/* -------------------------------------------------------------------------
   FRANK CHAT APPLICATION — RESPONSIVE DESIGN SYSTEM
   Mobile-First, Dynamic Viewports (100dvh), Safe Area Insets,
   Zero Horizontal Scroll, Sticky Mobile Composer & Bottom Sheet Menus
   Breakpoints: 320px, 360px, 375px, 390px, 414px, 480px, 600px, 768px, 820px, 1024px, 1280px+
   ------------------------------------------------------------------------- */

/* Prevent horizontal overflow page-wide */
html, body {
    overflow-x: hidden;
    max-width: 100vw;
    -webkit-text-size-adjust: 100%;
}

/* Mobile backdrop overlay for sidebar & off-canvas drawers */
.mobile-overlay {
    position: fixed;
    inset: 0;
    background: rgba(11, 17, 32, 0.65);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    z-index: 990;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-base), visibility var(--transition-base);
}

.mobile-overlay.show {
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto !important;
}

/* Desktop default: Hide mobile-only elements */
.chat-more-header,
.chat-more-cancel,
.mobile-header-brand,
.mobile-tabs-container,
.mobile-bottom-nav {
    display: none !important;
}

/* Desktop: Show chat list title */
.desktop-header-title {
    display: flex !important;
    align-items: center;
    font-size: 19px;
    font-weight: 800;
    color: var(--text);
    margin: 0;
}

/* Desktop: Hide duplicate header brand and duplicate header new chat button */
.desktop-header-brand {
    display: none !important;
}

.desktop-profile-btn-wrap {
    display: flex !important;
}

.desktop-new-chat-btn {
    display: none !important;
}

#openSidebarBtn {
    display: inline-flex !important;
}

/* Desktop layout: Overlay Navigation Drawer + Conversation Panel (360px) + Chat Window (flex: 1) */
@media (min-width: 768px) {
    .sidebar {
        position: fixed !important;
        top: calc(56px + var(--safe-top, env(safe-area-inset-top, 0px))) !important;
        left: 0 !important;
        bottom: 0 !important;
        width: 280px !important;
        max-width: 86vw !important;
        height: calc(100vh - 56px) !important;
        height: calc(100dvh - 56px) !important;
        background: var(--sidebar-bg, var(--surface, #FFF9F0)) !important;
        border-right: 1px solid var(--border, #D8C5AA) !important;
        z-index: 1000 !important;
        display: flex !important;
        flex-direction: column !important;
        padding: 16px !important;
        transform: translateX(-100%) !important;
        transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1) !important;
        box-shadow: 4px 0 24px rgba(0, 0, 0, 0.14) !important;
        overflow-y: auto !important;
        overflow-x: hidden !important;
        box-sizing: border-box !important;
        visibility: visible !important;
        pointer-events: auto !important;
    }

    .sidebar.open {
        transform: translateX(0) !important;
    }

    .chat-main-layout {
        display: flex !important;
        flex: 1 !important;
        min-height: 0 !important;
        height: calc(100vh - 56px) !important;
        height: calc(100dvh - 56px) !important;
        width: 100vw !important;
        position: relative !important;
        overflow: hidden !important;
    }

    .main-chat-workspace {
        display: flex !important;
        flex: 1 !important;
        min-width: 0 !important;
        height: 100% !important;
        width: 100% !important;
        position: relative !important;
        overflow: hidden !important;
    }

    .conversation-panel {
        display: flex !important;
        flex-direction: column !important;
        width: 360px !important;
        min-width: 320px !important;
        max-width: 380px !important;
        flex-shrink: 0 !important;
        height: 100% !important;
        position: relative !important;
        z-index: 10 !important;
        border-right: 1px solid var(--border, #D8C5AA) !important;
        background: var(--chat-list-bg, var(--bg-surface, #FFF9F0)) !important;
        overflow: hidden !important;
    }

    .chat-window {
        position: relative !important;
        inset: auto !important;
        width: auto !important;
        height: 100% !important;
        flex: 1 !important;
        min-width: 0 !important;
        display: flex !important;
        flex-direction: column !important;
        z-index: 1 !important;
        background: var(--chat-bg, #F4EBDD) !important;
        overflow: hidden !important;
    }
}

/* -------------------------------------------------------------------------
   DESKTOP & LARGE DISPLAYS (1280px+)
   ------------------------------------------------------------------------- */
@media (min-width: 1280px) {
    .chat-app {
        height: 100vh;
        height: 100dvh;
    }

    .sidebar {
        width: 280px !important;
    }

    .conversation-panel {
        width: 360px !important;
    }

    /* Widen the new chat button on large screens */
    .desktop-new-chat-btn span[data-i18n] {
        display: inline !important;
    }
}

/* -------------------------------------------------------------------------
   LAPTOPS & DESKTOPS (1024px - 1279px)
   ------------------------------------------------------------------------- */
@media (max-width: 1200px) {
    .chat-details-drawer {
        position: fixed;
        right: 0;
        top: 0;
        bottom: 0;
        width: 320px;
        max-width: 85vw;
        z-index: 160;
        box-shadow: var(--shadow-xl);
        transform: translateX(100%);
        transition: transform var(--transition-smooth);
    }

    .chat-details-drawer.open {
        transform: translateX(0);
    }
}

/* -------------------------------------------------------------------------
   TABLETS & MEDIUM SCREENS (768px - 1024px)
   ------------------------------------------------------------------------- */
@media (min-width: 768px) and (max-width: 1024px) {
    .sidebar {
        width: 280px !important;
        display: flex !important;
    }

    .conversation-panel {
        width: 320px !important;
    }

    .brand-title-wrap {
        display: flex;
    }

    .chat-window {
        flex: 1;
        min-width: 0;
    }

    .chat-header {
        padding: 0 var(--space-4);
    }
}

/* -------------------------------------------------------------------------
   TABLETS LANDING & MARKETING (max-width: 900px)
   ------------------------------------------------------------------------- */
@media (max-width: 900px) {
    .landing-nav {
        display: none;
    }

    .hero {
        grid-template-columns: 1fr;
        padding-top: var(--space-8);
        text-align: center;
        overflow: hidden;
    }

    .hero-content {
        align-items: center;
        text-align: center;
        max-width: 100%;
    }

    .hero-content h1 {
        font-size: clamp(28px, 7vw, 44px);
        letter-spacing: -0.5px;
        word-break: break-word;
        max-width: 100%;
    }

    .hero-content p {
        font-size: 16px;
        margin: 0 auto;
        max-width: 100%;
    }

    .hero-actions,
    .hero-actions-group {
        align-items: center;
        width: 100%;
        margin-left: auto;
        margin-right: auto;
    }

    .hero-primary-btns {
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: center;
        gap: 12px;
        width: 100%;
        max-width: 420px;
    }

    .hero-secondary-btns {
        display: flex;
        justify-content: center;
        width: 100%;
    }

    .hero-stats {
        justify-content: center;
        flex-wrap: wrap;
        gap: var(--space-6);
    }

    .feature-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 640px) {
    .header {
        padding: 0 var(--space-3);
    }

    .header-actions {
        gap: var(--space-1);
    }

    .header-actions .btn {
        padding: 6px 10px;
        font-size: 12px;
    }

    .feature-grid {
        grid-template-columns: 1fr;
    }

    .security-grid {
        grid-template-columns: 1fr !important;
    }

    .hero-preview {
        max-width: 100%;
    }

    .hero-actions .btn:not(.hero-start-btn):not(.hero-login-btn):not(.hero-explore-btn) {
        width: 100%;
        max-width: 280px;
    }

    .hero-primary-btns {
        display: flex;
        flex-direction: row;
        align-items: stretch;
        justify-content: center;
        width: 100%;
        max-width: 380px;
        gap: 10px;
    }

    .hero-primary-btns .hero-start-btn {
        flex: 1 1 auto;
        min-width: 140px;
        padding: 11px 16px;
        font-size: 14.5px;
        min-height: 48px;
        white-space: nowrap;
        justify-content: center;
    }

    .hero-primary-btns .hero-login-btn {
        flex: 0 0 auto;
        min-width: 88px;
        padding: 11px 20px;
        font-size: 14.5px;
        min-height: 48px;
        white-space: nowrap;
        justify-content: center;
    }

    .hero-secondary-btns {
        display: flex;
        justify-content: center;
        width: 100%;
    }

    .hero-download-wrapper {
        align-items: center;
        width: 100%;
    }

    .hero-android-btn {
        width: 100%;
        max-width: 380px;
        justify-content: center;
    }

    .hero-download-note {
        text-align: left;
        max-width: 380px;
    }

    .hero-stats {
        gap: var(--space-4);
    }

    .hero-stat-item strong {
        font-size: 18px;
    }
}

@media (max-width: 340px) {
    .hero-primary-btns {
        flex-direction: column !important;
        align-items: center !important;
        gap: 8px !important;
        width: 100% !important;
        max-width: 260px !important;
    }

    .hero-primary-btns .btn {
        width: 100% !important;
        max-width: 100% !important;
        flex: none !important;
    }
}

/* -------------------------------------------------------------------------
   MOBILE PHONES (max-width: 767px)
   Screen 1 (Conversation List) vs Screen 2 (Active Chat) Switching
   ------------------------------------------------------------------------- */
@media (max-width: 767px) {
    /* Application Container */
    .chat-app {
        height: 100vh;
        height: -webkit-fill-available;
        height: 100dvh;
        width: 100vw;
        overflow: hidden;
        position: relative;
        background: var(--chat-bg, var(--bg-primary));
    }

    /* 1. Off-Canvas Mobile Sidebar Drawer */
    .sidebar {
        position: fixed !important;
        left: 0 !important;
        top: calc(54px + var(--safe-top, env(safe-area-inset-top, 0px))) !important;
        bottom: 0 !important;
        width: min(320px, 86vw) !important;
        height: calc(100vh - 52px) !important;
        height: calc(100dvh - 52px) !important;
        z-index: 1000 !important;
        transform: translateX(-100%) !important;
        background: var(--sidebar-bg, var(--surface, #FFF9F0)) !important;
        border-right: 1px solid var(--border, #D8C5AA) !important;
        box-shadow: 4px 0 24px rgba(0, 0, 0, 0.18) !important;
        transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1) !important;
        overflow-y: auto !important;
        -webkit-overflow-scrolling: touch !important;
        display: flex !important;
        flex-direction: column !important;
        padding: 16px !important;
        box-sizing: border-box !important;
    }

    .sidebar.open {
        transform: translateX(0) !important;
    }

    .sidebar-user {
        background: var(--surface-elevated) !important;
        border: 1px solid var(--border) !important;
        color: var(--text) !important;
    }

    .sidebar-user-name {
        color: var(--text) !important;
    }

    .sidebar-user-status {
        color: var(--text-muted) !important;
    }

    #sidebarDirectSignOutBtn {
        background: rgba(239, 68, 68, 0.12) !important;
        border: 1px solid rgba(239, 68, 68, 0.25) !important;
        color: #EF4444 !important;
    }

    #sidebarDirectSignOutBtn:hover,
    #sidebarDirectSignOutBtn:active {
        background: rgba(239, 68, 68, 0.2) !important;
    }

    .sidebar .nav-item span {
        color: var(--text-secondary) !important;
        font-weight: 600;
    }

    .sidebar .nav-item.active span,
    .sidebar .nav-item:hover span {
        color: var(--sidebar-item-active-text, var(--text)) !important;
    }

    .sidebar .nav-item svg {
        stroke: var(--text-secondary) !important;
    }

    .sidebar .nav-item.active svg {
        stroke: var(--primary) !important;
    }

    .sidebar-section-title {
        color: var(--text-muted) !important;
    }

    .sidebar-brand .brand-title-text {
        color: var(--text) !important;
        font-weight: 800;
    }

    .sidebar-brand .brand-tagline-text {
        color: var(--text-muted) !important;
    }

    .sidebar-brand-title {
        color: var(--text) !important;
    }

    .mobile-back-btn svg {
        stroke: var(--text) !important;
    }

    .chat-header-actions .btn-icon svg {
        stroke: var(--text-secondary) !important;
    }

    .mobile-nav-toggle {
        display: none !important;
    }

    /* 2. SCREEN 1: Conversation Panel */
    .conversation-panel {
        width: 100% !important;
        max-width: 100vw !important;
        height: 100% !important;
        display: flex !important;
        flex-direction: column !important;
        border-right: none !important;
        overflow: hidden !important;
        background: var(--chat-list-bg, var(--bg-surface, #FFF9F0)) !important;
        position: relative !important;
    }

    .conversation-header {
        height: calc(54px + var(--safe-top, env(safe-area-inset-top, 0px))) !important;
        min-height: calc(54px + var(--safe-top, env(safe-area-inset-top, 0px))) !important;
        padding-top: var(--safe-top, env(safe-area-inset-top, 0px)) !important;
        padding-bottom: 0 !important;
        padding-left: max(12px, env(safe-area-inset-left, 0px)) !important;
        padding-right: max(12px, env(safe-area-inset-right, 0px)) !important;
        flex-shrink: 0 !important;
        display: flex !important;
        align-items: center !important;
        justify-content: space-between !important;
        background: var(--chat-header-bg, var(--bg-surface, #FFF9F0)) !important;
        border-bottom: 1px solid var(--border, #D8C5AA) !important;
        box-sizing: border-box !important;
    }

    .desktop-header-title {
        display: flex !important;
        align-items: center !important;
        font-size: 18px !important;
        font-weight: 800 !important;
        color: var(--text, #2D241D) !important;
        margin: 0 !important;
    }

    .desktop-new-chat-btn,
    .desktop-header-brand {
        display: none !important;
    }

    .conversation-header-actions {
        display: flex !important;
        align-items: center !important;
        gap: 6px !important;
        flex-shrink: 0 !important;
    }

    .conversation-header-actions .btn-icon {
        width: 38px !important;
        height: 38px !important;
        min-width: 38px !important;
        min-height: 38px !important;
        padding: 0 !important;
        display: inline-flex !important;
        align-items: center !important;
        justify-content: center !important;
    }

    /* Top header adjustments for mobile screens — Safe area and robust responsive flex */
    .app-top-header {
        height: calc(54px + var(--safe-top, env(safe-area-inset-top, 0px))) !important;
        min-height: calc(54px + var(--safe-top, env(safe-area-inset-top, 0px))) !important;
        padding-top: var(--safe-top, env(safe-area-inset-top, 0px)) !important;
        padding-bottom: 0 !important;
        padding-left: max(8px, env(safe-area-inset-left, 0px)) !important;
        padding-right: max(8px, env(safe-area-inset-right, 0px)) !important;
        gap: 6px !important;
        box-sizing: border-box !important;
        display: flex !important;
        align-items: center !important;
        justify-content: space-between !important;
        flex-wrap: nowrap !important;
        overflow: hidden !important;
    }

    .top-header-center {
        display: none !important;
    }

    .top-header-left {
        display: flex !important;
        align-items: center !important;
        gap: 6px !important;
        flex: 0 1 auto !important;
        min-width: 0 !important;
        flex-shrink: 1 !important;
        overflow: hidden !important;
    }

    .top-header-brand {
        display: inline-flex !important;
        align-items: center !important;
        gap: 5px !important;
        text-decoration: none !important;
        min-width: 0 !important;
        flex-shrink: 1 !important;
    }

    .brand-logo-img {
        width: 24px !important;
        height: 24px !important;
        flex-shrink: 0 !important;
        border-radius: 6px !important;
    }

    .brand-title-wrap {
        display: inline-flex !important;
        align-items: baseline !important;
        gap: 3px !important;
        min-width: 0 !important;
        flex-shrink: 0 !important;
    }

    .brand-title-text {
        font-size: 15px !important;
        font-weight: 800 !important;
        letter-spacing: -0.3px !important;
        color: var(--text, #2D241D) !important;
        line-height: 1.1 !important;
        flex-shrink: 0 !important;
    }

    .brand-tagline-text {
        display: inline-block !important;
        font-size: 11px !important;
        font-weight: 600 !important;
        color: var(--text-muted, #8F7B67) !important;
        line-height: 1.1 !important;
        flex-shrink: 0 !important;
    }

    .brand-badge.pro-badge {
        font-size: 9px !important;
        font-weight: 700 !important;
        padding: 1.5px 5px !important;
        border-radius: 9999px !important;
        line-height: 1.1 !important;
        flex-shrink: 0 !important;
        margin-left: 2px !important;
    }

    .app-hamburger-btn {
        width: 34px !important;
        height: 34px !important;
        min-width: 34px !important;
        min-height: 34px !important;
        padding: 0 !important;
        flex-shrink: 0 !important;
    }

    .top-header-right {
        display: flex !important;
        align-items: center !important;
        gap: 6px !important;
        flex: 0 0 auto !important;
        justify-content: flex-end !important;
        min-width: 0 !important;
        flex-shrink: 0 !important;
    }

    #dashLangSelector {
        display: inline-flex !important;
        align-items: center !important;
        flex-shrink: 0 !important;
    }

    #dashLangSelector .lang-btn {
        height: 32px !important;
        min-height: 32px !important;
        padding: 0 6px !important;
        gap: 4px !important;
        font-size: 11.5px !important;
        border-radius: 9999px !important;
        box-sizing: border-box !important;
    }

    #dashLangSelector .lang-icon {
        width: 14px !important;
        height: 14px !important;
        flex-shrink: 0 !important;
    }

    #dashLangSelector .current-lang-label {
        display: inline-block !important;
        font-size: 11.5px !important;
        font-weight: 600 !important;
    }

    .top-header-notification-btn {
        width: 32px !important;
        height: 32px !important;
        min-width: 32px !important;
        min-height: 32px !important;
        padding: 0 !important;
        flex-shrink: 0 !important;
        box-sizing: border-box !important;
    }

    .top-header-notification-btn svg {
        width: 16px !important;
        height: 16px !important;
    }

    .desktop-profile-btn-wrap {
        display: inline-flex !important;
        align-items: center !important;
        flex-shrink: 0 !important;
    }

    .desktop-profile-trigger {
        width: 32px !important;
        height: 32px !important;
        min-width: 32px !important;
        min-height: 32px !important;
        padding: 0 !important;
        border: none !important;
        background: transparent !important;
        box-sizing: border-box !important;
    }

    .desktop-profile-trigger .avatar {
        width: 28px !important;
        height: 28px !important;
        min-width: 28px !important;
        min-height: 28px !important;
        font-size: 11px !important;
    }

    .top-header-user-meta {
        display: none !important;
    }

    .desktop-profile-trigger .chevron-icon {
        display: none !important;
    }

    .desktop-profile-dropdown {
        top: calc(54px + var(--safe-top, env(safe-area-inset-top, 0px))) !important;
        right: 8px !important;
    }

    .top-header-notif-dropdown {
        top: calc(54px + var(--safe-top, env(safe-area-inset-top, 0px))) !important;
        right: 48px !important;
    }

    .mobile-menu-btn {
        display: flex !important;
        align-items: center;
        justify-content: center;
        min-width: 44px;
        min-height: 44px;
        width: 44px;
        height: 44px;
        color: var(--text);
        border-radius: var(--radius-md);
        background: transparent;
        border: none;
        cursor: pointer;
    }

    /* Mobile Tabs (Chats, Groups, Contacts) */
    .mobile-tabs-container {
        display: flex !important;
        padding: 8px var(--space-3) 4px var(--space-3);
        gap: 8px;
        background: transparent;
        width: 100%;
        box-sizing: border-box;
        flex-shrink: 0;
    }

    .mobile-tab-btn {
        flex: 1;
        min-height: 44px;
        height: 44px;
        border-radius: 12px;
        border: 1px solid var(--border);
        background: var(--surface-elevated);
        color: var(--text-secondary);
        font-size: 14px;
        font-weight: 700;
        display: flex;
        align-items: center;
        justify-content: center;
        cursor: pointer;
        transition: all 0.18s cubic-bezier(0.16, 1, 0.3, 1);
        outline: none;
        user-select: none;
        -webkit-tap-highlight-color: transparent;
    }

    .mobile-tab-btn.active {
        background: var(--primary) !important;
        color: var(--primary-text, #ffffff) !important;
        border-color: var(--primary) !important;
        box-shadow: 0 0 14px var(--primary-glow) !important;
    }

    .conversation-search-wrap {
        padding: 6px var(--space-3) 8px var(--space-3);
        flex-shrink: 0;
        width: 100%;
        box-sizing: border-box;
    }

    .conversation-search {
        display: flex;
        align-items: center;
        background: var(--theme-input);
        border: 1px solid var(--theme-input-border);
        border-radius: 12px;
        padding: 0 12px;
        height: 44px;
        min-height: 44px;
        width: 100%;
        box-sizing: border-box;
    }

    .conversation-search input {
        font-size: 14px;
        background: transparent;
        border: none;
        outline: none;
        color: var(--text);
        flex: 1;
        min-width: 0;
        padding-left: 8px;
    }

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

    .conversation-list {
        flex: 1;
        min-height: 0;
        overflow-y: auto;
        overflow-x: hidden;
        -webkit-overflow-scrolling: touch;
        overscroll-behavior-y: contain;
        padding-bottom: calc(64px + env(safe-area-inset-bottom, 0px));
    }

    .conversation-card {
        padding: 10px var(--space-3);
        min-height: 60px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.04);
        background: transparent;
    }

    .conversation-card:active,
    .conversation-card.active {
        background: rgba(37, 99, 235, 0.12);
    }

    .conversation-name {
        font-size: 14px;
    }

    .conversation-snippet {
        font-size: 12px;
    }

    /* Mobile Bottom Navigation */
    .mobile-bottom-nav {
        display: flex !important;
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        width: 100%;
        height: calc(56px + env(safe-area-inset-bottom, 0px));
        padding: 4px 6px max(4px, env(safe-area-inset-bottom, 0px)) 6px;
        background: var(--bg-surface);
        border-top: 1px solid var(--border);
        backdrop-filter: blur(12px);
        -webkit-backdrop-filter: blur(12px);
        z-index: 90;
        box-sizing: border-box;
        align-items: center;
        justify-content: space-around;
    }

    .chat-app.has-active-chat .mobile-bottom-nav {
        display: none !important;
    }

    .mobile-bottom-nav-item {
        flex: 1;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 3px;
        height: 48px;
        min-height: 44px;
        background: transparent;
        border: none;
        color: var(--text-muted);
        font-size: 11px;
        font-weight: 600;
        cursor: pointer;
        transition: color 0.15s ease;
        -webkit-tap-highlight-color: transparent;
    }

    .mobile-bottom-nav-item svg {
        width: 20px;
        height: 20px;
        stroke: currentColor;
    }

    .mobile-bottom-nav-item.active {
        color: var(--primary);
    }

    .mobile-bottom-nav-item.active svg {
        stroke: var(--primary);
        filter: drop-shadow(0 0 6px var(--primary-glow));
    }

    /* 3. SCREEN 2: Active Chat Window Switching */
    .chat-app.has-active-chat .app-top-header {
        display: none !important;
    }

    .chat-window {
        display: none;
        position: fixed;
        inset: 0;
        width: 100vw;
        height: 100vh;
        height: -webkit-fill-available;
        height: 100dvh;
        z-index: 200 !important;
        background: var(--chat-bg, var(--bg-primary)) !important;
        flex-direction: column;
        overflow: hidden;
    }

    /* When Chat is Active: Screen 1 hides, Screen 2 fills display */
    .chat-app.has-active-chat .conversation-panel {
        display: none !important;
    }

    .chat-app.has-active-chat .chat-window,
    .chat-window.mobile-open {
        display: flex !important;
        z-index: 200 !important;
    }

    /* Chat Header */
    .chat-header {
        height: calc(56px + var(--safe-top, env(safe-area-inset-top, 0px))) !important;
        min-height: calc(56px + var(--safe-top, env(safe-area-inset-top, 0px))) !important;
        padding-top: var(--safe-top, env(safe-area-inset-top, 0px)) !important;
        padding-bottom: 0 !important;
        padding-left: max(10px, env(safe-area-inset-left, 0px)) !important;
        padding-right: max(10px, env(safe-area-inset-right, 0px)) !important;
        flex-shrink: 0 !important;
        gap: 6px !important;
        z-index: 210 !important;
        background: var(--chat-header-bg, var(--bg-surface)) !important;
        border-bottom: 1px solid var(--border) !important;
        box-sizing: border-box !important;
    }

    .mobile-back-btn {
        display: flex !important;
        align-items: center;
        justify-content: center;
        width: 36px;
        height: 36px;
        min-width: 36px;
        min-height: 36px;
        color: var(--text);
        flex-shrink: 0;
        padding: 0;
    }

    .chat-partner-info {
        flex: 1;
        min-width: 0;
        gap: 8px;
    }

    .chat-partner-meta {
        flex: 1;
        min-width: 0;
    }

    .chat-partner-title-row {
        gap: 6px;
        flex-wrap: nowrap;
        min-width: 0;
    }

    .chat-partner-name {
        font-size: 14px;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
        color: var(--text) !important;
        flex: 0 1 auto;
        min-width: 50px;
    }

    .chat-header-frank-id-wrap {
        padding: 1px 4px;
        flex-shrink: 0;
    }

    .header-fid-label {
        display: none;
    }

    .header-fid-badge {
        font-size: 10px;
    }

    .chat-partner-presence {
        font-size: 11px;
        color: var(--text-muted) !important;
    }

    .chat-header-actions {
        display: flex;
        align-items: center;
        gap: 2px;
        flex-shrink: 0;
    }

    .chat-header-actions .btn-icon {
        width: 34px;
        height: 34px;
        min-width: 34px;
        min-height: 34px;
        display: flex;
        align-items: center;
        justify-content: center;
        padding: 0;
    }

    /* Chat Search Bar */
    .chat-search-bar {
        padding: var(--space-2) var(--space-3);
        flex-shrink: 0;
        background: var(--chat-header-bg, var(--bg-surface)) !important;
    }

    .chat-search-bar input {
        font-size: 14px;
    }

    /* 4. Messages Container */
    .messages-container {
        flex: 1 1 auto;
        min-height: 0;
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
        overscroll-behavior-y: contain;
        padding: var(--space-3) var(--space-3) var(--space-2);
        background: var(--chat-bg, var(--bg-primary)) !important;
    }

    .message-row {
        max-width: 88%;
    }

    /* Mobile Message Actions Toolbar */
    .message-actions-toolbar {
        max-width: min(calc(100vw - 24px), 360px);
        flex-direction: row;
        flex-wrap: nowrap;
        white-space: nowrap;
        overflow-x: auto;
        overflow-y: hidden;
        -webkit-overflow-scrolling: touch;
        scrollbar-width: none;
        border-radius: 9999px;
        gap: 2px;
        padding: 2px 4px;
        top: -24px;
        box-shadow: 0 4px 20px rgba(0, 0, 0, 0.22);
    }
    .message-actions-toolbar::-webkit-scrollbar {
        display: none;
    }

    .message-row.sent .message-actions-toolbar {
        right: 4px;
        left: auto;
    }

    .message-row.received .message-actions-toolbar {
        left: 4px;
        right: auto;
    }

    .message-row:first-child .message-actions-toolbar,
    .message-row.toolbar-below .message-actions-toolbar {
        top: auto;
        bottom: -28px;
    }

    .action-tool-btn {
        width: 32px;
        height: 32px;
        min-width: 32px;
        font-size: 14px;
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }

    .message-bubble {
        padding: 9px 13px;
        font-size: 14px;
        word-break: break-word;
        overflow-wrap: anywhere;
    }

    /* Outgoing: aligned with theme message tokens */
    .message-row.sent .message-bubble {
        background: var(--message-sent) !important;
        color: var(--message-sent-text, #FFFFFF) !important;
        border: none !important;
        box-shadow: var(--shadow-xs) !important;
    }

    /* Incoming: aligned with theme message tokens */
    .message-row.received .message-bubble {
        background: var(--message-received) !important;
        color: var(--message-received-text) !important;
        border: 1px solid var(--border) !important;
    }

    .message-row.received .message-time {
        color: var(--text-muted) !important;
    }

    .message-bubble.document-bubble {
        min-width: 0 !important;
        max-width: 100% !important;
        width: 100%;
        padding: 10px 12px;
    }

    .doc-bubble-icon {
        width: 38px;
        height: 38px;
    }

    .doc-bubble-name {
        max-width: 140px;
        font-size: 13px;
    }

    .message-media-img,
    .message-media-video {
        max-width: 100%;
        max-height: 260px;
    }

    /* 5. Sticky Composer & Safe Area Inset */
    .chat-composer-container {
        position: sticky;
        bottom: 0;
        left: 0;
        right: 0;
        width: 100%;
        padding: 6px var(--space-3) max(6px, env(safe-area-inset-bottom));
        background: var(--composer-container-bg, var(--bg-surface)) !important;
        border-top: 1px solid var(--border) !important;
        flex-shrink: 0;
        z-index: 50;
    }

    .chat-composer {
        padding: 5px 6px 5px 10px;
        border-radius: var(--radius-xl);
        background: var(--composer-bg, var(--surface)) !important;
        border: 1px solid var(--composer-border, var(--border)) !important;
        align-items: flex-end;
    }

    /* Prevent iOS Safari 16px auto-zoom while vertically centering placeholder & text */
    .composer-textarea {
        font-size: 16px !important;
        line-height: 24px !important;
        min-height: 40px !important;
        height: 40px;
        max-height: 110px;
        padding: 8px 4px !important;
        box-sizing: border-box !important;
        color: var(--text) !important;
        overflow-y: hidden;
    }

    .composer-textarea::placeholder {
        color: var(--text-muted) !important;
        line-height: 24px !important;
        opacity: 0.85;
    }

    .chat-composer .btn-icon,
    .composer-send-btn,
    .composer-action-btn {
        min-width: 40px;
        min-height: 40px;
        width: 40px;
        height: 40px;
        flex-shrink: 0;
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }

    .composer-reply-strip {
        padding: 6px 10px;
        margin-bottom: 6px;
    }

    /* 6. Mobile Bottom Sheet: More Menu */
    .chat-more-menu {
        position: fixed !important;
        top: auto !important;
        bottom: 0 !important;
        left: 0 !important;
        right: 0 !important;
        width: 100% !important;
        min-width: 100% !important;
        max-height: 80vh !important;
        overflow-y: auto !important;
        -webkit-overflow-scrolling: touch !important;
        border-radius: 24px 24px 0 0 !important;
        padding: var(--space-3) var(--space-4) max(var(--space-4), env(safe-area-inset-bottom)) !important;
        box-shadow: 0 -10px 40px rgba(0, 0, 0, 0.35) !important;
        z-index: 300 !important;
        background: var(--surface) !important;
        border-top: 1px solid var(--border) !important;
        border-left: none !important;
        border-right: none !important;
        border-bottom: none !important;
        animation: mobileSheetSlideUp 0.22s cubic-bezier(0.16, 1, 0.3, 1) !important;
    }

    .chat-more-header {
        display: block !important;
        text-align: center;
        font-weight: 700;
        font-size: 13px;
        color: var(--text-muted);
        text-transform: uppercase;
        letter-spacing: 0.6px;
        padding: var(--space-2) 0 var(--space-3) 0;
        border-bottom: 1px solid var(--border);
        margin-bottom: var(--space-2);
    }

    .chat-more-item {
        min-height: 48px;
        padding: 12px var(--space-4);
        font-size: 15px;
        border-radius: var(--radius-md);
    }

    .chat-more-cancel {
        display: flex !important;
        justify-content: center;
        align-items: center;
        min-height: 48px;
        width: 100%;
        font-weight: 600;
        font-size: 15px;
        color: var(--text-secondary);
        background: var(--surface-elevated);
        border-radius: var(--radius-lg);
        margin-top: var(--space-2);
        border: 1px solid var(--border);
    }

    /* 7. Mobile Bottom Sheet: Modals */
    .modal-backdrop {
        align-items: flex-end !important;
        padding: 0 !important;
        z-index: 350;
    }

    .modal-card {
        border-radius: 24px 24px 0 0 !important;
        max-width: 100% !important;
        width: 100% !important;
        max-height: 90vh !important;
        max-height: 90dvh !important;
        margin: 0 !important;
        transform: translateY(100%);
        transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
        display: flex;
        flex-direction: column;
    }

    .modal-backdrop.open .modal-card {
        transform: translateY(0);
    }

    .modal-header {
        padding: var(--space-4) var(--space-5);
        flex-shrink: 0;
    }

    .modal-body {
        padding: var(--space-4) var(--space-5);
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
        flex: 1;
        max-height: calc(90dvh - 130px);
    }

    .modal-footer {
        padding: var(--space-3) var(--space-5) max(var(--space-4), env(safe-area-inset-bottom));
        flex-wrap: wrap;
        gap: var(--space-2);
        flex-shrink: 0;
    }

    .modal-footer .btn {
        flex: 1;
        min-height: 46px;
        justify-content: center;
    }

    /* 8. Popovers on Mobile */
    .emoji-popover,
    .attachment-popover {
        position: fixed !important;
        bottom: 0 !important;
        left: 0 !important;
        right: 0 !important;
        width: 100% !important;
        border-radius: 24px 24px 0 0 !important;
        border: 1px solid var(--border) !important;
        border-bottom: none !important;
        z-index: 250 !important;
        box-shadow: var(--shadow-2xl);
    }

    .emoji-popover {
        max-height: 48vh;
        padding-bottom: max(var(--space-4), env(safe-area-inset-bottom));
    }

    .emoji-grid {
        grid-template-columns: repeat(6, 1fr);
        gap: 6px;
        padding: var(--space-3);
    }

    .emoji-btn {
        font-size: 24px;
        height: 44px;
        display: flex;
        align-items: center;
        justify-content: center;
    }

    .attachment-popover {
        padding: var(--space-3) var(--space-4) max(var(--space-4), env(safe-area-inset-bottom));
    }

    .attachment-menu-item {
        min-height: 48px;
        padding: 12px var(--space-3);
        font-size: 15px;
    }

    /* 9. Off-Canvas Details Drawer */
    .chat-details-drawer {
        position: fixed;
        right: 0;
        top: 0;
        bottom: 0;
        width: 100%;
        max-width: min(340px, 100vw);
        z-index: 210;
        box-shadow: var(--shadow-2xl);
        transform: translateX(100%);
        transition: transform var(--transition-smooth);
        box-sizing: border-box;
    }

    .chat-details-drawer.open {
        transform: translateX(0);
    }

    /* 10. Settings & Profile Layouts */
    .settings-layout {
        grid-template-columns: 1fr !important;
    }

    .settings-sidebar {
        border-right: none !important;
        border-bottom: 1px solid var(--border) !important;
        flex-direction: row !important;
        overflow-x: auto !important;
        -webkit-overflow-scrolling: touch !important;
        padding: var(--space-2) var(--space-3) !important;
    }

    .settings-nav-btn {
        white-space: nowrap !important;
        padding: 8px 14px !important;
        font-size: 13px !important;
    }

    .theme-picker-grid {
        grid-template-columns: 1fr !important;
    }

    .frank-id-card {
        flex-direction: column !important;
        align-items: flex-start !important;
        gap: 12px !important;
    }

    .frank-id-actions {
        width: 100%;
        display: flex;
        justify-content: flex-end;
    }

    /* 11. Touch Target Standardization */
    .btn,
    .nav-item,
    .filter-chip,
    .action-btn {
        min-height: 44px;
    }

    /* Form Inputs on Mobile */
    .form-input,
    .form-textarea {
        font-size: 16px !important;
    }

    /* Landing Page on Mobile */
    .feature-grid {
        grid-template-columns: 1fr;
    }
}

/* -------------------------------------------------------------------------
   NARROW PHONES (320px - 375px)
   iPhone SE, Galaxy Fold outer screen, older compact devices
   ------------------------------------------------------------------------- */
@media (max-width: 375px) {
    .conversation-header {
        padding: 0 8px !important;
        height: 52px !important;
    }

    .conversation-header-title {
        font-size: 16px !important;
    }

    .conversation-header-actions {
        gap: 3px !important;
    }

    .conversation-header-actions .btn-icon {
        width: 34px !important;
        height: 34px !important;
        min-width: 34px !important;
        min-height: 34px !important;
    }

    .conversation-search input {
        font-size: 12px;
    }

    .filter-chip {
        padding: 4px 10px;
        font-size: 11px;
    }

    .chat-header {
        padding: 0 6px;
        height: 56px;
    }

    .chat-partner-name {
        max-width: 115px;
        font-size: 13px;
    }

    .chat-partner-presence {
        font-size: 10px;
    }

    .chat-header-actions .btn-icon {
        min-width: 36px;
        min-height: 36px;
    }

    .message-row {
        max-width: 92%;
    }

    .message-bubble {
        padding: 8px 10px;
        font-size: 13px;
    }

    .doc-bubble-name {
        max-width: 110px;
        font-size: 12px;
    }

    .chat-composer-container {
        padding: 4px 6px max(4px, env(safe-area-inset-bottom));
    }

    .chat-composer {
        gap: 4px;
        padding: 3px 4px 3px 8px;
        align-items: flex-end;
    }

    .chat-composer .btn-icon,
    .composer-send-btn,
    .composer-action-btn {
        min-width: 38px;
        min-height: 38px;
        width: 38px;
        height: 38px;
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }

    .emoji-grid {
        grid-template-columns: repeat(5, 1fr);
    }

    .app-top-header {
        padding-top: var(--safe-top, env(safe-area-inset-top, 0px)) !important;
        padding-bottom: 0 !important;
        padding-left: max(6px, env(safe-area-inset-left, 0px)) !important;
        padding-right: max(6px, env(safe-area-inset-right, 0px)) !important;
        gap: 5px !important;
    }

    .top-header-left {
        gap: 5px !important;
    }

    .top-header-right {
        gap: 5px !important;
    }

    .brand-title-text {
        font-size: 14px !important;
    }

    .brand-tagline-text {
        display: inline-block !important;
        font-size: 10.5px !important;
    }

    .brand-badge.pro-badge {
        font-size: 8.5px !important;
        padding: 1px 4px !important;
    }

    #dashLangSelector .chevron-icon {
        display: none !important;
    }

    #dashLangSelector .lang-btn {
        padding: 0 5px !important;
        font-size: 11px !important;
        gap: 3px !important;
    }
}

/* -------------------------------------------------------------------------
   MICRO SCREENS (320px absolute minimum)
   ------------------------------------------------------------------------- */
@media (max-width: 350px) {
    .app-top-header {
        padding-top: var(--safe-top, env(safe-area-inset-top, 0px)) !important;
        padding-bottom: 0 !important;
        padding-left: max(4px, env(safe-area-inset-left, 0px)) !important;
        padding-right: max(4px, env(safe-area-inset-right, 0px)) !important;
        gap: 4px !important;
    }

    .top-header-left {
        gap: 4px !important;
    }

    .top-header-right {
        gap: 4px !important;
    }

    .app-hamburger-btn {
        width: 30px !important;
        height: 30px !important;
        min-width: 30px !important;
        min-height: 30px !important;
    }

    .brand-logo-img {
        width: 20px !important;
        height: 20px !important;
    }

    .brand-title-text {
        font-size: 13px !important;
    }

    .brand-tagline-text {
        display: inline-block !important;
        font-size: 9.5px !important;
    }

    .brand-badge.pro-badge {
        font-size: 8px !important;
        padding: 1px 3px !important;
    }

    #dashLangSelector .current-lang-label,
    #dashLangSelector .chevron-icon {
        display: none !important;
    }

    #dashLangSelector .lang-btn {
        width: 30px !important;
        min-width: 30px !important;
        height: 30px !important;
        min-height: 30px !important;
        padding: 0 !important;
        justify-content: center !important;
    }

    .top-header-notification-btn {
        width: 30px !important;
        height: 30px !important;
        min-width: 30px !important;
        min-height: 30px !important;
    }

    .desktop-profile-trigger {
        width: 28px !important;
        height: 28px !important;
        min-width: 28px !important;
        min-height: 28px !important;
    }

    .desktop-profile-trigger .avatar {
        width: 26px !important;
        height: 26px !important;
        min-width: 26px !important;
        min-height: 26px !important;
        font-size: 10px !important;
    }

    .chat-partner-name {
        max-width: 95px;
    }

    .chat-header-actions {
        gap: 0;
    }

    .chat-composer {
        padding: 2px 2px 2px 6px;
    }

    .sidebar {
        width: 250px !important;
    }
}

/* Animation for Mobile Bottom Sheet */
@keyframes mobileSheetSlideUp {
    from {
        transform: translateY(100%);
    }
    to {
        transform: translateY(0);
    }
}

/* -------------------------------------------------------------------------
   MEDIA & COMPOSER ATTACHMENTS RESPONSIVE ADJUSTMENTS
   ------------------------------------------------------------------------- */
@media (max-width: 600px) {
    .composer-attachment-tray {
        padding: 8px 10px;
    }

    .tray-preview-wrap {
        width: 40px;
        height: 40px;
    }

    .tray-filename {
        font-size: 12px;
    }

    .composer-recording-bar {
        padding: 8px 12px;
    }

    .recording-timer-label {
        font-size: 13px;
    }

    .composer-voice-preview-bar {
        padding: 6px 10px;
        gap: 8px;
    }

    .message-voice-card {
        min-width: unset;
        width: 100%;
        max-width: 260px;
    }

    .message-photo-card {
        max-width: 100%;
    }

    .message-video-card {
        max-width: 100%;
    }
}

@media (max-width: 360px) {
    .message-voice-card {
        max-width: 215px;
    }

    .voice-card-player {
        gap: 6px;
        padding: 4px 6px;
    }

    .voice-play-toggle-btn {
        width: 30px;
        height: 30px;
    }

    .composer-action-btn {
        min-width: 44px !important;
        min-height: 44px !important;
        width: 44px !important;
        height: 44px !important;
    }

    .tray-file-card {
        gap: 8px;
    }
}