body {
    font-family: Arial, sans-serif;
    background: #f4f9fb;
    padding: 20px;
    text-align: center;
    background-color:#1aefda33;
}

.app-container {
  max-width: 900px;
  margin: 40px auto;
  padding: 0 20px;
  
}


.filter-box {
    display: inline-block;
    background: white;
    padding: 15px;
    margin: 8px;
    border-radius: 8px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
}

.filter-box label {
    display: block;
    margin-bottom: 6px;
    font-weight: bold;
}

select, button {
    padding: 6px;
    font-size: 1rem;
}

.hidden {
    display: none;
}

.flashcard {
  margin: 30px auto;
  perspective: 1200px;
  display: flex;
  justify-content: center;
  align-items: center;
}
@media (min-width: 600px) {
  .flashcard {
    max-width: 420px;
    height: 250px;
  }
}
@media (min-width: 900px) {
  .flashcard {
    max-width: 500px;
    height: 280px;
  }
}


.flashcard-inner {
  width: 100%;
  height: 100%;
  position: relative;
  transition: transform 0.6s ease;
  transform-style: preserve-3d;
  transform-origin: center center;
}


.flashcard.flip .flashcard-inner {
    transform: rotateY(180deg);
}

.flashcard-front,
.flashcard-back {
    position: absolute;
    inset: 0;
    backface-visibility: hidden;
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    font-size: 1.3rem;
    color: #333;
}

.flashcard-back {
    transform: rotateY(180deg);
    background: #e3f2fd;
}
.response-buttons {
    margin-top: 20px;
}

.response-buttons button {
    padding: 12px 24px;
    font-size: 1.1rem;
    margin: 0 10px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
}




.panel {
  background: #ffffff;
  border-radius: 14px;
  padding: 25px;
  margin-bottom: 25px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
}

.panel-controls {
  border-top: 6px solid #1e88e5;
  padding:5px;
  
}

.panel-session {
  border-top: 6px solid #26a69a;
  text-align: center;
}


.panel-controls select {
  
  padding: 12px 14px;
  font-size: 1rem;
  border-radius: 10px;
  border: 1px solid #bcdde8;
  background: #ffffff;
  color: #1e88e5;
  font-weight: 500;
}

.panel-controls select option[disabled] {
  color: #90a4ae;
}


select {
  border-radius: 6px;
  border: 1px solid #bcdde8;

}

.counter {
  font-size: 1.5rem;
  font-weight: 600;
  color: #1e88e5;
  margin-bottom: 15px;
  margin-top: 15px;
}

.btn-primary,
button {
  background: linear-gradient(135deg, #1e88e5, #26a69a);
  color: #fff;
  padding: 12px 26px;
  font-size: 1rem;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  box-shadow: 0 4px 10px rgba(30, 136, 229, 0.3);
}

button:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 14px rgba(30, 136, 229, 0.35);
}

button:disabled {
  background: #cfd8dc;
  cursor: not-allowed;
  box-shadow: none;
}

/* =========================
   MOBILE FLASHCARD FIX
   ========================= */
@media (max-width: 600px) {

  /* Reduce excess panel spacing */
  .panel {
    padding: 16px;
    margin-bottom: 18px;
  }

  /* Flashcard should feel dominant */
  .flashcard {
    width: 100%;
    max-width: 100%;
    height: 280px;          /* 🔹 give it real presence */
    margin: 12px auto;      /* 🔹 reduce vertical gaps */
    perspective: 1200px;
  }

  /* Card faces: readable + centred */
  .flashcard-front,
  .flashcard-back {
    font-size: 1.25rem;
    padding: 18px;
    line-height: 1.4;
  }

  /* Pull counter closer to card */
  .counter {
    margin-bottom: 8px;
  }

  /* Pull Next button closer */
  .panel-session button {
    margin-top: 12px;
  }

}