/* ===== Split Screen Layout ===== */

body.split-screen-active .chat-container-main {
    overflow: hidden;
    justify-content: flex-start;
}

body.split-screen-active #chatArea {
    display: none !important;
}

body.split-screen-active #chatContainerWelcome {
    display: none !important;
}

body.split-screen-active #scrollToBottomBtn {
    display: none !important;
}

.split-screen-wrapper {
    display: none;
    flex: 1;
    flex-direction: row;
    min-height: 0;
    overflow: hidden;
    width: 100%;
}

body.split-screen-active .split-screen-wrapper {
    display: flex;
}

/* ===== Panels ===== */

.split-screen-panel {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
    overflow: hidden;
    position: relative;
}

.split-chat-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    scroll-behavior: smooth;
    padding: 20px;
    min-height: 0;
    container-type: inline-size;
    container-name: chat-files-layout;
}

.split-chat-area-container {
    display: flex;
    flex-direction: column;
    gap: 12px;
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
}

.split-screen-panel-header {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    padding: 6px 12px;
    border-bottom: 1px solid var(--border-color);
    min-height: 40px;
    gap: 8px;
    flex-shrink: 0;
    background: var(--background);
}

.split-screen-panel-model {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 8px;
    transition: background-color 0.15s ease;
    position: relative;
    min-width: 0;
    max-width: min(280px, 55%);
}

.split-panel-thinking-control {
    position: relative;
    flex: 0 1 auto;
    min-width: 0;
}

.split-panel-thinking-control[hidden] {
    display: none !important;
}

.split-panel-thinking-button {
    max-width: 150px;
    height: 30px;
    padding-inline: 10px;
}

.split-panel-thinking-control .split-panel-thinking-dropdown {
    position: absolute;
    top: calc(100% + 6px);
    bottom: auto;
    left: 0;
    z-index: 100;
    transform-origin: top left;
}

.split-screen-panel-actions {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-left: auto;
    flex-shrink: 0;
}

@media (hover: hover) and (pointer: fine) {
    .split-screen-panel-model:hover {
        background-color: var(--hover);
    }
}

.split-panel-model-caret {
    flex-shrink: 0;
    opacity: 0.5;
    transition: transform 0.15s ease;
}

.split-screen-panel-model.open .split-panel-model-caret {
    transform: rotate(180deg);
}

.split-panel-model-dropdown {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    z-index: 100;
    min-width: 240px;
    max-width: 320px;
    max-height: 360px;
    overflow-y: auto;
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
    padding: 4px;
    margin-top: 4px;
}

.split-panel-model-dropdown.open {
    display: block;
}

.split-screen-panel-model-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
    flex-shrink: 0;
}

.split-screen-panel-model-icon svg {
    width: 20px;
    height: 20px;
}

.split-screen-panel-model-icon img {
    width: 20px;
    height: 20px;
    object-fit: contain;
    display: block;
    border-radius: 6px;
}

.split-screen-panel-model-name {
    font-size: 13px;
    font-weight: 500;
    color: var(--text-color);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.split-screen-panel-close {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 8px;
    color: var(--text-color-secondary, #64748b);
    flex-shrink: 0;
    transition: background-color 0.15s ease, color 0.15s ease;
}

@media (hover: hover) and (pointer: fine) {
    .split-screen-panel-close:hover {
        background-color: var(--hover);
        color: var(--text-color);
    }
}

.split-screen-panel-close svg {
    width: 16px;
    height: 16px;
}

.split-screen-panel-save {
    display: none;
    align-items: center;
    justify-content: center;
    gap: 4px;
    height: 28px;
    padding: 0 10px;
    border-radius: 9999px;
    color: var(--text-color-secondary, #64748b);
    flex-shrink: 0;
    font-size: 12px;
    transition: background-color 0.15s ease, color 0.15s ease;
}

@media (hover: hover) and (pointer: fine) {
    .split-screen-panel-save:hover {
        background: color-mix(in srgb, var(--primary-color, #3b82f6) 12%, transparent);
        color: var(--text-color);
    }
}

.split-screen-panel-save:disabled {
    opacity: 0.55;
    cursor: default;
    pointer-events: none;
}

.split-screen-panel-save svg {
    width: 14px;
    height: 14px;
}

/* Panel chat area */
.split-screen-panel .split-chat-area {
    flex: 1;
    width: 100%;
    overflow-y: auto;
    padding: 0 16px;
    display: flex;
    justify-content: center;
}

.split-screen-panel .split-chat-area-container {
    height: 100%;
    max-width: 100%;
    min-width: 0;
    width: 100%;
}

.split-screen-panel .split-chat-area-container::after {
    content: "";
    display: block;
    flex: 0 0 140px;
    height: 140px;
}

/* Panel empty state */
.split-screen-panel-empty {
    display: flex;
    flex: 1;
    align-items: center;
    justify-content: center;
    padding: 20px;
    color: var(--text-color-secondary, #64748b);
    font-size: 14px;
    text-align: center;
    user-select: none;
}

.split-screen-panel-empty p {
    max-width: 200px;
    line-height: 1.5;
}

.split-screen-panel.has-chat .split-screen-panel-empty {
    display: none;
}

.split-screen-panel:not(.has-chat) .split-chat-area {
    display: none;
}

/* Panel scroll-to-bottom */
.split-screen-panel .split-scroll-to-bottom-btn {
    position: absolute;
    bottom: 12px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 5;
    display: none;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--bg-normal-elevated, var(--background));
    border: 1px solid var(--border-color);
    box-shadow: 0 2px 6px var(--shadow-color, rgba(0,0,0,0.08));
    color: var(--text-color);
    cursor: pointer;
    transition: background-color 0.15s ease;
}

.split-screen-panel .split-scroll-to-bottom-btn.visible {
    display: flex;
}

@media (hover: hover) and (pointer: fine) {
    .split-screen-panel .split-scroll-to-bottom-btn:hover {
        background: linear-gradient(var(--hover), var(--hover)), var(--bg-normal-elevated, var(--background));
    }
}

.split-screen-panel .split-scroll-to-bottom-btn svg {
    width: 16px;
    height: 16px;
}

/* ===== Divider ===== */

.split-screen-divider {
    width: 1px;
    background: var(--border-color);
    flex-shrink: 0;
    position: relative;
    cursor: col-resize;
    z-index: 2;
    transition: background-color 0.15s ease;
}

.split-screen-divider::before {
    content: "";
    position: absolute;
    top: 0;
    left: -4px;
    right: -4px;
    bottom: 0;
    z-index: 1;
    transition: background-color 0.15s ease;
}

.split-screen-divider.dragging {
    background: var(--accent-color, #3b82f6);
}

@media (hover: hover) and (pointer: fine) {
    .split-screen-divider:hover {
        background: var(--accent-color, #3b82f6);
    }
}

.split-screen-divider.dragging::before {
    background: color-mix(in srgb, var(--accent-color, #3b82f6) 12%, transparent);
}

@media (hover: hover) and (pointer: fine) {
    .split-screen-divider:hover::before {
        background: color-mix(in srgb, var(--accent-color, #3b82f6) 12%, transparent);
    }
}

/* ===== Drop Zone ===== */

.split-screen-panel.drop-target {
    outline: 2px dashed var(--accent-color, #3b82f6);
    outline-offset: -4px;
    background-color: rgba(59, 130, 246, 0.04);
}

.split-screen-panel.drop-target .split-screen-panel-empty p {
    color: var(--accent-color, #3b82f6);
    font-weight: 500;
}

/* Drop target on main chat area for entering split-screen */
#chatArea.drop-target-split {
    outline: 2px dashed var(--accent-color, #3b82f6);
    outline-offset: -4px;
    background-color: rgba(59, 130, 246, 0.04);
    position: relative;
}

#chatArea.drop-target-split::before {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    left: 50%;
    width: 2px;
    background: var(--accent-color, #3b82f6);
    opacity: 0.5;
    z-index: 10;
    pointer-events: none;
}

/* ===== Send Target Dropdown ===== */

.split-send-target-wrapper {
    display: none;
    position: relative;
}

body.split-screen-active .split-send-target-wrapper {
    display: flex;
}

.split-send-target-dropdown {
    position: absolute;
    bottom: calc(100% + 6px);
    left: 0;
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 4px;
    display: none;
    flex-direction: column;
    min-width: 120px;
    z-index: 20;
    box-shadow: 0 4px 12px var(--shadow-color, rgba(0,0,0,0.08));
}

.split-send-target-dropdown.open {
    display: flex;
}

.split-send-target-option {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 10px;
    border-radius: 8px;
    font-size: 13px;
    color: var(--text-color);
    cursor: pointer;
    transition: background-color 0.12s ease;
    white-space: nowrap;
}

@media (hover: hover) and (pointer: fine) {
    .split-send-target-option:hover {
        background-color: var(--hover);
    }
}

.split-send-target-option.active {
    font-weight: 600;
    color: var(--accent-color, #3b82f6);
}

.split-send-target-current-icon,
.split-send-target-option-icon,
.split-settings-tab-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.split-send-target-current-icon,
.split-send-target-option-icon {
    width: 16px;
    height: 16px;
}

.split-send-target-current-icon svg,
.split-send-target-option-icon svg {
    width: 16px;
    height: 16px;
}

/* ===== Toggle Button in Header ===== */

.split-screen-toggle-btn {
    display: flex;
    align-items: center;
    justify-content: center;
}

.split-screen-toggle-btn.active {
    background-color: color-mix(in srgb, var(--primary-color) 18%, transparent);
}

/* ===== Responsive Modal ===== */

.split-screen-responsive-modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.split-screen-responsive-modal-overlay.open {
    display: flex;
}

.split-screen-responsive-modal {
    background: var(--background);
    border-radius: 16px;
    padding: 24px;
    max-width: 340px;
    width: 100%;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
}

.split-screen-responsive-modal h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 8px;
}

.split-screen-responsive-modal p {
    font-size: 14px;
    color: var(--text-color-secondary, #64748b);
    line-height: 1.5;
    margin-bottom: 20px;
}

.split-screen-responsive-modal-actions {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.split-screen-responsive-modal-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 10px 16px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.15s ease;
    border: 1px solid var(--border-color);
    color: var(--text-color);
    background: var(--background);
}

@media (hover: hover) and (pointer: fine) {
    .split-screen-responsive-modal-btn:hover {
        background-color: var(--hover);
    }
}

.split-screen-responsive-modal-btn.primary {
    background: var(--accent-color, #3b82f6);
    color: #fff;
    border-color: transparent;
}

@media (hover: hover) and (pointer: fine) {
    .split-screen-responsive-modal-btn.primary:hover {
        opacity: 0.9;
    }
}

/* ===== Model Settings Panel Tabs ===== */

.split-settings-panel-tabs {
    display: flex;
    gap: 4px;
    padding: 4px 8px 6px;
    border-top: 1px solid var(--border-color);
    flex-shrink: 0;
}

.split-settings-tab {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 6px 12px;
    border-radius: 8px;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-color-secondary, #64748b);
    background: transparent;
    border: 1px solid transparent;
    cursor: pointer;
    transition: background-color 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

@media (hover: hover) and (pointer: fine) {
    .split-settings-tab:hover {
        background-color: var(--hover);
    }
}

.split-settings-tab.active {
    color: var(--text-color);
    background-color: var(--hover);
    border-color: var(--border-color);
}

.split-settings-tab-icon {
    width: 16px;
    height: 16px;
}

.split-settings-tab-icon svg {
    width: 16px;
    height: 16px;
}

/* ===== Responsive ===== */

@media (max-width: 700px) {
    .split-screen-toggle-btn {
        display: none;
    }

    body.split-screen-active .split-screen-wrapper {
        flex-direction: column;
    }

    .split-screen-divider {
        width: 100%;
        height: 1px;
        cursor: row-resize;
    }

    .split-screen-divider::before {
        top: -4px;
        bottom: -4px;
        left: 0;
        right: 0;
    }
     }