@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');

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

:root {
  --bg: #0a0a0f;
  --surface: #111118;
  --border: rgba(255,255,255,0.07);
  --accent: #7c6af7;
  --accent-glow: rgba(124, 106, 247, 0.35);
  --accent-2: #4fd1c5;
  --text: #f0f0f8;
  --muted: #888899;
  --grid-line: rgba(255,255,255,0.025);
  --gradient-hero: linear-gradient(135deg, #fff 30%, var(--accent) 70%, var(--accent-2) 100%);
  --gradient-stat: linear-gradient(135deg, #fff, var(--accent));
}

[data-theme="light"] {
  --bg: #f5f5fa;
  --surface: #ffffff;
  --border: rgba(0,0,0,0.08);
  --accent: #6c5ce7;
  --accent-glow: rgba(108, 92, 231, 0.2);
  --accent-2: #00b894;
  --text: #1a1a2e;
  --muted: #666680;
  --grid-line: rgba(0,0,0,0.04);
  --gradient-hero: linear-gradient(135deg, #1a1a2e 30%, var(--accent) 70%, var(--accent-2) 100%);
  --gradient-stat: linear-gradient(135deg, #1a1a2e, var(--accent));
}

html, body {
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', system-ui, sans-serif;
  overflow-x: hidden;
  transition: background 0.3s ease, color 0.3s ease;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% -10%, rgba(124,106,247,0.18) 0%, transparent 70%),
    radial-gradient(ellipse 50% 40% at 80% 80%, rgba(79,209,197,0.10) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
}

body::after {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
  z-index: 0;
}

.container {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 48px 24px;
  gap: 48px;
}

/* Back nav */
.back-nav {
  position: fixed;
  top: 20px;
  left: 20px;
  z-index: 10;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 100px;
  padding: 8px 18px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text);
  text-decoration: none;
  transition: border-color 0.2s, transform 0.2s, background 0.3s;
}

.back-nav:hover {
  border-color: rgba(124,106,247,0.4);
  transform: translateX(-2px);
}

.back-nav svg {
  width: 16px;
  height: 16px;
  stroke: var(--muted);
}

/* Page header */
.page-header {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.page-icon {
  font-size: 56px;
  line-height: 1;
}

.page-title {
  font-size: clamp(32px, 6vw, 52px);
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1;
  background: var(--gradient-hero);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.page-subtitle {
  font-size: clamp(14px, 2.5vw, 18px);
  font-weight: 400;
  color: var(--muted);
  max-width: 560px;
}

/* Content cards */
.content-section {
  max-width: 720px;
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.content-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px 24px;
  transition: border-color 0.2s, transform 0.2s, background 0.3s ease;
}

.content-card:hover {
  border-color: rgba(124,106,247,0.4);
  transform: translateY(-2px);
}

.content-card h3 {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text);
}

.content-card p {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.6;
}

.content-card code {
  font-size: 12px;
  background: rgba(124,106,247,0.1);
  border: 1px solid rgba(124,106,247,0.2);
  border-radius: 4px;
  padding: 1px 6px;
  color: var(--accent);
  font-family: 'SF Mono', 'Fira Code', monospace;
}

.highlight {
  color: var(--accent-2);
  font-weight: 500;
}

/* Theme toggle */
.theme-toggle {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 10;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 50%;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 20px;
  transition: border-color 0.2s, transform 0.2s, background 0.3s;
  line-height: 1;
}

.theme-toggle:hover {
  border-color: rgba(124,106,247,0.4);
  transform: scale(1.1);
}

/* Floating particles */
.particles {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.particle {
  position: absolute;
  width: 2px;
  height: 2px;
  border-radius: 50%;
  background: var(--accent);
  opacity: 0;
  animation: float-up linear infinite;
}

@keyframes float-up {
  0% { transform: translateY(100vh) scale(0); opacity: 0; }
  10% { opacity: 0.6; }
  90% { opacity: 0.3; }
  100% { transform: translateY(-10vh) scale(1); opacity: 0; }
}

/* Footer */
.footer {
  font-size: 12px;
  color: var(--muted);
  text-align: center;
  letter-spacing: 0.04em;
}

.footer a {
  color: var(--accent);
  text-decoration: none;
}