*{
    margin: 0;
    padding: 0;
    font-family: Calisto MT,sans-serif;
    box-sizing: border-box;
}

body{
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background:linear-gradient(45deg,#181818,#162943)
}

.container{
    border: 2px solid #717371;
    padding: 20px;
    width: 90%;
    max-width: 400px;
    background: transparent;
    border-radius: 15px;
    box-shadow: 0px 3px 15px rgba(113,115,119,0.5);
}

.container > input {
  width: 100%;
  padding: 16px;
  margin-bottom: 12px;
  font-size: 2rem;
  text-align: right;
  border: none;
  background: transparent;
  color: white;
  box-shadow: 0 3px 15px rgba(84,84,84,0.2);
}

.container > input::placeholder {
  color: white;
}



input::placeholder{
    color: white;
}

/* make each row a flex container */
.container > div {
  display: flex;
  justify-content: space-between;
  margin-bottom: 8px;
}

button {
  flex: 1;
  margin: 4px;
  height: 60px;
  font-size: 1.25rem;
  color: white;
  border: none;
  border-radius: 50px;
  background: transparent;
  box-shadow: -4px -4px 12px rgba(255,255,255,0.2);
  cursor: pointer;
}

.color-sec{
  color: yellow;
}


button.equal {
  background-color: orange;
}

button.icon {
  color: #ffc654;
  background-color: rgb(63, 61, 61);
}

/* Small‑phone (up to 360px) */
@media (max-width: 360px) {
  .container {
    padding: 12px;
  }
  .container > input {
    padding: 12px;
    font-size: 1.5rem;
  }
  button {
    margin: 2px;
    height: 48px;
    font-size: 1rem;
  }
}

/* Phone (361px to 600px) */
@media (min-width: 361px) and (max-width: 600px) {
  .container {
    padding: 14px;
  }
  .container > input {
    padding: 14px;
    font-size: 1.75rem;
  }
  button {
    margin: 3px;
    height: 54px;
    font-size: 1.1rem;
  }
}

/* Tablet (601px to 900px) */
@media (min-width: 601px) and (max-width: 900px) {
  .container {
    padding: 18px;
  }
  .container > input {
    padding: 18px;
    font-size: 2rem;
  }
  button {
    margin: 4px;
    height: 60px;
    font-size: 1.25rem;
  }
}

/* Small‑desktop (901px to 1200px) */
@media (min-width: 901px) and (max-width: 1200px) {
  .container {
    padding: 20px;
  }
  .container > input {
    padding: 20px;
    font-size: 2.25rem;
  }
  button {
    margin: 6px;
    height: 66px;
    font-size: 1.4rem;
  }
}

/* Above 1200px – keep max‑width at 400px */
@media (min-width: 1201px) {
  .container {
    padding: 20px;
  }
  .container > input {
    padding: 24px;
    font-size: 2.5rem;
  }
  button {
    margin: 8px;
    height: 72px;
    font-size: 1.5rem;
  }
}