/* ---------------- CGPA CONTAINER ---------------- */
.cgpa-container {
  max-width: 1000px;  
  width: 90%;          
  margin: 60px auto;
  padding: 30px;
  background: #0b0b0b;
  color: #fff;
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.7);
  transition: transform 0.3s;
}

.cgpa-container:hover {
  transform: translateY(-5px);
}

.cgpa-container h1 {
  text-align: center;
  margin-bottom: 10px;
  color: #4fd1c5;
  font-size: 28px;
  letter-spacing: 1px;
}

.info-text {
  text-align: center;
  font-size: 14px;
  color: #bbb;
  margin-bottom: 25px;
}

.range-label {
  display: block;
  margin-bottom: 10px;
}

input[type="range"] {
  width: 100%;
  margin-bottom: 25px;
  accent-color: #4fd1c5;
}

/* ---------------- SUBJECT ROW ---------------- */
.subject-row {
  display: flex;
  justify-content: space-evenly;
  flex-wrap: wrap;
  gap: 15px;
  margin-bottom: 15px;
}

.subject-row input {
  flex: 1 1 120px; 
  max-width: 150px;
  min-width: 100px;
  padding: 12px;
  border-radius: 8px;
  border: none;
  outline: none;
  background: #1a1a1a;
  color: white;
  text-align: center;
  transition: all 0.3s;
}

.subject-row input::placeholder {
  color: #888;
}

.subject-row input:focus {
  background: #111;
  box-shadow: 0 0 8px #4fd1c5;
  transform: scale(1.05);
}

/* ---------------- BUTTON ---------------- */
.btn {
  width: 100%;
  padding: 14px;
  background: linear-gradient(135deg, #4fd1c5, #38b2ac);
  border: none;
  border-radius: 10px;
  font-size: 16px;
  cursor: pointer;
  margin-top: 15px;
  color: #fff;
  font-weight: 500;
  transition: all 0.3s;
}

.btn:hover {
  background: linear-gradient(135deg, #38b2ac, #2c7a7b);
  transform: scale(1.03);
  box-shadow: 0 5px 15px rgba(63, 191, 182, 0.5);
}

/* ---------------- RESULT BOX ---------------- */
.result-box {
  margin-top: 30px;
  text-align: center;
  background: #111;
  padding: 25px;
  border-radius: 12px;
  box-shadow: 0 8px 25px rgba(0,0,0,0.6);
  transition: transform 0.3s, box-shadow 0.3s;
}

.result-box:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(0,0,0,0.8);
}

.result-box span {
  color: #4fd1c5;
  font-weight: bold;
  font-size: 18px;
}

/* ---------------- FORMULA BOX ---------------- */
.formula-box {
  margin-top: 30px;
  padding: 20px;
  background: #111;
  border-radius: 12px;
  font-size: 14px;
  color: #ccc;
  box-shadow: 0 6px 20px rgba(0,0,0,0.5);
  transition: transform 0.3s, box-shadow 0.3s;
}

.formula-box:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 25px rgba(0,0,0,0.7);
}

/* ---------------- GRADE REFERENCE ---------------- */
.grade-reference {
  margin-top: 40px;
  background: #111;
  padding: 25px;
  border-radius: 12px;
  color: #fff;
  box-shadow: 0 8px 25px rgba(0,0,0,0.6);
}

.grade-reference h3 {
  text-align: center;
  margin-bottom: 15px;
  color: #4fd1c5;
}

.grade-reference table {
  width: 100%;
  border-collapse: collapse;
}

.grade-reference th,
.grade-reference td {
  padding: 12px;
  text-align: center;
  border-bottom: 1px solid #222;
  transition: background 0.3s;
}

.grade-reference th {
  background: #1a1a1a;
  color: #4fd1c5;
}

.grade-reference tr:hover {
  background: #1f1f1f;
}

.note {
  margin-top: 12px;
  font-size: 13px;
  color: #aaa;
  text-align: center;
}

/* ---------------- RESPONSIVE STYLES ---------------- */

/* Tablets (up to 768px) */
@media (max-width: 768px) {
  .cgpa-container {
    padding: 25px;
    margin: 40px 15px;
  }

  .cgpa-container h1 {
    font-size: 24px;
  }

  .subject-row input {
    flex: 1 1 100px;
  }

  .formula-box, .grade-reference {
    font-size: 13px;
    padding: 15px;
  }

  .btn {
    font-size: 15px;
  }
}

/* Small phones (up to 480px) */
@media (max-width: 480px) {
  .cgpa-container {
    padding: 15px;
    margin: 30px 10px;
  }

  .cgpa-container h1 {
    font-size: 22px;
  }

  .info-text {
    font-size: 13px;
  }

  .subject-row input {
    flex: 1 1 90px;
  }

  .btn {
    font-size: 14px;
    padding: 10px;
  }

  .formula-box, .grade-reference {
    font-size: 12px;
    padding: 10px;
  }

  .grade-reference th, .grade-reference td {
    padding: 8px;
    font-size: 12px;
  }
}

/* Large desktops (min-width 1200px) */
@media (min-width: 1200px) {
  .cgpa-container {
    padding: 40px;
    margin: 60px auto;
  }

  .subject-row input {
    flex: 1 1 140px;
  }

  .btn {
    font-size: 17px;
    padding: 14px;
  }

  .formula-box, .grade-reference {
    font-size: 15px;
    padding: 20px;
  }
}