:root {
  color-scheme: light;
  --bg: #f3f4f6;
  --card: #ffffff;
  --text: #111827;
  --muted: #4b5563;
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --border: #d1d5db;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  min-height: 100dvh;
  padding: 16px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: linear-gradient(180deg, #e5e7eb 0%, #f9fafb 100%);
  color: var(--text);
}

.app {
  width: min(100%, 900px);
  margin: 0 auto;
  display: grid;
  gap: 14px;
}

.hero,
.card {
  background: var(--card);
  border-radius: 14px;
  padding: 16px;
  border: 1px solid var(--border);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.06);
}

h1,
h2 {
  margin: 0;
}

.hero p {
  margin: 8px 0 0;
  color: var(--muted);
}

.hint {
  margin: 8px 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.form-grid {
  display: grid;
  gap: 10px;
}

label {
  display: grid;
  gap: 6px;
  font-size: 0.94rem;
}

input {
  border: 1px solid var(--border);
  border-radius: 8px;
  min-height: 40px;
  padding: 8px 10px;
  font-size: 1rem;
}

button {
  margin-top: 10px;
  border: none;
  border-radius: 10px;
  min-height: 42px;
  padding: 10px 14px;
  font-size: 0.96rem;
  font-weight: 700;
  cursor: pointer;
  background: var(--primary);
  color: #fff;
}

button:hover {
  background: var(--primary-dark);
}

.status {
  margin: 6px 0 10px;
  font-weight: 600;
}

.result {
  margin: 0;
  padding: 10px;
  border-radius: 8px;
  background: #0b1220;
  color: #d1fae5;
  overflow: auto;
  max-height: 360px;
}

@media (min-width: 720px) {
  .form-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}