/* -------------------------
   PAGE TITLE
-------------------------- */
#tnebTool .page-title {
  text-align: center;
  margin: 20px;
  font-size: 24px;
  font-weight: 600;
}

#tnebTool .input-label {
  display: block;
  margin-bottom: 10px;
  font-weight: 500;
  color: #e5e7eb;
  font-size: 14px;
}

/* -------------------------
   WRAPPER (CENTERED PERFECTLY)
-------------------------- */
#tnebTool .tneb-wrapper {
  max-width: 420px;
  margin: 40px auto;   /* add top spacing */
  padding: 0 10px;     /* prevent edge touching */
}

/* -------------------------
   MODERN CALCULATOR CARD
-------------------------- */
#tnebTool .calc-ui {
  background: #2d2f33;
  padding: 22px;
  border-radius: 20px;
  box-shadow: 0 15px 35px rgba(0,0,0,0.3);
}

/* -------------------------
   DISPLAY SCREEN
-------------------------- */
#tnebTool #unitsInput {
  width: 100%;
  height: 65px;
  font-size: 24px;
  text-align: right;
  padding: 12px 15px;
  border-radius: 14px;
  border: none;
  background: linear-gradient(to bottom, #e5e7eb, #9ca3af);
  margin-bottom: 20px;
  box-sizing: border-box;
  font-weight: 600;
}

/* -------------------------
   KEYPAD GRID (4 COLUMN)
-------------------------- */
#tnebTool .keypad {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

/* -------------------------
   BUTTON BASE STYLE
-------------------------- */
#tnebTool .calc-ui button {
  height: 55px;
  border-radius: 14px;
  border: none;
  font-size: 18px;
  font-weight: 600;
  cursor: pointer;

  background: linear-gradient(145deg, #f3f4f6, #d1d5db);

  box-shadow: 
    4px 4px 8px rgba(0,0,0,0.25),
    -2px -2px 5px rgba(255,255,255,0.15);

  transition: all 0.15s ease;
}

/* -------------------------
   HOVER EFFECT
-------------------------- */
#tnebTool .calc-ui button:hover {
  transform: translateY(-2px);
  background: linear-gradient(145deg, #ffffff, #e5e7eb);
}

/* -------------------------
   CLICK EFFECT (IMPORTANT)
-------------------------- */
#tnebTool .calc-ui button:active {
  transform: scale(0.95);
  box-shadow: inset 3px 3px 6px rgba(0,0,0,0.3);
}

/* -------------------------
   SPECIAL BUTTONS
-------------------------- */

/* DELETE */
#tnebTool .calc-ui .delete {
  background: #9ca3af;
  color: white;
}

/* CLEAR */
#tnebTool .calc-ui .clear {
  background: #ef4444;
  color: white;
}

/* EQUAL / CALCULATE */
#tnebTool .calc-ui .submit-btn {
  background: #f59e0b;
  color: white;
}

/* -------------------------
   ZERO BUTTON (WIDER)
-------------------------- */
#tnebTool .calc-ui .keypad button:nth-last-child(1) {
  grid-column: span 2;
}

#tnebTool .tneb-result {
  max-width: 700px;     /* SAME as info-card */
  margin: 25px auto;
  background: #ffffff;
  padding: 22px;
  border-radius: 14px;
  box-shadow: 0 6px 20px rgba(0,0,0,0.05);
  line-height: 1.6;
}

#tnebTool .tneb-result h3 {
  font-size: 18px;
  margin-bottom: 10px;
}

#tnebTool .tneb-result ul {
  padding-left: 18px;
  margin-bottom: 10px;
}

#tnebTool #finalAmount {
  font-size: 20px;
  font-weight: 700;
  color: #16a34a;
}

/* -------------------------
   INFO + FAQ SECTIONS
-------------------------- */
#tnebTool .info-card,
#tnebTool .faq-card {
  max-width: 700px;
  margin: 20px auto;
  background: #ffffff;
  padding: 22px;
  border-radius: 14px;
  box-shadow: 0 6px 20px rgba(0,0,0,0.05);
}

/* -------------------------
   MOBILE OPTIMIZATION
-------------------------- */
@media (max-width: 480px) {
  #tnebTool .tneb-wrapper {
    padding: 0 10px;
  }

  #tnebTool .calc-ui {
    padding: 16px;
  }

  #tnebTool .calc-ui button {
    height: 50px;
    font-size: 16px;
  }

  #tnebTool #unitsInput {
    height: 55px;
    font-size: 20px;
  }
}