* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'PingFang SC', '微软雅黑', sans-serif;
}

body {
  background: linear-gradient(135deg, #f0f4ff, #e8eeff);
  min-height: 100vh;
  padding: 60px 25px;
  position: relative;
  overflow-x: hidden;
}

.bg-ball {
  position: absolute;
  border-radius: 50%;
  opacity: 0.5;
  z-index: 0;
}

.b1 {
  width: 150px;
  height: 150px;
  background: #d6e0ff;
  top: -50px;
  right: -40px;
}

.b2 {
  width: 100px;
  height: 100px;
  background: #c5d4ff;
  bottom: 80px;
  left: -30px;
}

.header {
  position: relative;
  z-index: 2;
  margin-bottom: 45px;
}

.title {
  font-size: 28px;
  font-weight: 700;
  color: #2c3a77;
  margin-bottom: 10px;
}

.desc {
  font-size: 14px;
  color: #6b7cb8;
}

.register-card {
  position: relative;
  z-index: 2;
  background: #fff;
  border-radius: 24px;
  padding: 35px 25px;
  box-shadow: 0 10px 35px rgba(60, 90, 200, 0.15);
}

.invite-wrap {
  margin-bottom: 20px;
}

.invite-label {
  display: block;
  font-size: 14px;
  color: #6b7cb8;
  margin-bottom: 8px;
}

input.invite-readonly {
  background: #eef2f7 !important;
  color: #334155;
  cursor: not-allowed;
}

.input-item {
  margin-bottom: 20px;
}

.input-item input {
  width: 100%;
  height: 52px;
  padding: 0 18px;
  background: #f7f9ff;
  border: 1px solid #e4ebff;
  border-radius: 12px;
  font-size: 15px;
  outline: none;
  transition: border-color 0.3s, background 0.3s;
}

.input-item input:focus {
  border-color: #5271ff;
  background: #fff;
}

.code-row {
  display: flex;
  gap: 12px;
}

.code-row input {
  flex: 1;
}

.code-btn {
  width: 110px;
  height: 52px;
  background: linear-gradient(135deg, #5271ff, #3a54e0);
  color: #fff;
  border: none;
  border-radius: 12px;
  font-size: 14px;
  white-space: nowrap;
  flex-shrink: 0;
}

.code-btn.disabled,
.code-btn:disabled {
  background: #b4c2f0;
  cursor: not-allowed;
}

.reg-btn {
  width: 100%;
  height: 54px;
  background: linear-gradient(135deg, #5271ff, #3a54e0);
  color: #fff;
  border: none;
  border-radius: 12px;
  font-size: 16px;
  font-weight: 600;
  margin-top: 10px;
  box-shadow: 0 6px 20px rgba(82, 113, 255, 0.3);
}

.reg-btn:disabled {
  opacity: 0.65;
  cursor: not-allowed;
  box-shadow: none;
}

.bottom-tip {
  text-align: center;
  margin-top: 30px;
  font-size: 14px;
  color: #6b7cb8;
  position: relative;
  z-index: 2;
}

.bottom-tip a {
  color: #5271ff;
  text-decoration: none;
}