body {
  margin: 0;
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial,
    sans-serif;
  background: #f9f9f7;
}

.container {
  font-family:
    ui-monospace, "Cascadia Code", "Source Code Pro", Menlo, Consolas, monospace;
  font-weight: 500;
  text-align: center;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 100%;
  max-width: 360px;
  padding: 0 24px;
  box-sizing: border-box;
}

.welcome-message {
  margin: 0 0 8px 0;
  font-size: 22px;
  letter-spacing: 0.04em;
}

.tagline {
  margin: 0 0 28px 0;
  font-size: 13px;
  color: #666;
  font-weight: 400;
}

/* ── Form ── */
form {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

button {
  padding: 12px 32px;
  font-size: 14px;
  font-weight: 600;
  font-family: inherit;
  letter-spacing: 0.05em;
  background-color: #1a1a1a;
  color: #ffffff;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: opacity 0.15s;
}

button:hover {
  opacity: 0.85;
}

button[disabled] {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ── Result states ── */
.result {
  padding: 20px 0;
}

.result-title {
  margin: 0 0 8px 0;
  font-size: 16px;
}

.result-sub {
  margin: 0;
  font-size: 13px;
  color: #555;
  font-weight: 400;
  line-height: 1.6;
}

.result.error .result-title {
  color: #c0392b;
}

/* ── Invalid link page ── */
.back-link {
  display: inline-block;
  margin-top: 20px;
  font-size: 13px;
  color: #1a1a1a;
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}