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

:root {
  --cyan: #00d4ff;
  --cyan-light: #5ce1ff;
  --cyan-dark: #0099cc;
  --purple: #7c3aed;
  --purple-light: #a78bfa;
  --green: #10b981;
  --gold: #f0b90b;
  --red: #ef4444;
  --bg-dark: #0a0e17;
  --bg-card: rgba(15, 23, 42, 0.92);
  --border: rgba(0, 212, 255, 0.25);
  --text: #f1f5f9;
  --text-muted: rgba(241, 245, 249, 0.6);
  --radius: 16px;
  --shadow: 0 0 40px rgba(0, 212, 255, 0.15);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg-dark);
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.6;
}

.bg-animation {
  position: fixed;
  inset: 0;
  z-index: 0;
  background: linear-gradient(135deg, #0a0e17 0%, #0f172a 30%, #1a0a2e 60%, #0a0e17 100%);
  animation: bgShift 20s ease infinite;
}

@keyframes bgShift {
  0%, 100% { filter: hue-rotate(0deg); }
  50% { filter: hue-rotate(15deg); }
}

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

.particle {
  position: absolute;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.4) 0%, transparent 70%);
  animation: float 18s infinite ease-in-out;
}

.particle:nth-child(1) { width: 120px; height: 120px; top: 10%; left: 5%; animation-delay: 0s; }
.particle:nth-child(2) { width: 80px; height: 80px; top: 60%; left: 80%; animation-delay: -4s; }
.particle:nth-child(3) { width: 60px; height: 60px; top: 30%; left: 70%; animation-delay: -8s; }
.particle:nth-child(4) { width: 100px; height: 100px; top: 80%; left: 20%; animation-delay: -12s; }
.particle:nth-child(5) { width: 50px; height: 50px; top: 45%; left: 40%; animation-delay: -6s; }

@keyframes float {
  0%, 100% { transform: translate(0, 0) scale(1); opacity: 0.3; }
  50% { transform: translate(30px, -60px) scale(1.1); opacity: 0.6; }
}

.hidden { display: none !important; }

.top-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 24px;
  background: rgba(10, 14, 23, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.1rem;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--cyan), var(--purple));
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
}

.demo-badge {
  font-size: 10px;
  font-weight: 700;
  padding: 3px 8px;
  background: rgba(124, 58, 237, 0.3);
  border: 1px solid var(--purple-light);
  border-radius: 6px;
  color: var(--purple-light);
  letter-spacing: 1px;
}

.lang-select {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 8px 12px;
  border-radius: 10px;
  font-size: 14px;
  cursor: pointer;
}

.main-wrap {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  padding: 90px 20px 40px;
  display: flex;
  justify-content: center;
  align-items: center;
}

.card {
  width: 100%;
  max-width: 560px;
  background: var(--bg-card);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 32px;
  box-shadow: var(--shadow);
  animation: cardGlow 8s infinite alternate;
  text-align: center;
}

@keyframes cardGlow {
  0% { border-color: rgba(0, 212, 255, 0.25); box-shadow: 0 0 40px rgba(0, 212, 255, 0.12); }
  100% { border-color: rgba(124, 58, 237, 0.35); box-shadow: 0 0 50px rgba(124, 58, 237, 0.15); }
}

.card.success-card {
  border-color: rgba(16, 185, 129, 0.4);
  animation: successGlow 6s infinite alternate;
}

@keyframes successGlow {
  0% { box-shadow: 0 0 40px rgba(16, 185, 129, 0.2); }
  100% { box-shadow: 0 0 60px rgba(16, 185, 129, 0.35); }
}

.hero-icon {
  width: 72px;
  height: 72px;
  margin: 0 auto 20px;
  background: linear-gradient(135deg, var(--cyan), var(--purple));
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 32px;
  animation: pulse 3s ease infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

h1 {
  font-size: 1.75rem;
  font-weight: 800;
  margin-bottom: 12px;
  background: linear-gradient(90deg, var(--cyan-light), var(--purple-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

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

.features {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 28px;
  text-align: left;
}

.feature-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  background: rgba(255, 255, 255, 0.04);
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.06);
  font-size: 0.85rem;
}

.feature-item i {
  color: var(--cyan);
  font-size: 14px;
}

.price-box {
  margin-bottom: 24px;
  padding: 20px;
  background: rgba(0, 212, 255, 0.06);
  border: 1px solid rgba(0, 212, 255, 0.2);
  border-radius: 14px;
}

.price-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 8px;
}

.price-display {
  font-size: 2rem;
  font-weight: 900;
}

.price-usd { color: var(--cyan-light); }
.price-sep { color: var(--text-muted); margin: 0 8px; }
.price-bdt { color: var(--green); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 16px 32px;
  border: none;
  border-radius: 14px;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.3s ease;
  width: 100%;
}

.btn-primary {
  background: linear-gradient(135deg, var(--cyan), var(--cyan-dark));
  color: #0a0e17;
  box-shadow: 0 4px 20px rgba(0, 212, 255, 0.35);
}

.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 212, 255, 0.45);
}

.btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
}

.btn-success {
  background: linear-gradient(135deg, var(--green), #059669);
  color: white;
}

.btn-outline {
  background: transparent;
  border: 1.5px solid var(--cyan);
  color: var(--cyan-light);
}

.btn-sm {
  padding: 10px 18px;
  font-size: 0.875rem;
  width: auto;
}

.btn-group {
  display: flex;
  gap: 12px;
  margin-top: 16px;
}

.btn-group .btn {
  flex: 1;
}

.spinner {
  display: inline-block;
  width: 18px;
  height: 18px;
  border: 3px solid rgba(255, 255, 255, 0.2);
  border-top-color: currentColor;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.loading-screen {
  text-align: center;
}

.loading-screen .spinner {
  width: 48px;
  height: 48px;
  border-width: 4px;
  border-top-color: var(--cyan);
  margin-bottom: 16px;
}

.pm-btn {
  display: flex;
  align-items: center;
  gap: 14px;
  width: 100%;
  padding: 16px 18px;
  margin-bottom: 12px;
  background: rgba(255, 255, 255, 0.04);
  border: 1.5px solid rgba(255, 255, 255, 0.1);
  border-radius: 14px;
  color: var(--text);
  cursor: pointer;
  transition: all 0.3s;
  text-align: left;
}

.pm-btn:hover {
  border-color: var(--cyan);
  background: rgba(0, 212, 255, 0.06);
}

.pm-btn.active {
  border-color: var(--cyan);
  background: rgba(0, 212, 255, 0.1);
  box-shadow: 0 0 20px rgba(0, 212, 255, 0.15);
}

.pm-btn.binance-btn:hover,
.pm-btn.binance-btn.active {
  border-color: var(--gold);
  background: rgba(240, 185, 11, 0.08);
}

.pm-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  flex-shrink: 0;
}

.pm-icon.bdt { background: rgba(16, 185, 129, 0.15); color: var(--green); }
.pm-icon.crypto { background: rgba(124, 58, 237, 0.15); color: var(--purple-light); }
.pm-icon.binance { background: rgba(240, 185, 11, 0.15); color: var(--gold); }

.pm-info { flex: 1; }
.pm-title { font-weight: 700; font-size: 0.95rem; }
.pm-price { font-size: 0.8rem; color: var(--text-muted); margin-top: 4px; }

.pay-error {
  display: none;
  margin: 12px 0;
  padding: 12px;
  background: rgba(239, 68, 68, 0.12);
  border: 1px solid rgba(239, 68, 68, 0.3);
  border-radius: 10px;
  color: #fca5a5;
  font-size: 0.875rem;
}

.alert {
  padding: 14px 16px;
  border-radius: 12px;
  font-size: 0.875rem;
  margin-bottom: 16px;
  text-align: left;
}

.alert-warning {
  background: rgba(245, 158, 11, 0.12);
  border: 1px solid rgba(245, 158, 11, 0.35);
  color: #fcd34d;
}

.alert-danger {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.3);
  color: #fca5a5;
}

.bookmark-input-wrap {
  display: flex;
  gap: 8px;
  margin: 16px 0;
}

.bookmark-input {
  flex: 1;
  padding: 14px 16px;
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid var(--border);
  border-radius: 12px;
  color: var(--cyan-light);
  font-size: 0.85rem;
  font-family: monospace;
  word-break: break-all;
}

.copy-toast {
  position: fixed;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--green);
  color: white;
  padding: 12px 24px;
  border-radius: 10px;
  font-weight: 600;
  opacity: 0;
  transition: all 0.3s;
  z-index: 200;
  pointer-events: none;
}

.copy-toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 300;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s;
}

.modal-overlay.show {
  opacity: 1;
  visibility: visible;
}

.modal {
  width: 100%;
  max-width: 440px;
  background: var(--bg-card);
  border: 2px solid rgba(240, 185, 11, 0.3);
  border-radius: var(--radius);
  padding: 28px 24px;
  max-height: 90vh;
  overflow-y: auto;
}

.modal h3 {
  color: var(--gold);
  margin-bottom: 20px;
  font-size: 1.2rem;
}

.bnb-field {
  background: rgba(240, 185, 11, 0.06);
  border: 1px solid rgba(240, 185, 11, 0.2);
  border-radius: 12px;
  padding: 14px;
  margin-bottom: 14px;
  text-align: center;
}

.bnb-field label {
  display: block;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.bnb-field .value {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--gold);
}

.bnb-value-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
}

.bnb-copy-btn {
  flex-shrink: 0;
  padding: 8px 14px;
  font-size: 0.8rem;
  white-space: nowrap;
}

.bnb-steps {
  text-align: left;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin: 16px 0;
  line-height: 1.8;
}

.bnb-input {
  width: 100%;
  padding: 14px;
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid rgba(240, 185, 11, 0.3);
  border-radius: 10px;
  color: white;
  font-size: 0.9rem;
  margin-bottom: 12px;
}

.bnb-status {
  font-size: 0.85rem;
  margin-bottom: 12px;
  min-height: 20px;
}

.bnb-status.status-error { color: var(--red); }
.bnb-status.status-info { color: var(--text-muted); }
.bnb-name { font-size: 0.8rem; color: var(--text-muted); margin-top: 6px; }

.promo-box {
  background: rgba(0, 212, 255, 0.06);
  border: 1px solid rgba(0, 212, 255, 0.2);
  border-radius: 12px;
  padding: 14px;
  margin-bottom: 18px;
  text-align: left;
}

.promo-label { display: block; font-size: 0.8rem; color: var(--text-muted); margin-bottom: 8px; }

.promo-row {
  display: flex;
  gap: 8px;
}

.promo-input {
  flex: 1;
  padding: 12px 14px;
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: white;
  font-size: 0.9rem;
  text-transform: uppercase;
}

.promo-msg { font-size: 0.8rem; margin-top: 8px; min-height: 18px; }
.promo-msg.ok { color: var(--green); }
.promo-msg.err { color: #fca5a5; }

.promo-badge {
  margin-top: 8px;
  font-size: 0.8rem;
  color: var(--cyan-light);
  font-weight: 600;
}

.promo-clear-link {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 0.75rem;
  margin-top: 6px;
  cursor: pointer;
  text-decoration: underline;
  padding: 0;
}

.price-old {
  text-decoration: line-through;
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-right: 4px;
}

.back-btn { margin-bottom: 16px; width: auto; }
.pay-hint { font-size: 0.75rem; color: var(--text-muted); margin-top: 12px; }
.success-icon { background: linear-gradient(135deg, var(--green), #059669) !important; }
.share-warn { margin-top: 20px; }
.inline-spin { width: 18px; height: 18px; border-width: 2px; vertical-align: middle; margin-right: 6px; }

.crypto-how-link {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  margin: -6px 0 14px;
  padding: 10px 14px;
  background: rgba(124, 58, 237, 0.08);
  border: 1px dashed rgba(124, 58, 237, 0.35);
  border-radius: 10px;
  color: var(--purple-light);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, border-color 0.2s;
}

.crypto-how-link:hover {
  background: rgba(124, 58, 237, 0.14);
  border-color: rgba(124, 58, 237, 0.55);
}

.guide-modal { max-width: 440px; text-align: left; }
.guide-intro { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 16px; }
.guide-video-wrap { margin-bottom: 16px; border-radius: 12px; overflow: hidden; background: #000; }
.guide-video, .guide-youtube { width: 100%; display: block; border: none; min-height: 200px; }
.guide-steps {
  background: rgba(16, 185, 129, 0.08);
  border: 1px solid rgba(16, 185, 129, 0.2);
  border-radius: 12px;
  padding: 14px 16px;
  margin-bottom: 14px;
}
.guide-steps-title { font-size: 0.85rem; font-weight: 700; color: var(--green); margin-bottom: 10px; }
.guide-list { margin: 0; padding-left: 20px; font-size: 0.82rem; color: var(--text-muted); line-height: 1.7; }
.guide-list li { margin-bottom: 6px; }
.guide-note { font-size: 0.78rem; color: var(--text-muted); margin-bottom: 16px; line-height: 1.5; }

.status-error { color: var(--red); }
.status-info { color: var(--text-muted); }

.modal-actions {
  display: flex;
  gap: 10px;
}

.modal-actions .btn { flex: 1; }

.checking-spinner {
  width: 56px;
  height: 56px;
  border: 4px solid rgba(0, 212, 255, 0.2);
  border-top-color: var(--cyan);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 0 auto 20px;
}

@media (max-width: 480px) {
  .features { grid-template-columns: 1fr; }
  .card { padding: 28px 20px; }
  h1 { font-size: 1.4rem; }
  .btn-group { flex-direction: column; }
}