* {
    box-sizing: border-box;
}

body {
    background: #0f1115;
    color: #e4e6eb;
    font-family: system-ui, -apple-system, Segoe UI, Roboto, Inter, sans-serif;
    margin: 40px auto;
    max-width: 1100px;
}

/* layout */

.container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
}

/* panels */

.panel {
    background: #171a21;
    border: 1px solid #2f3645;
    border-radius: 10px;
    padding: 20px;
    border-color: #3f4a63;
}

.panel h2 {
    margin-top: 0;
    font-weight: 600;
    font-size: 18px;
}

/* output */

.panel pre {
    background: #0f1115;
    border: 1px solid #262b36;
    border-radius: 6px;
    padding: 14px;
    overflow: auto;
}

/* controls */

.controls {
    display: flex;
    gap: 40px;
    margin-bottom: 30px;
}

.control {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.control label {
    font-size: 13px;
    color: #9aa3b2;
}

/* number input group */

.number-input {
    display: flex;
    align-items: center;
    border: 1px solid #262b36;
    border-radius: 8px;
    overflow: hidden;
    background: #171a21;
}

.number-input input {
    width: 60px;
    text-align: center;
    border: none;
    background: transparent;
    color: #e4e6eb;
    font-size: 15px;
}

/* remove native spinners */

input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

/* buttons */

.number-input button {
    background: #1f2430;
    border: none;
    color: #c9d1d9;
    width: 32px;
    height: 32px;
    cursor: pointer;
    font-size: 16px;
}

.number-input button:hover {
    background: #2a3040;
}

.number-input button:active {
    background: #353c50;
}


/* remove number input arrows */

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

input[type="number"] {
    -moz-appearance: textfield; /* Firefox */
}

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

input[type="number"] {
  -moz-appearance: textfield;
}


.header {
    margin-bottom: 35px;
    max-width: 700px;
}

.header h1 {
    margin: 0 0 8px 0;
    font-size: 24px;
    font-weight: 600;
}

.header p {
    margin: 0;
    color: #9aa3b2;
    font-size: 14px;
    line-height: 1.4;
}

.footer {
    margin-top: 60px;
    padding-top: 20px;
    border-top: 1px solid #262b36;
}

.footer-inner {
    display: flex;
    flex-direction: column;
    flex-wrap: wrap;
    gap: 16px;
    font-size: 13px;
    color: #7f8796;
}

.footer a {
    color: #9aa3b2;
    text-decoration: none;
}

.footer a:hover {
    color: #cbd5e1;
}

.footer-tip {
    color: #9aa3b2;
}

.footer kbd {
    background: #1f2430;
    border: 1px solid #2f3645;
    border-radius: 4px;
    padding: 2px 6px;
    font-size: 12px;
    font-family: inherit;
}

/* ---------------- MOBILE ---------------- */

@media (max-width: 900px) {

  body {
    margin: 25px 20px;
  }

  .container {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .controls {
    flex-wrap: wrap;
    gap: 20px;
  }

  .control {
    flex: 1 1 160px;
  }

  .panel {
    padding: 16px;
  }

  .panel pre {
    font-size: 13px;
    overflow-x: auto;
    white-space: pre;
  }

}

@media (max-width: 600px) {

  .header h1 {
    font-size: 20px;
  }

  .header p {
    font-size: 13px;
  }

}