Box Model and Layout Fundamentals

/* Traditional box model (content-box) */
.box {
    width: 200px;         /* Content width */
    height: 100px;        /* Content height */
    padding: 20px;        /* +40px to width, +40px to height */
    border: 5px solid;    /* +10px to width, +10px to height */
    margin: 10px;         /* Spacing outside (doesn't add to size) */
    /* Total width: 200 + 40 + 10 = 250px */
    /* Total height: 100 + 40 + 10 = 150px */
}

/* Shorthand patterns */
.padding-all { padding: 20px; } /* All sides */
.padding-vh { padding: 10px 20px; } /* V: 10px, H: 20px */
.padding-3 { padding: 10px 20px 30px; } /* T: 10px, H: 20px, B: 30px */
.padding-4 { padding: 10px 20px 30px 40px; } /* T R B L (clockwise) */

/* Centering with auto margin */
.centered {
    width: 80%;
    max-width: 1200px;
    margin: 0 auto; /* Horizontal centering */
}

/* Individual sides */
.custom {
    margin-top: 2rem;
    margin-bottom: 1rem;
    padding-left: 1.5rem;
    padding-right: 1.5rem;
}

/* Global best practice - apply to all elements */
*, *::before, *::after {
    box-sizing: border-box;
}

/* content-box example (default) */
.content-box {
    box-sizing: content-box;
    width: 200px;
    padding: 20px;
    border: 5px solid;
    /* Total width: 200 + 20*2 + 5*2 = 250px */
}

/* border-box example (recommended) */
.border-box {
    box-sizing: border-box;
    width: 200px;
    padding: 20px;
    border: 5px solid;
    /* Total width: 200px (includes padding and border) */
    /* Content width: 200 - 20*2 - 5*2 = 150px */
}

/* Practical use - predictable layouts */
.container {
    box-sizing: border-box;
    width: 100%;
    padding: 20px; /* Doesn't cause horizontal overflow */
}

/* min-content - smallest possible width */
.min-width {
    width: min-content;
    /* Width = longest word or unbreakable content */
}

/* max-content - no wrapping */
.max-width {
    width: max-content;
    /* Expands to fit all content on one line */
}

/* fit-content - smart adaptive */
.fit-width {
    width: fit-content;
    /* Uses max-content if space available, otherwise wraps */
    max-width: 100%; /* Prevent overflow */
}

/* fit-content with limit */
.limited {
    width: fit-content(500px);
    /* Max 500px, shrinks if less space available */
}

/* Practical: button sizing */
button {
    width: fit-content; /* Wraps text naturally */
    min-width: 120px;   /* Minimum size */
}

/* Stretch - fill available space */
.stretch {
    width: stretch; /* Fills parent (like width: 100%) */
}

/* Card with dynamic width based on content */
.card {
    width: fit-content;
    min-width: 250px;
    max-width: 100%;
}

/* Table column sizing */
th, td {
    width: max-content; /* Fit content without wrapping */
}

/* Navigation items */
.nav-item {
    width: fit-content; /* Shrinks to content */
    padding: 0.5rem 1rem;
}

/* Grid with intrinsic columns */
.grid {
    display: grid;
    grid-template-columns: 
        min-content    /* Icon/image column - smallest possible */
        1fr            /* Main content - fills space */
        max-content;   /* Action buttons - no wrap */
}

/* Video container - 16:9 ratio */
.video-wrapper {
    width: 100%;
    aspect-ratio: 16 / 9;
    /* Height automatically calculated */
}

/* Square elements */
.avatar {
    width: 100px;
    aspect-ratio: 1 / 1; /* Square */
}

/* Card with consistent ratio */
.card {
    width: 100%;
    max-width: 400px;
    aspect-ratio: 3 / 4; /* Portrait card */
}

/* Image placeholder before loading */
.image-placeholder {
    width: 100%;
    aspect-ratio: 16 / 9;
    background: #f0f0f0;
}

/* Responsive grid items maintaining ratio */
.grid-item {
    width: 100%;
    aspect-ratio: 4 / 3;
}

/* With min/max constraints */
.constrained {
    aspect-ratio: 1 / 1;
    width: clamp(100px, 50vw, 500px);
    /* Height follows aspect ratio */
}

/* OLD WAY - padding-top hack */
.old-ratio {
    position: relative;
    width: 100%;
    padding-top: 56.25%; /* 16:9 ratio (9/16 = 0.5625) */
}

.old-ratio > * {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

/* NEW WAY - aspect-ratio property */
.new-ratio {
    width: 100%;
    aspect-ratio: 16 / 9; /* Much simpler! */
}

/* Combining with object-fit for images */
.responsive-image {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover; /* Fill without distortion */
}

/* Common pattern: responsive images */
.image-container {
    width: 300px;
    height: 200px;
}

/* cover - fills space, crops if needed */
.hero-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center; /* Focus on center */
}

/* contain - shows all, may have gaps */
.product-image {
    width: 100%;
    height: 100%;
    object-fit: contain;
    object-position: center;
}

/* scale-down - never enlarges */
.thumbnail {
    max-width: 150px;
    max-height: 150px;
    object-fit: scale-down;
}

/* none - original size */
.icon {
    width: 48px;
    height: 48px;
    object-fit: none;
}

/* Focus on top of image (faces, important content) */
.portrait {
    object-fit: cover;
    object-position: center top;
}

/* Focus on bottom */
.landscape {
    object-fit: cover;
    object-position: center bottom;
}

/* Precise positioning with percentages */
.off-center {
    object-fit: cover;
    object-position: 75% 25%; /* Right-upper focus */
}

/* Video element */
video {
    width: 100%;
    height: 400px;
    object-fit: cover;
    object-position: center;
}

/* Profile pictures - always square, centered */
.avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
    border-radius: 50%;
}

/* Auto - most common (scrollbar when needed) */
.scrollable-container {
    max-height: 400px;
    overflow: auto;
}

/* Hidden - clip overflow */
.image-container {
    overflow: hidden; /* Clips overflow content */
    border-radius: 8px; /* Creates rounded images */
}

/* Separate x and y control */
.horizontal-scroll {
    overflow-x: auto;   /* Horizontal scroll when needed */
    overflow-y: hidden; /* No vertical scroll */
    white-space: nowrap; /* Prevent wrapping */
}

/* Vertical scroll only */
.chat-box {
    height: 500px;
    overflow-y: auto;   /* Vertical scroll */
    overflow-x: hidden; /* No horizontal scroll */
}

/* Clip - hard clip (no scroll programmatically) */
.strict-clip {
    overflow: clip; /* Cannot be scrolled even with JS */
}

/* Single line ellipsis */
.truncate {
    white-space: nowrap;      /* Prevent wrapping */
    overflow: hidden;         /* Hide overflow */
    text-overflow: ellipsis;  /* Show ... */
}

/* Multi-line ellipsis (webkit only) */
.multi-line-ellipsis {
    display: -webkit-box;
    -webkit-line-clamp: 3;    /* 3 lines */
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* Word breaking for long content */
.break-words {
    overflow-wrap: break-word; /* Break long words */
    word-break: break-word;    /* Alternative */
}

/* Card title truncation */
.card-title {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 300px;
}

/* Scrollable sidebar */
.sidebar {
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    overflow-x: hidden;
}

/* Horizontal scrolling gallery */
.gallery {
    display: flex;
    gap: 1rem;
    overflow-x: auto;
    overflow-y: hidden;
    scroll-snap-type: x mandatory; /* Snap scrolling */
}

/* Table with fixed header */
.table-container {
    max-height: 500px;
    overflow-y: auto;
}

/* Modal content */
.modal-content {
    max-height: 80vh;
    overflow-y: auto;
    overflow-x: hidden;
}

/* Code block with horizontal scroll */
pre {
    overflow-x: auto;
    white-space: pre;
}