/* ---------------------------------------------------------------------------
   Source Code Drawer -- shadcn/vaul-style bottom drawer
   --------------------------------------------------------------------------- */

/* Header toggle button */
.source-viewer-toggle {
    font-family: var(--rb-font-code);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    line-height: 1;
}

/* Body scroll lock when drawer is open */
body.source-drawer-open {
    overflow: hidden;
}

/* Backdrop overlay */
.source-drawer-backdrop {
    position: fixed;
    inset: 0;
    z-index: 399;
    background: rgba(0, 0, 0, 0.5);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

body.source-drawer-open .source-drawer-backdrop {
    opacity: 1;
    pointer-events: auto;
}

/* Drawer panel -- slides up from bottom */
.source-drawer {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 400;
    display: grid;
    grid-template-rows: auto auto 1fr;
    grid-template-columns: var(--source-tree-width, 320px) auto 1fr;
    height: 88vh;
    max-height: 100vh;
    background: var(--rb-code-bg);
    color: var(--rb-text);
    border-top-left-radius: 12px;
    border-top-right-radius: 12px;
    box-shadow: 0 -4px 32px rgba(0, 0, 0, 0.15);
    transform: translateY(100%);
    transition: transform 0.35s cubic-bezier(0.32, 0.72, 0, 1);
    pointer-events: none;
}

body.source-drawer-open .source-drawer {
    transform: translateY(0);
    pointer-events: auto;
}

/* Drag handle */
.source-drawer__handle {
    grid-column: 1 / -1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.6rem 0 0.2rem;
    cursor: grab;
}

.source-drawer__handle::after {
    content: "";
    display: block;
    width: 3rem;
    height: 0.25rem;
    border-radius: 9999px;
    background: var(--rb-text-lighter);
    opacity: 0.3;
}

/* Header bar spanning both columns */
.source-drawer__header {
    grid-column: 1 / -1;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.3rem 1rem 0.6rem;
    border-bottom: 1px solid var(--rb-code-border);
    font-family: var(--rb-font-code);
    font-size: var(--rb-nav-size);
    user-select: none;
}

.source-drawer__title {
    font-weight: 600;
    letter-spacing: 0.03em;
}

.source-drawer__close {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 2rem;
    height: 2rem;
    border: none;
    border-radius: 6px;
    background: transparent;
    color: var(--rb-text-lighter);
    font-size: 1.2rem;
    cursor: pointer;
    transition: background 0.15s;
}

.source-drawer__close:hover,
.source-drawer__close:focus-visible {
    background: var(--rb-code-border);
}

/* File tree pane -- matches book's .file-tree styling */
.source-drawer__tree {
    grid-row: 3;
    grid-column: 1;
    overflow: hidden;
    padding: 0;
    border-right: 1px solid var(--rb-code-border);
    display: flex;
    flex-direction: column;
    font-family: var(--rb-font-code);
    font-size: calc(var(--rb-body-size) * 0.85 * 0.95);
    line-height: 1.7;
    -webkit-font-smoothing: auto;
    -moz-osx-font-smoothing: auto;
    text-rendering: auto;
}

.source-drawer__tree > ul[role="tree"] {
    flex: 1;
    overflow-y: auto;
    padding: 0.5rem 0;
}

.source-drawer__tree ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.source-drawer__tree li {
    padding: 0;
}

/* Shared icon base for tree items (same technique as book's .file-tree) */
.source-drawer__dir-icon,
.source-drawer__file-icon {
    display: inline-block;
    width: 1.2em;
    height: 1.2em;
    vertical-align: -0.2em;
    flex-shrink: 0;
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
}

/* Directory icon -- flat folder, Gruvbox yellow (same SVG as book) */
.source-drawer__dir-icon {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' fill='%23d79921'%3E%3Cpath d='M2 4.5A1.5 1.5 0 013.5 3h3.29a1.5 1.5 0 011.06.44l1.3 1.3a.5.5 0 00.35.14h4a1.5 1.5 0 011.5 1.5v.62H3.5A1.5 1.5 0 002 5.88V4.5z'/%3E%3Cpath d='M3.5 7A1.5 1.5 0 002 8.5v5A1.5 1.5 0 003.5 15h11a1.5 1.5 0 001.5-1.5v-6A1.5 1.5 0 0014.5 6h-4a.5.5 0 01-.35-.15l-1.3-1.3A1.5 1.5 0 007.79 4H3.5A1.5 1.5 0 002 5.5V7h1.5z'/%3E%3C/svg%3E");
}

/* File icon -- flat document, gray (same SVG as book) */
.source-drawer__file-icon {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' fill='%23888'%3E%3Cpath fill-rule='evenodd' d='M4 4a2 2 0 012-2h4.586A2 2 0 0112 2.586L15.414 6A2 2 0 0116 7.414V16a2 2 0 01-2 2H6a2 2 0 01-2-2V4zm2 6a1 1 0 011-1h6a1 1 0 110 2H7a1 1 0 01-1-1zm1 3a1 1 0 100 2h6a1 1 0 100-2H7z' clip-rule='evenodd'/%3E%3C/svg%3E");
}

/* Dark mode: lighten file icon (same as book) */
[data-md-color-scheme="slate"] .source-drawer__file-icon {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' fill='%23999'%3E%3Cpath fill-rule='evenodd' d='M4 4a2 2 0 012-2h4.586A2 2 0 0112 2.586L15.414 6A2 2 0 0116 7.414V16a2 2 0 01-2 2H6a2 2 0 01-2-2V4zm2 6a1 1 0 011-1h6a1 1 0 110 2H7a1 1 0 01-1-1zm1 3a1 1 0 100 2h6a1 1 0 100-2H7z' clip-rule='evenodd'/%3E%3C/svg%3E");
}

/* Directory items */
.source-drawer__dir-toggle {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    width: 100%;
    padding: 0.2rem 0.75rem;
    border: none;
    background: transparent;
    color: var(--rb-text);
    font: inherit;
    font-weight: 600;
    cursor: pointer;
    user-select: none;
    text-align: left;
    border-radius: 0;
}

.source-drawer__dir-toggle:hover,
.source-drawer__dir-toggle:focus-visible {
    background: var(--rb-code-border);
}

.source-drawer__dir-toggle .chevron {
    display: inline-block;
    width: 1em;
    text-align: center;
    transition: transform 0.15s;
    font-size: 0.7em;
    flex-shrink: 0;
}

.source-drawer__dir-toggle.open .chevron {
    transform: rotate(90deg);
}

.source-drawer__dir-children {
    padding-left: 1.4em;
    margin-left: 0.45em;
}

.source-drawer__dir-children.collapsed {
    display: none;
}

/* File items */
.source-drawer__file-btn {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    width: 100%;
    padding: 0.2rem 0.75rem 0.2rem 1.5rem;
    border: none;
    background: transparent;
    color: var(--rb-text-lighter);
    font: inherit;
    cursor: pointer;
    text-align: left;
    border-radius: 0;
}

.source-drawer__file-btn:hover,
.source-drawer__file-btn:focus-visible {
    background: var(--rb-code-border);
    color: var(--rb-text);
}

.source-drawer__file-btn.active {
    background: var(--rb-link);
    color: #fff;
}

/* Hide file icon in active state (white text on colored bg) */
.source-drawer__file-btn.active .source-drawer__file-icon {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' fill='%23fff'%3E%3Cpath fill-rule='evenodd' d='M4 4a2 2 0 012-2h4.586A2 2 0 0112 2.586L15.414 6A2 2 0 0116 7.414V16a2 2 0 01-2 2H6a2 2 0 01-2-2V4zm2 6a1 1 0 011-1h6a1 1 0 110 2H7a1 1 0 01-1-1zm1 3a1 1 0 100 2h6a1 1 0 100-2H7z' clip-rule='evenodd'/%3E%3C/svg%3E");
}

/* Fold legend at bottom of file tree */
.source-drawer__legend {
    flex-shrink: 0;
    padding: 0.6rem 0.75rem;
    border-top: 1px solid var(--rb-code-border);
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
    font-family: var(--rb-font-code);
    font-size: calc(var(--rb-body-size) * 0.7);
    color: var(--rb-text-lighter);
}

.source-drawer__legend-item {
    display: flex;
    align-items: center;
    gap: 0.4em;
}

.source-drawer__legend-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1.4em;
    font-weight: 600;
}

.source-drawer__legend-icon.legend-entangled {
    color: var(--rb-accent, #427b58);
}

[data-md-color-scheme="slate"] .source-drawer__legend-icon.legend-entangled {
    color: var(--rb-accent, #8ec07c);
}

/* Resize handle between tree and code panes */
.source-drawer__resize-handle {
    grid-row: 3;
    grid-column: 2;
    width: 5px;
    cursor: col-resize;
    background: transparent;
    position: relative;
    z-index: 2;
    transition: background 0.15s;
    margin-left: -3px;
}

.source-drawer__resize-handle:hover,
.source-drawer__resize-handle.dragging {
    background: var(--rb-link);
}

/* Code viewer pane */
.source-drawer__code {
    grid-row: 3;
    grid-column: 3;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.source-drawer__code-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 1rem;
    border-bottom: 1px solid var(--rb-code-border);
    font-family: var(--rb-font-code);
    font-size: var(--rb-nav-size);
    color: var(--rb-text-lighter);
    min-height: 2rem;
}

.source-drawer__code-path {
    font-weight: 500;
    color: var(--rb-text);
}

.source-drawer__code-body {
    flex: 1;
    overflow: auto;
    padding: 0;
    background: var(--rb-code-bg);
}

/* CodeMirror overrides to match book theme */
.source-drawer__code-body .cm-editor {
    height: 100%;
    font-family: var(--rb-font-code);
    /* --rb-code-size is 0.85em relative to body (21px) = ~17.85px.
       Set an absolute base so it matches the book's code blocks exactly. */
    font-size: calc(var(--rb-body-size) * 0.85);
    /* Match book's font rendering (subpixel, not grayscale antialiasing) */
    -webkit-font-smoothing: auto;
    -moz-osx-font-smoothing: auto;
    text-rendering: optimizeLegibility;
}

.source-drawer__code-body .cm-editor .cm-scroller {
    overflow: auto;
}

/* Override CodeMirror's default monospace on content/lines to match book */
.source-drawer__code-body .cm-editor .cm-content,
.source-drawer__code-body .cm-editor .cm-line {
    font-family: var(--rb-font-code);
    -webkit-font-smoothing: auto;
    -moz-osx-font-smoothing: auto;
    font-feature-settings: "kern";
    text-rendering: auto;
}

.source-drawer__code-body .cm-editor .cm-gutterElement {
    font-family: var(--rb-font-code);
}

.source-drawer__code-body .cm-editor .cm-gutters {
    background: var(--rb-code-bg);
    border-right: 1px solid var(--rb-code-border);
    color: var(--rb-text-lighter);
}

.source-drawer__code-body .cm-editor .cm-content {
    padding: 1em 1.2em;
}

.source-drawer__code-body .cm-editor .cm-line {
    line-height: 1.5;
}

.source-drawer__code-body .cm-editor .cm-activeLine {
    background: transparent;
}

.source-drawer__code-body .cm-editor .cm-selectionBackground {
    background: var(--rb-code-border) !important;
}

/* Entangled fold markers -- «» echoing the <<reference>> syntax */
.cm-foldGutter .cm-gutterElement.cm-entangled-fold > span {
    font-size: 0;
    color: var(--rb-accent, #427b58);
}

.cm-foldGutter .cm-gutterElement.cm-entangled-fold > span::after {
    content: "»";
    font-size: .8rem;
    font-weight: 600;
    display: inline-block;
    transition: transform 0.15s ease;
    transform: rotate(90deg);
}

.cm-foldGutter .cm-gutterElement.cm-entangled-fold > span[title="Unfold line"]::after {
    transform: rotate(0deg);
}

[data-md-color-scheme="slate"] .cm-foldGutter .cm-gutterElement.cm-entangled-fold > span {
    color: var(--rb-accent, #8ec07c);
}

/* Entangled marker lines -- dimmed section separators */
.source-drawer__code-body .cm-editor .cm-line.cm-entangled-marker {
    opacity: 0.4;
    font-style: italic;
}

[data-md-color-scheme="slate"] .source-drawer__code-body .cm-editor .cm-line.cm-entangled-marker {
    opacity: 0.5;
}

/* Block highlight when scrolling to a specific code block */
.source-drawer__code-body .cm-editor .cm-line.cm-block-highlight {
    background: rgba(215, 153, 33, 0.12);
    transition: background 0.6s ease;
}

[data-md-color-scheme="slate"] .source-drawer__code-body .cm-editor .cm-line.cm-block-highlight {
    background: rgba(250, 189, 47, 0.1);
}

/* ---------------------------------------------------------------------------
   File link buttons on entangled code blocks
   --------------------------------------------------------------------------- */
.source-link-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-left: 0.5em;
    padding: 0.1em 0.4em;
    border: none;
    border-radius: 4px;
    background: transparent;
    color: var(--rb-text-lighter);
    font-family: var(--rb-font-code);
    font-size: 0.85em;
    font-weight: 400;
    line-height: 1;
    cursor: pointer;
    vertical-align: baseline;
    transition: background 0.15s, color 0.15s;
}

.source-link-btn:hover,
.source-link-btn:focus-visible {
    background: var(--rb-code-border);
    color: var(--rb-text);
}

@media (max-width: 768px) {
    .source-link-btn {
        min-height: 44px;
        min-width: 44px;
        padding: 0.2em 0.6em;
    }
}

@media (prefers-reduced-motion: reduce) {
    .source-link-btn {
        transition: none;
    }
}

/* Placeholder when no file selected */
.source-drawer__placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: var(--rb-text-lighter);
    font-family: var(--rb-font-code);
    font-size: var(--rb-code-size);
}

/* Loading spinner */
.source-drawer__spinner {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: var(--rb-text-lighter);
    font-family: var(--rb-font-code);
    font-size: var(--rb-nav-size);
}

/* Mobile: back-nav button shown in code header */
.source-drawer__back-btn {
    display: none;
    align-items: center;
    gap: 0.25rem;
    padding: 0.2rem 0.5rem;
    border: 1px solid var(--rb-code-border);
    border-radius: 4px;
    background: transparent;
    color: var(--rb-text-lighter);
    font: inherit;
    cursor: pointer;
}

.source-drawer__back-btn:focus-visible {
    background: var(--rb-code-border);
}

/* ---------------------------------------------------------------------------
   Reduced motion
   --------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
    .source-drawer-backdrop {
        transition: none;
    }

    .source-drawer {
        transition: none;
    }

    .source-drawer__dir-toggle .chevron {
        transition: none;
    }

    .source-drawer__close {
        transition: none;
    }
}

/* ---------------------------------------------------------------------------
   Mobile: single-pane with back navigation
   --------------------------------------------------------------------------- */
@media (max-width: 768px) {
    .source-drawer {
        grid-template-columns: 1fr;
        height: 92vh;
        border-top-left-radius: 8px;
        border-top-right-radius: 8px;
    }

    /* Hide resize handle on mobile */
    .source-drawer__resize-handle {
        display: none;
    }

    /* Tree takes full width by default */
    .source-drawer__tree {
        grid-column: 1;
        border-right: none;
    }

    /* Code pane hidden until a file is selected */
    .source-drawer__code {
        grid-column: 1;
        display: none;
    }

    /* When viewing a file on mobile */
    .source-drawer.viewing-file .source-drawer__tree {
        display: none;
    }

    .source-drawer.viewing-file .source-drawer__code {
        display: flex;
    }

    .source-drawer.viewing-file .source-drawer__back-btn {
        display: flex;
    }

    /* File buttons: less left padding on mobile */
    .source-drawer__file-btn {
        padding-left: 0.75rem;
    }
}