:root {
  color-scheme: dark;
  --bg: #0f172a;
  --bg-alt: #020617;
  --surface: rgba(30, 41, 59, 0.7);
  --surface-alt: rgba(15, 23, 42, 0.8);
  --surface-hover: rgba(30, 41, 59, 0.9);
  --accent: #06b6d4; /* Cyan-500 */
  --accent-dark: #0891b2;
  --accent-glow: rgba(6, 182, 212, 0.5);
  --text: #f1f5f9;
  --text-muted: #94a3b8;
  --border: rgba(148, 163, 184, 0.1);
  --border-hover: rgba(148, 163, 184, 0.25);
  --nav-height: 70px;
  --font-main: 'Inter', system-ui, -apple-system, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background-color: var(--bg-alt);
  color: var(--text);
  font-family: var(--font-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  padding-top: var(--nav-height);
}

h1, h2, h3, h4, h5, h6 {
  line-height: 1.2;
  margin-top: 0;
  color: #fff;
  letter-spacing: -0.02em;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s ease;
}

/* --- Header & Navigation --- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  background: rgba(2, 6, 23, 0.8);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.site-nav {
  max-width: 1200px;
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.5rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  font-size: 1.2rem;
  color: #fff;
}

.brand-symbol {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  border-radius: 10px;
  color: #fff;
  font-weight: 800;
  box-shadow: 0 0 15px var(--accent-glow);
}

/* Desktop Nav */
.nav-list {
  display: flex;
  list-style: none;
  padding: 0;
  margin: 0;
  gap: 2rem;
  align-items: center;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  padding: 0.5rem 0;
  position: relative;
}

.nav-link:hover,
.nav-link--active {
  color: #fff;
}

.nav-link--active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent);
}

/* Mobile Nav Toggle (Hamburger) */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.5rem;
  z-index: 1100;
}

/* Mobile Nav Overlay */
@media (max-width: 768px) {
  .nav-toggle {
    display: block;
  }

  .nav-list {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: 75%;
    max-width: 300px;
    background: var(--bg-alt);
    flex-direction: column;
    align-items: flex-start;
    padding: 6rem 2rem;
    gap: 1.5rem;
    transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: -10px 0 30px rgba(0, 0, 0, 0.5);
    border-left: 1px solid var(--border);
    backdrop-filter: blur(10px); /* Support for some browsers */
  }

  .nav-list.open {
    transform: translateX(0);
  }

  .nav-link {
    font-size: 1.1rem;
    color: var(--text);
    width: 100%;
    border-bottom: 1px solid var(--border);
    padding-bottom: 0.5rem;
  }
  
  .nav-link:hover {
    color: var(--accent);
    border-color: var(--accent);
  }

  .nav-link--active::after {
    display: none; /* Remove underline on mobile, use color/border */
  }
  
  .nav-user {
     margin-top: auto;
     width: 100%;
     padding-top: 1rem;
  }
  
  /* Overlay background when menu is open */
  .nav-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
    z-index: 999;
  }
  
  .nav-overlay.open {
    opacity: 1;
    pointer-events: auto;
  }
}

/* --- Buttons --- */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  border-radius: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 0.95rem;
  border: 1px solid transparent;
}

.button-primary {
  background: var(--accent);
  color: #000;
  box-shadow: 0 0 15px rgba(6, 182, 212, 0.25);
}

.button-primary:hover {
  background: var(--accent-dark);
  transform: translateY(-2px);
  box-shadow: 0 0 25px rgba(6, 182, 212, 0.4);
}

.button-secondary {
  background: rgba(255, 255, 255, 0.05);
  border-color: var(--border);
  color: var(--text);
}

.button-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--text-muted);
}

/* --- Global Layout --- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Card Styles (Global) */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.5rem;
  transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
  background: var(--surface-hover);
}

.card h3 {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
}

.card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}