:root {
  --ink: #111827;
  --muted: #5b6472;
  --line: #d8dde6;
  --surface: #ffffff;
  --field: #f8fafc;
  --accent: #374151;
  --accent-dark: #111827;
  --error: #b91c1c;
  --success: #15803d;
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  font-size: 16px;
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  font-family: Arial, Helvetica, sans-serif;
  background:
    linear-gradient(135deg, rgba(75, 85, 99, 0.16), rgba(17, 24, 39, 0.04)),
    #f3f6f8;
}

button,
input,
select,
textarea {
  font: inherit;
}

.promo-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 22px;
}

.promo-panel {
  width: min(100%, 760px);
  background: var(--surface);
  border: 1px solid rgba(17, 24, 39, 0.08);
  border-radius: 8px;
  box-shadow: 0 24px 70px rgba(17, 24, 39, 0.14);
  padding: clamp(22px, 5vw, 44px);
}

.promo-copy {
  margin-bottom: 26px;
}

.promo-kicker {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.promo-copy h1 {
  margin: 0;
  font-size: clamp(2rem, 7vw, 3.8rem);
  line-height: 0.98;
}

.promo-copy p:last-child {
  max-width: 560px;
  margin: 14px 0 0;
  color: var(--muted);
  font-size: clamp(1rem, 2.4vw, 1.18rem);
  line-height: 1.45;
}

.promo-alert {
  margin-bottom: 20px;
  border-radius: 6px;
  padding: 12px 14px;
  color: #fff;
  font-weight: 700;
  text-align: center;
}

.promo-alert-error {
  background: var(--error);
}

.promo-alert-success {
  background: var(--success);
}

.promo-form {
  display: grid;
  gap: 18px;
}

.form-grid {
  display: grid;
  gap: 18px;
}

.form-field {
  display: grid;
  gap: 8px;
}

.form-field label {
  font-weight: 800;
}

.form-field input,
.form-field select,
.form-field textarea {
  width: 100%;
  min-height: 48px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--field);
  padding: 11px 13px;
  color: var(--ink);
  outline: none;
}

.form-field textarea {
  resize: vertical;
}

.form-field input:focus,
.form-field select:focus,
.form-field textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(55, 65, 81, 0.16);
}

.form-field span {
  color: var(--error);
  font-size: 0.9rem;
  font-weight: 700;
}

.promo-button {
  min-height: 52px;
  border: 0;
  border-radius: 6px;
  background: #262b35;
  color: #fff;
  font-weight: 900;
  cursor: pointer;
}

.promo-button:hover {
  background: #111827;
}

.promo-button:disabled,
.form-field input:disabled,
.form-field select:disabled,
.form-field textarea:disabled {
  cursor: not-allowed;
  opacity: 0.62;
}

.text-danger {
  color: var(--error);
  font-weight: 700;
}

.promo-alert-hide {
  opacity: 0;
  transform: translateY(-4px);
  transition: opacity 200ms ease, transform 200ms ease;
}

@media (min-width: 720px) {
  .form-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}