/* ==========================================================================
   FlexNet BEM Starter — BASE STRUCTURE (Token Exchange Architecture)
   
   THIS FILE CONTAINS:
   - All BEM class definitions
   - All layout rules
   - All component patterns
   - CSS variable REFERENCES only (var(--token-name))
   
   THIS FILE DOES NOT CONTAIN:
   - Design token definitions
   - Color values
   - Shadow definitions
   - Gradient definitions
   
   LOAD ORDER: 
   1. THIS FILE (bem-starter-base.css)
   2. ONE THEME FILE (theme-*.css)
   ========================================================================== */

/* == 0) Reset / Base ====================================================== */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; height: 100%; }
body {
  margin: 0; height: 100%;
  font: 400 16px/1.65 system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  color: var(--color-fg); 
  background: var(--color-bg);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased; 
  -moz-osx-font-smoothing: grayscale;
}
img, svg, video, canvas, iframe { display: block; max-width: 100%; height: auto; }
button, input, select, textarea { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid color-mix(in srgb, var(--color-primary) 60%, transparent); outline-offset: 2px; }

/* == 1) Layout Tokens (non-visual) ======================================= */
:root {
  --header-h: 92px;
  --header-pad-y: 12px;
  --header-pad-x: clamp(18px, 4.5vw, 44px);
  --logo-h: 68px;
  --brand-gap: 8px;
  --brand-nudge: 0px;
  --header-gap-below: clamp(36px, 5vh, 56px);
  --layout-gap: clamp(22px, 3vw, 36px);
  --stack-top: clamp(10px, 1.2vh, 18px);
  --radius-sm: .375rem; 
  --radius-md: .625rem; 
  --radius-lg: .875rem; 
  --radius-xl: 1.25rem;
  --z-header: 100;
  --z-overlay: 900;
}

/* == 2) Page Shell ======================================================== */
.c-doc-layout { 
  min-height: 100svh; 
  background: var(--bg-gradient); 
}

/* == 3) Header (fixed, full-width) ======================================= */
.c-doc-header {
  position: fixed; 
  inset: 0 0 auto 0;
  height: var(--header-h);
  z-index: var(--z-header);
  background: var(--header-gradient);
  backdrop-filter: var(--backdrop-filter);
  border-bottom: 1px solid color-mix(in srgb, var(--color-border) 75%, transparent);
  box-shadow: var(--header-shadow);
}

.c-doc-header__inner {
  height: 100%;
  display: flex;
  align-items: center;
  gap: max(0px, var(--brand-gap));
  padding: var(--header-pad-y) var(--header-pad-x);
}

.c-doc-header__logo {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  text-decoration: none;
}
.c-doc-header__logo img { 
  display: block; 
  height: var(--logo-h); 
  width: auto; 
  filter: var(--logo-filter);
}

.c-doc-header__brand {
  flex: 0 1 auto;
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-width: 0;
  white-space: nowrap;
  margin-left: var(--brand-nudge);
}
.c-doc-header__title {
  margin: 0; 
  font-weight: 800; 
  letter-spacing: .2px; 
  line-height: 1;
  font-size: clamp(22px, 2.2vw + 10px, 34px);
  text-shadow: var(--text-shadow-primary);
}
.c-doc-header__subtitle {
  margin: 2px 0 0 0; 
  color: var(--color-fg-muted);
  font-size: .95rem; 
  line-height: 1.05; 
  white-space: nowrap;
}

.c-doc-header__nav { 
  margin-left: auto; 
  display: flex; 
  align-items: center; 
  gap: clamp(12px, 2vw, 28px); 
}
.c-doc-header__link { 
  text-decoration: none; 
  color: var(--color-fg-muted); 
  font-weight: 500; 
  transition: color .2s ease, text-shadow .2s ease;
}
.c-doc-header__link[aria-current="page"], 
.c-doc-header__link:hover { 
  color: var(--color-fg); 
  text-shadow: var(--text-shadow-accent);
}

/* == 4) Main band ======================================================== */
.c-doc-layout__main {
  display: grid;
  grid-template-columns: minmax(240px, 300px) 1fr;
  gap: var(--layout-gap);
  padding-inline: var(--header-pad-x);
  padding-top: calc(var(--header-h) + var(--header-gap-below));
  padding-bottom: clamp(40px, 6vh, 72px);
}

/* == 5) Sidebar ========================================================== */
.c-sidebar {
  position: sticky; 
  top: calc(var(--header-h) + var(--header-gap-below)); 
  align-self: start;
  background: var(--panel-gradient), linear-gradient(180deg, rgba(255,255,255,.02), rgba(255,255,255,0));
  border: 1px solid color-mix(in srgb, var(--color-border) 78%, transparent);
  border-radius: var(--radius-xl); 
  box-shadow: var(--panel-shadow);
  padding: clamp(16px, 2.4vw, 22px);
}
.c-sidebar__nav { 
  display: flex; 
  flex-direction: column; 
  gap: 0; 
}
.c-sidebar__title { 
  margin: 0; 
  font-weight: 700; 
  color: var(--color-fg); 
  letter-spacing: .2px; 
  line-height: 1.05; 
  text-shadow: var(--text-shadow-accent);
}
.c-sidebar__title + .c-sidebar__items { margin-top: 6px; }
.c-sidebar__items { 
  list-style: disc; 
  padding-left: 20px; 
  margin: 0; 
  color: var(--color-fg-muted); 
}
.c-sidebar__item + .c-sidebar__item { margin-top: 10px; }
.c-sidebar__link { 
  color: var(--color-primary); 
  text-decoration: none; 
  transition: color .2s ease, text-shadow .2s ease;
}
.c-sidebar__link:hover { 
  text-decoration: underline; 
  text-shadow: var(--text-shadow-accent);
}
.c-sidebar > * { 
  background: transparent; 
  box-shadow: none; 
  border: 0; 
}

/* == 5a) Sidebar Pills ==================================================== */
.c-pill-group {
  list-style: none;
  padding: 0;
  margin: 10px 0 0 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.c-pill-group__item { margin: 0; }

.c-pill {
  --_bg: color-mix(in srgb, var(--color-bg-elev) 92%, transparent);
  --_bd: color-mix(in srgb, var(--color-border) 92%, transparent);
  --_fg: var(--color-fg);

  display: block;
  text-decoration: none;
  user-select: none;
  padding: 10px 14px;
  border-radius: 9999px;
  background: var(--_bg);
  border: 1px solid var(--_bd);
  color: var(--_fg);
  box-shadow: var(--shadow-sm);
  transition: transform .15s ease, box-shadow .2s ease, background .2s ease, border-color .2s ease, color .2s ease;
}

.c-pill__label {
  display: inline-block;
  font-weight: 600;
  letter-spacing: .2px;
  line-height: 1.1;
}

.c-pill:hover,
.c-pill:focus-visible {
  border-color: color-mix(in srgb, var(--color-primary) 55%, var(--color-border));
  box-shadow: var(--pill-hover-shadow);
  transform: translateY(-1px);
}

.c-pill--active {
  --_bg: var(--pill-active-bg);
  --_bd: color-mix(in srgb, var(--color-primary) 82%, var(--color-border));
  --_fg: var(--color-primary-contrast);
  color: var(--_fg);
  box-shadow: var(--pill-active-shadow);
}

[data-theme="light"] .c-pill { --_bg: #ffffff; }

/* == 6) Content ========================================================== */
.c-doc-layout__content { min-width: 0; }
.c-doc-layout__content-inner { 
  max-width: 1100px; 
  margin-inline: auto; 
}

/* == 7) Hero ============================================================= */
.c-hero {
  margin-top: calc(var(--stack-top) + 2px);
  background: var(--panel-gradient), linear-gradient(180deg, rgba(255,255,255,.02), rgba(255,255,255,0));
  border: 1px solid color-mix(in srgb, var(--color-border) 78%, transparent);
  border-radius: var(--radius-xl); 
  box-shadow: var(--panel-shadow);
  padding: clamp(18px, 3.5vw, 28px) clamp(18px, 4vw, 36px);
}
.c-hero__title {
  margin: 0 0 10px 0; 
  font-weight: 800;
  font-size: clamp(28px, 2.4vw + 16px, 56px); 
  letter-spacing: .3px; 
  line-height: 1.1;
  color: var(--color-fg); 
  text-shadow: var(--hero-title-shadow);
}
.c-hero__subtitle { 
  margin: 0 0 18px 0; 
  color: var(--color-fg-muted); 
  font-size: clamp(14px, .35vw + 14px, 18px); 
}
.c-hero__actions { 
  display: flex; 
  gap: 14px; 
  flex-wrap: wrap; 
}

/* == 8) Buttons ========================================================== */
.c-button {
  --_bg: var(--color-primary); 
  --_fg: var(--color-primary-contrast); 
  --_bd: transparent;
  display: inline-flex; 
  align-items: center; 
  justify-content: center; 
  gap: .5rem;
  padding: .6rem 1rem; 
  border-radius: 999px;
  border: 1px solid var(--_bd); 
  background: var(--_bg); 
  color: var(--_fg);
  text-decoration: none; 
  cursor: pointer;
  box-shadow: var(--button-shadow);
  transition: transform .06s ease, box-shadow .2s ease, background .2s ease, color .2s ease, border-color .2s ease;
}
.c-button:hover { 
  transform: translateY(-1px); 
  box-shadow: var(--button-hover-shadow); 
}
.c-button:active { 
  transform: none; 
  box-shadow: var(--button-active-shadow); 
}
.c-button--ghost { 
  --_bg: transparent; 
  --_fg: var(--color-primary); 
  --_bd: color-mix(in srgb, var(--color-primary) 70%, var(--color-border)); 
  box-shadow: none; 
}
.c-button--secondary { 
  --_bg: var(--button-secondary-bg); 
  box-shadow: var(--button-secondary-shadow);
}
.c-button--secondary:hover {
  box-shadow: var(--button-secondary-hover-shadow);
}

/* == 9) Cards, Alerts, Tables =========================================== */
.c-card { 
  background: var(--color-bg-elev); 
  border: 1px solid var(--color-border); 
  border-radius: var(--radius-lg); 
  box-shadow: var(--shadow-md); 
  overflow: hidden; 
}
.c-card__header, .c-card__body, .c-card__footer { padding: 16px 18px; }
.c-card__header { 
  font-weight: 700; 
  border-bottom: 1px solid var(--color-border); 
}
.c-card__footer { 
  border-top: 1px solid var(--color-border); 
}

.c-alert { 
  border: 1px solid var(--color-border); 
  border-left-width: 4px; 
  padding: 12px 16px; 
  border-radius: var(--radius-md); 
  background: color-mix(in srgb, var(--color-bg) 94%, transparent); 
}
.c-alert--success { 
  border-left-color: #16a34a; 
  box-shadow: 0 0 8px rgba(22,163,74,.3); 
}
.c-alert--warning { 
  border-left-color: #ca8a04; 
  box-shadow: 0 0 8px rgba(202,138,4,.3); 
}
.c-alert--danger { 
  border-left-color: #dc2626; 
  box-shadow: 0 0 8px rgba(220,38,38,.3); 
}
.c-alert__title { 
  font-weight: 700; 
  margin: 0 0 4px; 
}
.c-alert__desc { 
  color: var(--color-fg-muted); 
  margin: 0; 
}

.c-table { 
  width: 100%; 
  border-collapse: collapse; 
  border: 1px solid var(--color-border); 
  border-radius: var(--radius-md); 
  overflow: hidden; 
}
.c-table th, .c-table td { 
  padding: 12px 16px; 
  border-bottom: 1px solid var(--color-border); 
}
.c-table thead th { 
  text-align: left; 
  color: var(--color-fg-muted); 
  background: color-mix(in srgb, var(--color-bg) 92%, transparent); 
  text-shadow: var(--text-shadow-accent);
}

/* == 10) Tabs ============================================================ */
.c-tabs { 
  display: grid; 
  gap: 10px; 
}
.c-tabs__list { 
  display: flex; 
  gap: 8px; 
  border-bottom: 1px solid var(--color-border); 
}
.c-tabs__tab { 
  appearance: none; 
  background: transparent; 
  border: none; 
  padding: 8px 10px; 
  border-bottom: 2px solid transparent; 
  cursor: pointer; 
  color: var(--color-fg-muted); 
  transition: color .2s ease, border-color .2s ease, text-shadow .2s ease;
}
.c-tabs__tab[aria-selected="true"] { 
  color: var(--color-fg); 
  border-bottom-color: var(--color-primary); 
  text-shadow: var(--text-shadow-accent);
}
.c-tabs__tab:hover { 
  text-shadow: var(--text-shadow-accent); 
}
.c-tabs__panel { display: none; }
.c-tabs__panel[aria-hidden="false"] { display: block; }

/* == 11) Documentation Content ========================================== */
.c-doc-content { max-width: none; }
.c-doc-content h1 { 
  font-size: clamp(28px, 2.2vw + 14px, 44px); 
  line-height: 1.2; 
  margin: 0 0 12px; 
  font-weight: 800; 
  color: var(--color-fg); 
  text-shadow: var(--text-shadow-accent);
}
.c-doc-content h2 { 
  font-size: clamp(22px, 1.4vw + 12px, 28px); 
  line-height: 1.3; 
  margin: 28px 0 10px; 
  font-weight: 700; 
  border-bottom: 2px solid color-mix(in srgb, var(--color-primary) 55%, transparent); 
  padding-bottom: 6px; 
  text-shadow: var(--text-shadow-accent);
}
.c-doc-content h3 { 
  font-size: clamp(18px, .9vw + 12px, 22px); 
  margin: 20px 0 8px; 
  font-weight: 700; 
  text-shadow: var(--text-shadow-accent);
}
.c-doc-content p, .c-doc-content ul, .c-doc-content ol { 
  color: var(--color-fg-muted); 
}
.c-doc-content code { 
  background: color-mix(in srgb, var(--color-bg) 90%, transparent); 
  color: var(--code-color); 
  padding: .125rem .375rem; 
  border-radius: var(--radius-sm); 
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; 
  font-size: .9em; 
  box-shadow: var(--code-shadow);
}

/* == 12) Footer ========================================================== */
.c-footer { 
  border-top: 1px solid color-mix(in srgb, var(--color-border) 75%, transparent); 
  background: transparent; 
}
.c-footer__inner { 
  min-height: 64px; 
  display: flex; 
  align-items: center; 
  justify-content: center; 
  padding: 16px; 
  color: var(--color-fg-muted); 
  text-align: center; 
}

.c-doc-footer {
  margin-top: clamp(24px, 4vw, 64px);
  background: var(--footer-bg);
}

.c-doc-footer__grid {
  background: transparent;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(16px, 2vw, 28px);
  max-width: 1100px;
  padding: clamp(20px, 2.4vw, 28px) clamp(20px, 3vw, 36px) clamp(36px, 3vw, 48px);
  margin: 0 auto clamp(22px, 3vw, 36px);
  border-top: 1px solid color-mix(in srgb, var(--color-border) 70%, transparent);
  border-radius: 16px 16px 0 0;
}
@media (min-width: 900px) {
  .c-doc-footer__grid { 
    grid-template-columns: repeat(3, minmax(0, 1fr)); 
    gap: clamp(24px, 3vw, 40px); 
  }
}

.c-doc-footer__section {
  background: var(--footer-section-bg);
  border: 1px solid color-mix(in srgb, var(--color-border) 78%, transparent);
  border-radius: var(--radius-lg);
  box-shadow: var(--panel-shadow);
  padding: clamp(18px, 2.6vw, 24px);
}
.c-doc-footer__section-title { 
  margin: 0 0 8px; 
  font-size: 1rem; 
  font-weight: 700; 
  line-height: 1.2; 
  color: var(--color-fg); 
  text-shadow: var(--text-shadow-accent);
}
.c-doc-footer__section-content { 
  font-size: .95rem; 
  color: var(--color-fg-muted); 
}

.c-doc-footer__links { 
  list-style: none; 
  padding: 0; 
  margin: 0; 
  display: grid; 
  row-gap: 6px; 
}
.c-doc-footer__link { 
  color: var(--color-primary); 
  text-decoration: none; 
  transition: color .2s ease, text-shadow .2s ease;
}
.c-doc-footer__link:hover, 
.c-doc-footer__link:focus { 
  text-decoration: underline; 
  text-shadow: var(--text-shadow-accent);
}

.c-doc-footer__bottom {
  background: var(--footer-bottom-bg);
  width: 100%;
  margin: 0;
  padding: clamp(14px, 2vw, 22px);
  border-top: 1px solid color-mix(in srgb, var(--color-border) 75%, transparent);
  text-align: center;
}
.c-doc-footer__copyright { 
  margin: 0; 
  font-size: .9rem; 
  color: var(--color-fg-muted); 
}

/* == 13) Utilities ======================================================= */
.u-hidden { display: none !important; }
.u-flex { display: flex !important; }
.u-items-center { align-items: center !important; }
.u-justify-between { justify-content: space-between !important; }
.u-text-center { text-align: center !important; }
.u-w-full { width: 100% !important; }
.u-rounded-lg { border-radius: var(--radius-lg) !important; }
.u-border { border: 1px solid var(--color-border) !important; }
.u-shadow-sm { box-shadow: var(--shadow-sm) !important; }
.u-mt-0 { margin-top: 0 !important; }
.u-mb-0 { margin-bottom: 0 !important; }
.u-mt-4 { margin-top: 1rem !important; }
.u-mb-4 { margin-bottom: 1rem !important; }
.u-p-4 { padding: 1rem !important; }
.u-space-y-2 > * + * { margin-top: .5rem !important; }
.u-space-y-4 > * + * { margin-top: 1rem !important; }
.u-space-y-6 > * + * { margin-top: 1.5rem !important; }

/* == 14) Reduced Motion ================================================== */
@media (prefers-reduced-motion: reduce) {
  * { 
    animation-duration: .01ms !important; 
    animation-iteration-count: 1 !important; 
    transition-duration: .01ms !important; 
    scroll-behavior: auto !important; 
  }
}

/* == 15) Responsive Tweaks ============================================== */
@media (max-width: 980px) {
  .c-doc-layout__main { grid-template-columns: 1fr; }
  .c-sidebar { order: -1; }
  .c-doc-header__title { font-size: clamp(20px, 5.2vw, 30px); }
  .c-doc-header__subtitle { font-size: .9rem; }
}

/* ==========================================================================
   END OF BASE STRUCTURE FILE
   
   This file contains ZERO color definitions, ZERO shadow values, ZERO gradients.
   All visual styling comes from theme files loaded AFTER this file.
   ========================================================================== */