:root {
  --bg: #f3f6fb;
  --card: #ffffff;
  --text: #1b1d22;
  --muted: #5c6473;
  --primary: #1f6feb;
  --primary-dark: #174ea6;
  --line: #dde3ee;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Pretendard", "Noto Sans KR", system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
}

.app-header {
  background: linear-gradient(135deg, #0f172a, #1e3a8a);
  color: #fff;
  text-align: center;
  padding: 2rem 1rem;
}

.app-header h1 {
  margin: 0;
  font-size: 2rem;
}

.app-header p {
  margin-top: 0.5rem;
  color: #dbeafe;
}

.container {
  max-width: 960px;
  margin: 1.5rem auto 3rem;
  padding: 0 1rem;
  display: grid;
  gap: 1rem;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 1rem;
  box-shadow: 0 6px 16px rgba(15, 23, 42, 0.06);
}

.card h2 {
  margin-top: 0;
  font-size: 1.2rem;
}

.row {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  align-items: center;
}

input,
select,
button {
  font: inherit;
}

input,
select {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.55rem 0.7rem;
  min-height: 42px;
}

button {
  border: none;
  border-radius: 10px;
  background: var(--primary);
  color: #fff;
  padding: 0.6rem 0.9rem;
  cursor: pointer;
}

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

.icon-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 0.6rem;
}

.device-btn {
  text-align: left;
  padding: 0.8rem;
}

.camera-area {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.6rem;
}

.camera-btn {
  font-weight: 700;
}

.steps {
  margin-top: 0.8rem;
  color: var(--muted);
  line-height: 1.55;
}

.guide {
  margin-top: 0.8rem;
  color: var(--muted);
}

.success {
  border-left: 5px solid #16a34a;
}

@media (max-width: 640px) {
  .camera-area {
    grid-template-columns: 1fr;
  }
}