/* Variables */
:root {
    --transition-duration: 150ms;
    
    /* Color variables - Light mode (default) */
    --toolbar-border: #ccc;
    --toolbar-bg: #f8f8f8;
    --row-outline: #ddd;
    --row-bg: #f0f0f0;
    --input-bg: #f0f0f0;
    --resize-handle-bg: #88888833;
    --resize-handle-hover-bg: #333333;
    --resize-handle-pinned-bg: #66666655;
    --drop-target-hover-bg: #f0f5ff;
    --content-bg: #fff;
    --button-hover-bg: rgba(0, 0, 0, 0.1);
    --grid-line-bg: rgba(136, 136, 136, 0.067);
    --grid-line-nearest-bg: #888;
    --loading-overlay-bg: rgba(255, 255, 255, 0.85);
    --placeholder-content-bg: rgba(255, 0, 0, 0.3);
    --placeholder-content-border: red;
    --text-color: black;
    --segment-column-border: blue;
    --segment-column-bg: rgba(0, 0, 255, 0.05);
    --segment-row-border: green;
    --segment-row-bg: rgba(0, 255, 0, 0.05);
    --button-bg: rgba(0, 0, 0, 0);
    --button-hover-bg-strong: rgba(0, 0, 0, 0.7);
}

/* Dark mode - based on system preference */
@media (prefers-color-scheme: dark) {
    :root {
        --toolbar-border: #444;
        --toolbar-bg: #222;
        --row-outline: #444;
        --row-bg: #2a2a2a;
        --input-bg: #333;
        --resize-handle-bg: #88888855;
        --resize-handle-hover-bg: #aaaaaa;
        --resize-handle-pinned-bg: #99999977;
        --drop-target-hover-bg: #334466;
        --content-bg: #1a1a1a;
        --button-hover-bg: rgba(255, 255, 255, 0.2);
        --grid-line-bg: rgba(136, 136, 136, 0.15);
        --grid-line-nearest-bg: #999;
        --loading-overlay-bg: rgba(30, 30, 30, 0.85);
        --placeholder-content-bg: rgba(255, 0, 0, 0.2);
        --placeholder-content-border: #ff5555;
        --text-color: #e0e0e0;
        --segment-column-border: #5555ff;
        --segment-column-bg: rgba(0, 0, 255, 0.1);
        --segment-row-border: #55aa55;
        --segment-row-bg: rgba(0, 255, 0, 0.1);
        --button-bg: rgba(0, 0, 0, 0);
        --button-hover-bg-strong: rgba(255, 255, 255, 0.7);
    }
    
    body {
        background-color: #1a1a1a;
        color: var(--text-color);
    }
}

/* ===== BASE ELEMENTS ===== */
body {
    display: flex;
    flex-direction: column;
    margin: 0;
    height: 100vh;
    font-family: sans-serif;

    &.body-dragging {
        cursor: grabbing !important;

        .column,
        .row,
        .resize-handle,
        .row-resize-handle,
        .content-overlay iframe.overlay-iframe {
            transition: none !important;
        }
    }

    &.body-resizing {
        .row-controls {
            visibility: hidden !important;
            opacity: 0 !important;
            pointer-events: none !important;
        }

        .resize-handle,
        .row-resize-handle {
            transition: none !important;
            background-color: #333333;
        }

        .content-overlay iframe.overlay-iframe {
            transition: none !important;
        }

        .resize-handle:not(.active):hover,
        .row-resize-handle:not(.active):hover {
            background-color: #88888833;
        }
    }

    &.body-layout-transitioning {
        .row-controls {
            visibility: hidden !important;
            opacity: 0 !important;
            pointer-events: none !important;
        }

        .content-overlay iframe.overlay-iframe {
            transition: none !important;
        }

        .resize-handle:not(.active):hover,
        .row-resize-handle:not(.active):hover {
            background-color: #88888833;
        }

        .resize-handle.transitioning:hover,
        .row-resize-handle.transitioning:hover {
            background-color: #88888833;
        }
    }
}

.toolbar {
    display: none;
    border-bottom: 1px solid var(--toolbar-border);
    background-color: var(--toolbar-bg);
    padding: 10px;

    button {
        margin-right: 5px;
    }
}

/* ===== LAYOUT STRUCTURE ===== */
.column-container-wrapper {
    display: flex;
    position: relative;
    flex-grow: 1;
}

.column-container {
    display: flex;
    position: relative;
    flex-grow: 1;
    overflow: hidden;
}

/* Columns */
.column {
    box-sizing: border-box;
    position: relative;
    transition: flex-basis var(--transition-duration) ease-in-out, 
                margin-left var(--transition-duration) ease-in-out, 
                margin-right var(--transition-duration) ease-in-out;
    overflow: hidden;

    &[draggable="true"] {
        cursor: move;
    }

    &.transitioning .row {
        transition: none !important;
    }

    &.column-resetting.transitioning .row {
        transition: flex-basis var(--transition-duration) ease-in-out,
            margin-top var(--transition-duration) ease-in-out,
            margin-bottom var(--transition-duration) ease-in-out,
            padding var(--transition-duration) ease-in-out,
            opacity var(--transition-duration) ease-in-out !important;
    }

    &.removing {
        flex-basis: 0px !important;
        flex-grow: 0 !important;
        flex-shrink: 0 !important;
        transition: flex-basis var(--transition-duration) ease-in-out, 
                    opacity var(--transition-duration) ease-in-out;
        opacity: 0 !important;
        margin-right: 0 !important;
        margin-left: 0 !important;
        overflow: hidden !important;
    }

    /* Column Controls */
    .column-controls {
        position: absolute;
        top: 0;
        right: 0;
        bottom: 0;
        left: 0;
        z-index: 50; 
        pointer-events: none;
        visibility: hidden;
        opacity: 0;
        display: flex; 
        align-items: stretch; 
        justify-content: space-between;
        
        .hover-btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            opacity: 1; 
            margin: 0; 
            border: none;
            background-color: transparent; 
            padding: 0; 
            width: 3vw; 
            height: 100%; 
            color: transparent;
            font-size: 0.75em; 
            pointer-events: auto;
            z-index: 51;

            &:hover {
                opacity: 1;
                background-color: rgba(0, 0, 0, 0.1);
            }
        }

        .col-control-add-left {
            cursor: w-resize;
        }

        .col-control-add-right {
            cursor: e-resize;
        }
    }

    &:hover .column-controls {
        visibility: visible;
        opacity: 1;
    }
}

/* Rows */
.row-container {
    display: flex;
    flex-direction: column;
    width: 100%;
    height: 100%;
    overflow: hidden;
}

.row {
    box-sizing: border-box;
    position: relative;
    flex-basis: 0;
    flex-grow: 1;
    transition: flex-basis var(--transition-duration) ease-in-out, 
                margin-top var(--transition-duration) ease-in-out, 
                margin-bottom var(--transition-duration) ease-in-out, 
                padding var(--transition-duration) ease-in-out, 
                opacity var(--transition-duration) ease-in-out;
    outline: 1px solid var(--row-outline);
    background-color: var(--row-bg);
    overflow: auto;

    &.removing {
        flex-basis: 0px !important;
        flex-grow: 0 !important;
        flex-shrink: 0 !important;
        opacity: 0 !important;
        margin-top: 0 !important;
        margin-bottom: 0 !important;
        outline-width: 0px !important;
        padding-top: 0 !important;
        padding-bottom: 0 !important;
        overflow: hidden !important;
    }

    &.dragging {
        transform: scale(1.02);
        opacity: 0.6;
        z-index: 1000;
    }

    &.drop-target-hover {
        background-color: var(--drop-target-hover-bg);
    }

    &.dragged-source-row {
        filter: saturate(0);
        opacity: 0.25 !important;
        cursor: grabbing;
    }

    /* Row Controls */
    .row-controls {
        display: grid;
        position: absolute;
        top: 0;
        right: 0;
        bottom: 0;
        left: 0;
        grid-template-rows: 3vw 1fr 3vw;
        grid-template-columns: 3vw 1fr 3vw;
        visibility: hidden;
        opacity: 0;
        z-index: 22;
        pointer-events: none;

        &.drag-active-no-hover {
            visibility: hidden !important;
            opacity: 0 !important;
            pointer-events: none !important;
        }

        .hover-btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            opacity: 1;
            margin: 0;
            border: none;
            background-color: var(--button-bg);
            padding: 0;
            width: 100%;
            height: 100%;
            color: transparent;
            font-size: 0.75em;
            pointer-events: auto;

            &:hover {
                opacity: 1;
                background-color: var(--button-hover-bg);
            }
        }
    }

    &:hover .row-controls {
        visibility: visible;
        opacity: 1;
        pointer-events: auto;
    }

    /* Row top buttons */
    .row-top-buttons-container {
        box-sizing: border-box;
        position: absolute;
        top: 3vw;
        left: 3vw;
        right: 3vw;
        display: flex;
        justify-content: space-between;
        align-items: center;
        pointer-events: none;
        z-index: 23;
        visibility: hidden;
        opacity: 0;
    }

    &:hover .row-top-buttons-container {
        visibility: visible;
        opacity: 1;
        pointer-events: auto;
    }

    /* URL input */
    .url-input-container {
        box-sizing: border-box;
        display: block;
        position: absolute;
        top: 3vw;
        right: 3vw;
        left: 3vw;
        transform: translateY(-20px);
        transition: opacity var(--transition-duration) ease-in-out, 
                    transform var(--transition-duration) ease-in-out, 
                    visibility 0s linear var(--transition-duration);
        visibility: hidden;
        opacity: 0;
        z-index: 23;
        background: #fff;
        height: 3vw;

        &.visible {
            transform: translateY(0);
            transition: opacity var(--transition-duration) ease-in-out, 
                        transform var(--transition-duration) ease-in-out, 
                        visibility 0s linear 0s;
            visibility: visible;
            opacity: 1;
        }

        .url-input-field {
            box-sizing: border-box;
            text-align: center;
            border: none;
            border-radius: 3px;
            background-color: var(--input-bg);
            padding: 8px;
            width: 100%;
            height: 100%;
            font-size: 0.9em;
            color: var(--text-color);
        }
    }

    /* Loading states */
    &.row-loading {
        .row-controls {
            visibility: hidden !important;
            opacity: 0 !important;
            pointer-events: none !important;
        }

        .iframe-content-container + * {
            opacity: 0.5;
        }
    }
}

.row-ghost {
    box-sizing: border-box;
    position: absolute;
    z-index: 1001;
    background-color: rgba(200, 200, 200, 0.5);
    pointer-events: none;
    user-select: none;
}

/* ===== RESIZE HANDLES ===== */
/* Column Resize Handles */
.handle-container {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    z-index: 30;
    overflow: hidden;
    pointer-events: none;
}

.resize-handle {
    box-sizing: border-box;
    position: absolute;
    top: 0;
    bottom: 0;
    transform: translateX(-50%);
    z-index: 32;
    background-clip: content-box;
    background-color: var(--resize-handle-bg);
    cursor: col-resize;
    padding: 0 11px;
    width: 23px;
    pointer-events: auto;

    &:hover {
        z-index: 33;
        background-color: var(--resize-handle-hover-bg);
        width: 26px;
    }

    &.pinned {
        background-color: var(--resize-handle-pinned-bg);
        width: 24px;

        &:hover {
            z-index: 34;
            background-color: var(--resize-handle-hover-bg);
            width: 26px;
        }
    }

    &.active {
        z-index: 35;
        background-clip: padding-box;
        background-color: transparent;
        width: 27px;
    }

    &.transitioning {
        transition: none !important;
        pointer-events: none !important;
    }
}

/* Row Resize Handles */
.row-handle-container {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    z-index: 24;
    overflow: hidden;
    pointer-events: none;
}

.row-resize-handle {
    box-sizing: border-box;
    position: absolute;
    right: 0;
    left: 0;
    transform: translateY(-50%);
    z-index: 25;
    background-clip: content-box;
    background-color: var(--resize-handle-bg);
    cursor: row-resize;
    padding: 7px 0;
    height: 15px;
    pointer-events: auto;

    &:hover {
        z-index: 26;
        background-color: var(--resize-handle-hover-bg);
        height: 18px;
    }

    &.pinned {
        background-color: var(--resize-handle-pinned-bg);
        height: 16px;

        &:hover {
            z-index: 27;
            background-color: var(--resize-handle-hover-bg);
            height: 18px;
        }
    }

    &.active {
        z-index: 28;
        background-clip: padding-box;
        background-color: transparent;
        height: 19px;
    }

    &.transitioning {
        transition: none !important;
        opacity: 1;
        pointer-events: none !important;
    }
}

/* ===== CONTENT ===== */
/* Grid Overlay */
.grid-overlay {
    display: none;
    position: absolute;
    top: 0;
    left: 0;
    transition: opacity var(--transition-duration) ease-in-out;
    opacity: 0;
    z-index: 5;
    width: 100%;
    height: 100%;
    pointer-events: none;

    &.vertical .grid-line {
        top: 0;
        bottom: 0;
        width: 1px;

        &.nearest {
            width: 3px;
        }
    }

    &.horizontal .grid-line {
        right: 0;
        left: 0;
        height: 1px;

        &.nearest {
            height: 3px;
        }
    }
}

.grid-line {
    position: absolute;
    background-color: var(--grid-line-bg);

    &.nearest {
        background-color: var(--grid-line-nearest-bg);
    }
}

/* Content Elements */
.iframe-content-container {
    display: none;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 1;
    background-color: var(--content-bg);
    width: 100%;
    height: 100%;
    overflow: hidden;

    iframe {
        border: none;
        width: 100%;
        height: 100%;
    }
}

.iframe-loading-overlay {
    position: absolute;
    top: 0;
    left: 0;
    transition: opacity var(--transition-duration) ease-in-out;
    opacity: 1;
    z-index: 2;
    background-color: var(--loading-overlay-bg);
    background-image: url('throbber.svg');
    background-repeat: no-repeat;
    background-position: center center;
    background-size: 32px 32px;
    width: 100%;
    height: 100%;

    &.fade-out {
        opacity: 0;
        pointer-events: none;
    }
}

.content-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 4;
    pointer-events: none;
    overflow: hidden;

    .placeholder-content {
        position: absolute;
        background-color: var(--placeholder-content-bg);
        border: 1px dashed var(--placeholder-content-border);
        box-sizing: border-box;
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 10px;
        color: var(--text-color);
        padding: 5px;
        text-align: center;
    }

    .content-segment-column {
        border: 1px solid var(--segment-column-border);
        background-color: var(--segment-column-bg);
    }

    .content-segment-row {
        border: 1px solid var(--segment-row-border);
        background-color: var(--segment-row-bg);
    }

    iframe.overlay-iframe {
        background-color: var(--content-bg);
        transition: top var(--transition-duration) ease-in-out, 
                    left var(--transition-duration) ease-in-out, 
                    width var(--transition-duration) ease-in-out, 
                    height var(--transition-duration) ease-in-out;
        will-change: top, left, width, height;
        backface-visibility: hidden;
        transform: translateZ(0);

        &.no-transition {
            transition: none !important;
            will-change: auto;
        }
    }
}

/* ===== BUTTONS ===== */
.hover-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    opacity: 0.7;
    margin: 0 3px;
    border: none;
    background-color: var(--button-bg);
    cursor: pointer;
    padding: 0;
    width: 24px;
    height: 24px;
    line-height: 1;
    font-size: 1em;
    color: var(--text-color);

    &:hover {
        opacity: 1;
        background-color: var(--button-hover-bg-strong);
    }

    &[data-action="drag-row"] {
        cursor: grab;
    }

    &[data-action="row-info"] {
        cursor: help;
    }

    &[data-action="row-options"] {
        cursor: context-menu;
    }

    &[data-action="add-row-above"] {
        cursor: n-resize;
    }

    &[data-action="add-row-below"] {
        cursor: s-resize;
    }

    &[data-action="add-col-left-from-row"] {
        cursor: w-resize;
    }

    &[data-action="add-col-right-from-row"] {
        cursor: e-resize;
    }

    &[data-action="remove-row"] {
        cursor: pointer;
    }

    &[data-action="load-url"] {
        cursor: alias;

        &:hover {
            cursor: context-menu;
        }
    }
}

/* Global state classes to hide controls during special states */
body.body-resizing .column-controls,
body.body-layout-transitioning .column-controls,
body.body-dragging .column-controls {
    visibility: hidden !important;
    opacity: 0 !important;
    pointer-events: none !important;
}