:root{
  --bg1: #f6f7fb;
  --bg2: #eef2ff;
  --card: #ffffff;
  --text: #111827;
  --muted: #6b7280;
  --border: #e5e7eb;
  --shadow: 0 10px 30px rgba(0,0,0,.08);

  --accent: #4f46e5;
  --focus: rgba(79,70,229,.35);

  /* 検証用バナー色（目立つ） */
  --test-bg: #fff7ed;        /* orange-50 */
  --test-border: #fb923c;    /* orange-400 */
  --test-text: #9a3412;      /* orange-800 */

  --radius: 14px;
}

@media (prefers-color-scheme: dark){
  :root{
    --bg1: #0b1020;
    --bg2: #111a33;
    --card: rgba(255,255,255,.06);
    --text: rgba(255,255,255,.92);
    --muted: rgba(255,255,255,.65);
    --border: rgba(255,255,255,.14);
    --shadow: 0 16px 40px rgba(0,0,0,.45);
    --focus: rgba(99,102,241,.35);

    --test-bg: rgba(251,146,60,.14);
    --test-border: rgba(251,146,60,.9);
    --test-text: rgba(255,255,255,.9);
  }
}

*{ box-sizing: border-box; }
html, body{ height:100%; }

body{
  margin:0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", sans-serif;
  color: var(--text);
  background:
    radial-gradient(900px 500px at 20% 20%, rgba(79,70,229,.12), transparent 60%),
    radial-gradient(800px 450px at 90% 15%, rgba(34,197,94,.10), transparent 60%),
    linear-gradient(180deg, var(--bg1), var(--bg2));
  display:flex;
  align-items:center;
  justify-content:center;
  padding: 18px;
}

.card{
  width: min(520px, 100%);
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 22px 20px 18px;
}

/* ★追加：検証用バナー（見た瞬間わかる帯） */
.env-banner{
  margin: -22px -20px 14px;          /* cardのpadding分を打ち消して上部いっぱいに */
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
  border-top-left-radius: var(--radius);
  border-top-right-radius: var(--radius);

  text-align: center;
  font-weight: 800;
  letter-spacing: .06em;

  color: var(--test-text);
  background:
    repeating-linear-gradient(
      45deg,
      rgba(251,146,60,.18) 0,
      rgba(251,146,60,.18) 10px,
      rgba(251,146,60,.06) 10px,
      rgba(251,146,60,.06) 20px
    ),
    var(--test-bg);
  border-bottom: 2px solid var(--test-border);
}

.brand{
  display:flex;
  align-items:center;
  gap: 10px;
  margin-bottom: 12px;
}

.logo{
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--accent), rgba(79,70,229,.35));
  border: 1px solid rgba(255,255,255,.14);
}

.title{
  margin: 0;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: .02em;
}

.subtitle{
  margin: 6px 0 0;
  font-size: 13px;
  color: var(--muted);
  line-height: 1.55;
}

.form{
  margin-top: 14px;
  display: grid;
  gap: 12px;
}

label{
  display:block;
  margin-bottom: 6px;
  font-size: 13px;
  color: var(--muted);
}

.otp{
  width: 100%;
  padding: 12px 12px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: rgba(0,0,0,.02);
  color: var(--text);

  font-size: 22px;
  text-align: center;
  letter-spacing: .35em;
  font-variant-numeric: tabular-nums;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

  outline: none;
  transition: border-color .15s ease, box-shadow .15s ease, background .15s ease;
}

@media (prefers-color-scheme: dark){
  .otp{ background: rgba(255,255,255,.04); }
}

.otp:focus{
  border-color: rgba(79,70,229,.7);
  box-shadow: 0 0 0 4px var(--focus);
}

.hint{
  margin: 0;
  font-size: 12px;
  color: var(--muted);
  line-height: 1.5;
}

.actions{
  margin-top: 2px;
}

button{
  width: 100%;
  padding: 11px 12px;
  border: 1px solid rgba(79,70,229,.25);
  border-radius: 10px;
  background: linear-gradient(135deg, var(--accent), rgba(79,70,229,.78));
  color: #fff;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: filter .15s ease, transform .08s ease;
}

button:hover{ filter: brightness(1.04); }
button:active{ transform: translateY(1px); }

.footer{
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px solid var(--border);
  font-size: 12px;
  color: var(--muted);
}

button, input{ -webkit-appearance: none; appearance: none; }