/* ============================================================
   Enforce [hidden] regardless of any display: flex overrides
   ============================================================ */
[hidden] {
    display: none !important;
}

/* ============================================================
   CSS Custom Properties — edit here to retheme the whole page
   ============================================================ */
:root {
    /* Page / app background (supports color, gradient or image) */
    --page-bg: linear-gradient(135deg, #ffffff 0%, #f8ffef 100%);

    /* Header */
    --header-bg: rgba(0, 0, 0, 0);
    --header-height: 56px;
    --header-icon-size: 36px;
    --header-title-color: #000000;
    --header-teaser-color: #111111;
    --header-padding: 0 20px;

    /* Menu panel */
    --menu-width: 260px;
    --menu-bg: linear-gradient(135deg, rgba(255, 255, 255, 0.98) 0%, rgba(255, 255, 255, 0.8) 100%);
    --menu-border: 0px solid rgba(255, 255, 255, 0.06);

    /* Menu cells */
    --cell-padding: 12px 14px;
    --cell-img-size: 56px;
    --cell-border-bottom: 0px solid rgba(255, 255, 255, 0.05);
    --cell-bg: transparent;
    --cell-hover-bg: linear-gradient(180deg, #ffffff 0%, #d0f8d0 44%, #aaeeaa 44%, #bbffbb 100%);
    --cell-active-bg: linear-gradient(180deg, rgba(255, 255, 255, 1) 0%, rgba(120, 220, 120, 1) 44%, rgba(50, 200, 50, 1) 44%, rgba(128, 255, 128, 1) 100%);

    --cell-active-border-left: 3px solid rgba(255, 255, 255, 0);
    --cell-press-bg: rgba(255, 255, 255, 0.03);

    /* Cell text */
    --cell-title-color: #000000;
    --cell-title-size: 0.95rem;
    --cell-title-weight: 600;
    --cell-desc-color: #111111;
    --cell-desc-size: 0.8rem;

    /* Content area */
    --content-bg: rgba(255, 255, 255, 0);
    --content-padding: 28px 32px;

    /* Content items */
    --item-title-color: #000000;
    --item-title-size: 1.05rem;
    --item-title-weight: 700;
    --item-title-align: center;
    --item-desc-color: #111111;
    --item-desc-size: 0.95rem;
    --item-hover-bg: rgba(0, 0, 0, 0.03);
    --item-cursor: pointer;
    --item-border-radius: 6px;
    --item-padding: 4px;

    /* Toggle buttons */
    --toggle-btn-size: 40px;
    --toggle-btn-bg: rgba(255, 255, 255, 0);
    --toggle-btn-hover-bg: rgba(0, 0, 0, 0.1);
    --toggle-btn-color: #222222;
    --toggle-btn-radius: 6px;

}

/* ============================================================
   Reset & base
   ============================================================ */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html, body {
    height: 100%;
    overflow: hidden;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    font-size: 16px;
    line-height: 1.5;
}

/* ============================================================
   App shell
   ============================================================ */
#app {
    height: 100%;
    display: flex;
    flex-direction: column;
    background: var(--page-bg);
}

/* ============================================================
   Header
   ============================================================ */
#site-header {
    flex-shrink: 0;
    height: var(--header-height);
    background: var(--header-bg);
    display: flex;
    align-items: center;
    gap: 14px;
    padding: var(--header-padding);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

#header-icon {
    width: var(--header-icon-size);
    height: var(--header-icon-size);
    object-fit: contain;
    border-radius: 6px;
    flex-shrink: 0;
}

#header-content {
    display: flex;
    flex-direction: column;
    gap: 1px;
    min-width: 0;
}

#header-title {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--header-title-color);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

#header-teaser {
    font-size: 0.8rem;
    color: var(--header-teaser-color);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* ============================================================
   Main layout
   ============================================================ */
#main {
    flex: 1;
    display: flex;
    overflow: hidden;
    position: relative;
}

/* ============================================================
   Menu toggle buttons (hamburger / close)
   ============================================================ */
.menu-toggle-btn {
    width: var(--toggle-btn-size);
    height: var(--toggle-btn-size);
    background: var(--toggle-btn-bg);
    color: var(--toggle-btn-color);
    border: none;
    border-radius: var(--toggle-btn-radius);
    font-size: 1.2rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.15s;
    flex-shrink: 0;
}

.menu-toggle-btn:hover {
    background: var(--toggle-btn-hover-bg);
}

/* Expand button — lives in the header, shown when menu is collapsed on narrow viewport.
   Being a normal flex item in the dark header makes it always visible,
   avoids z-index/stacking issues, and avoids colour-on-white invisibility. */
#expand-btn {
    flex-shrink: 0;
}

/* ============================================================
   Menu panel
   ============================================================ */
#menu-panel {
    /* Wide viewport: normal in-flow flex item */
    width: var(--menu-width);
    min-width: var(--menu-width);
    background: var(--menu-bg);
    border-right: var(--menu-border);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    /* No width/layout transition — animating layout properties causes
       the content area to fight for the same space (visible as flicker). */
}

/* Collapsed: hidden entirely so it has zero layout impact.
   display:none removes it from the flex flow, so the content area
   fills the full width with no animation or fighting. */
#menu-panel.collapsed {
    display: none;
}

/* Narrow viewport — user opened the menu: fixed overlay, slides in from left.
   position:fixed means it is completely outside the layout flow so the
   content area keeps its full width underneath. */
#menu-panel.narrow-expanded {
    position: fixed;
    top: 0;
    left: 0;
    width: var(--menu-width);
    min-width: var(--menu-width);
    height: 100%;
    z-index: 150;
    box-shadow: 4px 0 24px rgba(0, 0, 0, 0.6);
    border-right: none;
    animation: menuSlideIn 0.22s ease forwards;
}

@keyframes menuSlideIn {
    from { transform: translateX(-100%); }
    to   { transform: translateX(0); }
}

#menu-panel-header {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding: 8px 8px 0;
    min-height: 48px;
    flex-shrink: 0;
}

/* Hide the header area when not needed (wide viewport, menu is normal) */
#menu-panel:not(.narrow-expanded) #menu-panel-header {
    min-height: 0;
    padding: 0;
}

#menu-items {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
}

/* ============================================================
   Backdrop behind menu overlay on narrow viewport
   ============================================================ */
#menu-backdrop {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.55);
    z-index: 149;
}

/* ============================================================
   Menu cells
   ============================================================ */
.menu-cell {
    padding: var(--cell-padding);
    border-bottom: var(--cell-border-bottom);
    background: var(--cell-bg);
    cursor: pointer;
    border-left: 3px solid transparent;
    transition: background 0.15s;
    min-width: 0;
}

.menu-cell:hover {
    background: var(--cell-hover-bg);
}

.menu-cell:active {
    background: var(--cell-press-bg);
}

.menu-cell.active {
    background: var(--cell-active-bg);
    border-left: var(--cell-active-border-left);
}

/* Variant a & b: flex row — image on left, text on right */
.menu-cell.cell-a,
.menu-cell.cell-b {
    display: flex;
    align-items: center;
    gap: 12px;
}

/* Variant c & d: block layout — text stacked */
.menu-cell.cell-c,
.menu-cell.cell-d {
    display: flex;
    flex-direction: column;
    gap: 3px;
}

/* Cell image */
.cell-img {
    width: var(--cell-img-size);
    height: var(--cell-img-size);
    object-fit: cover;
    border-radius: 8px;
    flex-shrink: 0;
}

/* Text block (variant a: holds title + desc vertically) */
.cell-text {
    display: flex;
    flex-direction: column;
    gap: 3px;
    min-width: 0;
}

/* Cell title */
.cell-title {
    font-size: var(--cell-title-size);
    font-weight: var(--cell-title-weight);
    color: var(--cell-title-color);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* Cell description */
.cell-desc {
    font-size: var(--cell-desc-size);
    color: var(--cell-desc-color);
    word-break: break-word;
    overflow-wrap: break-word;
}

/* ============================================================
   Content area
   ============================================================ */
#content-area {
    flex: 1;
    background: var(--content-bg);
    overflow-y: auto;
    overflow-x: hidden;
    padding: var(--content-padding);
    min-width: 0;
}

/* ============================================================
   Content items
   ============================================================ */
.content-item {
    padding: var(--item-padding);
    border-radius: var(--item-border-radius);
}

.content-item.clickable {
    background: var(--item-hover-bg);
    cursor: var(--item-cursor);
    transition: background 0.15s;
}

.content-item.clickable:hover {
    background: var(--item-hover-bg);
}

.content-title {
    display: block;
    text-align: var(--item-title-align);
    font-size: var(--item-title-size);
    font-weight: var(--item-title-weight);
    color: var(--item-title-color);
    margin-bottom: 6px;
}

.content-img {
    display: block;
    max-width: 100%;
    height: auto;
    margin: 8px auto;
    border-radius: 4px;
}

.content-desc {
    display: block;
    text-align: left;
    font-size: var(--item-desc-size);
    color: var(--item-desc-color);
    word-break: break-word;
    overflow-wrap: break-word;
    margin-bottom: 4px;
}

/* ============================================================
   Loading / error states
   ============================================================ */
.loading,
.error {
    padding: 32px;
    text-align: center;
    font-size: 0.95rem;
    color: #90a4ae;
}

.error {
    color: #e57373;
}