:root {
  --blue: #1a73e8;
  --green: #1e8e3e;
  --red: #d93025;
  --gray: #5f6368;
  --bg: #f5f6f8;
  --card: #ffffff;
  --border: #e0e0e0;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: #202124;
}
.topnav {
  display: flex;
  align-items: center;
  gap: 4px;
  background: var(--card);
  border-bottom: 1px solid var(--border);
  padding: 10px 12px;
  overflow-x: auto;
  white-space: nowrap;
  position: sticky;
  top: 0;
  z-index: 10;
}
.topnav .brand { font-weight: 700; margin-right: 12px; }
.topnav a {
  color: var(--gray);
  text-decoration: none;
  padding: 8px 10px;
  border-radius: 6px;
  font-size: 14px;
}
.topnav a:hover { background: var(--bg); }
.topnav .logout { margin-left: auto; color: var(--red); }
.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 16px;
}
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px;
  margin-bottom: 16px;
}
h1 { font-size: 22px; margin: 8px 0 16px; }
h2 { font-size: 17px; margin: 0 0 12px; }
label { display: block; font-size: 13px; font-weight: 600; margin: 12px 0 4px; color: var(--gray); }
input[type=text], input[type=password], input[type=number], input[type=file], textarea, select {
  width: 100%;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 16px;
  background: #fff;
}
textarea { min-height: 90px; font-family: inherit; }
button, .btn {
  display: inline-block;
  background: var(--blue);
  color: #fff;
  border: none;
  padding: 13px 20px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  margin-top: 14px;
}
button.secondary, .btn.secondary { background: var(--gray); }
button.danger, .btn.danger { background: var(--red); }
.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-bottom: 16px;
}
.stat {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px;
  text-align: center;
}
.stat .num { font-size: 24px; font-weight: 700; }
.stat .label { font-size: 12px; color: var(--gray); }
.sent { color: var(--green); }
.pending { color: #f9a825; }
.failed { color: var(--red); }
table { width: 100%; border-collapse: collapse; font-size: 14px; }
th, td { text-align: left; padding: 8px 6px; border-bottom: 1px solid var(--border); }
.badge { padding: 2px 8px; border-radius: 20px; font-size: 12px; font-weight: 600; }
.badge.sent { background: #e6f4ea; }
.badge.pending { background: #fef7e0; }
.badge.failed { background: #fce8e6; }
.badge.sending { background: #e8f0fe; }
.hint { font-size: 13px; color: var(--gray); margin-top: 4px; }
.alert { padding: 12px; border-radius: 8px; margin-bottom: 14px; font-size: 14px; }
.alert.error { background: #fce8e6; color: var(--red); }
.alert.success { background: #e6f4ea; color: var(--green); }
.code-box {
  background: #202124;
  color: #e8eaed;
  padding: 12px;
  border-radius: 8px;
  font-family: monospace;
  font-size: 13px;
  overflow-x: auto;
  margin-top: 8px;
}