:root {
   --bg: #fafafa;
   --card: #fff;
   --accent: #235775;
   --muted: #666;
}

* {
   box-sizing: border-box
}



.containercalc {
   max-width: 980px;
   margin: 0 auto;
   background: var(--card);
   padding: 20px;
   border-radius: 8px;
   box-shadow: 0 6px 18px rgba(20, 20, 20, 0.06);
}

h1 {
   margin: 0 0 12px;
   font-size: 1.6rem
}

.block {
   margin-bottom: 16px;
   padding-bottom: 8px;
   border-bottom: 1px solid #eee
}

.block h2 {
   margin: 0 0 8px;
   font-size: 1rem;
   color: var(--muted)
}

label {
   display: block;
   margin: 6px 0;
   font-size: 0.95rem;
   cursor: pointer;
}

input[type="number"] {
   width: 100%;
   padding: 8px 10px;
   margin-top: 6px;
   border: 1px solid #dcdcdc;
   border-radius: 4px;
   font-size: 0.95rem;
}

.controls {
   display: flex;
   gap: 12px;
   margin-top: 12px;
}

button {
   flex: 1;
   padding: 10px 14px;
   border: 0;
   border-radius: 6px;
   font-size: 1rem;
   cursor: pointer;
}

#calcBtn {
   background: var(--accent);
   color: #fff
}

#resetBtn {
   background: #eee;
   color: #333
}

.result {
   margin-top: 18px;
   padding: 12px;
   border-radius: 6px;
   background: #fff;
   border: 1px solid #eee;
}

/* мобильная адаптивность */
@media (max-width:720px) {
   .containercalc {
      padding: 14px
   }

   h1 {
      font-size: 1.3rem
   }

   .controls {
      flex-direction: column
   }

   button {
      width: 100%
   }

   label {
      font-size: 0.98rem
   }
}