:root {
  --blue: #2563eb;
  --blue-dark: #1d4ed8;
  --green: #22c55e;
  --red: #ef4444;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-500: #6b7280;
  --gray-700: #374151;
  --gray-900: #111827;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--gray-50);
  color: var(--gray-900);
  line-height: 1.6;
}

.container { max-width: 680px; margin: 0 auto; padding: 0 24px; }

.nav { padding: 20px 0; display: flex; align-items: center; justify-content: space-between; }
.nav-activate {
  font-size: 14px; font-weight: 600; color: var(--blue);
  background: none; border: 1.5px solid var(--blue); border-radius: 8px;
  padding: 8px 16px; cursor: pointer;
}
.nav-activate:hover { background: var(--blue); color: #fff; }
.logo { font-size: 18px; font-weight: 700; }

.hero { text-align: center; padding: 56px 0 32px; }
.hero h1 { font-size: 40px; line-height: 1.2; margin-bottom: 16px; }
.highlight { color: var(--blue); }
.subtitle { font-size: 17px; color: var(--gray-500); max-width: 500px; margin: 0 auto 26px; }
.price-box { display: flex; align-items: baseline; justify-content: center; gap: 8px; }
.price { font-size: 36px; font-weight: 700; }
.price-note { font-size: 14px; color: var(--gray-500); }

.btn-primary {
  display: inline-block; padding: 14px 32px; font-size: 16px; font-weight: 600;
  color: #fff; background: var(--blue); border: none; border-radius: 10px; cursor: pointer;
  transition: background 0.15s;
}
.btn-primary:hover { background: var(--blue-dark); }
.btn-primary:disabled { background: var(--gray-500); cursor: not-allowed; }

.msg { font-size: 13px; color: var(--red); min-height: 18px; }
.msg.ok { color: var(--green); }

.try-it, .buy, .faq { padding: 36px 0; }
.try-it h2, .buy h2, .faq h2 { font-size: 22px; margin-bottom: 6px; text-align: center; }
.try-it .subtitle, .buy .subtitle { text-align: center; margin-bottom: 18px; }

#brief-input {
  width: 100%; min-height: 120px; padding: 14px 16px; font-size: 14px; font-family: inherit;
  border: 1px solid var(--gray-200); border-radius: 10px; resize: vertical; background: #fff;
}
#brief-input:focus { outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15); }
.try-it-row { display: flex; align-items: center; gap: 12px; margin-top: 12px; }
.try-it-row .msg { flex: 1; }

.proposal {
  margin-top: 16px; background: #fff; border: 1px solid var(--gray-200);
  border-radius: 10px; padding: 20px;
}
.proposal-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; margin-bottom: 12px; }
.proposal-label { font-size: 11px; font-weight: 600; text-transform: uppercase; color: var(--gray-500); letter-spacing: 0.5px; }
.proposal h3 { font-size: 18px; margin-top: 4px; }
.btn-copy {
  white-space: nowrap; font-size: 13px; font-weight: 600; padding: 8px 14px; cursor: pointer;
  background: #fff; border: 1px solid var(--gray-200); border-radius: 8px; color: var(--gray-700);
}
.btn-copy:hover { background: var(--gray-100); }
.p-block { margin-top: 14px; font-size: 14px; color: var(--gray-700); }
.p-heading { font-size: 12px; font-weight: 700; text-transform: uppercase; color: var(--gray-500); letter-spacing: 0.5px; margin-bottom: 6px; }
.p-block ul { padding-left: 18px; }
.p-block li { margin-bottom: 4px; }

.checkout-form { display: flex; flex-direction: column; align-items: center; gap: 10px; }
#email-input, #key-input {
  width: 320px; max-width: 100%; padding: 12px 16px; font-size: 15px;
  border: 1px solid var(--gray-200); border-radius: 10px;
}
#email-input:focus, #key-input:focus { outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15); }
.activate { margin-top: 16px; display: flex; flex-direction: column; align-items: center; gap: 10px; }

details { background: #fff; border: 1px solid var(--gray-200); border-radius: 8px; margin-bottom: 8px; overflow: hidden; }
summary { padding: 14px 16px; font-size: 15px; font-weight: 500; cursor: pointer; list-style: none; }
summary::before { content: "+ "; color: var(--gray-500); }
details[open] summary::before { content: "− "; }
details p { padding: 0 16px 14px; font-size: 14px; color: var(--gray-500); }

.footer { text-align: center; padding: 40px 0; font-size: 13px; color: var(--gray-500); border-top: 1px solid var(--gray-200); margin-top: 20px; }
.footer a { color: var(--blue); text-decoration: none; }