:root {
    color-scheme: light;
    --navy: #12304a;
    --blue: #1769aa;
    --green: #087f5b;
    --page: #f3f7fb;
    --border: #dbe5ee;
}

* { box-sizing: border-box; }
body { margin: 0; font-family: Arial, sans-serif; background: var(--page); color: var(--navy); }
.shell { width: min(920px, 94%); margin: 40px auto; }
.header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; }
.badge { padding: 7px 11px; border-radius: 999px; background: #fff3cd; color: #735c0f; font-size: 13px; }
.panel { background: white; border: 1px solid var(--border); border-radius: 16px; box-shadow: 0 12px 35px rgba(18,48,74,.10); overflow: hidden; }
.intro { padding: 28px; border-bottom: 1px solid var(--border); }
.intro h1 { margin: 0 0 8px; }
.intro p { margin: 0; line-height: 1.5; color: #52697b; }
.chat { min-height: 260px; padding: 24px; }
.notice { padding: 14px 16px; border-radius: 10px; background: #eef5fb; line-height: 1.5; }
.composer { display: flex; gap: 10px; padding: 18px; border-top: 1px solid var(--border); }
.composer textarea { flex: 1; min-height: 62px; resize: vertical; border: 1px solid var(--border); border-radius: 10px; padding: 12px; font: inherit; }
.composer button { border: 0; border-radius: 10px; padding: 0 22px; background: var(--blue); color: white; font-weight: 700; }
.composer button:disabled { background: #9fb1bf; cursor: not-allowed; }
.foot { margin-top: 12px; font-size: 12px; color: #667c8d; text-align: center; }