/* ==========================================================================
   Explorer SPA Stylesheet
   Uses CSS variables from style.css (dark/light theme)
   ========================================================================== */

/* ==========================================================================
   Layout
   ========================================================================== */

.explorer-container {
    display: flex;
    min-height: calc(100vh - 48px); /* minus toolbar */
}

/* ==========================================================================
   Sidebar
   ========================================================================== */

.explorer-sidebar {
    width: 260px;
    flex-shrink: 0;
    background: var(--bg-nav);
    border-right: 1px solid var(--border-primary);
    position: sticky;
    top: 48px; /* below toolbar */
    height: calc(100vh - 48px);
    overflow-y: auto;
    padding: 0;
}

.sidebar-header {
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border-primary);
    display: flex;
    align-items: baseline;
    gap: 0.5rem;
}

.sidebar-header h2 {
    margin: 0;
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
}

.sidebar-count {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.sidebar-tree {
    padding: 0.5rem 0;
}

/* Category group in sidebar */
.sidebar-category {
    margin-bottom: 0.25rem;
}

.sidebar-category-label {
    display: block;
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-primary);
    font-weight: 700;
    padding: 0.75rem 1rem 0.3rem;
    opacity: 0.85;
}

/* Document entry */
.sidebar-doc {
    display: flex;
    align-items: center;
    padding: 0.35rem 1rem 0.35rem 1.25rem;
    color: var(--text-secondary);
    font-size: 0.85rem;
    cursor: pointer;
    border-radius: 0;
    text-decoration: none;
    transition: background 0.12s, color 0.12s;
    border: none;
    background: none;
    width: 100%;
    text-align: left;
    font-family: inherit;
}

.sidebar-doc:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.sidebar-doc.active {
    background: var(--active-nav-bg);
    color: var(--active-nav-text);
}

.sidebar-doc-count {
    margin-left: auto;
    font-size: 0.7rem;
    color: var(--text-muted);
    opacity: 0.7;
}

.sidebar-doc.active .sidebar-doc-count {
    color: var(--active-nav-text);
    opacity: 0.8;
}

/* Sections under a document (collapsible) */
.sidebar-sections {
    display: none;
    padding-left: 0.5rem;
}

.sidebar-sections.open {
    display: block;
}

.sidebar-section {
    display: block;
    padding: 0.25rem 1rem 0.25rem 2rem;
    color: var(--text-muted);
    font-size: 0.8rem;
    cursor: pointer;
    border: none;
    background: none;
    width: 100%;
    text-align: left;
    font-family: inherit;
    transition: background 0.12s, color 0.12s;
}

.sidebar-section:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.sidebar-section.active {
    color: var(--accent-color);
    font-weight: 600;
}

/* ==========================================================================
   Main area
   ========================================================================== */

.explorer-main {
    flex: 1;
    min-width: 0;
    padding: 1rem 1.5rem;
    max-width: 960px;
}

/* ==========================================================================
   Search bar
   ========================================================================== */

.explorer-search {
    margin-bottom: 1rem;
}

.search-input-wrap {
    position: relative;
    margin-bottom: 0.75rem;
}

.search-input {
    width: 100%;
    padding: 0.6rem 1rem;
    padding-right: 5rem;
    font-size: 0.95rem;
    font-family: inherit;
    background: var(--bg-editor);
    color: var(--text-primary);
    border: 1px solid var(--border-secondary);
    border-radius: 6px;
    outline: none;
    transition: border-color 0.15s;
}

.search-input:focus {
    border-color: var(--accent-color);
}

.search-input::placeholder {
    color: var(--text-muted);
}

.btn-clear-filters {
    position: absolute;
    right: 5.5rem;
    top: 50%;
    transform: translateY(-50%);
    padding: 0.15rem 0.5rem;
    font-size: 0.75rem;
    font-family: inherit;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border: 1px solid var(--border-primary);
    border-radius: 4px;
    cursor: pointer;
    transition: background 0.12s, color 0.12s, opacity 0.2s;
    display: none;
}

.btn-clear-filters.visible {
    display: inline-block;
}

.btn-clear-filters:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
    border-color: var(--border-secondary);
}

.search-count {
    position: absolute;
    right: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ==========================================================================
   Tag cloud
   ========================================================================== */

.tag-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem 0.5rem;
    margin-bottom: 0.75rem;
}

.tag-group {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.2rem;
    margin-right: 0.5rem;
}

.tag-group-label {
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--text-muted);
    margin-right: 0.15rem;
}

.tag-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.2rem;
    padding: 0.15rem 0.5rem;
    font-size: 0.75rem;
    font-family: inherit;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border: 1px solid var(--border-primary);
    border-radius: 12px;
    cursor: pointer;
    transition: background 0.12s, color 0.12s, border-color 0.12s;
    white-space: nowrap;
}

.tag-pill:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
    border-color: var(--border-secondary);
}

.tag-pill.active {
    background: var(--accent-color);
    color: #fff;
    border-color: var(--accent-color);
}

.tag-pill .tag-count {
    font-size: 0.65rem;
    opacity: 0.7;
}

.tag-pill.active .tag-count {
    opacity: 0.9;
}

/* ==========================================================================
   Filter chips (Level, Status)
   ========================================================================== */

.filter-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.chip-group {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.chip-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-right: 0.25rem;
}

.chip {
    padding: 0.2rem 0.6rem;
    font-size: 0.75rem;
    font-family: inherit;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border: 1px solid var(--border-primary);
    border-radius: 4px;
    cursor: pointer;
    transition: background 0.12s, color 0.12s, border-color 0.12s;
}

.chip:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.chip.active {
    background: var(--accent-color);
    color: #fff;
    border-color: var(--accent-color);
}

/* ==========================================================================
   Result cards
   ========================================================================== */

.explorer-results {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.result-card {
    background: var(--bg-card);
    border: 1px solid var(--border-primary);
    border-radius: 6px;
    cursor: pointer;
    transition: border-color 0.15s, background 0.15s;
}

.result-card:hover {
    border-color: var(--border-secondary);
}

.result-card.expanded {
    border-color: var(--accent-color);
}

/* Card header (always visible) */
.card-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.6rem 1rem;
}

.card-title {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
    flex: 1;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.card-level {
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    padding: 0.15rem 0.45rem;
    border-radius: 3px;
    font-weight: 600;
    flex-shrink: 0;
}

.card-level.beginner { background: var(--success-bg); color: var(--success-text); border: 1px solid var(--success-border); }
.card-level.intermediate { background: var(--btn-download-bg); color: var(--btn-download-text); border: 1px solid var(--btn-download-border); }
.card-level.advanced { background: var(--error-bg); color: var(--error-text); border: 1px solid var(--error-border); }

.card-source {
    font-size: 0.75rem;
    color: var(--text-muted);
    flex-shrink: 0;
}

.card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.2rem;
    padding: 0 1rem 0.5rem;
}

.card-tags .tag-pill {
    font-size: 0.7rem;
    padding: 0.1rem 0.4rem;
    cursor: pointer;
}

/* ==========================================================================
   Detail pane (expanded card)
   ========================================================================== */

.card-detail {
    display: none;
    padding: 0 1rem 1rem;
    border-top: 1px solid var(--border-primary);
}

.result-card.expanded .card-detail {
    display: block;
}

.card-prose {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    line-height: 1.5;
}

/* Code editor area */
.card-editor-wrap {
    position: relative;
    margin-bottom: 0.5rem;
}

.card-editor-container {
    display: flex;
    background: var(--bg-editor);
    border: 1px solid var(--border-primary);
    border-radius: 4px;
    overflow: hidden;
}

.card-line-numbers {
    background: var(--bg-editor-lines);
    color: var(--text-muted);
    padding: 0.5rem 0.5rem;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 0.8rem;
    line-height: 1.5;
    text-align: right;
    user-select: none;
    white-space: pre;
    min-width: 2.5em;
    border-right: 1px solid var(--border-primary);
}

.card-editor {
    flex: 1;
    background: var(--bg-editor);
    color: var(--text-editor);
    border: none;
    padding: 0.5rem 0.75rem;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 0.8rem;
    line-height: 1.5;
    resize: vertical;
    min-height: 4rem;
    outline: none;
    tab-size: 2;
}

.card-edited-badge {
    position: absolute;
    top: 0.3rem;
    right: 0.5rem;
    font-size: 0.65rem;
    color: var(--accent-color);
    background: var(--bg-card);
    padding: 0.1rem 0.35rem;
    border-radius: 3px;
    border: 1px solid var(--accent-color);
    opacity: 0;
    transition: opacity 0.2s;
}

.card-edited-badge.visible {
    opacity: 1;
}

/* Toolbar under code editor */
.card-toolbar {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
    flex-wrap: wrap;
    align-items: center;
}

.card-toolbar button {
    padding: 0.3rem 0.75rem;
    font-size: 0.8rem;
    font-family: inherit;
    border-radius: 4px;
    cursor: pointer;
    border: 1px solid;
    transition: opacity 0.12s;
}

.card-toolbar .btn-play {
    background: var(--btn-play-bg);
    border-color: var(--btn-play-border);
    color: var(--btn-play-text);
}

.card-toolbar .btn-stop {
    background: var(--btn-stop-bg);
    border-color: var(--btn-stop-border);
    color: var(--btn-stop-text);
}

.card-toolbar .btn-reset {
    background: var(--btn-reset-bg);
    border-color: var(--btn-reset-border);
    color: var(--btn-reset-text);
}

.card-toolbar .btn-download {
    background: var(--btn-download-bg);
    border-color: var(--btn-download-border);
    color: var(--btn-download-text);
    margin-left: auto;
}

.card-toolbar button:hover {
    opacity: 0.85;
}

.card-play-status {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-left: 0.5rem;
}

/* Related links and metadata */
.card-meta {
    font-size: 0.8rem;
    color: var(--text-secondary);
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem 1.5rem;
    align-items: center;
}

.card-meta a {
    color: var(--link-color);
    text-decoration: none;
}

.card-meta a:hover {
    color: var(--link-hover);
    text-decoration: underline;
}

/* Loading spinner */
.card-loading {
    text-align: center;
    padding: 2rem;
    color: var(--text-muted);
    font-size: 0.85rem;
}

.card-loading::before {
    content: '';
    display: inline-block;
    width: 1rem;
    height: 1rem;
    border: 2px solid var(--border-secondary);
    border-top-color: var(--accent-color);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
    margin-right: 0.5rem;
    vertical-align: middle;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Empty state */
.explorer-empty {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-muted);
}

.explorer-empty h3 {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

/* ==========================================================================
   Rating widget
   ========================================================================== */

.card-rating {
    display: inline-flex;
    gap: 1px;
    margin-left: 0.5rem;
    flex-shrink: 0;
}

.card-rating .star {
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--text-muted, #888);
    opacity: 0.3;
    transition: color 0.12s, opacity 0.12s;
    user-select: none;
    line-height: 1;
}

.card-rating .star:hover {
    color: #f59e0b;
    opacity: 0.8;
}

.card-rating .star.active {
    color: #f59e0b;
    opacity: 1;
}

.card-rating .star.preview {
    color: #f59e0b;
    opacity: 0.6;
}

.card-rating .star.active.preview {
    opacity: 1;
}

/* Sidebar rated entry */
.sidebar-rated {
    border-left: 3px solid transparent;
}

.sidebar-rated.active {
    border-left-color: #f59e0b;
}

/* ==========================================================================
   Responsive
   ========================================================================== */

@media (max-width: 900px) {
    .explorer-container {
        flex-direction: column;
    }

    .explorer-sidebar {
        width: 100%;
        height: auto;
        max-height: 200px;
        position: static;
        border-right: none;
        border-bottom: 1px solid var(--border-primary);
    }

    .explorer-main {
        padding: 1rem;
    }
}

@media (max-width: 600px) {
    .card-header {
        flex-wrap: wrap;
        gap: 0.4rem;
    }

    .card-title {
        width: 100%;
        white-space: normal;
    }

    .tag-cloud {
        gap: 0.15rem 0.35rem;
    }
}

/* Print */
@media print {
    .explorer-sidebar, .global-toolbar, .explorer-search,
    .card-toolbar, .theme-switcher { display: none; }
    .explorer-container { display: block; }
    .result-card { break-inside: avoid; }
}