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

:root {
  --color-background: #2e2e2e;
  --color-accent: #f3ff17;
  --color-secondary: #49dcf5;
  --color-white: #fff;
  --divider: #4b4b4b;
  --placeholder-text: #828282;
  --gradient-linear: linear-gradient(to bottom, #f2f6a4, #f3ff17);
  --gradient-radial: radial-gradient(
    183.33% 152.15% at 107.56% -10.3%,
    #213ddd 0%,
    #7a90ce 35.43%,
    #a8faffc2 60.53%,
    #f3ff17 100%
  );
  --gradient-glass: linear-gradient(180deg, #9090904d 0%, #7372724d 100%);
}

body {
  margin: 0;
  font-family: "Montserrat", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--color-background);
  color: var(--color-white);
  line-height: 1.5;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background: var(--gradient-radial);
  opacity: 0.18;
  pointer-events: none;
  z-index: 0;
}

.checkout,
.success {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 480px;
  margin: 0 auto;
  padding: 2.5rem 1.25rem;
}

.checkout__header {
  margin-bottom: 1.5rem;
  text-align: center;
}

.checkout__header h1 {
  margin: 0 0 0.25rem;
  font-size: 1.75rem;
  font-weight: 600;
  letter-spacing: -0.025em;
  background: var(--gradient-linear);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.checkout__header p {
  margin: 0;
  color: var(--placeholder-text);
  font-size: 0.95rem;
}

.steps {
  display: flex;
  justify-content: center;
  gap: 0.25rem;
  list-style: none;
  margin: 0 0 1.5rem;
  padding: 0.25rem;
  background: rgba(0, 0, 0, 0.25);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 999px;
}

.steps__item {
  flex: 1;
  text-align: center;
  padding: 0.5rem 0.25rem;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--placeholder-text);
  border-radius: 999px;
  transition: color 0.2s, background 0.2s;
}

.steps__item--active {
  color: #1a1a1a;
  background: var(--gradient-linear);
  box-shadow: 0 0 16px rgba(243, 255, 23, 0.35);
}

.steps__item--done {
  color: var(--color-secondary);
}

.checkout__card {
  background: var(--gradient-glass);
  backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 16px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.45), inset 0 1px 0 rgba(255, 255, 255, 0.08);
  padding: 1.75rem;
  margin-bottom: 1rem;
}

.checkout__card h2 {
  margin: 0 0 1rem;
  font-size: 1rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-white);
}

.step--hidden {
  display: none;
}

.step__summary {
  margin: -0.5rem 0 1rem;
  font-size: 0.9rem;
  color: var(--placeholder-text);
}

.field {
  margin-bottom: 1rem;
}

.field label {
  display: block;
  margin-bottom: 0.35rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-white);
}

.phone-input {
  display: flex;
  align-items: center;
  border: 1px solid var(--divider);
  border-radius: 8px;
  overflow: hidden;
  background: rgba(0, 0, 0, 0.25);
}

.phone-input__prefix {
  padding: 0.65rem 0.75rem;
  background: rgba(255, 255, 255, 0.04);
  border-right: 1px solid var(--divider);
  color: var(--placeholder-text);
  font-size: 1rem;
  white-space: nowrap;
}

.phone-input input {
  flex: 1;
  border: 0;
  padding: 0.65rem 0.75rem;
  font-size: 1rem;
  font-family: inherit;
  outline: none;
  background: transparent;
  color: var(--color-white);
}

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

.phone-input:focus-within {
  border-color: var(--color-accent);
}

.amount-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.amount-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 1.25rem 0.75rem;
  border: 2px solid var(--divider);
  border-radius: 10px;
  background: rgba(0, 0, 0, 0.2);
  color: var(--color-white);
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
}

.amount-btn:hover {
  border-color: var(--color-secondary);
  background: rgba(73, 220, 245, 0.08);
}

.amount-btn--selected {
  border-color: var(--color-accent);
  background: rgba(243, 255, 23, 0.1);
  box-shadow: 0 0 0 1px var(--color-accent), 0 0 20px rgba(243, 255, 23, 0.3);
}

.amount-btn--selected .amount-btn__value {
  color: var(--color-accent);
}

.amount-btn__value {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--color-white);
}

.amount-btn__currency {
  font-size: 0.8rem;
  color: var(--placeholder-text);
  margin-top: 0.15rem;
}

.btn {
  display: block;
  width: 100%;
  padding: 0.75rem;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  border: 0;
  transition: opacity 0.15s, background 0.15s;
}

.btn--primary {
  background: var(--gradient-linear);
  color: #1a1a1a;
  box-shadow: 0 4px 20px rgba(243, 255, 23, 0.25);
}

.btn--primary:not(:disabled):hover {
  opacity: 0.9;
  box-shadow: 0 4px 24px rgba(243, 255, 23, 0.4);
}

.btn--primary:disabled {
  background: rgba(255, 255, 255, 0.06);
  color: var(--placeholder-text);
  box-shadow: none;
  cursor: not-allowed;
}

.btn--ghost {
  margin-top: 0.75rem;
  background: transparent;
  color: var(--placeholder-text);
  border: 1px solid var(--divider);
}

.btn--ghost:hover {
  background: rgba(255, 255, 255, 0.05);
  color: var(--color-white);
}

#payment-container {
  min-height: 200px;
}

.status {
  padding: 0.75rem 1rem;
  border-radius: 8px;
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.status--error {
  background: rgba(235, 0, 27, 0.12);
  color: #ff8a93;
  border: 1px solid rgba(235, 0, 27, 0.35);
}

.status--loading {
  background: rgba(73, 220, 245, 0.1);
  color: var(--color-secondary);
  border: 1px solid rgba(73, 220, 245, 0.35);
}

.status--hidden {
  display: none;
}

.success {
  text-align: center;
  background: var(--gradient-glass);
  backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 16px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.45), inset 0 1px 0 rgba(255, 255, 255, 0.08);
  padding: 2.5rem 2rem;
}

.success__icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 1.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--gradient-linear);
  box-shadow: 0 0 24px rgba(243, 255, 23, 0.4);
}

.success__icon svg {
  width: 28px;
  height: 28px;
  stroke: #1a1a1a;
}

.success h1 {
  margin: 0 0 0.5rem;
  font-size: 1.6rem;
  font-weight: 600;
  background: var(--gradient-linear);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.success p {
  color: var(--placeholder-text);
}

.success a {
  display: inline-block;
  margin-top: 0.5rem;
  color: var(--color-secondary);
  text-decoration: none;
  font-weight: 600;
}

.success a:hover {
  text-decoration: underline;
}