CSS Grid: Build Any Layout

.container {
    display: grid;
    grid-template-columns: 200px 1fr 200px; /* 3 columns */
    grid-template-rows: 80px 1fr 60px;      /* 3 rows */
    gap: 16px;                               /* Space between cells */
}

/* Fixed widths */
grid-template-columns: 100px 200px 100px;

/* Percentage widths */
grid-template-columns: 25% 50% 25%;

/* Fractional units — responsive by default */
grid-template-columns: 1fr 2fr 1fr;

/* Mixed */
grid-template-columns: 200px 1fr;  /* Fixed sidebar, flexible content */

/* repeat() — less repetition */
grid-template-columns: repeat(3, 1fr);     /* 3 equal columns */
grid-template-columns: repeat(4, 200px);   /* 4 fixed columns */

/* Creates as many columns as fit, each at least 250px wide */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 24px;
}

/* auto-fill: creates empty columns if there's space */
/* auto-fit: collapses empty columns (usually what you want) */
.card-grid {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.item {
    grid-column: 1 / 3;    /* Start at line 1, end at line 3 (spans 2 columns) */
    grid-row: 1 / 2;       /* First row only */
}

/* Shorthand: grid-column-start / grid-column-end */
.header  { grid-column: 1 / -1; }  /* -1 = last line → spans full width */
.sidebar { grid-column: 1 / 2; grid-row: 2 / 4; }  /* Spans 2 rows */
.main    { grid-column: 2 / -1; grid-row: 2 / 3; }

.feature-card {
    grid-column: span 2;  /* Spans 2 columns from its current position */
    grid-row: span 2;     /* Spans 2 rows */
}

.page {
    display: grid;
    grid-template-columns: 220px 1fr;
    grid-template-rows: 70px 1fr 60px;
    grid-template-areas:
        "header  header"
        "sidebar main  "
        "footer  footer";
    gap: 0;
    min-height: 100vh;
}

.header  { grid-area: header; }
.sidebar { grid-area: sidebar; }
.main    { grid-area: main; }
.footer  { grid-area: footer; }

/* Align all items within the grid */
.container {
    justify-items: start | center | end | stretch;  /* Along row axis */
    align-items:   start | center | end | stretch;  /* Along column axis */
    place-items:   center;                          /* Shorthand for both */
}

/* Align the entire grid within its container */
.container {
    justify-content: start | center | end | space-between | space-around;
    align-content:   start | center | end | space-between;
}

/* Override alignment for a single item */
.special-item {
    justify-self: center;
    align-self: end;
    place-self: center end;  /* Shorthand */
}

<div class="blog-layout">
    <header class="blog-header">Header</header>
    <main class="blog-main">Article Content</main>
    <aside class="blog-sidebar">Sidebar</aside>
    <footer class="blog-footer">Footer</footer>
</div>

.blog-layout {
    display: grid;
    grid-template-columns: 1fr 300px;
    grid-template-rows: auto 1fr auto;
    grid-template-areas:
        "header  header"
        "main    sidebar"
        "footer  footer";
    gap: 24px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
}

.blog-header { grid-area: header; }
.blog-main   { grid-area: main; }
.blog-sidebar{ grid-area: sidebar; }
.blog-footer { grid-area: footer; }

/* Responsive: stack on mobile */
@media (max-width: 768px) {
    .blog-layout {
        grid-template-columns: 1fr;
        grid-template-areas:
            "header"
            "main"
            "sidebar"
            "footer";
    }
}

.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 32px;
    padding: 40px 20px;
}

/* Feature one card: spans 2 columns */
.product-card.featured {
    grid-column: span 2;
}

@media (max-width: 600px) {
    .product-card.featured {
        grid-column: span 1;
    }
}

.dashboard {
    display: grid;
    grid-template-columns: 250px 1fr 1fr;
    grid-template-rows: 64px repeat(3, 1fr);
    grid-template-areas:
        "nav    header  header"
        "nav    stats   stats "
        "nav    chart   table "
        "nav    chart   table ";
    height: 100vh;
    gap: 0;
}