/* ===== Reset & Variables ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --color-bg: #1A1A2E;
  --color-brand: #E63946;
  --color-silver: #C0C0C0;
  --color-blue: #00B4D8;
  --color-purple: #7B2CBF;
  --color-white: #FFFFFF;
  --color-text: #E0E0E0;
  --color-muted: #9CA3AF;
  --color-border: #2E2E4A;
  --color-hover: #FF5A67;
  --font-heading: 'Inter', 'Poppins', system-ui, sans-serif;
  --font-body: 'Inter', system-ui, sans-serif;
  --sidebar-width: 280px;
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 2rem;
  --spacing-xl: 4rem;
  --max-width: 1200px;
  --transition: 0.25s ease-out;
}
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
a { color: var(--color-blue); text-decoration: none; }
a:hover, a:focus { color: var(--color-hover); }
:focus-visible { outline: 2px solid var(--color-blue); outline-offset: 2px; }
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition-duration: 0s !important; animation-duration: 0s !important; }
}

/* ===== Skip Link ===== */
.skip-link {
  position: absolute;
  top: -100px;
  left: 0;
  background: var(--color-brand);
  color: var(--color-white);
  padding: var(--spacing-sm) var(--spacing-md);
  z-index: 1000;
  transition: top 0.2s;
}
.skip-link:focus { top: 0; }

/* ===== Header & Sidebar ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-width);
  height: 100vh;
  z-index: 999;
  background: var(--color-bg);
  border-right: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
}
.site-sidebar {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: var(--spacing-lg) var(--spacing-md);
  overflow-y: auto;
}
.site-logo {
  margin-bottom: var(--spacing-xl);
  padding-left: var(--spacing-sm);
}
.logo-text {
  font-family: var(--font-heading);
  font-size: 1.8rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  transform: skewX(-2deg);
  display: block;
  color: var(--color-white);
  background: linear-gradient(135deg, var(--color-brand), var(--color-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.logo-tagline {
  font-size: 0.75rem;
  color: var(--color-muted);
  letter-spacing: 0.15em;
  margin-top: var(--spacing-xs);
  display: block;
}
.site-nav ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}
.site-nav a {
  display: block;
  padding: var(--spacing-sm) var(--spacing-md);
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--color-silver);
  border-radius: 0;
  border-left: 3px solid transparent;
  transition: border-color var(--transition), background var(--transition);
}
.site-nav a:hover,
.site-nav a:focus-visible {
  border-left-color: var(--color-blue);
  background: rgba(0, 180, 216, 0.1);
  color: var(--color-white);
}
.site-nav a[aria-current="page"] {
  border-left-color: var(--color-blue);
  background: rgba(0, 180, 216, 0.15);
  color: var(--color-blue);
  font-weight: 700;
}
.nav-toggle {
  display: none;
  position: fixed;
  top: var(--spacing-md);
  left: var(--spacing-md);
  z-index: 1001;
  background: transparent;
  border: none;
  cursor: pointer;
  width: 36px;
  height: 36px;
  padding: 4px;
  flex-direction: column;
  justify-content: space-around;
}
.nav-toggle .bar {
  display: block;
  height: 3px;
  background: var(--color-silver);
  border-radius: 2px;
  transition: background var(--transition);
}
.nav-toggle:hover .bar { background: var(--color-blue); }
.nav-close {
  display: none;
  position: absolute;
  top: var(--spacing-md);
  right: var(--spacing-md);
  background: transparent;
  border: none;
  color: var(--color-silver);
  font-size: 1.5rem;
  cursor: pointer;
}

/* ===== Main content shift ===== */
#main-content {
  margin-left: var(--sidebar-width);
  padding: var(--spacing-lg);
  flex: 1;
}
/* ===== Footer ===== */
.site-footer {
  margin-left: var(--sidebar-width);
  background: #10101F;
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-lg) 0;
  font-size: 0.875rem;
}
.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  color: var(--color-muted);
}
.footer-brand { font-weight: 600; color: var(--color-silver); }
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  margin: var(--spacing-sm) 0;
}
.footer-links a { color: var(--color-muted); transition: color var(--transition); }
.footer-links a:hover { color: var(--color-blue); }
.footer-contact { margin: var(--spacing-sm) 0; line-height: 1.8; }
.footer-contact a { color: var(--color-muted); }
.footer-note {
  font-size: 0.75rem;
  color: var(--color-border);
  margin-top: var(--spacing-sm);
}
/* ===== Utility components ===== */
.btn-primary {
  display: inline-block;
  background: var(--color-brand);
  color: var(--color-white);
  font-family: var(--font-heading);
  font-weight: 700;
  letter-spacing: 0.03em;
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: 0;
  cursor: pointer;
  transition: background var(--transition);
  text-transform: uppercase;
}
.btn-primary:hover { background: var(--color-hover); color: #fff; }
.btn-secondary {
  display: inline-block;
  background: transparent;
  color: var(--color-blue);
  border: 2px solid var(--color-blue);
  font-family: var(--font-heading);
  font-weight: 600;
  padding: 0.65rem 1.5rem;
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
}
.btn-secondary:hover { background: var(--color-blue); color: var(--color-bg); }
.section-label {
  font-family: var(--font-heading);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  color: var(--color-muted);
  display: inline-block;
  margin-bottom: var(--spacing-sm);
}
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--spacing-lg);
  margin: var(--spacing-lg) 0;
}
.data-indicator {
  width: 100%;
  height: 4px;
  background: var(--color-border);
  position: relative;
  overflow: hidden;
}
.data-indicator::after {
  content: '';
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--color-blue), var(--color-purple));
  width: 60%;
  animation: sweep 2s ease-in-out infinite;
}
@keyframes sweep {
  0%, 100% { transform: translateX(-100%); }
  50% { transform: translateX(100%); }
}
/* ===== Scroll progress ===== */
[data-scroll-progress] {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  z-index: 1002;
  background: rgba(0,0,0,0.2);
}
[data-scroll-progress]::after {
  content: '';
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--color-brand), var(--color-blue));
  width: 0%;
  transition: width 0.1s linear;
}
/* ===== Responsive ===== */
@media (max-width: 1024px) {
  :root { --sidebar-width: 240px; }
  .site-logo .logo-text { font-size: 1.5rem; }
}
@media (max-width: 768px) {
  .site-header {
    width: 100%;
    height: auto;
    position: fixed;
    top: 0;
    left: 0;
    background: transparent;
    border-right: none;
    pointer-events: none;
  }
  .site-sidebar {
    position: fixed;
    top: 0;
    left: -100%;
    width: 280px;
    height: 100vh;
    background: var(--color-bg);
    border-right: 2px solid var(--color-border);
    z-index: 1000;
    transition: left 0.3s ease-out;
    pointer-events: all;
    padding-top: var(--spacing-xl);
  }
  .site-sidebar[data-open] { left: 0; }
  .nav-toggle {
    display: flex;
    position: fixed;
    top: var(--spacing-md);
    left: var(--spacing-md);
    z-index: 1001;
    pointer-events: all;
  }
  .nav-close {
    display: block;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
  }
  #main-content,
  .site-footer {
    margin-left: 0;
  }
  #main-content { padding-top: calc(48px + var(--spacing-lg)); }
  .site-footer { margin-top: 0; }
}
@media (max-width: 480px) {
  .site-sidebar { width: 100%; }
}