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

:root {
  --bg-primary: #171a21;
  --bg-secondary: #1b2838;
  --bg-card: #212d3d;
  --accent-primary: #1a9fff;
  --accent-secondary: #66c0f4;
  --text-primary: #ffffff;
  --text-secondary: #b8b8b8;
  --border-color: #2a3f5f;
  --error-color: #ff4444;
  --success-color: #00ff88;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.landing {
  min-height: 100vh;
}

.hero {
  background: linear-gradient(135deg, #1a2332 0%, #1b2838 50%, #2a3f5f 100%);
  padding: 80px 0 100px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 20% 50%, rgba(26, 159, 255, 0.1) 0%, transparent 50%),
              radial-gradient(circle at 80% 80%, rgba(102, 192, 244, 0.1) 0%, transparent 50%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 600px;
  margin: 0 auto;
  text-align: center;
}

.hero-title {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 3rem;
}

.topup-form {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 2.5rem;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

.form-group {
  margin-bottom: 1.5rem;
  text-align: left;
}

.form-label {
  display: block;
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.form-input,
.form-select {
  width: 100%;
  padding: 0.875rem 1rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 1rem;
  transition: all 0.3s ease;
}

.form-input:focus,
.form-select:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(26, 159, 255, 0.1);
}

.form-input::placeholder {
  color: var(--text-secondary);
}

.amount-presets {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.amount-preset {
  padding: 0.75rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
}

.amount-preset:hover {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  transform: translateY(-2px);
}

.amount-preset.active {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
}

.form-error {
  color: var(--error-color);
  font-size: 0.875rem;
  margin-top: 0.5rem;
  display: none;
}

.form-error.active {
  display: block;
}

.form-success {
  color: var(--success-color);
  font-size: 0.875rem;
  margin-top: 0.5rem;
  display: none;
}

.form-success.active {
  display: block;
}

.btn-submit {
  width: 100%;
  padding: 1rem;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  border: none;
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 1.125rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.btn-submit:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 10px 30px rgba(26, 159, 255, 0.3);
}

.btn-submit:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.btn-loader {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.spinner {
  width: 16px;
  height: 16px;
  border: 2px solid var(--text-primary);
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

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

.section-title {
  font-size: 2.5rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 3rem;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.how-it-works {
  padding: 80px 0;
  background: var(--bg-primary);
}

.steps {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  max-width: 800px;
  margin: 0 auto;
}

.step {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 2rem;
  text-align: left;
  transition: all 0.3s ease;
}

.step:hover {
  transform: translateY(-5px);
  border-color: var(--accent-primary);
  box-shadow: 0 10px 30px rgba(26, 159, 255, 0.2);
}

.step-number {
  width: 60px;
  height: 60px;
  margin: 0 auto 1.5rem;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 700;
}

.step-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

.step-description {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.benefits {
  padding: 80px 0;
  background: var(--bg-secondary);
}

.benefits-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.benefit-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 2.5rem;
  text-align: center;
  transition: all 0.3s ease;
}

.benefit-card:hover {
  transform: translateY(-5px);
  border-color: var(--accent-primary);
  box-shadow: 0 10px 30px rgba(26, 159, 255, 0.2);
}

.benefit-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.benefit-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.benefit-description {
  color: var(--text-secondary);
  font-size: 1rem;
}

.faq {
  padding: 80px 0;
  background: var(--bg-primary);
}

.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  margin-bottom: 1rem;
  overflow: hidden;
  transition: all 0.3s ease;
}

.faq-item:hover {
  border-color: var(--accent-primary);
}

.faq-question {
  width: 100%;
  padding: 1.5rem;
  background: transparent;
  border: none;
  color: var(--text-primary);
  font-size: 1.125rem;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: all 0.3s ease;
}

.faq-question:hover {
  color: var(--accent-secondary);
}

.faq-icon {
  transition: transform 0.3s ease;
  color: var(--accent-primary);
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
  max-height: 500px;
}

.faq-answer p {
  padding: 0 1.5rem 1.5rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 60px 0 30px;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 3rem;
  margin-bottom: 2rem;
}

.footer-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.footer-description {
  color: var(--text-secondary);
}

.footer-subtitle {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.footer-links {
  list-style: none;
}

.footer-link {
  color: var(--text-secondary);
  text-decoration: none;
  display: block;
  padding: 0.5rem 0;
  transition: color 0.3s ease;
}

.footer-link:hover {
  color: var(--accent-secondary);
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
}

.footer-copyright {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

.footer-contact-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.3s ease;
}

.footer-contact-link:hover {
  color: var(--accent-secondary);
  transform: translateX(5px);
}

.contact-icon {
  font-size: 1.25rem;
  display: inline-block;
}

.payment-buttons {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-bottom: 0.5rem;
}

.payment-button {
  padding: 1rem;
  background: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.payment-button:hover:not(:disabled) {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  transform: translateY(-2px);
}

.payment-button.active {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(26, 159, 255, 0.2);
}

.payment-summary {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 12px;
  padding: 20px;
  margin-top: 8px;
}

.payment-summary-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 0;
  color: rgba(255, 255, 255, 0.8);
  font-size: 15px;
}

.payment-summary-row:not(:last-child) {
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.payment-summary-total {
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  margin-top: 8px;
  padding-top: 16px;
  border-top: 2px solid rgba(26, 159, 255, 0.3) !important;
}

.payment-summary-total span:last-child {
  color: var(--accent-primary);
  font-size: 22px;
}

.payment-button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.payment-button-icon {
  font-size: 1.5rem;
}

.payment-button-text {
  font-size: 0.95rem;
}

@media (max-width: 768px) {
  .hero-title {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .topup-form {
    padding: 1.5rem;
  }

  .amount-presets {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 480px) {
  .amount-presets {
    grid-template-columns: repeat(2, 1fr);
  }

  .section-title {
    font-size: 2rem;
  }

  .benefits-grid {
    grid-template-columns: 1fr;
  }

  .footer-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: 60px 0 80px;
  }

  .hero-title {
    font-size: 1.75rem;
  }

  .topup-form {
    padding: 1rem;
  }

  .how-it-works,
  .benefits,
  .faq {
    padding: 60px 0;
  }
}