/**
 * OJS SSL 头部导航（submission_guidelines 风格）
 * @author GCG
 */
.ssi-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: #fff;
    border-bottom: 1px solid var(--ssi-outline-variant);
}

.ssi-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    min-height: var(--ssi-header-height);
    padding: 12px var(--ssi-margin-mobile);
    max-width: var(--ssi-container-max);
    margin: 0 auto;
}

@media (min-width: 768px) {
    .ssi-header__inner { padding: 12px var(--ssi-margin-desktop); }
}

.ssi-header__left {
    display: flex;
    align-items: center;
    gap: 24px;
    flex: 1;
    min-width: 0;
}

.ssi-header__logo img {
    height: 40px;
    width: auto;
    object-fit: contain;
}

@media (min-width: 992px) {
    .ssi-header__logo img { height: 48px; }
}

.ssi-header__logo-text {
    font-family: var(--ssi-font-display);
    font-weight: 700;
    font-size: 16px;
    color: var(--ssi-deep-navy);
}

.ssi-header__nav {
    display: none;
}

@media (min-width: 992px) {
    .ssi-header__nav {
        display: flex;
        align-items: center;
        gap: 8px;
    }
}

.ssi-nav-item {
    position: relative;
}

.ssi-nav-link,
.ssi-nav-item > a {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 16px 8px;
    font-family: var(--ssi-font-label);
    font-size: 14px;
    font-weight: 500;
    line-height: 1.2;
    color: var(--ssi-deep-navy);
    border-bottom: 2px solid transparent;
    cursor: pointer;
    white-space: nowrap;
    transition: color 0.2s;
}

.ssi-nav-link:hover,
.ssi-nav-item > a:hover,
.ssi-nav-item:hover > .ssi-nav-label {
    color: var(--ssi-action-blue);
}

.ssi-nav-item.is-active > a,
.ssi-nav-item.is-active > .ssi-nav-link {
    color: var(--ssi-primary);
    font-weight: 700;
}

.ssi-nav-chevron {
    transition: transform 0.2s;
}

@media (min-width: 992px) {
    .ssi-nav-item.is-open .ssi-nav-chevron {
        transform: rotate(180deg);
    }
}

.ssi-nav-submenu {
    display: none;
    position: absolute;
    top: calc(100% - 2px);
    left: 0;
    min-width: 256px;
    padding-top: 10px;
    background: transparent;
    border: none;
    box-shadow: none;
    z-index: 100;
    flex-direction: column;
    gap: 0;
}

.ssi-nav-submenu::before {
    content: '';
    position: absolute;
    top: 0;
    left: -8px;
    right: -8px;
    height: 12px;
}

.ssi-nav-submenu__inner {
    position: relative;
    background: #fff;
    border: 1px solid var(--ssi-outline-variant);
    border-radius: var(--ssi-radius-lg);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.1);
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

/* 桌面端子菜单仅由 is-open / focus-within 控制，避免 hover 切换时叠层 */
@media (min-width: 992px) {
    .ssi-nav-item.is-open .ssi-nav-submenu,
    .ssi-nav-item:focus-within .ssi-nav-submenu {
        display: flex;
    }
}

.ssi-nav-submenu__accent {
    position: absolute;
    top: 0;
    left: 16px;
    right: 16px;
    height: 4px;
    background: var(--ssi-action-blue);
    border-radius: var(--ssi-radius);
}

.ssi-nav-submenu a {
    display: block;
    font-family: var(--ssi-font-label);
    font-size: 14px;
    font-weight: 500;
    color: var(--ssi-primary);
    transition: color 0.2s;
}

.ssi-nav-submenu a:hover {
    color: var(--ssi-action-blue);
}

.ssi-header__actions {
    display: flex;
    align-items: center;
    gap: 18px;
    flex-shrink: 0;
}

.ssi-header__search {
    display: none;
    position: relative;
}

@media (min-width: 768px) {
    .ssi-header__search { display: block; }
}

.ssi-header__search input {
    width: 192px;
    padding: 8px 36px 8px 16px;
    border: none;
    border-radius: var(--ssi-radius);
    background: var(--ssi-surface-container);
    color: var(--ssi-on-surface);
    font-family: var(--ssi-font-label);
    font-size: 14px;
    outline: none;
    transition: width 0.3s, box-shadow 0.2s;
}

.ssi-header__search input:focus {
    width: 256px;
    box-shadow: 0 0 0 2px rgba(0, 85, 255, 0.15);
}

.ssi-header__search input::placeholder {
    color: var(--ssi-on-surface-variant);
}

.ssi-header__search-submit {
    position: absolute;
    right: 4px;
    top: 50%;
    transform: translateY(-50%);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    padding: 0;
    border: none;
    border-radius: var(--ssi-radius);
    background: transparent;
    color: var(--ssi-on-surface-variant);
    cursor: pointer;
    transition: color 0.2s, background 0.2s;
}

.ssi-header__search-submit:hover {
    color: var(--ssi-primary);
    background: rgba(0, 0, 86, 0.06);
}

.ssi-header__search-icon {
    display: block;
}

.ssi-header__login {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

/* 未登录：Login / Register 文字链 */
.ssi-auth-guest {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-family: var(--ssi-font-label);
    font-size: 14px;
    font-weight: 600;
    white-space: nowrap;
}

.ssi-auth-guest--loading {
    color: var(--ssi-muted-gray);
    opacity: 0.7;
}

.ssi-auth-guest__link {
    color: var(--ssi-deep-navy);
    padding: 8px 2px;
    line-height: 1.2;
    transition: color 0.2s;
}

.ssi-auth-guest__link:hover {
    color: var(--ssi-primary);
}

.ssi-auth-guest__sep {
    color: var(--ssi-outline);
    font-weight: 400;
    user-select: none;
}

.ssi-user-info-wrapper {
    position: relative;
}

.ssi-user-info-button {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 4px 8px 4px 4px;
    border: none;
    border-radius: var(--ssi-radius);
    background: transparent;
    cursor: pointer;
    font-family: var(--ssi-font-label);
    font-size: 14px;
    font-weight: 500;
    color: var(--ssi-deep-navy);
    transition: background 0.2s;
}

.ssi-user-info-wrapper:hover .ssi-user-info-button,
.ssi-user-info-wrapper.is-open .ssi-user-info-button {
    background: var(--ssi-surface-container-low);
}

.ssi-user-info-button .ssi-user-avatar,
.ssi-user-info-button .ssi-user-avatar-placeholder {
    width: 36px;
    height: 36px;
}

.ssi-user-name {
    max-width: 120px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

@media (max-width: 575px) {
    .ssi-user-name { display: none; }
}

.ssi-user-dropdown {
    display: none;
    position: absolute;
    top: 100%;
    right: 0;
    min-width: 256px;
    padding-top: 10px;
    background: transparent;
    border: none;
    box-shadow: none;
    z-index: 200;
}

.ssi-user-dropdown::before {
    content: '';
    position: absolute;
    top: 0;
    left: -8px;
    right: -8px;
    height: 12px;
}

.ssi-user-dropdown__inner {
    position: relative;
    background: #fff;
    border: 1px solid var(--ssi-outline-variant);
    border-radius: var(--ssi-radius-lg);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.1);
    padding: 24px;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
}

.ssi-user-dropdown__accent {
    position: absolute;
    top: 0;
    left: 16px;
    right: 16px;
    height: 4px;
    background: var(--ssi-action-blue);
    border-radius: var(--ssi-radius);
}

.ssi-user-info-wrapper.is-open .ssi-user-dropdown {
    display: block;
}

.ssi-user-dropdown a {
    display: block;
    font-family: var(--ssi-font-label);
    font-size: 14px;
    font-weight: 500;
    color: var(--ssi-primary);
    line-height: 1.4;
    white-space: nowrap;
    transition: color 0.2s;
}

.ssi-user-dropdown a:hover {
    color: var(--ssi-action-blue);
}

.ssi-user-dropdown a.ssi-logout-btn {
    color: var(--ssi-error);
}

.ssi-user-dropdown a.ssi-logout-btn:hover {
    color: var(--ssi-error);
    opacity: 0.85;
}

.ssi-header__login a,
.ssi-header__login .ssi-login-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--ssi-deep-navy);
    padding: 4px;
}

.ssi-header__login .ssi-user-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    object-fit: cover;
}

.ssi-header__login .ssi-user-avatar-placeholder {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--ssi-primary-fixed);
    color: var(--ssi-primary);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 14px;
}

.ssi-mobile-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: 1px solid var(--ssi-outline-variant);
    border-radius: var(--ssi-radius);
    background: #fff;
    cursor: pointer;
    color: var(--ssi-deep-navy);
}

@media (min-width: 992px) {
    .ssi-mobile-toggle { display: none; }
}

.ssi-mobile-nav {
    display: none;
    position: fixed;
    top: var(--ssi-header-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: #fff;
    overflow-y: auto;
    z-index: 999;
    padding: 16px;
}

.ssi-mobile-nav.is-open { display: block; }

.ssi-mobile-nav .ssi-nav-item > a,
.ssi-mobile-nav .ssi-nav-label {
    display: block;
    padding: 12px 0;
    border-bottom: 1px solid var(--ssi-outline-variant);
    font-family: var(--ssi-font-label);
    font-size: 14px;
    color: var(--ssi-deep-navy);
}

.ssi-mobile-nav .ssi-nav-submenu {
    position: static;
    display: none;
    box-shadow: none;
    border: none;
    padding: 0 0 8px 16px;
    min-width: 0;
}

.ssi-mobile-nav .ssi-nav-item.is-expanded .ssi-nav-submenu { display: flex; }

.ssi-icon {
    width: 24px;
    height: 24px;
    flex-shrink: 0;
}

.ssi-icon--sm {
    width: 18px;
    height: 18px;
}