body { font-family: 'Segoe UI', 'PingFang SC', Arial, sans-serif; background: #f4f6fa; margin: 0; }
    .container {
      width: 96%;
      margin: 8px 2%;
      padding: 24px 0 32px 0;
      background: #fff;
      border-radius: 14px;
      box-shadow: 0 4px 24px rgba(0,0,0,0.08);
    }
    .inner {
      max-width: 620px;
      margin: 20px auto;
      padding: 0 8px;
    }
    h2 { text-align: center; margin-bottom: 22px; font-size: 2rem; font-weight: bold !important;font-family: 'Segoe UI Bold', 'PingFang SC', 'Microsoft YaHei', 'Arial', 'Helvetica', 'sans-serif', '黑体', 'Heiti SC', 'SimHei'; letter-spacing: 1px; }
    .logout { float: right; color: #1976d2; cursor: pointer; font-weight: 500; }
    .error { color: #e57373; margin-bottom: 8px; }
    .success { color: #43a047; margin-bottom: 8px; }
    .section { margin-bottom: 32px; }
    input, button {
      font-family: inherit;
      font-size: 16px;
      border-radius: 7px;
      outline: none;
    }
    input {
      padding: 10px 12px;
      margin-right: 8px;
      margin-top: 10px;
      border: 1.5px solid #d0d7de;
      width: 100%;
      box-sizing: border-box;
      margin-bottom: 12px;
      transition: border 0.2s;
      background: #f8fafb;
    }
    input:focus {
      border: 1.5px solid #1976d2;
      background: #fff;
    }
    button {
      padding: 5px 18px;
      background-color: #1976d2;
      color: #fff;
      border: none;
      border-radius: 7px;
      cursor: pointer;
      margin-bottom: 8px;
      transition: background 0.2s, box-shadow 0.2s;
      font-size: 16px;
      font-weight: bold !important;
      font-family: 'Segoe UI Bold', 'PingFang SC', 'Microsoft YaHei', 'Arial', 'Helvetica', 'sans-serif', '黑体', 'Heiti SC', 'SimHei';
      box-shadow: 0 1px 4px rgba(25,118,210,0.3);
      display: inline-block;
    }
    button:disabled {
      background: #b0b0b0;
      cursor: not-allowed;
      color: #fff;
      opacity: 0.85;
    }
    button:hover:not(:disabled) {
      background: #1565c0;
      box-shadow: 0 2px 8px rgba(25,118,210,0.13);
    }
    #bindBtn, .group-btn, .bind-btn {
      display: block;
      margin: 0 auto 8px auto;
      min-width: 120px;
      font-weight: bold !important;
      font-family: 'Segoe UI Bold', 'PingFang SC', 'Microsoft YaHei', 'Arial', 'Helvetica', 'sans-serif', '黑体', 'Heiti SC', 'SimHei';
      font-size: 15px;
      border-radius: 7px;
    }
    .assign-ip-btn {
      display: block;
      margin: 0 auto 22px auto;
      min-width: 180px;
      font-weight: 600;
      background: #1976d2;
      color: #fff;
      border: none;
      border-radius: 7px;
      padding: 11px 36px;
      font-size: 17px;
      box-shadow: 0 2px 8px rgba(25,118,210,0.10);
      transition: background 0.2s;
    }
    .assign-ip-btn:hover:not(:disabled) {
      background: #1256a3;
    }
    .account-list {
      background: transparent;
      border-radius: 12px;
      box-shadow: none;
      padding: 0;
      margin-bottom: 10px;
      overflow: visible;
    }
    .account-group {
      margin: 28px 0 32px 0;
      background: #fff;
      border-radius: 12px;
      box-shadow: 0 2px 12px rgba(25,118,210,0.07);
      padding: 0 0 10px 0;
      border: 1.5px solid #e3eaf3;
    }
    .account-group-title {
      font-weight: bold !important;
      font-family: 'Segoe UI Bold', 'PingFang SC', 'Microsoft YaHei', 'Arial', 'Helvetica', 'sans-serif', '黑体', 'Heiti SC', 'SimHei';
      color: #1976d2;
      background: #f0f4f8;
      border-radius: 12px 12px 0 0;
      padding: 16px 20px 10px 20px;
      font-size: 18px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      letter-spacing: 0.5px;
    }
    .account-group-title.unbound {
      background: #e3f2fd;
      color: #1976d2;
      font-weight: bold !important;
      font-family: 'Segoe UI Bold', 'PingFang SC', 'Microsoft YaHei', 'Arial', 'Helvetica', 'sans-serif', '黑体', 'Heiti SC', 'SimHei';
    }
    .account-group.unbound {
      background: #f7fbff;
      border: 1.5px solid #e3f2fd;
    }
    .account-header {
      display: flex;
      font-weight: bold !important;
      font-family: 'Segoe UI Bold', 'PingFang SC', 'Microsoft YaHei', 'Arial', 'Helvetica', 'sans-serif', '黑体', 'Heiti SC', 'SimHei';
      background: #f5f7fa;
      padding: 12px 0 12px 0;
      color: #1976d2;
      font-size: 15px;
      justify-content: space-between;
      border-bottom: 1px solid #e0e0e0;
      letter-spacing: 0.5px;
    }
    .account-header span {
      flex: 1 1 0;
      text-align: left;
      padding-left: 14px;
      min-width: 70px;
      font-size: 15px;
      font-weight: 500;
      letter-spacing: 0.5px;
      display: flex;
      align-items: center;
    }
    .account-header .account-col,
    .account-item .account-col {
      flex: 2 1 0;
      text-align: left;
      padding-left: 14px;
      min-width: 180px;
      max-width: 340px;
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
      font-weight: 500;
      font-size: 17px;
      letter-spacing: 0.5px;
    }
    .account-item {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 14px 0;
      border-bottom: 1px solid #f0f0f0;
      background: #fff;
      font-size: 15px;
      min-height: 44px;
      transition: background 0.2s;
    }
    .account-item:last-child {
      border-bottom: none;
    }
    .account-item span {
      flex: 1 1 0;
      text-align: left;
      padding-left: 14px;
      min-width: 70px;
      word-break: break-all;
      display: flex;
      align-items: center;
      font-size: 16px;
    }
    .account-item .account-col {
      flex: 2 1 0;
      text-align: left;
      padding-left: 14px;
      min-width: 180px;
      max-width: 340px;
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
      font-weight: 500;
      font-size: 17px;
      letter-spacing: 0.5px;
    }
    .account-item button {
      flex: 0 0 auto;
      margin-left: 10px;
      background: #1976d2;
      color: #fff;
      border: none;
      border-radius: 7px;
      padding: 7px 24px;
      cursor: pointer;
      font-size: 15px;
      min-width: 60px;
      box-shadow: 0 1px 4px rgba(25,118,210,0.08);
      height: 30px;
      line-height: 1;
      display: inline-block;
      font-weight: 500;
      transition: background 0.2s;
    }
    .account-item button:hover:not(:disabled) {
      background: #1256a3;
    }
    .account-item.unbound {
      background: #f7fbff;
      opacity: 1;
    }
    .account-item input[type="checkbox"] {
      margin-right: 12px;
      transform: scale(1.18);
    }
    .group-btn, .bind-btn {
      margin: 12px auto 0 auto;
      min-width: 120px;
      font-weight: bold !important;
      font-family: 'Segoe UI Bold', 'PingFang SC', 'Microsoft YaHei', 'Arial', 'Helvetica', 'sans-serif', '黑体', 'Heiti SC', 'SimHei';
      font-size: 16px;
      border-radius: 7px;
      padding: 5px 28px;
    }
    .group-btn:disabled, .bind-btn:disabled {
      background: #b0b0b0;
      cursor: not-allowed;
      color: #fff;
      opacity: 0.85;
    }
    .group-btn:hover:not(:disabled), .bind-btn:hover:not(:disabled) {
      background: #1256a3;
    }
    .group-tip, .bind-tip {
      text-align: center;
      margin: 10px 0 0 0;
      font-size: 15px;
      min-height: 20px;
      letter-spacing: 0.2px;
    }
    .group-tip {
      color: #e57373;
    }
    .group-tip.success {
      color: #43a047;
    }
    .bind-tip {
      color: #e57373;
    }
    .bind-tip.success {
      color: #43a047;
    }
    .col {
      display: flex;
      align-items: center;
      font-size: 13.5px;
      font-weight: 500;
      white-space: nowrap;
      overflow: visible;
      text-overflow: unset;
      justify-content: center;
      text-align: center;
    }
    .col-account { width: 100%; padding: 0 10px; display: flex; align-items: center; justify-content: space-between; text-align: left; }
    .col-plugin { flex: 0.5 1 0; }
    .col-ip { flex: 3 1 0; }
    .col-action { flex: 0.5 1 0; }
    .col-checkbox { flex: 0 0 36px; display: flex; align-items: center; justify-content: center; }
    .col-account { flex: 1.5 1 0; text-align: left; }
    .top-bar {
      position: relative;
      margin-bottom: 18px;
      min-height: 48px;
    }
    .main-title {
      text-align: center;
      font-size: 2.3rem;
      font-weight: 700 !important;
      font-family: 'Segoe UI Bold', 'PingFang SC', 'Microsoft YaHei', 'Arial', 'Helvetica', 'sans-serif', '黑体', 'Heiti SC', 'SimHei';
      color: #222;
      margin: 0;
      letter-spacing: 1px;
    }
    .logout-btn {
      position: absolute;
      right: 0;
      top: 0;
      background: #fff;
      color: #1976d2; 
      border-radius: 7px;
      font-size: 15px;
      font-weight: 500;
      padding: 6px 18px;
      box-shadow: none;
      transition: background 0.2s, color 0.2s;
      cursor: pointer;
    }
    .logout-btn:hover {
      background: #e3f2fd;
      color: #1256a3;
      border-color: #1256a3;
    }
    .tutorial-link {
      text-decoration: none;
    }
    @media (max-width: 600px) {
      .inner {
        max-width: 100vw;
        padding: 0 2px;
      }
      .account-header span, .account-item span, .account-item .account-col {
        font-size: 14px;
        padding-left: 6px;
        min-width: 40px;
      }
      button, input {
        font-size: 15px;
      }
      .account-item button {
        min-width: 60px;
        padding: 6px 10px;
        height: 32px;
      }
      .account-item .account-col {
        min-width: 100px;
        max-width: 180px;
      }
      .account-group-title, .account-group-title.unbound {
        font-size: 15px;
        padding: 10px 8px 7px 8px;
      }
    }
    @media (min-width: 601px) {
      table {
        display: table;
        width: 100%;
      }
    }