/* ==========================================================================
   notfound.css — 404 page
   Theme: dark grey base, dim accents, cyan + kahoot purple, ambient background
   ========================================================================== */

:root {
  --bg-900: #0a0a0f;
  --surface: rgba(26, 26, 36, 0.55);
  --border-strong: rgba(255, 255, 255, 0.16);
  --text-100: #f5f5fa;
  --text-200: #d4d4e0;
  --text-300: #b0b0c0;
  --text-400: #9090a4;
  --cyan: #22d3ee;
  --kahoot: #5010a8;
  --kahoot-bright: #8b5cf6;
  --font: "Inter", "Segoe UI", system-ui, -apple-system, sans-serif;
}

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

.notfound-page {
  font-family: var(--font);
  color: var(--text-100);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 24px;
  position: relative;
  z-index: 1;
  overflow: hidden;
}

#bg-canvas {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

.nf-content {
  position: relative;
  z-index: 1;
  max-width: 520px;
}

.nf-code {
  font-size: clamp(80px, 18vw, 180px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.04em;
  margin-bottom: 16px;
  background: linear-gradient(120deg, var(--cyan) 0%, var(--kahoot-bright) 55%, var(--kahoot) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  opacity: 0;
  animation: fadeUp 0.8s 0.1s forwards;
}

.nf-title {
  font-size: clamp(22px, 4vw, 32px);
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 14px;
  color: var(--text-100);
  opacity: 0;
  animation: fadeUp 0.8s 0.25s forwards;
}

.nf-sub {
  font-size: 17px;
  color: var(--text-300);
  line-height: 1.6;
  margin-bottom: 36px;
  opacity: 0;
  animation: fadeUp 0.8s 0.4s forwards;
}

.nf-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  opacity: 0;
  animation: fadeUp 0.8s 0.55s forwards;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 15px 30px;
  border-radius: 100px;
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  border: none;
  transition: transform 0.2s ease, box-shadow 0.3s ease, background 0.3s ease;
  font-family: var(--font);
}

.btn-primary {
  background: linear-gradient(120deg, var(--kahoot) 0%, var(--kahoot-bright) 100%);
  color: #fff;
  box-shadow: 0 8px 32px rgba(124, 58, 237, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 40px rgba(124, 58, 237, 0.55);
}

.btn-ghost {
  background: var(--surface);
  color: var(--text-100);
  border: 1px solid var(--border-strong);
  backdrop-filter: blur(12px);
}

.btn-ghost:hover {
  transform: translateY(-2px);
  border-color: var(--cyan);
  color: var(--cyan);
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 520px) {
  .nf-actions {
    flex-direction: column;
    align-items: stretch;
  }
  .btn {
    justify-content: center;
  }
}