:root {
  color-scheme: light;
  --ink: #17212b;
  --muted: #667482;
  --line: #dce4ea;
  --accent: #147d92;
  --accent-dark: #0d6172;
  --surface: #ffffff;
  --background: #edf3f5;
  --danger: #a23b43;
  --success: #17724d;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  color: var(--ink);
  background:
    linear-gradient(135deg, rgba(20, 125, 146, 0.08), transparent 42%),
    var(--background);
  font-family: "Segoe UI", "Microsoft YaHei", sans-serif;
}

.page-shell {
  display: grid;
  min-height: 100vh;
  place-items: center;
  padding: 32px 18px;
}

.login-panel,
.success-panel {
  width: min(100%, 430px);
  padding: 42px 42px 34px;
  background: var(--surface);
  border: 1px solid rgba(220, 228, 234, 0.9);
  box-shadow: 0 24px 60px rgba(29, 59, 72, 0.12);
}

.brand-mark,
.success-icon {
  display: grid;
  width: 48px;
  height: 48px;
  place-items: center;
  margin-bottom: 26px;
  color: #fff;
  background: var(--accent);
  border-radius: 12px;
  font-size: 22px;
  font-weight: 700;
}

.success-icon {
  background: var(--success);
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--accent-dark);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1.6px;
}

h1 {
  margin: 0;
  font-size: 30px;
  line-height: 1.2;
}

.subtitle {
  margin: 12px 0 28px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

.login-form {
  display: grid;
  gap: 10px;
}

label {
  margin-top: 6px;
  color: #31414e;
  font-size: 13px;
  font-weight: 600;
}

input {
  width: 100%;
  min-height: 46px;
  padding: 0 14px;
  color: var(--ink);
  background: #fbfcfd;
  border: 1px solid var(--line);
  border-radius: 8px;
  outline: none;
  font: inherit;
}

input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(20, 125, 146, 0.14);
}

button {
  min-height: 46px;
  margin-top: 14px;
  color: #fff;
  background: var(--accent);
  border: 0;
  border-radius: 8px;
  cursor: pointer;
  font: inherit;
  font-weight: 700;
}

button:hover {
  background: var(--accent-dark);
}

.hint {
  margin: 26px 0 0;
  padding: 12px 14px;
  color: #53616b;
  background: #f3f8f9;
  border-left: 3px solid var(--accent);
  font-size: 13px;
  line-height: 1.6;
}

.alert {
  margin: 0 0 16px;
  padding: 11px 13px;
  color: var(--danger);
  background: #fff3f3;
  border: 1px solid #f0d5d7;
  border-radius: 8px;
  font-size: 13px;
}

.footer-note {
  margin: 28px 0 0;
  color: #9aa6ae;
  font-size: 11px;
  text-align: center;
}

.flag {
  display: block;
  overflow-wrap: anywhere;
  margin: 18px 0 24px;
  padding: 16px;
  color: #0d573b;
  background: #eef9f3;
  border: 1px solid #c7ead7;
  border-radius: 8px;
  font-family: Consolas, "Courier New", monospace;
  font-size: 15px;
  line-height: 1.5;
}

.back-link {
  color: var(--accent-dark);
  font-size: 13px;
  text-decoration: none;
}

.back-link:hover {
  text-decoration: underline;
}

@media (max-width: 520px) {
  .login-panel,
  .success-panel {
    padding: 32px 24px 28px;
  }

  h1 {
    font-size: 26px;
  }
}