:root {
  --bg: #fff;
  --fg: #1d1d1f;
  --accent: #0071e3;
  --border: #e0e0e5;
  --radius: 12px;
  --shadow: 0 2px 12px rgba(0,0,0,0.04);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--fg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
}

main {
  width: 100%;
  max-width: 420px;
  margin: 64px 0 0 0;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 40px 32px 32px 32px;
  display: flex;
  flex-direction: column;
  align-items: stretch;
}

h1 {
  font-size: 2.2rem;
  font-weight: 600;
  margin-bottom: 2.5rem;
  letter-spacing: -0.02em;
  text-align: center;
}

label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
  font-size: 1.05rem;
  letter-spacing: 0.01em;
}

input[type=file],
select,
button {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1.05rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #fafafc;
  margin-bottom: 1.5rem;
  transition: border 0.2s, box-shadow 0.2s;
}

input[type=file]:focus,
select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(0,113,227,0.08);
}

button {
  background: var(--accent);
  color: #fff;
  border: none;
  font-weight: 600;
  letter-spacing: 0.01em;
  box-shadow: none;
  cursor: pointer;
  margin-top: 0.5rem;
  margin-bottom: 0;
  transition: background 0.2s;
}

button:hover:not([disabled]) {
  background: #005bb5;
}

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

#preview {
  max-width: 220px;
  margin: 2rem auto 0 auto;
  display: block;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  background: #fafafc;
  padding: 12px;
}

@media (max-width: 600px) {
  main {
    max-width: 98vw;
    padding: 24px 8px;
  }
  h1 {
    font-size: 1.4rem;
  }
}