/* ==========================================================================
   Design tokens
   ========================================================================== */
:root {
  --bg: #0f1115;
  --bg-alt: #161923;
  --card-bg: #1a1e29;
  --card-border: #2a2f3d;
  --text-primary: #f5f6fa;
  --text-secondary: #9aa1b1;
  --accent: #6366f1;
  --accent-hover: #4f52d6;
  --green: #22c55e;
  --red: #ef4444;
  --radius-lg: 20px;
  --radius-md: 12px;
  --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.45);
  --shadow-sm: 0 4px 14px rgba(0, 0, 0, 0.25);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
}

body {
  margin: 0;
  font-family: var(--font);
  background: radial-gradient(circle at top, #1b1f2b 0%, var(--bg) 60%);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow-x: hidden;
}

/* ==========================================================================
   Layout
   ========================================================================== */
.app {
  width: 100%;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.card {
  width: 100%;
  max-width: 440px;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 40px 36px;
  text-align: center;
  box-shadow: var(--shadow-lg);
  animation: card-in 0.5s ease both;
}

@keyframes card-in {
  from {
    opacity: 0;
    transform: translateY(16px) scale(0.98);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

/* ==========================================================================
   Status indicator
   ========================================================================== */
.status-dot {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  margin: 0 auto 20px;
  background: var(--green);
  box-shadow: 0 0 0 0 rgba(34, 197, 94, 0.6);
  animation: pulse-green 2s infinite;
}

.status-dot.offline {
  background: var(--red);
  animation: pulse-red 2s infinite;
}

@keyframes pulse-green {
  0% { box-shadow: 0 0 0 0 rgba(34, 197, 94, 0.55); }
  70% { box-shadow: 0 0 0 12px rgba(34, 197, 94, 0); }
  100% { box-shadow: 0 0 0 0 rgba(34, 197, 94, 0); }
}

@keyframes pulse-red {
  0% { box-shadow: 0 0 0 0 rgba(239, 68, 68, 0.55); }
  70% { box-shadow: 0 0 0 12px rgba(239, 68, 68, 0); }
  100% { box-shadow: 0 0 0 0 rgba(239, 68, 68, 0); }
}

h1 {
  font-size: 1.6rem;
  margin: 0 0 8px;
  letter-spacing: -0.02em;
}

h2 {
  font-size: 1.6rem;
  margin: 20px 0 8px;
  letter-spacing: -0.02em;
}

.subtitle {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin: 0 0 28px;
}

.hint {
  color: var(--text-secondary);
  font-size: 0.82rem;
  line-height: 1.5;
  margin-top: 20px;
}

.hint code {
  background: rgba(255, 255, 255, 0.06);
  padding: 2px 6px;
  border-radius: 6px;
  font-size: 0.78rem;
}

.divider {
  height: 1px;
  background: var(--card-border);
  margin: 24px 0;
}

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
  appearance: none;
  border: none;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  padding: 13px 28px;
  border-radius: var(--radius-md);
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
  box-shadow: var(--shadow-sm);
}

.btn:active {
  transform: scale(0.97);
}

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

.btn-primary:hover {
  background: var(--accent-hover);
  box-shadow: 0 6px 20px rgba(99, 102, 241, 0.35);
}

.btn-secondary {
  background: #fff;
  color: #111;
}

.btn-secondary:hover {
  box-shadow: 0 6px 20px rgba(255, 255, 255, 0.15);
  transform: scale(1.02);
}

.fetch-result {
  min-height: 22px;
  font-size: 0.85rem;
  margin: 14px 0 0;
  transition: color 0.2s ease;
}

.fetch-result.success {
  color: var(--green);
}

.fetch-result.error {
  color: var(--red);
}

.fetch-result.pending {
  color: var(--text-secondary);
}

/* ==========================================================================
   Full-screen offline overlay
   ========================================================================== */
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(6, 7, 10, 0.92);
  backdrop-filter: blur(6px);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.overlay.visible {
  display: flex;
  opacity: 1;
}

.overlay-content {
  text-align: center;
  max-width: 380px;
  padding: 40px 32px;
  animation: overlay-in 0.4s ease both;
}

@keyframes overlay-in {
  from {
    opacity: 0;
    transform: translateY(20px) scale(0.96);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.warning-icon {
  color: var(--red);
  margin-bottom: 8px;
  animation: shake 3s ease-in-out infinite;
}

.warning-icon.standalone {
  margin: 0 auto 8px;
}

@keyframes shake {
  0%, 92%, 100% { transform: rotate(0deg); }
  93% { transform: rotate(-4deg); }
  95% { transform: rotate(4deg); }
  97% { transform: rotate(-2deg); }
}

.overlay-content h2 {
  color: #fff;
}

.overlay-content p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.5;
  margin-bottom: 28px;
}

/* ==========================================================================
   Offline fallback page
   ========================================================================== */
.offline-page {
  background: radial-gradient(circle at top, #1b1f2b 0%, var(--bg) 60%);
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 480px) {
  .card {
    padding: 32px 24px;
  }

  h1, h2 {
    font-size: 1.35rem;
  }
}