/* ==========================================================================
   LAYOUT.CSS — Layout System & Utilities
   Option 3: Modern Tech / Neo-Corporate Dark Theme
   SRS Management Website
   ========================================================================== */

/* ---- Container ---- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 5vw;
  padding-right: 5vw;
}

.container--narrow {
  max-width: 860px;
}

.container--wide {
  max-width: 1400px;
}

/* ---- Section Padding ---- */
.section-pad {
  padding-top: var(--space-3xl);
  padding-bottom: var(--space-3xl);
}

.section-pad--sm {
  padding-top: var(--space-2xl);
  padding-bottom: var(--space-2xl);
}

.section-pad--lg {
  padding-top: 200px;
  padding-bottom: 200px;
}

/* ---- Navigation ---- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-nav);
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-left: 5vw;
  padding-right: 5vw;
  background-color: transparent;
  transition:
    background-color var(--duration-base) var(--ease-out),
    border-color var(--duration-base) var(--ease-out),
    backdrop-filter var(--duration-base) var(--ease-out);
  border-bottom: 1px solid transparent;
}

.nav--scrolled {
  background-color: var(--color-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom-color: var(--color-glass-border);
}

/* ---- Split Layout ---- */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: center;
}

.split--40-60 {
  grid-template-columns: 2fr 3fr;
}

.split--60-40 {
  grid-template-columns: 3fr 2fr;
}

.split--top {
  align-items: start;
}

/* ---- Standard Grids ---- */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

/* ---- Flex Utilities ---- */
.flex {
  display: flex;
}

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

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

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

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

.items-center {
  align-items: center;
}

.items-start {
  align-items: flex-start;
}

.items-end {
  align-items: flex-end;
}

.justify-center {
  justify-content: center;
}

.justify-between {
  justify-content: space-between;
}

.gap-xs  { gap: var(--space-xs); }
.gap-sm  { gap: var(--space-sm); }
.gap-md  { gap: var(--space-md); }
.gap-lg  { gap: var(--space-lg); }
.gap-xl  { gap: var(--space-xl); }

/* ---- Dividers ---- */
.divider {
  width: 100%;
  height: 1px;
  background-color: var(--color-border);
  border: none;
}

.divider--accent {
  background: linear-gradient(
    90deg,
    transparent 0%,
    var(--color-accent) 50%,
    transparent 100%
  );
  opacity: 0.3;
}

/* ---- Spacing Utilities ---- */
.mt-0   { margin-top: 0; }
.mt-xs  { margin-top: var(--space-xs); }
.mt-sm  { margin-top: var(--space-sm); }
.mt-md  { margin-top: var(--space-md); }
.mt-lg  { margin-top: var(--space-lg); }
.mt-xl  { margin-top: var(--space-xl); }
.mt-2xl { margin-top: var(--space-2xl); }
.mt-3xl { margin-top: var(--space-3xl); }

.mb-0   { margin-bottom: 0; }
.mb-xs  { margin-bottom: var(--space-xs); }
.mb-sm  { margin-bottom: var(--space-sm); }
.mb-md  { margin-bottom: var(--space-md); }
.mb-lg  { margin-bottom: var(--space-lg); }
.mb-xl  { margin-bottom: var(--space-xl); }
.mb-2xl { margin-bottom: var(--space-2xl); }
.mb-3xl { margin-bottom: var(--space-3xl); }

.pt-0   { padding-top: 0; }
.pt-sm  { padding-top: var(--space-sm); }
.pt-md  { padding-top: var(--space-md); }
.pt-lg  { padding-top: var(--space-lg); }
.pt-xl  { padding-top: var(--space-xl); }

.pb-0   { padding-bottom: 0; }
.pb-sm  { padding-bottom: var(--space-sm); }
.pb-md  { padding-bottom: var(--space-md); }
.pb-lg  { padding-bottom: var(--space-lg); }
.pb-xl  { padding-bottom: var(--space-xl); }

/* ---- Width Utilities ---- */
.w-full { width: 100%; }

.max-w-narrow {
  max-width: 550px;
}

.max-w-medium {
  max-width: 720px;
}

/* ---- Position Utilities ---- */
.relative { position: relative; }
.absolute { position: absolute; }

/* ---- Overflow ---- */
.overflow-hidden { overflow: hidden; }

/* ---- Visibility ---- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}