* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --gap: 20px;
  --container-max: 1200px;
  --break-sm: 576px;
  --break-md: 768px;
  --break-lg: 992px;
  --break-xl: 1200px;
}

body {
  font-family: Arial, sans-serif;
  line-height: 1.6;
  color: #333;
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 15px;
}


.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--gap);
}

.col-1  { grid-column: span 1; }
.col-2  { grid-column: span 2; }
.col-3  { grid-column: span 3; }
.col-4  { grid-column: span 4; }
.col-5  { grid-column: span 5; }
.col-6  { grid-column: span 6; }
.col-7  { grid-column: span 7; }
.col-8  { grid-column: span 8; }
.col-9  { grid-column: span 9; }
.col-10 { grid-column: span 10; }
.col-11 { grid-column: span 11; }
.col-12 { grid-column: span 12; }

@media (min-width: var(--break-sm)) {
  :root { --container-max: 540px; }
}
@media (min-width: var(--break-md)) {
  :root { --container-max: 720px; }
}
@media (min-width: var(--break-lg)) {
  :root { --container-max: 960px; }
}
@media (min-width: var(--break-xl)) {
  :root { --container-max: 1140px; }
}