* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Segoe UI", sans-serif;
  color: #1f2430;
  background: #fff;
}

.auth-layout {
  display: flex;
  min-height: 100vh;
}

.auth-panel {
  flex: 0 0 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #fff;
  padding: 48px 24px;
}

.auth-visual {
  flex: 1 1 50%;
  background-image: url("../img/nebula.jpg");
  background-size: cover;
  background-position: center;
  background-color: #05070d;
}

.auth-inner {
  width: 100%;
  max-width: 340px;
}

.brand {
  margin: 0 0 26px;
  font-size: 30px;
  font-weight: 700;
  letter-spacing: 4px;
  text-align: center;
  line-height: 1.2;
  word-break: break-word;
}

.brand .c1 { color: #e03a3e; }
.brand .c2 { color: #ec6a3c; }
.brand .c3 { color: #f0b429; }
.brand .c4 { color: #2f6bff; }

.brand .brand-rest { color: #1f2430; }

.auth-tabs {
  display: flex;
  gap: 14px;
  margin-bottom: 22px;
}

.auth-tabs .tab {
  font-size: 15px;
  color: #9aa1ad;
  text-decoration: none;
  padding-bottom: 2px;
  transition: color .15s ease;
}

.auth-tabs .tab:hover { color: #5b5bf7; }

.auth-tabs .tab.is-active {
  color: #1f2430;
  font-weight: 600;
}

.alert {
  margin-bottom: 16px;
  padding: 10px 12px;
  border-radius: 8px;
  font-size: 13px;
  line-height: 1.5;
}

.alert-error {
  background: #fff1f0;
  color: #d4380d;
  border: 1px solid #ffccc7;
}

.alert-info {
  background: #f0f5ff;
  color: #1d39c4;
  border: 1px solid #d6e4ff;
}

.field {
  margin-bottom: 16px;
}

.field label {
  display: block;
  margin-bottom: 8px;
  font-size: 13px;
  color: #5c6370;
}

.field label .hint {
  color: #a9b0bd;
  font-size: 12px;
  margin-left: 4px;
}

.field input {
  width: 100%;
  height: 44px;
  padding: 0 14px;
  font-size: 14px;
  color: #1f2430;
  background: #f4f4f7;
  border: 1px solid transparent;
  border-radius: 8px;
  outline: none;
  transition: background .15s ease, border-color .15s ease, box-shadow .15s ease;
}

.field input::placeholder { color: #aeb4bf; }

.field input:focus {
  background: #fff;
  border-color: #5b5bf7;
  box-shadow: 0 0 0 3px rgba(91, 91, 247, .12);
}

.captcha-row {
  display: flex;
  gap: 10px;
  align-items: center;
}

.captcha-row input { flex: 1 1 auto; }

.captcha-row img {
  height: 52px;
  width: 168px;
  border-radius: 8px;
  cursor: pointer;
  object-fit: contain;
  flex: 0 0 auto;
  background: #f6f6f9;
}

.btn-primary {
  width: 100%;
  height: 44px;
  margin-top: 30px;
  border: none;
  border-radius: 8px;
  background: #5b5bf7;
  color: #fff;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 2px;
  cursor: pointer;
  transition: background .15s ease, transform .05s ease;
}

.btn-primary:hover { background: #4a4aeb; }
.btn-primary:active { transform: translateY(1px); }

@media (max-width: 900px) {
  .auth-visual { display: none; }
  .auth-panel { flex: 1 1 100%; }
}