/* ==========================================================================
   Layout & Structure - Mobile-First Approach
   ========================================================================== */

/* ========================================
   Container - Responsive Wrapper
   ======================================== */
.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin: 20px auto;
  padding-left: var(--container-padding);
  padding-right: var(--container-padding);
}

/* ========================================
   Section Spacing - Mobile-First
   ======================================== */
.section {
  /* Mobile: smaller padding */
  padding-top: var(--section-padding-y-mobile);
  padding-bottom: var(--section-padding-y-mobile);
}

/* Tablet and up: larger padding */
@media (min-width: 768px) {
  .section {
    padding-top: var(--section-padding-y);
    padding-bottom: var(--section-padding-y);
  }
}

/* ========================================
   Section Backgrounds
   ======================================== */
.section--light {
  background-color: var(--color-white);
}

.section--gray {
  background-color: var(--color-bg-secondary);
}

.section--dark {
  background-color: var(--color-text-primary);
  color: var(--color-white);
}

/* ========================================
   Grid System - Mobile-First
   ======================================== */
.grid {
  display: grid;
  gap: var(--spacing-lg);
  width: 100%;
}

/* 2-column grid: mobile-first (stacks on mobile) */
.grid--2-cols {
  grid-template-columns: 1fr;
}

@media (min-width: 768px) {
  .grid--2-cols {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
  }
}

/* 3-column grid: mobile-first */
.grid--3-cols {
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .grid--3-cols {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .grid--3-cols {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* 4-column grid: mobile-first */
.grid--4-cols {
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .grid--4-cols {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .grid--4-cols {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* Responsive gap sizes */
.grid--gap-sm { gap: var(--spacing-sm); }
.grid--gap-md { gap: var(--spacing-md); }
.grid--gap-lg { gap: var(--spacing-lg); }
.grid--gap-xl { gap: var(--spacing-xl); }
.grid--gap-2xl { gap: var(--spacing-2xl); }

/* ========================================
   Flexbox Utilities - Mobile-Optimized
   ======================================== */
.flex {
  display: flex;
  gap: var(--spacing-md);
}

.flex-column {
  flex-direction: column;
}

.flex-row {
  flex-direction: row;
}

.flex-center {
  justify-content: center;
  align-items: center;
}

.flex-between {
  justify-content: space-between;
  align-items: center;
}

.flex-start {
  justify-content: flex-start;
  align-items: center;
}

.flex-end {
  justify-content: flex-end;
  align-items: center;
}

.flex-wrap {
  flex-wrap: wrap;
}

/* Flex item utilities */
.flex-1 { flex: 1; }
.flex-auto { flex: auto; }
.flex-none { flex: none; }

/* ========================================
   Spacing Utilities - 8px Grid System
   ======================================== */
/* Margin Top */
.mt-0 { margin-top: 0; }
.mt-xs { margin-top: var(--spacing-xs); }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }
.mt-2xl { margin-top: var(--spacing-2xl); }
.mt-3xl { margin-top: var(--spacing-3xl); }

/* Margin Bottom */
.mb-0 { margin-bottom: 0; }
.mb-xs { margin-bottom: var(--spacing-xs); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }
.mb-2xl { margin-bottom: var(--spacing-2xl); }
.mb-3xl { margin-bottom: var(--spacing-3xl); }

/* Margin Left & Right */
.mx-auto { 
  margin-left: auto; 
  margin-right: auto; 
}

/* Padding Top */
.pt-0 { padding-top: 0; }
.pt-xs { padding-top: var(--spacing-xs); }
.pt-sm { padding-top: var(--spacing-sm); }
.pt-md { padding-top: var(--spacing-md); }
.pt-lg { padding-top: var(--spacing-lg); }
.pt-xl { padding-top: var(--spacing-xl); }
.pt-2xl { padding-top: var(--spacing-2xl); }
.pt-3xl { padding-top: var(--spacing-3xl); }

/* Padding Bottom */
.pb-0 { padding-bottom: 0; }
.pb-xs { padding-bottom: var(--spacing-xs); }
.pb-sm { padding-bottom: var(--spacing-sm); }
.pb-md { padding-bottom: var(--spacing-md); }
.pb-lg { padding-bottom: var(--spacing-lg); }
.pb-xl { padding-bottom: var(--spacing-xl); }
.pb-2xl { padding-bottom: var(--spacing-2xl); }
.pb-3xl { padding-bottom: var(--spacing-3xl); }

/* Padding All Sides */
.p-0 { padding: 0; }
.p-xs { padding: var(--spacing-xs); }
.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }
.p-2xl { padding: var(--spacing-2xl); }

/* ========================================
   Width Utilities - Readability Optimized
   ======================================== */
.w-full { width: 100%; }
.w-auto { width: auto; }

/* Max-width utilities for content readability */
.max-w-xs {
  max-width: 320px;
  margin-left: auto;
  margin-right: auto;
}

.max-w-sm {
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}

.max-w-md {
  max-width: 768px;
  margin-left: auto;
  margin-right: auto;
}

.max-w-lg {
  max-width: 1024px;
  margin-left: auto;
  margin-right: auto;
}

.max-w-xl {
  max-width: 1280px;
  margin-left: auto;
  margin-right: auto;
}

/* Readable content width (65-75 characters) */
.max-w-prose {
  max-width: 65ch;
  margin-left: auto;
  margin-right: auto;
}

/* ========================================
   Display Utilities
   ======================================== */
.block { display: block; }
.inline-block { display: inline-block; }
.inline { display: inline; }
.hidden { display: none; }

/* Responsive display utilities */
@media (max-width: 639px) {
  .hidden-mobile { display: none; }
}

@media (min-width: 640px) {
  .visible-mobile-only { display: none; }
}

@media (min-width: 768px) {
  .hidden-tablet-up { display: none; }
}

/* ========================================
   Position Utilities
   ======================================== */
.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }
.sticky { position: sticky; }

/* ========================================
   Overflow Utilities
   ======================================== */
.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }
.overflow-x-hidden { overflow-x: hidden; }
.overflow-y-auto { overflow-y: auto; }