:root {
  --bg: #f2f2f7;
  --card: #ffffff;
  --text: #1c1c1e;
  --muted: #6c6c70;
  --border: #d1d1d6;
  --primary: #007aff;
  --primary-hover: #0066d6;
  --danger: #ff3b30;
  --input-bg: #ffffff;
}
[data-theme="dark"] {
  --bg: #0f1117;
  --card: #1a1d2e;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --border: #2d3148;
  --primary: #4f5fc0;
  --primary-hover: #6472d4;
  --danger: #ef4444;
  --input-bg: #0f1117;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.login-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 40px 36px;
  width: 100%;
  max-width: 380px;
}
.login-title {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 6px;
  color: var(--text);
}
.login-subtitle {
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 28px;
}
.form-row {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 16px;
}
label {
  font-size: 13px;
  font-weight: 500;
  color: var(--muted);
}
input[type="text"], input[type="password"] {
  background: var(--input-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-size: 14px;
  padding: 10px 12px;
  width: 100%;
  outline: none;
  transition: border-color 0.15s;
}
input:focus { border-color: var(--primary); }
.btn-submit {
  width: 100%;
  padding: 11px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  margin-top: 8px;
  transition: background 0.15s;
}
.btn-submit:hover { background: var(--primary-hover); }
.error-msg {
  background: #fff0ef;
  border: 1px solid var(--danger);
  color: var(--danger);
  border-radius: 7px;
  padding: 10px 14px;
  font-size: 13px;
  margin-bottom: 16px;
  display: none;
}
.error-msg.visible { display: block; }
[data-theme="dark"] .error-msg { background: #2d1a1a; }