:root {
    --center-brand: #1677ff;
    --center-brand-hover: #0958d9;
    --center-brand-soft: #e6f4ff;
    --center-info: #1e9fff;
    --center-info-soft: #eef8ff;
    --center-success: #16875d;
    --center-success-soft: #edf8f3;
    --center-warning: #b56b00;
    --center-warning-soft: #fff8e8;
    --center-danger: #dc2626;
    --center-bg-page: #f5f6f8;
    --center-bg-surface: #ffffff;
    --center-bg-subtle: #f2f2f2;
    --center-canvas-standard: #e9edf1;
    --center-canvas-focus: #171c22;
    --center-text-primary: #262626;
    --center-text-secondary: #666666;
    --center-text-muted: #8c8c8c;
    --center-text-white: #ffffff;
    --center-border: #e2e2e2;
    --center-focus: #1e9fff;
    --center-focus-ring: rgba(30, 159, 255, 0.28);
    --center-brand-shadow: rgba(22, 119, 255, 0.18);
    --center-logo-surface: #9d9d9d;
    --center-logo-surface-hover: #3f3d3d;
    --center-header-layer: 2000;
    --center-header-menu-layer: 2010;
    --center-radius-sm: 2px;
    --center-radius-md: 4px;
    --center-radius-lg: 8px;
    --center-shell-min: 1024px;
    --center-shell-max: 1440px;
    --center-shell-gutter: 16px;
    --center-header-height: 60px;
    --center-sidebar-width: 200px;
    --center-focus-sidebar-width: 450px;
    --center-footer-height: 48px;
    --center-shadow-card: 0 1px 2px rgba(0, 0, 0, 0.06), 0 6px 20px rgba(0, 0, 0, 0.05);
    --center-shadow-float: 0 1px 2px rgba(0, 0, 0, 0.1), 0 8px 24px rgba(0, 0, 0, 0.08);
    --study-chrome: #20262d;
    --study-chrome-raised: #2b333b;
}

/* Temporarily hide the legacy mobile-learning header entry. The QR markup
   remains in the templates so the entry can be re-enabled without a data or
   routing change when the new mobile-learning flow is ready. */
.center-header__mobile-learning {
    display: none !important;
}

.center-miniapp {
    display: none !important;
}

html:has(body.center-shell),
body.center-shell {
    min-width: var(--center-shell-min);
}

body.center-shell {
    color: var(--center-text-primary);
    font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
    letter-spacing: 0;
}

html:has(body.center-shell--standard),
body.center-shell--standard {
    background: var(--center-canvas-standard) !important;
}

html:has(body.center-shell--focus),
body.center-shell--focus {
    background: var(--center-canvas-focus) !important;
}

.center-shell--standard .center-header-shell {
    background: transparent !important;
}

.center-shell--standard .layui-layout-admin {
    background: transparent !important;
}

.center-shell--standard .layui-header {
    z-index: var(--center-header-layer) !important;
    color: var(--center-text-primary);
    border-bottom: 1px solid var(--center-border);
    border-radius: 0 0 var(--center-radius-lg) var(--center-radius-lg);
    background: var(--center-bg-surface) !important;
    box-shadow: var(--center-shadow-card);
}

.center-shell--standard .layui-header > .layui-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    width: var(--center-sidebar-width) !important;
    height: var(--center-header-height);
    padding: 4px;
    border-right: 1px solid var(--center-border);
    border-radius: 0 0 0 var(--center-radius-lg);
    background: var(--center-bg-surface);
    box-shadow: none !important;
    line-height: normal;
}

.center-shell--standard .layui-header > .layui-logo > a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: calc(100% - 16px);
    max-width: 100%;
    height: 46px;
    padding: 0 8px;
    border: 1px solid transparent;
    border-radius: var(--center-radius-md);
    background: var(--center-logo-surface);
    transition: background-color 150ms ease, box-shadow 150ms ease;
}

.center-shell--standard .layui-header > .layui-logo > a:hover,
.center-shell--standard .layui-header > .layui-logo > a:focus-visible {
    border-color: var(--center-logo-surface-hover);
    background: var(--center-logo-surface-hover);
}

.center-shell--standard .layui-header > .layui-logo > a:focus-visible {
    outline: 2px solid var(--center-focus);
    outline-offset: 2px;
}

.center-shell--standard .layui-header > .layui-logo img.layui-logo {
    position: static !important;
    width: 168px !important;
    max-width: 100%;
    height: 38px !important;
    padding: 0;
    border: 0;
    filter: none;
    opacity: 1;
    object-fit: contain;
    box-shadow: none !important;
}

.center-header__context {
    position: absolute;
    top: 0;
    left: calc(var(--center-sidebar-width) + 16px);
    display: flex;
    align-items: center;
    gap: 8px;
    height: var(--center-header-height);
}

.center-header__context span {
    display: inline-flex;
    align-items: center;
    min-height: 28px;
    padding: 0 10px;
    color: var(--center-text-secondary);
    border-radius: var(--center-radius-md);
    background: var(--center-bg-subtle);
    font-size: 12px;
    font-weight: 500;
}

.center-header__exam-status {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    min-height: 28px;
    padding: 0 8px 0 6px;
    border: 1px solid var(--center-border);
    border-radius: var(--center-radius-md);
    color: var(--center-text-secondary);
    background: var(--center-bg-surface);
    font-size: 12px;
    line-height: 20px;
    white-space: nowrap;
}

/* Shared exam switcher used by every learning-center header variant. */
.layui-nav .center-exam-switch-button,
.center-header__context .center-exam-switch-button,
.center-exam-header > .center-exam-switch-button {
    box-sizing: border-box;
    display: inline-flex !important;
    width: auto;
    min-width: 156px;
    max-width: 240px;
    height: 36px;
    min-height: 36px;
    align-items: center;
    gap: 0;
    margin: 0;
    padding: 0;
    border: 1px solid var(--center-brand) !important;
    border-radius: var(--center-radius-md);
    background: var(--center-brand) !important;
    color: var(--center-text-white) !important;
    line-height: normal !important;
    white-space: nowrap;
    transition: border-color 160ms ease, box-shadow 160ms ease, background-color 160ms ease;
}

.layui-nav .center-exam-switch-button:hover,
.layui-nav .center-exam-switch-button:focus-visible,
.center-header__context .center-exam-switch-button:hover,
.center-header__context .center-exam-switch-button:focus-visible,
.center-exam-header > .center-exam-switch-button:hover,
.center-exam-header > .center-exam-switch-button:focus-visible {
    border-color: var(--center-brand-hover) !important;
    background: var(--center-brand-hover) !important;
    box-shadow: 0 0 0 3px var(--center-focus);
}

.layui-nav .center-exam-switch-button:active,
.center-header__context .center-exam-switch-button:active,
.center-exam-header > .center-exam-switch-button:active {
    background: var(--center-brand-hover) !important;
    transform: translateY(1px);
}

.layui-nav .center-exam-switch-button__subject,
.center-header__context .center-exam-switch-button__subject,
.center-exam-header > .center-exam-switch-button .center-exam-switch-button__subject {
    min-width: 0;
    flex: 1 1 auto;
    padding: 0 10px;
    overflow: hidden;
    border-radius: 0;
    background: transparent;
    color: var(--center-text-white) !important;
    font-size: 12px;
    line-height: 34px;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.center-header__context .center-exam-switch-button > .center-exam-switch-button__subject,
.center-exam-header > .center-exam-switch-button > .center-exam-switch-button__subject {
    min-height: 0;
    background: transparent !important;
    color: var(--center-text-white) !important;
    font-weight: 500;
}

.layui-nav .center-exam-switch-button__label,
.center-header__context .center-exam-switch-button__label,
.center-exam-header > .center-exam-switch-button .center-exam-switch-button__label {
    flex: 0 0 auto;
    padding: 0 10px;
    border-left: 1px solid rgb(255 255 255 / 28%);
    color: var(--center-text-white);
    font-size: 12px;
    font-weight: 600;
    line-height: 34px;
}

.layui-nav-item > .center-exam-switch-button {
    vertical-align: middle;
}

.center-header__exam-status strong {
    font-weight: 500;
}

.center-header__exam-status .kaoshi {
    min-height: 24px;
    padding: 0 8px;
    color: var(--center-brand-hover);
    border-radius: var(--center-radius-md);
    background: var(--center-brand-soft);
    font-size: 12px;
    line-height: 24px;
}

.center-header__exam-status:hover .kaoshi,
.center-header__exam-status:focus-visible .kaoshi {
    color: var(--center-text-white);
    background: var(--center-brand);
}

.center-header__exam-status--countdown {
    border-color: var(--center-brand-shadow);
    color: var(--center-brand-hover);
    background: var(--center-brand-soft);
}

.center-header__exam-status--ongoing {
    color: var(--center-success);
    background: var(--center-success-soft);
}

.center-header__exam-status--unpublished {
    color: var(--center-text-muted);
    background: var(--center-bg-subtle);
}

.center-shell--focus .layui-header > .center-header__exam-status {
    position: absolute;
    top: 16px;
    left: 292px;
    z-index: 2;
}

.center-shell--focus .layui-header .center-header__link .layui-icon,
.center-shell--focus .layui-header .center-header__service .layui-icon,
.center-shell--focus .layui-header .center-header__mobile-learning .layui-icon,
.center-shell--focus .layui-header .center-focus-header__actions .layui-icon {
    position: static !important;
    font-size: 14px;
    top: auto !important;
    line-height: 1;
}

.center-shell--standard .layui-header .layui-layout-right {
    display: flex;
    align-items: center;
    gap: 2px;
    height: var(--center-header-height);
    padding: 0 8px;
    background: transparent;
}

.center-shell--standard .layui-header .layui-layout-right > .layui-nav-item {
    display: flex !important;
    flex: 0 0 auto;
    align-items: center;
    height: var(--center-header-height);
    line-height: normal;
}

.center-shell--standard .layui-header .layui-layout-right > .layui-nav-item > a {
    display: flex;
    align-items: center;
    gap: 7px;
    height: 38px;
    min-height: 38px;
    margin-top: 0;
    padding: 0 11px;
    color: var(--center-text-secondary) !important;
    border-radius: var(--center-radius-md);
    background: transparent !important;
    font-size: 14px;
    line-height: 20px;
    transition: color 150ms ease, background-color 150ms ease;
}

.center-shell--standard .layui-header .layui-layout-right > .layui-nav-item > a:hover,
.center-shell--standard .layui-header .layui-layout-right > .layui-nav-item > a:focus-visible {
    color: var(--center-brand) !important;
    background: var(--center-brand-soft) !important;
}

.center-shell--standard .layui-header .layui-layout-right > .layui-nav-item > a:active {
    color: var(--center-brand-hover) !important;
    background: var(--center-bg-subtle) !important;
}

.center-shell--standard .layui-header .layui-layout-right > .layui-nav-item > a[aria-disabled="true"],
.center-shell--standard .layui-header .layui-layout-right > .layui-nav-item.is-disabled > a {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

.center-shell--standard .layui-header .center-header__link .layui-icon,
.center-shell--standard .layui-header .center-header__service .layui-icon,
.center-shell--standard .layui-header .center-header__mobile-learning .layui-icon,
.center-shell--standard .layui-header .center-header__user .layui-icon  {
    position: static !important;
    font-size: 14px;
    top: auto !important;
    line-height: 1;
}

/* .center-shell--standard .layui-header .center-header__link .center-header-phone {
    padding-right: 10px;
} */

.center-shell--standard .layui-header .center-header__help .layui-icon {
    color: var(--center-info);
}

.center-shell--standard .layui-header .center-header__user {
    margin-left: 6px;
    padding-left: 7px;
}

.center-shell--standard .layui-header .center-header__user > a {
    position: relative;
    padding-right: 34px;
    border: 1px solid transparent;
}

.center-shell--standard .layui-header .center-header__user > a:hover,
.center-shell--standard .layui-header .center-header__user > a:focus-visible {
    border-color: var(--center-border);
}

.center-shell--standard .layui-header .center-header__user .layui-nav-more {
    top: 8px !important;
    /* margin-top: -3px; */
    font-size: 14px;
}

/* .center-shell--standard .layui-header .center-header__user > a::after {
    position: absolute;
    top: 50%;
    right: 13px;
    width: 7px;
    height: 7px;
    content: "";
    border-right: 1.5px solid var(--center-text-muted);
    border-bottom: 1.5px solid var(--center-text-muted);
    transform: translateY(-65%) rotate(45deg);
    transform-origin: center;
    transition: transform 150ms ease, border-color 150ms ease;
} */

/* .center-shell--standard .layui-header .center-header__user:hover > a::after,
.center-shell--standard .layui-header .center-header__user:focus-within > a::after {
    border-color: var(--center-brand);
    transform: translateY(-35%) rotate(225deg);
} */

.center-shell--standard .layui-header .center-header__user::before {
    position: absolute;
    top: 18px;
    bottom: 18px;
    left: 0;
    width: 1px;
    content: "";
    background: var(--center-border);
}

.center-shell--standard .layui-header .layui-nav-img {
    width: 32px;
    height: 32px;
    margin-right: 1px;
    border: 1px solid var(--center-border);
    object-fit: cover;
}

.center-header__username {
    display: block;
    max-width: 136px;
    /* padding-right: 8px; */
    overflow: hidden;
    color: var(--center-text-primary);
    font-size: 13px;
    font-variant-numeric: tabular-nums;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.usernameBG {
    color: var(--center-text-white);
}

.center-shell--standard .layui-header .layui-nav-bar {
    display: none;
}

.center-shell--standard .layui-header .layui-nav-child {
    top: 54px;
    padding: 6px;
    border: 1px solid var(--center-border);
    border-radius: var(--center-radius-lg);
    background: var(--center-bg-surface);
    box-shadow: var(--center-shadow-float);
}

.center-shell--standard .layui-header .layui-nav-child dd a {
    color: var(--center-text-primary) !important;
    border-radius: var(--center-radius-md);
    line-height: 36px;
}

.center-shell--standard .layui-header .layui-nav-child dd a:hover,
.center-shell--standard .layui-header .layui-nav-child dd a:focus-visible {
    color: var(--center-brand) !important;
    background: var(--center-brand-soft) !important;
}

.center-shell--standard .layui-header .layui-nav-child .loginout {
    cursor: pointer;
}

.center-shell *,
.center-shell *::before,
.center-shell *::after {
    box-sizing: border-box;
}

.center-shell .layui-layout-admin {
    min-width: var(--center-shell-min);
}

.center-shell .layui-fluid,
.center-shell .layui-container {
    width: 100%;
    max-width: 100%;
}

.center-shell--standard .layui-side .layui-nav {
    flex: 0 0 auto;
    width: 100%;
    padding: 0;
    background: transparent;
}

.center-shell--standard .layui-side .layui-side-scroll {
    display: flex;
    flex-direction: column;
    width: var(--center-sidebar-width) !important;
    padding: 14px 12px 16px;
    overflow-x: hidden;
    overflow-y: auto;
}

.center-sidebar__heading {
    display: flex;
    flex: 0 0 auto;
    align-items: center;
    gap: 8px;
    min-height: 32px;
    padding: 0 10px 8px;
    color: var(--center-text-muted);
    font-size: 12px;
    font-weight: 600;
    line-height: 20px;
}

.center-sidebar__heading .layui-icon {
    color: var(--center-brand);
    font-size: 15px;
}

.center-shell--standard .layui-side .layui-nav > hr {
    display: none;
}

.center-shell--standard .layui-side .layui-nav-item {
    position: relative;
    width: 100%;
    min-height: 42px;
    margin-bottom: 4px;
    overflow: hidden;
    border-radius: var(--center-radius-md);
}

.center-shell--standard .layui-side .layui-nav-item > a {
    display: flex;
    align-items: center;
    min-height: 42px;
    padding: 0 14px;
    color: var(--center-text-primary) !important;
    background: transparent !important;
    font-size: 15px;
    font-weight: 500;
    line-height: 20px;
    text-align: left;
    transition: color 150ms ease, background-color 150ms ease;
}

.center-shell--standard .layui-side .layui-nav-item > a:hover,
.center-shell--standard .layui-side .layui-nav-item > a:focus-visible {
    color: var(--center-brand) !important;
    background: var(--center-brand-soft) !important;
    text-decoration: none;
}

.center-shell--standard .layui-side .layui-nav-item.on,
.center-shell--standard .layui-side .layui-nav-item.layui-this {
    background: var(--center-brand) !important;
    box-shadow: 0 4px 12px var(--center-brand-shadow);
}

.center-shell--standard .layui-side .layui-nav-item.on > a,
.center-shell--standard .layui-side .layui-nav-item.on > a:hover,
.center-shell--standard .layui-side .layui-nav-item.on > a:focus-visible,
.center-shell--standard .layui-side .layui-nav-item.layui-this > a,
.center-shell--standard .layui-side .layui-nav-item.layui-this > a:hover,
.center-shell--standard .layui-side .layui-nav-item.layui-this > a:focus-visible {
    color: var(--center-bg-surface) !important;
    background: var(--center-brand) !important;
    font-weight: 600;
}

.center-shell--standard .layui-side .layui-nav-item > a:active {
    background: var(--center-bg-subtle) !important;
}

.center-shell--standard .layui-side .layui-nav-item.on > a:active,
.center-shell--standard .layui-side .layui-nav-item.layui-this > a:active {
    background: var(--center-brand-hover) !important;
}

.center-miniapp {
    position: static !important;
    display: block;
    flex: 0 0 auto;
    width: 100% !important;
    margin: auto 0 0;
    padding: 12px 10px 10px;
    color: var(--center-text-primary);
    border: 1px solid var(--center-border);
    border-radius: var(--center-radius-lg);
    background: var(--center-bg-subtle);
    text-align: center;
}

.center-miniapp__heading {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 10px;
    text-align: left;
}

.center-miniapp__heading > div {
    min-width: 0;
}

.center-miniapp__icon {
    display: inline-flex !important;
    flex: 0 0 auto;
    align-items: center;
    justify-content: center;
    width: 30px;
    height: 30px;
    color: var(--center-success);
    border-radius: var(--center-radius-md);
    background: var(--center-success-soft);
}

.center-miniapp__icon .layui-icon {
    font-size: 24px !important;
}

.center-miniapp__heading strong,
.center-miniapp__heading span {
    display: block;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.center-miniapp__heading strong {
    color: var(--center-text-primary);
    font-size: 12px;
    font-weight: 600;
    line-height: 18px;
}

.center-miniapp__heading div > span {
    color: var(--center-text-muted);
    font-size: 11px;
    line-height: 16px;
}

.center-miniapp__qr {
    width: 140px;
    height: 140px;
    margin: 0 auto;
    padding: 4px;
    border: 1px solid var(--center-border);
    border-radius: var(--center-radius-md);
    background: var(--center-bg-surface);
}

.center-miniapp__qr img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.center-miniapp p {
    margin: 7px 0 0;
    color: var(--center-text-secondary);
    font-size: 11px;
    line-height: 18px;
}

.center-miniapp__empty {
    display: flex;
    min-height: 104px;
    padding: 14px 8px;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    border: 1px dashed var(--center-border);
    border-radius: var(--center-radius-md);
    background: var(--center-bg-surface);
    box-sizing: border-box;
}

.center-miniapp__empty > i {
    margin-bottom: 7px;
    color: var(--center-text-muted);
    font-size: 26px;
}

.center-miniapp__empty strong,
.center-miniapp__empty span {
    display: block;
}

.center-miniapp__empty strong {
    color: var(--center-text-primary);
    font-size: 12px;
    line-height: 18px;
}

.center-miniapp__empty span {
    margin-top: 2px;
    color: var(--center-text-secondary);
    font-size: 11px;
    line-height: 17px;
}

.center-miniapp__empty a {
    display: inline-flex;
    min-height: 30px;
    margin-top: 9px;
    padding: 0 11px;
    align-items: center;
    border: 1px solid var(--center-success);
    border-radius: var(--center-radius-md);
    color: var(--center-success);
    font-size: 12px;
    line-height: 28px;
}

.center-miniapp__empty a:hover {
    background: var(--center-success-soft);
}

.center-miniapp__empty a:active {
    opacity: 0.75;
}

.center-miniapp__empty a:focus-visible {
    outline: 2px solid var(--center-focus);
    outline-offset: 2px;
}

.center-miniapp__empty--disabled {
    min-height: 88px;
}

.center-header__mobile-learning > span {
    display: inline-flex;
    min-height: 38px;
    padding: 0 11px;
    align-items: center;
    gap: 7px;
    line-height: 20px;
}

.center-header__mobile-learning--disabled {
    color: var(--center-text-muted) !important;
    cursor: not-allowed;
    opacity: 0.72;
}

.center-mobile-learning-menu {
    z-index: var(--center-header-menu-layer) !important;
    left: 50% !important;
    width: 156px !important;
    min-width: 156px !important;
    margin-left: -78px;
    padding: 10px !important;
    transform: none;
    border: 1px solid var(--center-border);
    border-radius: var(--center-radius-md);
    background: var(--center-bg-surface) !important;
    box-shadow: var(--center-shadow-float);
    box-sizing: border-box;
}

.center-mobile-learning-menu dd {
    text-align: center;
}

.center-mobile-learning-menu__heading {
    margin-bottom: 8px;
    color: var(--center-text-primary);
    font-size: 12px;
    font-weight: 600;
    line-height: 18px;
}

.center-mobile-learning-menu img {
    display: block;
    width: 132px;
    height: 132px;
    margin: 0 auto;
    object-fit: contain;
}

.center-mobile-learning-menu p {
    margin: 6px 0 0;
    color: var(--center-text-secondary);
    font-size: 11px;
    line-height: 17px;
}

.center-shell .layui-card,
.center-shell .layui-table-view,
.center-shell .layui-tab,
.center-shell fieldset {
    max-width: 100%;
}

.center-shell .layui-table-view {
    overflow-x: auto;
    overflow-y: hidden;
}

.center-shell .layui-table-box,
.center-shell .layui-table-header,
.center-shell .layui-table-body {
    min-width: 0;
}

.center-shell img,
.center-shell video,
.center-shell canvas {
    max-width: 100%;
}

.center-shell a:focus-visible,
.center-shell button:focus-visible,
.center-shell input:focus-visible,
.center-shell select:focus-visible,
.center-shell textarea:focus-visible,
.center-shell [tabindex]:focus-visible {
    outline: 3px solid var(--center-focus-ring);
    outline-offset: 2px;
}

.center-shell .center-footer {
    box-sizing: border-box;
    height: var(--center-footer-height) !important;
    min-height: var(--center-footer-height);
    padding: 0 16px !important;
    color: var(--center-text-secondary);
    border-top: 1px solid var(--center-border);
    background: #f8fafb !important;
    line-height: 1.5 !important;
}

.center-footer__content {
    display: flex;
    min-width: 0;
    height: 100%;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    text-align: center;
    white-space: nowrap;
}

.center-footer__content img {
    flex: 0 0 auto;
    max-height: 20px;
    object-fit: contain;
}

@media (min-width: 1024px) {
    .center-shell--standard .layui-header,
    .center-shell--standard .layui-footer,
    .center-shell--focus .layui-header {
        width: calc(100% - 2 * var(--center-shell-gutter)) !important;
        max-width: var(--center-shell-max);
        margin-right: auto !important;
        margin-left: auto !important;
    }

    .center-shell--standard .layui-side {
        left: max(var(--center-shell-gutter), calc((100% - var(--center-shell-max)) / 2)) !important;
        width: var(--center-sidebar-width);
        bottom: var(--center-footer-height) !important;
        background: var(--center-bg-surface);
    }

    .center-shell--standard .layui-body {
        right: max(var(--center-shell-gutter), calc((100% - var(--center-shell-max)) / 2)) !important;
        left: max(calc(var(--center-shell-gutter) + var(--center-sidebar-width)), calc((100% - var(--center-shell-max)) / 2 + var(--center-sidebar-width))) !important;
        bottom: var(--center-footer-height) !important;
        margin-right: 0 !important;
        margin-left: 0 !important;
        overflow-x: hidden !important;
        overflow-y: auto !important;
        background: var(--center-bg-page);
    }

    .center-shell--standard .layui-footer {
        right: auto !important;
        left: 50% !important;
        border-top: 1px solid var(--center-border);
        background: #f8fafb !important;
        transform: translateX(-50%);
    }

    .center-shell--focus .layui-breadcrumb {
        position: absolute;
        right: 300px;
        left: 470px;
        display: block;
        overflow: hidden;
        margin-left: 0 !important;
        text-align: left;
        text-overflow: ellipsis;
        white-space: nowrap;
    }

    .center-shell--focus .layui-header--no-exam .layui-breadcrumb {
        left: 320px;
    }

    .center-shell--focus .layui-body.video {
        right: max(var(--center-focus-sidebar-width), calc((100% - var(--center-shell-max)) / 2 + var(--center-focus-sidebar-width))) !important;
        left: max(0px, calc((100% - var(--center-shell-max)) / 2)) !important;
        width: auto !important;
        min-width: 0 !important;
        margin-left: 0 !important;
    }

    .center-shell--focus .layui-side1 {
        right: max(0px, calc((100% - var(--center-shell-max)) / 2)) !important;
        width: var(--center-focus-sidebar-width) !important;
    }

    .center-shell--focus .layui-side1 > .layui-side-scroll {
        max-width: calc(100% - 60px);
    }
}

@media (min-width: 1024px) and (max-width: 1199px) {
    :root {
        --center-shell-gutter: 12px;
        --center-focus-sidebar-width: 360px;
    }

    .center-shell--standard .layui-body > .layui-fluid,
    .center-shell--standard .layui-body > [style*="padding"] {
        padding-right: 12px !important;
        padding-left: 12px !important;
    }

    .center-shell--focus .layui-breadcrumb {
        right: 260px;
        left: 460px;
    }

    .center-shell--focus .layui-header--no-exam .layui-breadcrumb {
        left: 320px;
    }

    .center-shell--focus .layui-side1 > .layui-side-scroll {
        width: 320px !important;
        max-width: 100%;
    }
}

@media (min-width: 1024px) and (max-height: 760px) {
    .center-shell--standard .layui-side .layui-side-scroll {
        padding-top: 10px;
        padding-bottom: 10px;
    }

    .center-sidebar__heading {
        min-height: 28px;
        padding-bottom: 4px;
    }

    .center-shell--standard .layui-side .layui-nav-item {
        min-height: 38px;
        margin-bottom: 2px;
    }

    .center-shell--standard .layui-side .layui-nav-item > a {
        min-height: 38px;
    }

    .center-miniapp {
        padding: 8px;
    }

    .center-miniapp__heading {
        margin-bottom: 6px;
    }

    .center-miniapp__qr {
        width: 120px;
        height: 120px;
    }

    .center-miniapp p {
        margin-top: 3px;
    }
}

/* Shared header geometry. This layer intentionally overrides legacy head templates. */
.center-shell--standard .center-header__context {
    right: 480px;
    min-width: 0;
    overflow: hidden;
}

.center-header__exam-status strong {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
}

.center-header__exam-status { min-width: 0; }

.center-shell--focus .center-focus-header {
    position: relative;
    z-index: var(--center-header-layer) !important;
    display: block;
    box-sizing: border-box;
    height: var(--center-header-height);
    color: #fff;
    border-bottom: 1px solid rgb(255 255 255 / 9%);
    background: var(--study-chrome) !important;
    box-shadow: 0 1px 0 rgb(255 255 255 / 3%), 0 4px 16px rgb(0 0 0 / 14%);
}

.center-shell--focus .center-focus-header__brand,
.center-shell--focus .center-focus-header > .layui-logo {
    position: absolute !important;
    top: 0 !important;
    left: 0 !important;
    display: flex;
    align-items: center;
    width: 248px !important;
    height: var(--center-header-height) !important;
    padding: 0 10px;
    line-height: normal !important;
}

.center-shell--focus .center-focus-header__brand > a,
.center-shell--focus .center-focus-header > .layui-logo > a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 228px;
    height: 52px;
    border-radius: var(--center-radius-md);
    transition: background-color 150ms ease;
}

.center-shell--focus .center-focus-header__brand > a:hover,
.center-shell--focus .center-focus-header__brand > a:focus-visible,
.center-shell--focus .center-focus-header > .layui-logo > a:hover,
.center-shell--focus .center-focus-header > .layui-logo > a:focus-visible {
    background: rgb(255 255 255 / 8%);
}

.center-shell--focus .center-focus-header img.layui-logo {
    position: static !important;
    display: block;
    width: 220px !important;
    max-width: 220px !important;
    height: 44px !important;
    padding: 0 !important;
    object-fit: contain;
}

.center-shell--focus .center-focus-header > .center-header__exam-status {
    position: absolute;
    top: 15px;
    left: 256px;
    z-index: 2;
    box-sizing: border-box;
    max-width: 200px;
    min-height: 30px;
    color: #d8dde3;
    border-color: rgb(255 255 255 / 16%);
    background: rgb(255 255 255 / 7%);
}

.center-shell--focus .center-focus-header > .center-header__exam-status--countdown {
    color: var(--center-brand-soft);
    border-color: var(--center-brand);
    background: var(--center-brand-shadow);
}

.center-shell--focus .center-focus-header > .center-header__exam-status--ongoing {
    color: #b7ebc6;
    border-color: rgb(22 163 74 / 45%);
    background: rgb(22 163 74 / 12%);
}

.center-exam-header > .center-header__exam-status {
    position: absolute;
    top: 15px;
    left: 256px;
    z-index: 2;
    box-sizing: border-box;
    max-width: 200px;
    min-height: 30px;
}

/* Keep the exam switch directly after the status block in every header variant. */
.center-exam-header > .center-exam-switch-button {
    position: absolute;
    top: 12px;
    left: 472px;
    z-index: 2;
}

.center-exam-header > .center-header__exam-status + .center-exam-switch-button {
    left: 430px;
}

.center-exam-header > .center-exam-switch-button + .layui-breadcrumb,
.center-exam-header > .center-exam-switch-button ~ .center-focus-header__context {
    left: 728px;
    margin-left: 0 !important;
}

.center-shell--focus .center-focus-header__context,
.center-shell--focus .center-focus-header .layui-breadcrumb {
    position: absolute;
    top: 0;
    right: 340px;
    left: 728px;
    display: block;
    box-sizing: border-box;
    height: var(--center-header-height);
    margin: 0 !important;
    overflow: hidden;
    color: #c8cdd3;
    line-height: var(--center-header-height);
    text-align: left;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.center-shell--focus .center-focus-header--no-exam .center-focus-header__context,
.center-shell--focus .layui-header--no-exam .center-focus-header__context {
    left: 272px;
}

.center-shell--focus .center-focus-header__actions {
    position: absolute;
    top: 0;
    right: 0;
    display: flex;
    align-items: center;
    gap: 2px;
    height: var(--center-header-height);
    padding: 0 4px;
    background: transparent;
}

.center-shell--focus .center-focus-header__actions > .layui-nav-item {
    flex: 0 0 auto;
    height: 38px;
    line-height: 38px;
}

.center-shell--focus .center-focus-header__actions > .layui-nav-item > a {
    display: flex;
    align-items: center;
    gap: 6px;
    box-sizing: border-box;
    height: 38px;
    min-height: 38px;
    padding: 0 11px;
    color: #d8dde3;
    border: 1px solid transparent;
    border-radius: var(--center-radius-md);
    white-space: nowrap;
    transition: color 150ms ease, background-color 150ms ease;
}

.center-shell--focus .center-focus-header__actions .select_kaoshi {
    height: 34px !important;
    min-height: 34px !important;
    padding-top: 0 !important;
    padding-bottom: 0 !important;
    line-height: 32px !important;
}

.center-shell--focus .center-focus-header__actions .select_kaoshi .kaoshi {
    display: inline-flex;
    height: 24px;
    align-items: center;
    padding: 0 8px;
    line-height: 24px;
}

.center-shell--focus .center-focus-header__actions .center-exam-switch-button {
    width: auto;
    min-width: 156px;
    max-width: 220px;
    height: 36px !important;
    min-height: 36px !important;
    padding: 0 !important;
    border-color: var(--center-brand) !important;
    background: var(--center-brand) !important;
    line-height: 34px !important;
}

.center-shell--focus .center-focus-header__actions .center-exam-switch-button:hover,
.center-shell--focus .center-focus-header__actions .center-exam-switch-button:focus-visible {
    border-color: var(--center-brand-hover) !important;
    background: var(--center-brand-hover) !important;
}

@media (max-width: 1180px) {
    .center-exam-switch-button {
        min-width: 140px;
        max-width: 180px;
    }

    .center-shell--focus .center-focus-header__actions .center-exam-switch-button {
        min-width: 140px;
        max-width: 180px;
    }

}

.center-shell--focus .center-focus-header__actions > .layui-nav-item > a:hover,
.center-shell--focus .center-focus-header__actions > .layui-nav-item > a:focus-visible {
    color: #fff;
    border-color: rgb(255 255 255 / 12%);
    background: rgb(255 255 255 / 7%);
}

.center-shell--focus .center-focus-header__actions .layui-nav-img {
    width: 30px;
    height: 30px;
    margin-right: 2px;
}

.center-shell--focus .center-focus-header__actions .layui-nav-child {
    top: 44px;
}

.center-focus-mobile-qr {
    display: flex;
    width: 190px;
    box-sizing: border-box;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 14px;
    color: var(--center-text-primary);
    background: var(--center-bg-surface);
    text-align: center;
}

.center-focus-mobile-qr strong { font-size: 13px; font-weight: 600; }
.center-focus-mobile-qr img { display: block; width: 150px; height: 150px; object-fit: contain; }
.center-focus-mobile-qr span { color: var(--center-text-muted); font-size: 12px; line-height: 18px; }
.center-shell--focus .center-header__mobile-learning > .layui-nav-child { width: 190px; padding: 0; }
.center-shell--focus .center-focus-header__actions > .layui-nav-item > a:active { background: rgb(255 255 255 / 12%); }
.center-shell--focus .center-focus-header__actions > .layui-nav-item > a:focus-visible { outline: 2px solid var(--center-brand); outline-offset: -2px; }
.center-shell--focus .center-header__user .center-header__username { max-width: 72px; color: inherit; }
.center-shell--focus .center-header__user .layui-nav-child { min-width: 128px; }
.center-shell--focus .center-header__user .layui-nav-child a { color: var(--center-text-secondary); }
.center-shell--focus .center-header__user .layui-nav-child a:hover,
.center-shell--focus .center-header__user .layui-nav-child a:focus-visible { color: var(--center-brand-hover); background: var(--center-brand-soft); }
.center-shell--focus .center-header__mobile-learning--disabled > span { color: #8e98a3; cursor: not-allowed; }

@media (max-width: 1199px) {
    .center-shell--focus .center-focus-header__actions > .center-header__mobile-learning { display: none !important; }
    .center-shell--focus .center-focus-header__context,
    .center-shell--focus .center-focus-header .layui-breadcrumb { right: 220px; }
}

@media (min-width: 1024px) and (max-width: 1199px) {
    .center-shell--standard .center-header__context { right: 480px; }
    .center-shell--focus .center-focus-header__brand,
    .center-shell--focus .center-focus-header > .layui-logo { width: 224px !important; }
    .center-shell--focus .center-focus-header img.layui-logo { width: 204px !important; max-width: 204px !important; }
    .center-shell--focus .center-focus-header > .center-header__exam-status { left: 228px; max-width: 180px; }
    .center-shell--focus .center-focus-header__context,
    .center-shell--focus .center-focus-header .layui-breadcrumb { right: 220px; left: 660px; }
    .center-shell--focus .layui-header--no-exam .center-focus-header__context { left: 240px; }
    .center-shell--focus .center-focus-header__actions > .layui-nav-item > a { padding-right: 9px; padding-left: 9px; }
}

@media (prefers-reduced-motion: reduce) {
    .center-shell *,
    .center-shell *::before,
    .center-shell *::after {
        scroll-behavior: auto !important;
        transition-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
    }
}