* {
  box-sizing: border-box;
}

:root {
  --bg: #f5f7fb;
  --card: #ffffff;
  --text: #1f2933;
  --muted: #5f6c7b;
  --primary: #2563eb;
  --primary-strong: #1d4ed8;
  --accent: #f3f4f6;
  --border: #e5e7eb;
  --shadow: 0 10px 40px rgba(31, 41, 51, 0.12);
}

body {
  margin: 0;
  font-family: "Inter", "Segoe UI", system-ui, -apple-system, sans-serif;
  background: radial-gradient(circle at 20% 20%, rgba(37, 99, 235, 0.08), transparent 35%),
              radial-gradient(circle at 80% 10%, rgba(16, 185, 129, 0.08), transparent 30%),
              var(--bg);
  color: var(--text);
  min-height: 100vh;
  padding: 24px 14px 48px;
}

.page {
  max-width: 960px;
  margin: 0 auto;
}

.hero {
  text-align: center;
  margin-bottom: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
}

h1 {
  margin: 0;
  font-size: 1.9rem;
  letter-spacing: 0.4px;
}

.tagline {
  display: inline-block;
  margin: 6px 0 0;
  padding: 6px 10px;
  font-size: 1rem;
  color: var(--primary-strong);
  background: rgba(37, 99, 235, 0.1);
  border-radius: 10px;
}

.intro {
  margin: 16px auto 0;
  max-width: 720px;
  color: var(--text);
  line-height: 1.6;
}

.card {
  position: relative;
  background: linear-gradient(180deg, #ffffff 0%, #f9fbff 100%);
  border-radius: 22px;
  padding: 22px;
  box-shadow: var(--shadow);
  border: 1px solid #e3e8ef;
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  inset: -20% 40% auto -20%;
  height: 180px;
  background: radial-gradient(circle at 20% 40%, rgba(37, 99, 235, 0.18), transparent 40%),
              radial-gradient(circle at 70% 30%, rgba(14, 165, 233, 0.16), transparent 40%);
  z-index: 0;
}

.card > * {
  position: relative;
  z-index: 1;
}

.controls {
  display: grid;
  gap: 16px;
  grid-template-columns: 1fr;
}

.control-block h2 {
  margin: 0 0 12px;
  font-size: 1.1rem;
}

.platform-buttons {
  display: grid;
  gap: 10px;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
}

.platform-btn {
  padding: 14px 16px;
  border-radius: 12px;
  border: 1px solid #dae1ed;
  background: linear-gradient(135deg, #eef2ff, #f8fafc);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  transition: all 0.2s ease;
}

.platform-btn.active {
  background: linear-gradient(135deg, #2563eb, #0ea5e9);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 8px 24px rgba(37, 99, 235, 0.28);
}

.control-block {
  background: linear-gradient(135deg, #f8fafc, #eef2ff);
  border: 1px dashed #d6d9e0;
  border-radius: 14px;
  padding: 14px;
}

.platform-btn:hover,
.ghost-btn:hover,
.primary-btn:hover {
  transform: translateY(-1px);
}

label {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
  font-weight: 600;
}

select,
input[type="email"] {
  width: 100%;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: #fff;
  font-size: 1rem;
  color: var(--text);
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

select:focus,
input[type="email"]:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.platform-section {
  margin-top: 24px;
  padding-top: 8px;
  border-top: 1px solid var(--border);
}

.section-heading {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-bottom: 12px;
}

.muted {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.primary-btn {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  padding: 14px 16px;
  border: none;
  border-radius: 12px;
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  color: #fff;
  font-weight: 700;
  font-size: 1rem;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.2s ease, background 0.2s ease;
  box-shadow: 0 12px 24px rgba(37, 99, 235, 0.25);
}

.primary-btn.secondary {
  background: #0ea5e9;
  box-shadow: 0 12px 24px rgba(14, 165, 233, 0.25);
}

.ghost-btn {
  padding: 12px 16px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: #fff;
  font-weight: 700;
  cursor: pointer;
  transition: border-color 0.2s ease, transform 0.15s ease;
}

.ghost-btn:hover {
  border-color: var(--primary);
  transform: translateY(-1px);
}

.steps {
  margin: 14px 0 0;
  padding-left: 22px;
  line-height: 1.6;
  color: var(--text);
}

.steps li {
  margin-bottom: 9px;
}

.input-row {
  margin-bottom: 12px;
}

.input-actions {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
}

.hint {
  color: var(--muted);
  margin: 6px 0 0;
  font-size: 0.9rem;
}

.inline-link {
  margin: 12px 0;
  color: var(--text);
  font-weight: 600;
}

.inline-link span:last-child {
  display: inline-block;
  padding: 6px 10px;
  background: var(--accent);
  border-radius: 8px;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.95rem;
}

.hidden {
  display: none;
}

@media (min-width: 720px) {
  body {
    padding: 48px 32px 72px;
  }

  .controls {
    grid-template-columns: 3fr 2fr;
    align-items: center;
  }
}

@media (max-width: 480px) {
  h1 {
    font-size: 1.6rem;
  }

  .tagline {
    font-size: 0.95rem;
    padding: 5px 8px;
  }

  .card {
    padding: 18px;
  }

  .platform-btn,
  .primary-btn,
  .ghost-btn {
    font-size: 0.95rem;
    padding: 12px 14px;
  }

  .input-actions {
    grid-template-columns: 1fr;
  }

  .steps {
    padding-left: 18px;
    font-size: 0.98rem;
  }
}