/* Helios Open Reader — Reader Stylesheet */

/* -------------------------------------------------------------------------
   Section page header icon — nudges the icon up so it aligns with the
   visual cap-height of the large h1 rather than the box-centre.
   ------------------------------------------------------------------------- */

.hor-h1-icon {
    margin-top: -6px;
}

/* -------------------------------------------------------------------------
   Learning objectives block
   Extends the existing md-alert--tip styles from github-markdown-alerts.
   The hor-objectives class adds reader-specific spacing only.
   ------------------------------------------------------------------------- */

.hor-objectives {
    margin-bottom: 1.5rem;
}

/* -------------------------------------------------------------------------
   Key takeaways block
   Extends the existing md-alert--note styles from github-markdown-alerts.
   ------------------------------------------------------------------------- */

.hor-key-takeaways {
    margin-top: 2rem;
    margin-bottom: 1.5rem;
}

/* -------------------------------------------------------------------------
   Callout blocks
   Each extends an existing md-alert--* type from github-markdown-alerts.
   The hor-* class adds reader-specific spacing only.
   ------------------------------------------------------------------------- */

.hor-example,
.hor-exercise,
.hor-definition,
.hor-reflection,
.hor-case-study,
.hor-feedback-requested,
.hor-process-note,
.hor-project-brief {
    margin-top: 2rem;
    margin-bottom: 1.5rem;
}

/* Use base prose size (1rem) for all callout body text so it reads
   slightly smaller than the surrounding prose-lg (1.125rem) article text.
   Covers both hor-* shortcode callouts and native [!NOTE]-style callouts. */
.md-alert .md-alert-body {
    font-size: 1rem;
    line-height: 1.75;
}

/* -------------------------------------------------------------------------
   Parts feature — heading shown between card grids on the reader home page
   when sections are organised with the part-N-section-M folder naming pattern.
   ------------------------------------------------------------------------- */

.hor-part-heading {
    margin-top: 2rem;
    margin-bottom: 0.875rem;
}

.hor-part-heading h2 {
    font-size: 1.125rem;
    font-weight: 600;
    color: rgb(55 65 81);          /* gray-700 */
    padding-bottom: 0.5rem;
    border-bottom: 1px solid rgb(229 231 235); /* gray-200 */
    margin: 0;
}

.dark .hor-part-heading h2 {
    color: rgb(209 213 219);       /* gray-300 */
    border-bottom-color: rgb(55 65 81); /* gray-700 */
}

/* -------------------------------------------------------------------------
   Cover image sidebar layout
   Two-column: fixed-width image column left, content + cards right.
   Collapses to stacked on narrow screens.
   ------------------------------------------------------------------------- */

.hor-cover-sidebar {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

@media (min-width: 640px) {
    .hor-cover-sidebar {
        flex-direction: row;
        gap: 2rem;
        align-items: flex-start;
    }
}

.hor-cover-sidebar__image {
    flex-shrink: 0;
    width: 100%;
}

@media (min-width: 640px) {
    .hor-cover-sidebar__image {
        width: 12rem;
    }
}

.hor-cover-sidebar__image img {
    width: 100%;
    border-radius: 0.5rem;
    border: 1px solid rgb(229 231 235); /* gray-200 */
}

.dark .hor-cover-sidebar__image img {
    border-color: rgb(55 65 81); /* gray-700 */
}

.hor-cover-sidebar__content {
    flex: 1;
    min-width: 0;
}

/* -------------------------------------------------------------------------
   OER attribution block (footer)
   ------------------------------------------------------------------------- */

.hor-attribution {
    line-height: 1.6;
}

/* -------------------------------------------------------------------------
   Section number badge on section-page
   ------------------------------------------------------------------------- */

.hor-section-number {
    font-variant-numeric: tabular-nums;
}

/* -------------------------------------------------------------------------
   Top prev/next navigation
   Overrides Helios .prev-next-nav top-placement styles (mt-12, pt-8, border-t)
   with bottom-placement equivalents so the nav reads as a lead-in to content.
   ------------------------------------------------------------------------- */

.prev-next-nav--top {
    margin-top: 0;
    padding-top: 0;
    border-top: none;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid rgb(229 231 235); /* gray-200 */
}

/* Helios uses class-based dark mode (.dark on <html>) — no media query needed */
.dark .prev-next-nav--top {
    border-bottom-color: rgb(31 41 55); /* gray-800 */
}

/* -------------------------------------------------------------------------
   Resume Reading strip (reader home page)
   ------------------------------------------------------------------------- */

/* Ensure [hidden] is respected even though .hor-resume-strip sets display:flex.
   Author CSS beats the UA stylesheet, so we need this explicit override. */
#hor-resume-reading[hidden] {
    display: none;
}

.hor-resume-strip {
    display: flex;
    align-items: center;
    gap: 0.625rem;
    padding: 0.625rem 0.875rem;
    margin-bottom: 1.5rem;
    border-radius: 0.5rem;
    background-color: rgb(249 250 251); /* gray-50 */
    border: 1px solid rgb(229 231 235); /* gray-200 */
}

.dark .hor-resume-strip {
    background-color: rgb(31 41 55); /* gray-800 */
    border-color: rgb(55 65 81);     /* gray-700 */
}

.hor-resume-icon {
    width: 1rem;
    height: 1rem;
    flex-shrink: 0;
    color: var(--color-primary, #3b82f6);
}

.hor-resume-text {
    font-size: 0.875rem;
    color: rgb(75 85 99); /* gray-600 */
    flex: 1;
    min-width: 0;
}

.dark .hor-resume-text {
    color: rgb(156 163 175); /* gray-400 */
}

.hor-resume-text a {
    font-weight: 500;
    color: var(--color-primary, #3b82f6);
}

.hor-resume-text a:hover {
    text-decoration: underline;
}

.hor-resume-dismiss {
    background: none;
    border: none;
    padding: 0.125rem 0.25rem;
    margin-left: auto;
    font-size: 1rem;
    line-height: 1;
    color: rgb(156 163 175); /* gray-400 */
    cursor: pointer;
    flex-shrink: 0;
}

.hor-resume-dismiss:hover {
    color: rgb(75 85 99); /* gray-600 */
}

.dark .hor-resume-dismiss:hover {
    color: rgb(209 213 219); /* gray-300 */
}

/* -------------------------------------------------------------------------
   Section reading progress indicator (bottom prev/next area)
   ------------------------------------------------------------------------- */

.hor-progress {
    margin-top: 2rem;
    margin-bottom: 1.25rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.375rem;
}

.hor-progress-bar {
    width: 100%;
    max-width: 24rem;
    height: 3px;
    background-color: rgb(229 231 235); /* gray-200 */
    border-radius: 9999px;
    overflow: hidden;
}

.dark .hor-progress-bar {
    background-color: rgb(55 65 81); /* gray-700 */
}

.hor-progress-fill {
    height: 100%;
    background-color: var(--color-primary, #3b82f6);
    border-radius: 9999px;
}

.hor-progress-text {
    font-size: 0.875rem;
    color: rgb(107 114 128); /* gray-500 — 4.6:1 contrast on white, passes WCAG AA */
    margin: 0;
    text-align: center;
}

.dark .hor-progress-text {
    color: rgb(156 163 175); /* gray-400 — sufficient contrast on dark backgrounds */
}

/* Focus-visible styles — ensure keyboard users see clear focus rings */
.hor-resume-text a:focus-visible,
.hor-resume-dismiss:focus-visible {
    outline: 2px solid var(--color-primary, #3b82f6);
    outline-offset: 2px;
    border-radius: 2px;
}