/* ==========================================================================
   BlueLine Web Studio — Core stylesheet
   Reset -> Base -> Layout -> Header/Nav -> Footer -> Components -> Utilities
   ========================================================================== */

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img, svg, video { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; margin: 0; padding: 0; }
button { font: inherit; cursor: pointer; }
input, textarea, select { font: inherit; }

h1, h2, h3, h4, h5 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: var(--lh-tight);
  margin: 0 0 var(--space-4);
  letter-spacing: -0.02em;
}
p { margin: 0 0 var(--space-4); color: var(--color-text-muted); }
.on-dark p { color: var(--color-text-on-dark-muted); }

::selection { background: var(--color-primary); color: #fff; }

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---- Layout helpers ---- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-5);
}
@media (max-width: 640px) {
  .container { padding-inline: var(--space-4); }
}
.container--narrow { max-width: var(--container-narrow); }

.section { padding-block: var(--space-9); }
@media (max-width: 768px) {
  .section { padding-block: var(--space-7); }
}
.section--tight { padding-block: var(--space-7); }
.on-dark { background: var(--color-dark-1); color: var(--color-text-on-dark); }
.on-light { background: var(--color-bg); }
.on-surface { background: var(--color-surface); }

.grid { display: grid; gap: var(--space-6); }
.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 1024px) {
  .grid--4 { grid-template-columns: repeat(2, 1fr); }
  .grid--3 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .grid--2, .grid--3, .grid--4 { grid-template-columns: 1fr; }
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-display);
  font-size: var(--fs-micro);
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}
.eyebrow::before {
  content: "";
  width: 22px; height: 2px;
  background: var(--gradient-brand);
  border-radius: var(--radius-full);
}
.on-dark .eyebrow { color: var(--color-cyan); }

.text-gradient {
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.lede { font-size: var(--fs-body-lg); max-width: 60ch; }

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 15px 28px;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: var(--fs-body);
  border: 1px solid transparent;
  transition: transform var(--dur-base) var(--ease-out), box-shadow var(--dur-base) var(--ease-out), background var(--dur-base) var(--ease-out), color var(--dur-base) var(--ease-out);
  white-space: nowrap;
  min-height: 44px;
}
.btn:active { transform: scale(0.97); }
.btn:disabled { opacity: 0.6; cursor: not-allowed; transform: none !important; box-shadow: none !important; }
.btn-primary {
  background: var(--gradient-brand);
  color: #fff;
  box-shadow: var(--shadow-md);
}
.btn-primary:hover { box-shadow: var(--shadow-glow); transform: translateY(-2px); }
.btn-ghost {
  background: transparent;
  border-color: var(--color-border);
  color: var(--color-text);
}
.btn-ghost:hover { border-color: var(--color-primary); color: var(--color-primary); }
.on-dark .btn-ghost { border-color: var(--color-dark-border); color: var(--color-text-on-dark); }
.on-dark .btn-ghost:hover { border-color: var(--color-cyan); color: var(--color-cyan); }
.btn-sm { padding: 10px 20px; font-size: var(--fs-small); min-height: 38px; }
.btn-block { width: 100%; }

/* ---- Header / Nav ---- */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: var(--z-header);
  height: var(--header-h);
  display: flex;
  align-items: center;
  transition: background var(--dur-base) var(--ease-out), border-color var(--dur-base) var(--ease-out), backdrop-filter var(--dur-base) var(--ease-out);
  border-bottom: 1px solid transparent;
}
.site-header .container { display: flex; align-items: center; justify-content: space-between; width: 100%; }
.site-header.is-scrolled {
  background: rgba(5, 7, 13, 0.72);
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  border-bottom-color: var(--color-dark-border);
}
.site-header:not(.theme-dark-hero) { background: rgba(250,250,251,0.8); backdrop-filter: blur(16px); border-bottom-color: var(--color-border); }
.site-header:not(.theme-dark-hero):not(.is-scrolled) { background: transparent; border-bottom-color: transparent; }

.logo { display: flex; align-items: center; gap: var(--space-3); z-index: 2; }
.logo-mark { width: 38px; height: 38px; flex-shrink: 0; }
.logo-text {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-text-on-dark);
  letter-spacing: -0.01em;
}
.site-header:not(.theme-dark-hero):not(.is-scrolled) .logo-text,
.site-header:not(.theme-dark-hero) .logo-text { color: var(--color-text); }
.site-header.theme-dark-hero .logo-text { color: #fff; }
.logo-text .accent { background: var(--gradient-brand); -webkit-background-clip: text; background-clip: text; color: transparent; }

.nav-main { display: flex; align-items: center; gap: var(--space-7); }
.nav-links { display: flex; align-items: center; gap: var(--space-6); }
.nav-links a:not(.btn) {
  font-size: var(--fs-small);
  font-weight: 500;
  color: var(--color-text-on-dark-muted);
  position: relative;
  padding: 4px 0;
}
.site-header:not(.theme-dark-hero) .nav-links a { color: var(--color-text-muted); }
.nav-links a:hover, .nav-links a.is-active { color: var(--color-text-on-dark); }
.site-header:not(.theme-dark-hero) .nav-links a:hover,
.site-header:not(.theme-dark-hero) .nav-links a.is-active { color: var(--color-text); }
.nav-links a.is-active::after {
  content: "";
  position: absolute; left: 0; bottom: -6px;
  width: 100%; height: 2px;
  background: var(--gradient-brand);
  border-radius: var(--radius-full);
}

.nav-toggle {
  display: none;
  width: 44px; height: 44px;
  align-items: center; justify-content: center;
  background: none; border: none;
  z-index: 2;
}
.nav-toggle svg { color: var(--color-text-on-dark); }
.site-header:not(.theme-dark-hero) .nav-toggle svg { color: var(--color-text); }

@media (max-width: 900px) {
  .nav-links { position: fixed; inset: 0; z-index: 1; background: var(--color-dark-1);
    flex-direction: column; justify-content: center; align-items: center; gap: var(--space-6);
    transform: translateY(-100%); opacity: 0; transition: transform var(--dur-slow) var(--ease-in-out), opacity var(--dur-slow) var(--ease-in-out);
    pointer-events: none;
  }
  .nav-links a:not(.btn) { font-size: var(--fs-h3); color: #fff; }
  .nav-links.is-open { transform: translateY(0); opacity: 1; pointer-events: auto; }
  .nav-main .btn { display: none; }
  .nav-links .btn { display: inline-flex; margin-top: var(--space-4); }
  .nav-toggle { display: inline-flex; }
}

/* ---- Footer ---- */
.site-footer {
  background: var(--color-dark-1);
  color: var(--color-text-on-dark);
  padding-block: var(--space-9) var(--space-6);
  position: relative;
  overflow: hidden;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(3, 1fr);
  gap: var(--space-6);
  margin-bottom: var(--space-8);
}
@media (max-width: 900px) {
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 560px) {
  .footer-grid { grid-template-columns: 1fr; }
}
.footer-brand p { max-width: 32ch; margin-top: var(--space-4); }
.footer-col h4 { font-size: var(--fs-small); text-transform: uppercase; letter-spacing: 0.08em; color: var(--color-text-on-dark-muted); margin-bottom: var(--space-4); }
.footer-col a, .footer-col li { color: var(--color-text-on-dark-muted); display: block; margin-bottom: var(--space-3); font-size: var(--fs-small); transition: color var(--dur-fast); }
.footer-col a:hover { color: #fff; }
.footer-bottom {
  display: flex; justify-content: space-between; align-items: center;
  padding-top: var(--space-6); border-top: 1px solid var(--color-dark-border);
  font-size: var(--fs-micro); color: var(--color-text-on-dark-muted);
  flex-wrap: wrap; gap: var(--space-4);
}
.social-row { display: flex; gap: var(--space-3); }
.social-row a {
  width: 38px; height: 38px; border-radius: var(--radius-full);
  border: 1px solid var(--color-dark-border);
  display: flex; align-items: center; justify-content: center;
  transition: border-color var(--dur-fast), transform var(--dur-fast);
}
.social-row a:hover { border-color: var(--color-cyan); transform: translateY(-2px); }

/* ---- Cards ---- */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-6);
  transition: transform var(--dur-base) var(--ease-out), box-shadow var(--dur-base) var(--ease-out), border-color var(--dur-base) var(--ease-out);
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: transparent; }
.card-icon {
  width: 52px; height: 52px; border-radius: var(--radius-sm);
  background: var(--gradient-brand-soft);
  display: flex; align-items: center; justify-content: center;
  color: var(--color-primary);
  margin-bottom: var(--space-5);
}
.card-icon svg { width: 26px; height: 26px; }

.card--dark {
  background: var(--color-dark-2);
  border: 1px solid var(--color-dark-border);
  color: var(--color-text-on-dark);
}
.card--dark:hover { border-color: var(--color-primary); }

/* ---- Stats ---- */
.stat-num {
  font-family: var(--font-display);
  font-size: var(--fs-h1);
  font-weight: 700;
  background: var(--gradient-brand);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  display: inline-block;
}
.stat-label { font-size: var(--fs-small); color: var(--color-text-on-dark-muted); }

/* ---- Section header pattern ---- */
.section-head { max-width: 640px; margin-bottom: var(--space-8); }
.section-head--center { margin-inline: auto; text-align: center; }

/* ---- Utilities ---- */
.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.gap-2 { gap: var(--space-2); } .gap-3 { gap: var(--space-3); } .gap-4 { gap: var(--space-4); } .gap-5 { gap: var(--space-5); }
.mt-0 { margin-top: 0; } .mb-0 { margin-bottom: 0 !important; }
.text-center { text-align: center; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* ---- Page hero (non-home pages, light editorial) ---- */
.page-hero {
  padding-top: calc(var(--header-h) + var(--space-9));
  padding-bottom: var(--space-8);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}
.page-hero h1 { max-width: 16ch; }

/* ---- Back-to-top ---- */
.to-top {
  position: fixed; right: var(--space-5); bottom: var(--space-5);
  width: 48px; height: 48px; border-radius: var(--radius-full);
  background: var(--gradient-brand); color: #fff;
  display: flex; align-items: center; justify-content: center;
  box-shadow: var(--shadow-md);
  opacity: 0; pointer-events: none; transform: translateY(10px);
  transition: opacity var(--dur-base) var(--ease-out), transform var(--dur-base) var(--ease-out);
  z-index: var(--z-header);
  border: none;
}
.to-top.is-visible { opacity: 1; pointer-events: auto; transform: translateY(0); }

/* ---- Skip link ---- */
.skip-link {
  position: absolute; left: -999px; top: 0;
  background: var(--color-primary); color: #fff;
  padding: 12px 20px; z-index: 1000; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }