/* =============================================================================
 * 做题页 v2（新版预览）
 * 仅在 <html class="ps-v2"> 时生效，旧版完全不受影响。
 * 由 frontend/v2/problemsetV2.ts 负责加类、搬 DOM 与切换开关。
 * ============================================================================= */

html.ps-v2 {
    --ps-ink: #141A26;
    --ps-ink-2: #4B5563;
    --ps-ink-3: #6B7280;
    --ps-ink-4: #9CA3AF;
    --ps-line: rgba(20, 26, 38, .08);
    --ps-line-strong: rgba(20, 26, 38, .14);
    --ps-surface: #FFFFFF;
    --ps-soft: #F5F7FA;
    --ps-accent: #2B7FFF;
    --ps-accent-soft: rgba(43, 127, 255, .08);
    --ps-ok: #16A34A;
    --ps-warn: #D97706;
    --ps-bad: #DC2626;
}

html.ps-v2.theme--dark {
    --ps-ink: #F2F3F5;
    --ps-ink-2: #C4C9D2;
    --ps-ink-3: #8F96A3;
    --ps-ink-4: #6B7280;
    --ps-line: rgba(255, 255, 255, .08);
    --ps-line-strong: rgba(255, 255, 255, .16);
    --ps-surface: #1C1E24;
    --ps-soft: #23262E;
    --ps-accent: #4C93FF;
    --ps-accent-soft: rgba(76, 147, 255, .14);
    --ps-ok: #3FB950;
    --ps-warn: #E3A008;
    --ps-bad: #F87171;
}

/* ── 页头：紧凑单行卡 ───────────────────────────────────────────────── */
html.ps-v2 .page-header {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px 20px;
    margin-bottom: 14px;
    background: var(--ps-surface);
    border: 1px solid var(--ps-line);
    border-radius: 12px;
    box-shadow: none;
}

html.ps-v2 .header-left {
    order: 1;
    flex: 1 1 auto;
    min-width: 0;
    align-items: center;
    gap: 14px;
    padding-top: 0;
}

html.ps-v2 .header-image-wrapper,
html.ps-v2 .header-image,
html.ps-v2 .header-image-loading {
    width: 64px;
    height: 64px;
    border-radius: 10px;
}

html.ps-v2 .header-image-wrapper {
    display: flex !important;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background: var(--ps-soft);
}

html.ps-v2 .header-image-loading {
    background: var(--ps-soft);
}

html.ps-v2 .header-content {
    gap: 10px;
    flex: 1 1 auto;
    min-width: 0;
}

html.ps-v2 .header-title-section {
    min-width: 0;
}

html.ps-v2 .page-title {
    margin: 0 0 14px;
    font-size: 24px;
    font-weight: 600;
    line-height: 1.25;
    letter-spacing: -.01em;
    color: var(--ps-ink);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

html.ps-v2 .page-subtitle {
    display: none;
}

/* 右侧动作区：分享 / 编辑 / 购买 */
html.ps-v2 #header-right-actions {
    order: 2;
    position: static;
    display: flex;
    align-items: center;
    gap: 8px;
    margin-left: auto;
}

html.ps-v2 .header-buy-section {
    order: 2;
    align-self: center;
    margin-left: 0;
}

html.ps-v2 .edit-button {
    order: 3;
    position: static;
    width: 32px;
    height: 32px;
    background: transparent;
    border: 0;
    border-radius: 8px;
}

html.ps-v2 .share-button {
    position: static;
    width: 32px;
    height: 32px;
    background: transparent;
    border: 0;
    border-radius: 8px;
}

html.ps-v2 .share-button:hover,
html.ps-v2 .edit-button:hover {
    background: rgba(20, 26, 38, .06);
    border: 0;
}

html.ps-v2 .share-button svg,
html.ps-v2 .edit-button svg {
    width: 18px;
    height: 18px;
    color: var(--ps-ink-3);
}

html.ps-v2 .share-button:hover svg,
html.ps-v2 .edit-button:hover svg {
    color: var(--ps-ink);
}

html.ps-v2.theme--dark .share-button:hover,
html.ps-v2.theme--dark .edit-button:hover {
    background: rgba(255, 255, 255, .08);
}

/* 页头元信息 + 进度 + 快捷链接 */
html.ps-v2 .ps-meta {
    display: flex;
    align-items: center;
    gap: 10px;
    min-height: 16px;
    font-size: 13px;
    color: var(--ps-ink-3);
}

html.ps-v2 .ps-meta__bar {
    display: inline-block;
    width: 200px;
    height: 6px;
    border-radius: 999px;
    background: var(--ps-line);
    overflow: hidden;
    flex: none;
}

html.ps-v2 .ps-meta__bar i {
    display: block;
    height: 100%;
    width: 0;
    background: var(--ps-accent);
    border-radius: 999px;
}

html.ps-v2 .ps-meta__links {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 6px;
}

html.ps-v2 .ps-meta__links:empty {
    display: none;
}

html.ps-v2 .ps-meta__links .learning-progress-links {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 0 !important;
}

/* 页头主按钮：墨色胶囊 */
html.ps-v2 .buy-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    height: 34px;
    padding: 0 16px;
    border-radius: 999px;
    border: 1px solid var(--ps-ink);
    background: var(--ps-ink);
    color: var(--ps-surface) !important;
    font-size: 13px;
    font-weight: 600;
    line-height: 1;
    text-decoration: none;
    cursor: pointer;
    white-space: nowrap;
    transition: opacity .15s ease;
}

html.ps-v2 .buy-button:hover {
    opacity: .88;
    color: var(--ps-surface) !important;
    background: var(--ps-ink);
    border-color: var(--ps-ink);
}

/* 学习进度附带的快捷链接：轻量描边胶囊，放在页头最后一行 */
html.ps-v2 .lp-plain-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    height: 28px;
    padding: 0 12px;
    border-radius: 999px;
    border: 1px solid var(--ps-line-strong);
    background: transparent;
    color: var(--ps-ink-2) !important;
    font-size: 12.5px;
    font-weight: 500;
    line-height: 1;
    text-decoration: none;
    cursor: pointer;
    white-space: nowrap;
    transition: background-color .15s ease, color .15s ease;
}

html.ps-v2 .lp-plain-btn:hover,
html.ps-v2 .lp-plain-btn:focus-visible {
    background: var(--ps-soft);
    border-color: var(--ps-line-strong);
    color: var(--ps-ink) !important;
}

/* ── 去掉 tab 行 ───────────────────────────────────────────────────── */
html.ps-v2 .sidebar-tabs-row {
    display: none;
}

/* 隐藏侧栏「学习进度 / 开始学习」卡片（数字已搬到页头） */
html.ps-v2 #badge-section {
    display: none;
}

/* ── 搜索框：单行输入，无独立按钮 ─────────────────────────────────── */
html.ps-v2 .ps-search {
    margin-bottom: 12px;
    --ps-search-accent: var(--ps-accent);
    --ps-search-border: var(--ps-line);
    --ps-search-bg: var(--ps-surface);
    --ps-search-text: var(--ps-ink);
    --ps-search-muted: var(--ps-ink-4);
}

html.ps-v2 .ps-search__bar {
    gap: 0;
}

html.ps-v2 .ps-search {
    max-width: none;
    width: 100%;
}

html.ps-v2 .ps-search__field {
    width: 100%;
    height: 38px;
    border-radius: 10px;
    border: 1px solid var(--ps-line);
    background: var(--ps-surface);
}

html.ps-v2 .ps-search__submit {
    display: none;
}

/* ── 题目列表：整块细线卡 + 卡内分组 ───────────────────────────────── */
html.ps-v2 .problems-section {
    background: var(--ps-surface);
    border: 1px solid var(--ps-line);
    border-radius: 12px;
    overflow: hidden;
}

html.ps-v2 .topic-group {
    margin-bottom: 0;
    background: transparent;
    border-radius: 0;
    box-shadow: none;
    overflow: visible;
}

html.ps-v2 .topic-group + .topic-group {
    border-top: 1px solid var(--ps-line);
}

html.ps-v2 .topic-header {
    gap: 10px;
    padding: 14px 20px 4px;
    background: transparent;
    border-bottom: 0;
}

html.ps-v2 .topic-icon {
    display: none;
}

html.ps-v2 .topic-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--ps-ink);
    margin-right: auto;
}

html.ps-v2 .topic-count {
    display: none;
}

html.ps-v2 .topic-progress {
    order: 3;
    flex: 0 0 auto;
    width: auto;
    max-width: none;
    margin-left: 10px;
    gap: 8px;
}

html.ps-v2 .progress-bar {
    width: 80px;
    height: 5px;
    border-radius: 999px;
    background: var(--ps-line);
}

html.ps-v2 .progress-fill {
    background: var(--ps-accent);
}

html.ps-v2 .progress-text {
    font-size: 12px;
    color: var(--ps-ink-3);
    font-weight: 500;
}

html.ps-v2 .topic-completed {
    order: 3;
    margin-left: 10px;
    font-size: 12px;
    color: var(--ps-ok);
}

html.ps-v2 .topic-completed .completed-text {
    font-size: 12px;
    color: var(--ps-ink-3);
}

/* 模拟机考按钮：统一放到进度条左侧，做轻 */
html.ps-v2 a.ps-chapter-exam-btn,
html.ps-v2 a.ps-chapter-exam-btn:link,
html.ps-v2 a.ps-chapter-exam-btn:visited,
html.ps-v2 a.ps-chapter-exam-btn .ps-chapter-exam-btn__icon {
    cursor: pointer;
}

html.ps-v2 a.ps-chapter-exam-btn,
html.ps-v2 a.ps-chapter-exam-btn:link,
html.ps-v2 a.ps-chapter-exam-btn:visited {
    order: 2;
    margin-left: 0;
    height: 26px;
    padding: 0 10px;
    gap: 4px;
    border-radius: 999px;
    background: transparent;
    border: 1px solid var(--ps-line-strong);
    color: var(--ps-ink-2) !important;
    font-size: 12px;
    font-weight: 500;
}

html.ps-v2 a.ps-chapter-exam-btn:hover,
html.ps-v2 a.ps-chapter-exam-btn:focus {
    background: var(--ps-soft);
    border-color: var(--ps-line-strong);
    color: var(--ps-ink) !important;
}

html.ps-v2 a.ps-chapter-exam-btn.is-continue,
html.ps-v2 a.ps-chapter-exam-btn.is-continue:link,
html.ps-v2 a.ps-chapter-exam-btn.is-continue:visited {
    background: var(--ps-accent-soft);
    border-color: transparent;
    color: var(--ps-accent) !important;
}

/* 题目行 */
html.ps-v2 .problem-item {
    height: 44px;
    padding: 0 20px;
    gap: 12px;
    border-bottom: 0;
    border-radius: 8px;
}

html.ps-v2 .problem-item:hover {
    background: var(--ps-soft);
}

html.ps-v2 .problem-checkbox {
    width: 18px;
    height: 18px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

html.ps-v2 .problem-checkbox label {
    width: 18px;
    height: 18px;
    border: 1px solid var(--ps-line-strong);
    border-radius: 6px;
    box-sizing: border-box;
}

html.ps-v2 .problem-checkbox input[type="checkbox"]:checked + label {
    background: var(--ps-ok);
    border-color: var(--ps-ok);
}

html.ps-v2 .problem-checkbox input[type="checkbox"]:checked + label:after {
    left: 50%;
    top: 46%;
    width: 4px;
    height: 8px;
    margin: 0;
    border-width: 0 2px 2px 0;
    transform: translate(-50%, -60%) rotate(45deg);
}

html.ps-v2 .problem-title {
    font-size: 15px;
    font-weight: 400;
    color: var(--ps-ink);
}

html.ps-v2 .problem-title:hover {
    color: var(--ps-accent);
}

html.ps-v2 .problem-tags {
    display: none;
}

html.ps-v2 .problem-difficulty {
    min-width: 0;
    width: auto;
    padding: 0;
    border: 0;
    background: transparent;
    font-size: 13px;
    line-height: 1;
    font-weight: 500;
    color: var(--ps-ink-3);
    text-align: center;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
}

html.ps-v2 .problem-difficulty::before {
    content: "";
    width: 8px;
    height: 8px;
    border-radius: 999px;
    background: currentColor;
    display: inline-block;
    flex: none;
}

html.ps-v2 .problem-difficulty.easy { color: var(--ps-ok); }
html.ps-v2 .problem-difficulty.medium { color: var(--ps-warn); }
html.ps-v2 .problem-difficulty.hard { color: var(--ps-bad); }
html.ps-v2 .problem-difficulty.unknown { color: var(--ps-ink-4); }

html.ps-v2 .problem-video-icon {
    color: var(--ps-ink-4);
    opacity: 0;
    transition: opacity .12s ease;
}

html.ps-v2 .problem-item:hover .problem-video-icon {
    opacity: 1;
}

html.ps-v2 .problem-node-title {
    color: var(--ps-ink-4);
}

/* ── 侧栏卡片统一 ─────────────────────────────────────────────────── */
html.ps-v2 .sidebar {
    width: 300px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    align-self: flex-start;
}

html.ps-v2 .main-layout {
    align-items: flex-start;
}

@media (min-width: 1025px) {
    html.ps-v2 .main-layout {
        display: grid;
        grid-template-columns: minmax(0, 1fr) 300px;
        column-gap: 30px;
        row-gap: 12px;
        align-items: start;
    }

    html.ps-v2 .main-column {
        display: contents;
    }

    html.ps-v2 .ps-search {
        grid-column: 1;
        grid-row: 1;
        width: 100%;
        max-width: 100%;
        margin-bottom: 0;
    }

    html.ps-v2 .problems-section {
        grid-column: 1;
        grid-row: 2;
        margin-top: 0;
    }

    html.ps-v2 .sidebar {
        grid-column: 2;
        grid-row: 2;
        width: 300px;
    }
}

html.ps-v2 .main-column,
html.ps-v2 .problems-section {
    margin-top: 0;
}

html.ps-v2 .sidebar .badge-section,
html.ps-v2 .sidebar .weekly-ranking-section,
html.ps-v2 .sidebar .filter-section-wrapper,
html.ps-v2 .sidebar .ps-choice-card {
    margin: 0 !important;
}

html.ps-v2 .sidebar .badge-section,
html.ps-v2 .sidebar .weekly-ranking-section,
html.ps-v2 .sidebar .filter-section-wrapper {
    background: var(--ps-surface);
    border: 1px solid var(--ps-line);
    border-radius: 12px;
    box-shadow: none;
}

html.ps-v2 .sidebar .badge-title,
html.ps-v2 .weekly-ranking-title {
    color: var(--ps-ink);
    font-size: 15px;
    font-weight: 600;
}

html.ps-v2 .weekly-ranking-help,
html.ps-v2 .weekly-ranking-item,
html.ps-v2 .weekly-ranking-empty {
    color: var(--ps-ink-3);
}

html.ps-v2 .sidebar .problem-count {
    background: var(--ps-soft);
    color: var(--ps-ink-2);
    font-size: 12px;
    padding: 2px 10px;
    border-radius: 999px;
}

/* 选择题专项题库卡 */
html.ps-v2 .ps-choice-card {
    background: var(--ps-surface);
    border: 1px solid var(--ps-line);
    border-radius: 12px;
    box-shadow: none;
}

html.ps-v2 .ps-choice-title {
    color: var(--ps-ink);
    font-weight: 600;
}

html.ps-v2 .ps-choice-icon {
    color: var(--ps-accent);
}

html.ps-v2 .ps-choice-start-btn {
    background: var(--ps-ink);
    color: var(--ps-surface) !important;
    box-shadow: none;
    border-radius: 999px;
    padding: 5px 12px;
}

html.ps-v2 .ps-choice-admin-link {
    color: var(--ps-ink-4);
}

html.ps-v2 .ps-choice-ai-badge {
    padding: 0 5px;
    min-width: 0;
    min-height: 16px;
    font-size: 10px;
    font-weight: 600;
    letter-spacing: 0.08em;
    color: var(--ps-ink-3);
    background: transparent;
    border: 1px solid var(--ps-line-strong);
    border-radius: 4px;
    box-shadow: none;
}

/* 难度：暗色下也保持「圆点 + 文字」，去掉旧胶囊底色 */
html.ps-v2.theme--dark .problem-difficulty,
html.ps-v2.theme--dark .problem-difficulty.easy,
html.ps-v2.theme--dark .problem-difficulty.medium,
html.ps-v2.theme--dark .problem-difficulty.hard,
html.ps-v2.theme--dark .problem-difficulty.unknown {
    background: transparent;
    border: 0;
}

html.ps-v2.theme--dark .problem-difficulty.easy { color: var(--ps-ok); }
html.ps-v2.theme--dark .problem-difficulty.medium { color: var(--ps-warn); }
html.ps-v2.theme--dark .problem-difficulty.hard { color: var(--ps-bad); }
html.ps-v2.theme--dark .problem-difficulty.unknown { color: var(--ps-ink-4); }

/* 日历：跟随站点表面色，暗色下不再是白块 */
html.ps-v2 .calendar-day {
    border-radius: 6px;
    border-color: var(--ps-line);
    color: var(--ps-ink-2);
}

html.ps-v2 .calendar-day.other-month {
    color: var(--ps-ink-4);
}

html.ps-v2 .calendar-day.selected {
    background: var(--ps-accent-soft);
    color: var(--ps-accent);
}

html.ps-v2.theme--dark .calendar-day {
    background: var(--ps-soft);
    border-color: var(--ps-line);
    color: var(--ps-ink-2);
}

html.ps-v2.theme--dark .calendar-day.other-month {
    background: transparent;
    color: var(--ps-ink-4);
}

html.ps-v2.theme--dark .calendar-day.selected {
    background: var(--ps-accent-soft);
    color: var(--ps-accent);
}

html.ps-v2.theme--dark .calendar-header,
html.ps-v2.theme--dark .calendar-weekday {
    color: var(--ps-ink-3);
}

/* 未登录遮罩里的登录按钮：同样用墨色胶囊 */
html.ps-v2 .ps-problem-list-login-lock__btn {
    background: var(--ps-ink);
    background-image: none;
    border: 0;
    border-radius: 999px;
    color: var(--ps-surface) !important;
    box-shadow: none;
}

html.ps-v2 .ps-problem-list-login-lock__btn:hover {
    opacity: .88;
}

/* 列表里残留的旧橙色（章节图标已隐藏，这里兜底成灰阶） */
html.ps-v2 .topic-icon,
html.ps-v2 .topic-icon-svg {
    color: var(--ps-ink-3);
}

html.ps-v2 .course-tab-content,
html.ps-v2 .course-tab-content.fade-out,
html.ps-v2 .topic-group {
    animation: none !important;
    transition: none !important;
}

html.ps-v2 .sidebar-tab {
    color: var(--ps-ink-3);
}

html.ps-v2 .sidebar-tab.active {
    color: var(--ps-ink);
    border-color: var(--ps-accent);
}

/* 筛选器 & 概览 */
html.ps-v2 .filter-tab {
    color: var(--ps-ink-3);
    font-size: 14px;
    font-weight: 500;
}

html.ps-v2 .filter-tab:hover {
    color: var(--ps-ink);
}

html.ps-v2 .filter-tab.active {
    color: var(--ps-ink);
    font-weight: 600;
    border-bottom-color: var(--ps-accent);
}

html.ps-v2 .filter-section,
html.ps-v2.theme--dark .filter-section,
html.ps-v2 .theme--dark .filter-section {
    background: transparent;
    box-shadow: none;
    border-radius: 0;
    margin-top: 0;
}

html.ps-v2 .filter-section-wrapper .section-title,
html.ps-v2 .filter-module-title {
    color: var(--ps-ink);
}

html.ps-v2 .ranking-number {
    background: var(--ps-soft);
    color: var(--ps-ink-2);
    font-weight: 600;
}

html.ps-v2 .ranking-number.sn-rank-0,
html.ps-v2 .weekly-ranking-item:first-child .ranking-number {
    background: var(--ps-ink);
    color: var(--ps-surface);
}

html.ps-v2 .overview-box,
html.ps-v2 .analysis-box {
    background: var(--ps-surface);
    border: 1px solid var(--ps-line);
    border-radius: 12px;
    box-shadow: none;
}

html.ps-v2 .filter-tag {
    border-radius: 999px;
    border-color: var(--ps-line);
    color: var(--ps-ink-2);
}

html.ps-v2 .filter-tag.selected {
    background: var(--ps-accent-soft);
    border-color: transparent;
    color: var(--ps-accent);
}

/* ── 左下角「旧版 / 新版」切换（仅管理员可见） ─────────────────────── */
.ps-v2-switch {
    position: fixed;
    left: 16px;
    bottom: 16px;
    z-index: 9999;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    height: 34px;
    padding: 0 14px;
    border-radius: 999px;
    border: 1px solid rgba(20, 26, 38, .14);
    background: #fff;
    color: #141A26;
    font-size: 12.5px;
    font-weight: 600;
    line-height: 1;
    cursor: pointer;
    box-shadow: 0 6px 20px rgba(20, 26, 38, .12);
}

.ps-v2-switch:hover {
    background: #F5F7FA;
}

.ps-v2-switch__dot {
    width: 8px;
    height: 8px;
    border-radius: 999px;
    background: #9CA3AF;
}

.ps-v2-switch.is-on .ps-v2-switch__dot {
    background: #16A34A;
}

.theme--dark .ps-v2-switch {
    background: #1C1E24;
    border-color: rgba(255, 255, 255, .14);
    color: #F2F3F5;
    box-shadow: 0 6px 20px rgba(0, 0, 0, .4);
}

.theme--dark .ps-v2-switch:hover {
    background: #23262E;
}

@media (max-width: 1024px) {
    html.ps-v2 .sidebar {
        width: 100%;
    }
}