/* ================= BODY & LAYOUT ================= */
body {
  font-family: Times New Roman, sans-serif;
  display: flex;
  justify-content: center;   /* center horizontally */
  align-items: flex-start;   /* align from top */
  min-height: 100vh;
  background-color: #f4f2ef;
  padding: 20px;
  background: #f3f4f6;
}

.main-wrapper {
  display: flex;
  flex-direction: column;      /* stack content vertically */
  justify-content: flex-start;  /* top-align content */
  align-items: center;          /* center horizontally */
  gap: 20px;
  padding: 10px;
  width: 100%;
  max-width: 100%;
  box-sizing: border-box;
  margin: 0 auto;
  transition: margin-left 0.3s ease; /* smooth shift */
}

/* ================= QUIZ CONTAINER ================= */
.quiz-container {
  text-align: center;
  background: white;
  padding: 20px;
  border-radius: 10px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
  width: 90%;
  max-width: 500px;
  min-height: 100vh;            /* ensures full-screen centering */
  margin: 0 auto;
  transition: margin-left 0.3s ease; /* smooth shift */
}


h1 {
      margin-bottom: 20px;
      font-size: 1.8em;
      color: #333;
    }

    .list-selector {
      margin-bottom: 20px;
      font-size: 1em;
    }

    select {
      padding: 6px 10px;
      border-radius: 6px;
      border: 1px solid #ccc;
      cursor: pointer;
      font-size: 1em;
    }

    table {
      width: 100%;
      border-collapse: collapse;
      margin-top: 10px;
    }

    th, td {
      padding: 12px 15px;
      border: 1px solid #ddd;
      text-align: center;
      font-size: 1.2em;
    }

    th {
      background-color: #f0f0f0;
      font-weight: bold;
    }

    tbody tr:hover {
    background-color: #eef7ff;
     }

    tr:nth-child(even) {
      background-color: #fafafa;
    }

    .error {
      color: red;
      font-weight: bold;
      margin-top: 20px;
    }

.study-list {
  background: white;
  border-radius: 12px;
  box-shadow: 0 3px 8px rgba(0,0,0,0.1);
  margin-bottom: 20px;
  padding: 15px;
  text-align: center;
}

.study-list h2 {
  margin-bottom: 10px;
  font-size: 1.4em;
}

.list-buttons button {
  background: #2b6ea3;
  color: #fff;
  padding: 8px 12px;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  font-size: 0.95rem;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.list-buttons button:hover {
  background-color: #218838;
  opacity: 0.95;
  transform: translateY(-5px);
}