/* ===================================================================== */
/* READit Document Hub Custom Stylesheet (hub.css)                       */
/* ===================================================================== */

body {
    background-color: #202020;
    color: #FFFFFF;
    font-family: 'Inter', sans-serif;
    overflow: hidden;
}

/* Custom subtle scrollbars */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: #1B1B1B;
}
::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.14);
    border-radius: 9999px;
}
::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.28);
}

/* Collapsible Account Drawer Animation */
.hub-account-drawer {
    display: grid;
    grid-template-rows: 0fr;
    opacity: 0;
    transition: grid-template-rows 0.28s cubic-bezier(0.22, 1, 0.36, 1), opacity 0.22s ease;
}
.hub-account-drawer.open {
    grid-template-rows: 1fr;
    opacity: 1;
}
.hub-account-drawer-inner {
    overflow: hidden;
}

/* Crisp Academic PDF Paper Sheet */
.academic-paper-sheet {
    background-color: #FFFFFF;
    color: #111827;
    box-shadow: 
        0 24px 60px rgba(0, 0, 0, 0.75),
        0 0 0 1px rgba(255, 255, 255, 0.08);
}

/* Whole-Sentence Hover & Click Selection inside Smart Reader */
.readit-sentence {
    border-radius: 4px;
    padding: 2px 3px;
    margin: 0 -3px;
    transition: background-color 0.15s ease, box-shadow 0.15s ease, color 0.15s ease;
    cursor: pointer;
}
.readit-sentence:hover {
    background-color: rgba(118, 184, 67, 0.22);
    box-shadow: 0 0 0 1px rgba(118, 184, 67, 0.38);
}
.readit-sentence.active-sentence {
    background-color: #FEF08A;
    border-bottom: 2px solid #CA8A04;
    color: #000000;
}

/* Upload Card Hover / Dragover Border */
.upload-card-interactive {
    border: 1px solid rgba(255, 255, 255, 0.12);
    transition: border-color 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
}
.upload-card-interactive:hover,
.upload-card-interactive.drag-active {
    border-color: #9333EA;
    box-shadow: 0 0 0 1px rgba(147, 51, 234, 0.35);
    background-color: #262626;
}

/* Smooth Frosted Auth Modal Backdrop */
#auth-modal {
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    transition: opacity 0.35s cubic-bezier(0.16, 1, 0.3, 1), backdrop-filter 0.35s ease;
}

/* Sliding Auth Cards (Sign In vs Sign Up) */
.auth-card-slide {
    will-change: transform, opacity;
    transition: transform 0.52s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.4s ease;
}

/* =====================================================================
   SIDEBAR COLLAPSE / MINIMIZE SYSTEM
   ===================================================================== */
#hub-sidebar {
    transition: width 0.28s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Collapsed mode is strictly enabled on Desktop viewports (>= 768px) */
@media (min-width: 768px) {
    #hub-sidebar.sidebar-collapsed,
    #hub-sidebar.sidebar-minimized {
        width: 68px !important;
        min-width: 68px !important;
        max-width: 68px !important;
    }

    #hub-sidebar.sidebar-collapsed .sidebar-label,
    #hub-sidebar.sidebar-minimized .sidebar-label,
    #hub-sidebar.sidebar-collapsed #account-chevron-icon,
    #hub-sidebar.sidebar-minimized #account-chevron-icon {
        display: none !important;
        opacity: 0 !important;
        pointer-events: none !important;
    }

    #hub-sidebar.sidebar-collapsed .sidebar-header,
    #hub-sidebar.sidebar-minimized .sidebar-header {
        padding-left: 0.75rem !important;
        padding-right: 0.75rem !important;
        justify-content: center !important;
    }

    #hub-sidebar.sidebar-collapsed #sidebar-toggle-btn,
    #hub-sidebar.sidebar-minimized #sidebar-toggle-btn {
        position: absolute;
        right: -13px;
        top: 24px;
        z-index: 30;
        background: #282828;
        border: 1px solid rgba(255, 255, 255, 0.18);
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
    }

    #hub-sidebar.sidebar-collapsed #sidebar-toggle-icon,
    #hub-sidebar.sidebar-minimized #sidebar-toggle-icon {
        transform: rotate(180deg);
    }

    #hub-sidebar.sidebar-collapsed .sidebar-nav-container,
    #hub-sidebar.sidebar-minimized .sidebar-nav-container {
        padding-left: 0.5rem !important;
        padding-right: 0.5rem !important;
    }

    #hub-sidebar.sidebar-collapsed .sidebar-nav-btn,
    #hub-sidebar.sidebar-minimized .sidebar-nav-btn {
        padding: 0.65rem 0.5rem !important;
        justify-content: center !important;
        border-radius: 12px !important;
    }

    #hub-sidebar.sidebar-collapsed .sidebar-footer,
    #hub-sidebar.sidebar-minimized .sidebar-footer {
        padding-left: 0.5rem !important;
        padding-right: 0.5rem !important;
        justify-content: center !important;
    }

    #hub-sidebar.sidebar-collapsed #hub-account-trigger,
    #hub-sidebar.sidebar-minimized #hub-account-trigger {
        justify-content: center !important;
        pointer-events: auto !important;
        cursor: pointer !important;
        opacity: 1 !important;
    }

    #hub-sidebar.sidebar-collapsed #hub-account-trigger:hover #account-avatar-circle,
    #hub-sidebar.sidebar-minimized #hub-account-trigger:hover #account-avatar-circle {
        border-color: rgba(118, 184, 67, 0.8) !important;
        box-shadow: 0 0 10px rgba(118, 184, 67, 0.4);
        transform: scale(1.08);
    }

    #hub-sidebar.sidebar-collapsed #hub-account-drawer,
    #hub-sidebar.sidebar-minimized #hub-account-drawer {
        display: none !important;
    }
}

/* =====================================================================
   MULTI-TAB SYSTEM STYLING & DRAG-AND-DROP REORDERING
   ===================================================================== */
.reader-tab {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    padding: 0.35rem 0.75rem;
    border-radius: 8px;
    font-size: 11.5px;
    font-weight: 500;
    cursor: grab;
    border: 1px solid rgba(255, 255, 255, 0.08);
    background-color: rgba(255, 255, 255, 0.03);
    color: rgba(255, 255, 255, 0.6);
    transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease, transform 0.15s ease, opacity 0.15s ease;
    user-select: none;
    max-width: 220px;
    flex-shrink: 0;
}

.reader-tab:active {
    cursor: grabbing;
}

.reader-tab:hover {
    background-color: rgba(255, 255, 255, 0.07);
    color: rgba(255, 255, 255, 0.9);
    border-color: rgba(255, 255, 255, 0.16);
}

.reader-tab.active-tab {
    background-color: #242424;
    border-color: rgba(118, 184, 67, 0.7);
    color: #ffffff;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.25);
    font-weight: 600;
}

.reader-tab.active-tab .reader-tab-indicator {
    background-color: #76B843;
}

/* Visual cues for Drag-and-Drop Tab Reordering */
.reader-tab.is-dragging {
    opacity: 0.45;
    transform: scale(0.96);
    border-style: dashed !important;
    border-color: #76B843 !important;
    background-color: rgba(118, 184, 67, 0.1) !important;
}

.reader-tab.drag-over-left {
    border-left: 2px solid #76B843 !important;
    transform: translateX(2px);
}

.reader-tab.drag-over-right {
    border-right: 2px solid #76B843 !important;
    transform: translateX(-2px);
}

.reader-tab-close {
    width: 16px;
    height: 16px;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 10px;
    opacity: 0.5;
    transition: all 0.15s ease;
}

.reader-tab-close:hover {
    opacity: 1;
    background-color: rgba(255, 255, 255, 0.2);
    color: #fff;
}

/* =====================================================================
   GLOBAL FULL-SCREEN DRAG & DROP OVERLAY (UNDER 20MB)
   ===================================================================== */
#global-drag-overlay {
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

/* =====================================================================
   COLLAPSIBLE PAPER SWITCHER DRAWER (MOBILE VIEWPORT)
   ===================================================================== */
.paper-switcher-drawer {
    max-height: 0;
    opacity: 0;
    pointer-events: none;
    transition: max-height 0.35s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.25s ease;
}

.paper-switcher-drawer.open {
    max-height: 80vh !important;
    opacity: 1 !important;
    pointer-events: auto !important;
}

/* Floating Language Action Bar styling */
#reader-floating-action-bar {
    filter: drop-shadow(0 16px 36px rgba(0, 0, 0, 0.7));
}

/* Touch manipulation & safe responsive hitboxes (>= 44x44px) */
.touch-manipulation {
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
}

/* Mobile Sidebar (Off-Canvas Drawer) - Always shows full width and all button text */
@media (max-width: 767px) {
    #hub-sidebar {
        position: fixed !important;
        top: 0 !important;
        left: 0 !important;
        width: 260px !important;
        max-width: 85vw !important;
        height: 100vh !important;
        height: 100svh !important;
        height: 100dvh !important;
        max-height: 100dvh !important;
        bottom: auto !important;
        z-index: 50 !important;
        box-shadow: 6px 0 28px rgba(0, 0, 0, 0.75) !important;
        overflow-y: auto !important;
        overflow-x: hidden !important;
        -webkit-overflow-scrolling: touch !important;
    }

    /* Force all button labels and text to always display on mobile */
    #hub-sidebar .sidebar-label {
        display: inline-block !important;
        opacity: 1 !important;
        visibility: visible !important;
        pointer-events: auto !important;
    }

    #hub-sidebar .sidebar-nav-container {
        padding-left: 1.25rem !important;
        padding-right: 1.25rem !important;
    }

    #hub-sidebar .sidebar-nav-btn {
        display: flex !important;
        align-items: center !important;
        justify-content: flex-start !important;
        gap: 0.75rem !important;
        padding: 0.65rem 1rem !important;
        min-height: 44px !important;
        border-radius: 9999px !important;
        width: 100% !important;
        text-align: left !important;
    }

    #hub-sidebar .sidebar-nav-btn .sidebar-label {
        display: inline-block !important;
        font-size: 13.5px !important;
        font-weight: 500 !important;
        color: #ffffff !important;
        opacity: 1 !important;
        visibility: visible !important;
    }

    #hub-sidebar .sidebar-header {
        padding-left: 1.25rem !important;
        padding-right: 1.25rem !important;
        justify-content: space-between !important;
    }

    #hub-sidebar .sidebar-footer {
        padding-left: 1rem !important;
        padding-right: 1rem !important;
        padding-top: 1rem !important;
        padding-bottom: max(2.5rem, calc(env(safe-area-inset-bottom, 0px) + 2rem)) !important;
        background-color: #1B1B1B !important;
    }

    #hub-sidebar #account-chevron-icon {
        display: block !important;
        opacity: 1 !important;
        pointer-events: auto !important;
    }

    #hub-sidebar #hub-account-trigger {
        justify-content: space-between !important;
        pointer-events: auto !important;
        cursor: pointer !important;
        opacity: 1 !important;
    }

    #hub-sidebar #sidebar-toggle-btn {
        display: none !important;
    }
}

/* =====================================================================
   MOBILE DRAWER PAPER LIST DRAG-AND-DROP REORDERING
   ===================================================================== */
.drawer-paper-item {
    position: relative;
    transition: transform 0.15s ease, border-color 0.15s ease, background-color 0.15s ease, box-shadow 0.15s ease;
}

.drawer-paper-item.is-touch-dragging {
    opacity: 0.75;
    border-color: #76B843 !important;
    background-color: rgba(118, 184, 67, 0.16) !important;
    transform: scale(0.98);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.6);
    z-index: 30;
}

.drawer-paper-item.drag-over-top {
    border-top: 2px solid #76B843 !important;
    transform: translateY(2px);
}

.drawer-paper-item.drag-over-bottom {
    border-bottom: 2px solid #76B843 !important;
    transform: translateY(-2px);
}

.drawer-drag-handle {
    touch-action: none;
    -webkit-user-select: none;
    user-select: none;
}

/* =====================================================================
   NATIVE-STYLE PDF TEXT SELECTION LAYER (PDF.js)
   ===================================================================== */
.textLayer {
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    overflow: hidden;
    opacity: 1 !important;
    line-height: 1.0;
    user-select: text !important;
    -webkit-user-select: text !important;
    -moz-user-select: text !important;
    pointer-events: auto;
    z-index: 2;
}

.textLayer :is(span, br) {
    color: transparent !important;
    position: absolute;
    white-space: pre;
    cursor: text !important;
    transform-origin: 0% 0%;
    user-select: text !important;
    -webkit-user-select: text !important;
    -moz-user-select: text !important;
    pointer-events: auto;
}

.textLayer ::selection {
    background: rgba(59, 130, 246, 0.35) !important;
    color: transparent !important;
}
.textLayer ::-moz-selection {
    background: rgba(59, 130, 246, 0.35) !important;
    color: transparent !important;
}

/* =====================================================================
   BOTTOM EXPLANATION DRAWER & SPRING BUMP ANIMATION
   ===================================================================== */
/* Hide Context Ready indicator as requested */
#paper-context-pill {
    display: none !important;
}

@keyframes explanationBump {
    0% {
        transform: translateY(100%);
        opacity: 0;
    }
    70% {
        transform: translateY(-3px);
        opacity: 1;
    }
    100% {
        transform: translateY(0);
        opacity: 1;
    }
}

.animate-explanation-bump {
    animation: explanationBump 0.38s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

#bottom-explanation-drawer.drawer-open {
    transform: translateY(0) !important;
}

#bottom-explanation-backdrop.backdrop-active {
    display: block !important;
    opacity: 1 !important;
    pointer-events: auto !important;
}

/* =====================================================================
   DRAWER RESIZE SNAP STATES & PAPER SLIDE TRANSITIONS
   ===================================================================== */
#drawer-grab-bar-area {
    touch-action: none;
    user-select: none;
    -webkit-user-select: none;
}

#drawer-grab-bar {
    touch-action: none;
}

#bottom-drawer-sheet {
    will-change: height, transform;
}

#bottom-drawer-sheet.drawer-snap-small {
    height: 36vh;
}

#bottom-drawer-sheet.drawer-snap-medium {
    height: 62vh;
}

#bottom-drawer-sheet.drawer-snap-full {
    height: 96vh;
    max-height: 96vh;
}

@keyframes paperSlideUpEnter {
    0% {
        transform: translateY(28px);
        opacity: 0.65;
    }
    100% {
        transform: translateY(0);
        opacity: 1;
    }
}

@keyframes paperSlideDownEnter {
    0% {
        transform: translateY(-28px);
        opacity: 0.65;
    }
    100% {
        transform: translateY(0);
        opacity: 1;
    }
}

.animate-paper-slide-up {
    animation: paperSlideUpEnter 0.26s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.animate-paper-slide-down {
    animation: paperSlideDownEnter 0.26s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

/* =====================================================================
   RESTRICT BOTTOM EXPLANATION BUMP & DRAWER TO MOBILE VIEWPORTS ONLY
   On desktop (>= 1024px), explanations are rendered in the dedicated
   side companion inspector (#sentence-inspector). The bottom notification
   peek capsule, backdrop, and drawer are strictly suppressed.
   ===================================================================== */
@media (min-width: 1024px) {
    #bottom-explanation-peek,
    #bottom-explanation-backdrop,
    #bottom-explanation-drawer {
        display: none !important;
        pointer-events: none !important;
        visibility: hidden !important;
        opacity: 0 !important;
    }
}

/* =====================================================================
   STAR / BOOKMARK EXPLANATION BUTTONS (BREAKDOWN VIEWS)
   ===================================================================== */
.star-btn-active {
    background-color: rgba(251, 191, 36, 0.16) !important;
    border-color: rgba(251, 191, 36, 0.45) !important;
    color: #fde047 !important;
}

.star-btn-active .star-icon {
    fill: currentColor !important;
    filter: drop-shadow(0 0 6px rgba(251, 191, 36, 0.65));
    transform: scale(1.1);
}

/* Mobile Bottom Drawer Star Button: Clean touch circular icon-only, NO pill wrapper */
#btn-star-bottom-drawer {
    background-color: transparent !important;
    border: none !important;
}

#btn-star-bottom-drawer.star-btn-active {
    background-color: transparent !important;
    border: none !important;
    color: #fde047 !important;
}

#btn-star-bottom-drawer.star-btn-active .star-icon {
    fill: #fde047 !important;
    stroke: #fde047 !important;
    filter: drop-shadow(0 0 8px rgba(251, 191, 36, 0.8));
    transform: scale(1.18);
}

.star-icon {
    transition: transform 0.2s cubic-bezier(0.16, 1, 0.3, 1), fill 0.2s ease, filter 0.2s ease;
}