}
.division-bg #start-btn {
  background-color: #ff7f07;
  color: white;
}
.division-bg #start-btn:hover {
  background-color: #c96202;
}
.division-bg .home-btn {
  background-color: #ff7f07;
  color: white;
}
.division-bg .home-btn:hover {
  background-color: #c96202;
}

/* Division 2 */
.division2-levels a {
  background-color: #bebc10;
}
.division2-levels a:hover {
  background-color: #a5a314;
}
.division2-bg {
  background-color: #ffffe7;
}
.division2-bg #start-btn {
  background-color: #bebc10;
  color: white;
}
.division2-bg #start-btn:hover {
  background-color: #a5a314;
}
.division2-bg .home-btn {
  background-color: #bebc10;
  color: white;
}
.division2-bg .home-btn:hover {
  background-color: #a5a314;
}


.katex {
  font-family: Arial, sans-serif;
}

.disabled {
  display: none !important;
}

.long-division {
  display: inline-flex;
  align-items: flex-start;
  font-family: inherit;
  font-size: 3rem;
  line-height: 1;
  position: relative;
}

/* divisor with tall bar that overlaps the top line */
.long-division .divisor {
  border-right: 3px solid #222;
  padding-right: 0.6rem;
  margin-right: -0.1rem;
  display: inline-flex;
  align-items: center;
  min-width: 1ch;
  position: relative;
  z-index: 1;
}

/* dividend with top line */
.long-division .dividend {
  border-top: 3px solid #222;
  padding: 0.25rem 0.6rem;
  display: inline-block;
  text-align: left;
  min-width: 1.5ch;
  box-sizing: border-box;
  position: relative;
}

/* optional quotient */
.long-division .quotient {
  display: block;
  position: relative;
  left: 0.75rem;
  top: -1.1em;
  font-size: 0.6em;
  white-space: nowrap;
}

/* mobile tweaks */
@media (max-width: 520px) {
  .long-division { font-size: 2rem; }
  .long-division .divisor { padding-right: 0.4rem; margin-right: 0.4rem; }
  .long-division .dividend { padding: 0.2rem 0.4rem; }
}