/* Global Styles & Variables */
:root {
  --bg-main: #0b0f19;
  --bg-card: #161e2e;
  --bg-card-hover: #1f293d;
  --text-main: #f3f4f6;
  --text-muted: #9ca3af;
  --primary: #06b6d4;
  --secondary: #3b82f6;
  --accent: #10b981;
  --border: #1e293b;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --max-width: 1100px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg-main);
  color: var(--text-main);
  font-family: var(--font-family);
  line-height: 1.6;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* Header & Navigation */
header {
  background-color: rgba(15, 23, 42, 0.9);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
}

.header-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-main);
  font-weight: 700;
  font-size: 1.25rem;
}

.logo img {
  width: 32px;
  height: 32px;
}

nav ul {
  display: flex;
  list-style: none;
  gap: 1.5rem;
}

nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease;
}

nav a:hover,
nav a.active {
  color: var(--primary);
}

/* Main Container */
main {
  flex: 1;
  max-width: var(--max-width);
  width: 100%;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
}

/* Hero Section */
.hero {
  text-align: center;
  padding: 3rem 1rem;
  background: radial-gradient(circle at center, rgba(6, 182, 212, 0.15) 0%, transparent 70%);
  border-radius: 1rem;
  margin-bottom: 3rem;
  border: 1px solid var(--border);
}

.hero h1 {
  font-size: 2.75rem;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, #38bdf8, #818cf8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  font-size: 1.2rem;
  color: var(--text-muted);
  max-width: 700px;
  margin: 0 auto 1.5rem;
}

.cta-button {
  display: inline-block;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #fff;
  padding: 0.75rem 1.75rem;
  border-radius: 0.5rem;
  text-decoration: none;
  font-weight: 600;
  transition: opacity 0.2s;
}

.cta-button:hover {
  opacity: 0.9;
}

/* Grid Layout */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.card {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  padding: 1.5rem;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
  background-color: var(--bg-card-hover);
}

.card h3 {
  color: var(--primary);
  margin-bottom: 0.75rem;
  font-size: 1.25rem;
}

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

/* Feature Details & Content Sections */
.section-title {
  font-size: 2rem;
  margin-bottom: 1.5rem;
  border-bottom: 2px solid var(--border);
  padding-bottom: 0.5rem;
}

.content-block {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  padding: 2rem;
  margin-bottom: 2rem;
}

.content-block h2 {
  color: var(--secondary);
  margin-bottom: 1rem;
}

.content-block p {
  margin-bottom: 1rem;
  color: var(--text-muted);
}

.tech-specs {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1rem;
}

.tech-specs th, .tech-specs td {
  padding: 0.75rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.tech-specs th {
  background-color: rgba(255, 255, 255, 0.05);
  color: var(--primary);
}

.tech-specs td {
  color: var(--text-muted);
}

/* 404 Layout */
.error-page {
  text-align: center;
  padding: 4rem 1rem;
}

.error-code {
  font-size: 6rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
  margin-bottom: 1rem;
}

/* Interactive Element Demo */
.demo-box {
  background-color: rgba(0,0,0,0.3);
  border: 1px dashed var(--primary);
  padding: 1.5rem;
  border-radius: 0.5rem;
  margin-top: 1.5rem;
  text-align: center;
}

.demo-btn {
  background: var(--bg-card);
  border: 1px solid var(--primary);
  color: var(--primary);
  padding: 0.5rem 1.25rem;
  border-radius: 0.375rem;
  cursor: pointer;
  font-weight: 600;
  margin-top: 1rem;
  transition: all 0.2s;
}

.demo-btn:hover {
  background: var(--primary);
  color: #fff;
}

/* Footer */
footer {
  background-color: rgba(15, 23, 42, 0.9);
  border-top: 1px solid var(--border);
  padding: 2rem 1.5rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-top: auto;
}