/* ==========================================================================
           [SEC:CSS:LAYOUT]
           3. LAYOUT & RESPONSIVENESS
           ========================================================================== */

        #app-container {
            padding-top: env(safe-area-inset-top);
            padding-bottom: 0;
            transition: backdrop-filter 0.3s ease;
        }

        #chat-input-container {
            padding: 0.5rem;
        }

        /* --- Vertical Layout (Mobile) --- */
        body.layout-vertical #desktop-header {
            display: none;
        }

        body.layout-vertical #mobile-header {
            display: flex;
        }

        body.layout-vertical #app-container {
            padding: 0;
        }

        #main-header {
            position: relative;
            z-index: 10;
        }

        body.layout-vertical #main-header {
            position: absolute;
            top: env(safe-area-inset-top);
            left: 0;
            right: 0;
            z-index: 60;
            padding: 0.5rem;
            pointer-events: none;
        }

        body.layout-vertical #hamburger-menu-button-container {
            pointer-events: auto;
            opacity: 0.6;
            z-index: 51;
            position: relative;
        }

        body.layout-vertical #hamburger-menu-button-container:hover {
            opacity: 1;
        }

        body.layout-vertical #chat-window-container {
            margin: 0 !important;
            border-radius: 0;
            width: 100%;
        }

        body.layout-vertical #character-portrait-container {
            display: none;
        }

        body.layout-vertical #chat-input-container {
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            padding: 0.5rem;
            background: rgba(17, 24, 39, 0.5);
            -webkit-backdrop-filter: blur(10px);
            backdrop-filter: blur(10px);
            border-radius: var(--border-radius-md);
            z-index: 30;
        }

        /* --- Horizontal Layout (Desktop) --- */
        body.layout-horizontal #desktop-header {
            display: flex;
        }

        body.layout-horizontal #mobile-header {
            display: none;
        }

        body.layout-horizontal #app-container {
            padding: .5rem;
        }

        body.layout-horizontal #chat-window-container {
            background-color: rgba(0, 0, 0, 0.2);
            border-radius: var(--border-radius-md);
            justify-content: space-between;
        }

        body.layout-horizontal #chat-input-container {
            background: rgba(17, 24, 39, 0.5);
            -webkit-backdrop-filter: blur(10px);
            backdrop-filter: blur(10px);
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            border-radius: var(--border-radius-md);
        }

        /* CYOA Active Shrunk Chat Input Bar styling */
        #chat-input-container.cyoa-shrunk {
            height: auto !important;
            min-height: unset !important;
            padding-top: 0px !important;
            padding-bottom: 0px !important;
        }

        #chat-input-container.cyoa-shrunk #chat-input {
            height: 2.25rem !important;
            /* Extremely compact single-line view */
            min-height: unset !important;
            padding-top: 0.35rem !important;
            padding-bottom: 0.35rem !important;
            overflow-y: hidden;
        }

        #chat-input-container.cyoa-shrunk #chat-control-cluster {
            display: none !important;
        }

        #chat-input-container.cyoa-shrunk #bolt-btn {
            display: none !important;
        }

        #chat-input-container.cyoa-shrunk #chat-resizer {
            display: none !important;
        }

        #chat-input {
            transition: height 0.2s cubic-bezier(0.4, 0, 0.2, 1), padding 0.2s cubic-bezier(0.4, 0, 0.2, 1);
        }


        body.layout-horizontal #chat-window {
            width: 65%;
            margin: 0 auto;
        }

        body.layout-horizontal #character-portrait-container {
            display: flex;
            width: 35%;
            height: 100%;
            justify-content: center;
            align-items: inherit;
        }

        body.layout-horizontal #title-trigger-area {
            display: none;
        }

        /* FIX: Hide redundant close button in horizontal mode */
        body.layout-horizontal .story-details-close-btn {
            display: none;
        }

        #mobile-story-title-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 50;
            background: linear-gradient(to bottom, rgba(0, 0, 0, 0.8), transparent);
            padding-top: calc(0.5rem + env(safe-area-inset-top));
            padding-bottom: 1rem;
            text-align: center;
            opacity: 0;
            transition: opacity 0.3s ease;
            pointer-events: none;
            border: none;
            border-bottom: none;
            color: var(--chat-text-color);
            font-family: var(--chat-font-family);
        }

        #mobile-story-title-overlay:focus,
        #mobile-story-title-overlay:hover {
            opacity: 1 !important;
            pointer-events: auto;
        }