:root {
  --primary: #0f5da8;
  --primary-dark: #0b4a86;
  --text: #1f2933;
  --muted: #5f6b76;
  --border: #d5dde4;
  --bg: #eef2f5;
  --error: #b42318;
  --ok: #067647;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Hiragino Sans", "Yu Gothic UI", "Meiryo", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  display: flex;
  justify-content: center;
  padding: 2.5rem 1rem;
  min-height: 100vh;
}

.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
  max-width: 560px;
  width: 100%;
  padding: 2rem;
  height: fit-content;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

h1 { font-size: 1.3rem; margin: 0 0 0.25rem; }
.brand { color: var(--muted); font-size: 0.85rem; margin: 0 0 1.5rem; }

.step p { line-height: 1.7; }

label { display: block; font-weight: 600; margin-bottom: 0.4rem; font-size: 0.9rem; }

input {
  width: 100%;
  padding: 0.65rem 0.75rem;
  font-size: 1rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-bottom: 1rem;
}
input:focus { outline: 2px solid var(--primary); outline-offset: 1px; }
#input-otp { letter-spacing: 0.5em; font-size: 1.4rem; text-align: center; }

button {
  width: 100%;
  padding: 0.7rem;
  font-size: 1rem;
  font-weight: 600;
  color: #fff;
  background: var(--primary);
  border: none;
  border-radius: 6px;
  cursor: pointer;
}
button:hover { background: var(--primary-dark); }
button:disabled { background: var(--muted); cursor: not-allowed; }

.note { color: var(--muted); font-size: 0.8rem; line-height: 1.6; }

.meta { border: 1px solid var(--border); border-radius: 6px; padding: 0.75rem 1rem; margin: 0 0 1rem; }
.meta div { display: flex; gap: 1rem; }
.meta dt { width: 5.5em; color: var(--muted); font-size: 0.85rem; }
.meta dd { margin: 0; font-size: 0.9rem; word-break: break-all; }

.files { list-style: none; padding: 0; margin: 0 0 1rem; }
.files li {
  display: flex;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.6rem 0.25rem;
  border-bottom: 1px solid var(--border);
}
.files a { color: var(--primary); text-decoration: none; word-break: break-all; }
.files a:hover { text-decoration: underline; }
.files .size { color: var(--muted); font-size: 0.85rem; white-space: nowrap; }

.message { color: var(--ok); font-size: 0.9rem; }
.error {
  color: var(--error);
  background: #fef3f2;
  border: 1px solid #fecdca;
  border-radius: 6px;
  padding: 0.75rem 1rem;
  font-size: 0.9rem;
  line-height: 1.6;
}