:root {
    --font-size-body: 12pt;
    --font-size-h1: 16pt;
    --font-size-h2: 14pt;
    --font-size-h3: 12pt;
    --font-size-h4: 10pt;
    --font-size-h5: 10pt;
    --font-size-h6: 10pt;
    --block-padding-vertical: 10px;
    --block-padding-horizontal: 0px;
    --answer-box-length-multiplier: 2.5;
    --answer-box-width-multiplier: 2.0;
    --hanging-indent-width: 3em;
}

html {
    height: 100%;
}

body {
    font-family: sans-serif;
    margin: 0;
    padding: 15px;
    background-color: #f4f4f4;
    height: 100%;
    box-sizing: border-box;
    overflow: hidden;
}

.container {
    display: flex;
    gap: 0; /* Splitter will create the gap */
    height: 100%;
}

/* Left Column */
.settings-panel {
    width: 224px;
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    padding: 0 15px;
    border: 1px solid #ccc;
    background-color: #fff;
    font-size: 13px;
}

/* Center Column */
.editor-panel {
    flex: 1 1 50%;
    display: flex;
    flex-direction: column;
    min-width: 150px;
    padding: 0 15px;
    min-height: 0; /* Prevent vertical overflow */
}

.editor-panel h2, .preview-wrapper h2 {
    font-size: 16px;
    margin: 0 0 5px 0;
    color: #555;
}

.editor-content {
    flex-grow: 1;
    display: flex;
    min-height: 0; /* Prevent vertical overflow */
}

.line-gutter {
    width: 40px;
    flex-shrink: 0;
    background-color: #f7f7f7;
    border: 1px solid #ccc;
    border-right: none;
    box-sizing: border-box;
    overflow: hidden;
    text-align: right;
    padding-right: 5px;
    color: #aaa;
    font-family: monospace;
    font-size: 14px;
    line-height: 1.5;
}

.text-area-wrapper {
    position: relative;
    flex: 1;
    min-height: 0; /* allow flex child to shrink and enable scrolling */
}

.input-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
    white-space: pre;
    font-family: monospace;
    font-size: 14px;
    line-height: 1.5;
    color: transparent; /* keep text invisible; it's only background */
    overflow: auto; /* allow programmatic scroll syncing */
}

.input-bg .line-bg {
    padding: 0 5px; /* match textarea padding */
    min-height: 1.5em;
    box-sizing: border-box;
}

#inputText {
    position: relative;
    background: transparent;
    z-index: 2;
    height: 100%;
    overflow: auto;
    display: block;
}

.line-number.split { background-color: rgba(0, 0, 255, 0.2); }
.line-number.pagebreak { background-color: rgba(255, 0, 0, 0.2); }

/* very light colors for H1-H6 backgrounds */
.line-bg-h1 { background: rgba(255,0,0,0.12); }
.line-bg-h2 { background: rgba(255,165,0,0.12); }
.line-bg-h3 { background: rgba(255,255,0,0.12); }
.line-bg-h4 { background: rgba(0,128,0,0.12); }
.line-bg-h5 { background: rgba(0,0,255,0.12); }
.line-bg-h6 { background: rgba(128,0,128,0.12); }

.line-number {
    cursor: pointer;
    user-select: none;
}

.line-number:hover {
    color: #555;
}

.line-number.active {
    color: #fff;
    background-color: #007bff;
}

#inputText {
    flex-grow: 1;
    width: 100%;
    box-sizing: border-box;
    resize: none;
    border: 1px solid #ccc;
    border-left: none;
    font-size: 14px;
    line-height: 1.5;
    font-family: monospace;
    padding: 0 5px;
}

/* Splitter */
.splitter {
    flex-shrink: 0;
    width: 5px;
    background: #ddd;
    cursor: col-resize;
    transition: background-color 0.2s;
}
.splitter:hover {
    background: #ccc;
}

/* Right Column */
.preview-wrapper {
    flex: 1 1 50%;
    display: flex;
    flex-direction: column;
    min-width: 200px;
    padding: 0 15px;
}

.preview-panel {
    flex-grow: 1;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    border: 1px solid #ccc;
    background-color: #e9e9e9;
    width: 100%;
}

.preview-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
}

button {
    padding: 8px 12px;
    cursor: pointer;
    margin-bottom: 5px;
}

.setting-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 5px;
}

.setting-item label {
    margin-right: 8px;
    white-space: nowrap;
}

.settings-group, .actions-group {
    margin-top: 0;
    margin-bottom: 0;
    border-top: 1px solid #eee;
    padding-top: 5px;
}

.actions-group {
    border-top: none;
    padding-top: 0;
    display: flex;
    justify-content: center;
}

.button-group {
    display: flex;
    justify-content: center;
    gap: 10px;
}

.font-size-setting input[type="number"],
.numeric-input-short {
    width: 5ch;
    text-align: right;
}

#pagination-controls {
    display: flex;
    justify-content: center;
    align-items: center;
}

#page-indicator {
    margin: 0 15px;
}

#paper-container {
    position: relative;
    width: 210mm;
    height: 297mm;
    flex-shrink: 0;
    transform-origin: center center;
}

.a4-paper {
    background-color: white;
    border: 1px solid #ccc;
    width: 100%;
    height: 100%;
    padding: var(--page-margin-top, 20px) var(--page-margin-right, 20px) var(--page-margin-bottom, 20px) var(--page-margin-left, 20px);
    box-sizing: border-box;
    position: absolute;
    top: 0;
    left: 0;
    overflow: hidden;
    display: none;
}

.a4-paper.active {
    display: block;
}

.a4-paper.landscape {
    width: 297mm;
    height: 210mm;
}

#paper-container.landscape {
    width: 297mm;
    height: 210mm;
}

.a4-paper.split-layout::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 10px;
    right: 10px;
    border-top: 1px dashed #888;
    transform: translateY(-50%);
}

.text-block {
    writing-mode: vertical-rl;
    -webkit-writing-mode: vertical-rl;
    -ms-writing-mode: tb-rl;
    text-orientation: upright;
    border: 1px dashed #ccc;
    padding-top: var(--block-padding-vertical);
    padding-bottom: var(--block-padding-vertical);
    padding-left: var(--block-padding-horizontal);
    padding-right: var(--block-padding-horizontal);
    position: absolute;
    cursor: move;
    box-sizing: border-box;
    white-space: pre-wrap;
    overflow-wrap: break-word;
    max-height: calc(100% - 40px);
    font-size: var(--font-size-body);
}

.text-block.text-centered > * {
    margin-left: auto;
    margin-right: auto;
}

.text-block h1 { font-size: var(--font-size-h1); }
.text-block h2 { font-size: var(--font-size-h2); }
.text-block h3 { font-size: var(--font-size-h3); }
.text-block h4 { font-size: var(--font-size-h4); }
.text-block h5 { font-size: var(--font-size-h5); }
.text-block h6 { font-size: var(--font-size-h6); }

.text-block h1,
.text-block h2,
.text-block h3,
.text-block h4,
.text-block h5,
.text-block h6,
.text-block p {
    margin: 0;
    padding: 0;
}

.a4-paper.split-layout .text-block {
    max-height: calc(50% - 30px);
}

ruby { ruby-position: over; }

rt {
    font-size: 0.6em;
    margin-left: 0.2em;
}

rt.period-ruby {
    font-size: 0.6em;
    margin-left: 0;
    transform: translate(0.1em, 0.7em);
    -webkit-transform: translate(0.1em, 0.7em);
}

.text-block u { text-decoration: none; border-right: 1px solid black; }

.text-block blockquote {
    padding-top: 0em;
    margin: 0;
}

.text-block blockquote p {
    margin: 1px 0;
}

.answer-box {
    display: inline-block;
    box-sizing: border-box;
    width: calc(1em * var(--answer-box-width-multiplier));
    height: calc(var(--char-count, 1) * 1em * var(--answer-box-length-multiplier));
    border: 1px solid black !important;
    background-color: white;
    vertical-align: middle;
}

.answer-box-line {
    display: flex;
    justify-content: flex-end;
    height: 100%;
}

.text-block p.hanging-indent {
    padding-top: var(--hanging-indent-width);
    text-indent: calc(var(--hanging-indent-width) * -1);
}

/* Modal styles */
.modal {
    display: none; /* Hidden by default */
    position: fixed; /* Stay in place */
    z-index: 100; /* Sit on top */
    left: 0;
    top: 0;
    width: 100%; /* Full width */
    height: 100%; /* Full height */
    overflow: auto; /* Enable scroll if needed */
    background-color: rgba(0,0,0,0.4); /* Black w/ opacity */
}

.modal-content {
    background-color: #fefefe;
    margin: 5% auto;
    padding: 20px;
    border: 1px solid #888;
    width: 80%;
    max-width: 800px;
    border-radius: 8px;
    max-height: 80vh;
    overflow-y: auto;
}

.close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
}

.close:hover,
.close:focus {
    color: black;
    text-decoration: none;
    cursor: pointer;
}

/* Ensure visible modal shows and overlays other content */
.modal.visible {
    display: block !important;
    z-index: 9999;
}

/* prevent background scroll when modal open */
body.modal-open {
    overflow: hidden;
}

@media print {
    /* Hide non-essential UI elements */
    .settings-panel,
    .editor-panel,
    .splitter,
    .preview-wrapper h2,
    .preview-footer {
        display: none !important;
    }

    /* Reset layout for printable area */
    body, .container, .preview-wrapper, .preview-panel {
        display: block !important;
        position: static !important;
        width: 100% !important;
        height: 100% !important;
        padding: 0 !important;
        margin: 0 !important;
        border: none !important;
        overflow: visible !important;
        background: none !important;
    }

    #paper-container {
        transform: scale(1) !important;
        box-shadow: none !important;
        position: static !important;
    }

    /* Print each .a4-paper as a single A4 page.
       Default: portrait (210mm x 297mm). If the container or paper has
       the "landscape" class, swap dimensions so the page prints landscape.
       Use box-sizing:border-box so padding won't cause overflow. */
    .a4-paper {
        display: block !important;
        position: relative !important;
        width: 210mm !important;
        height: 297mm !important;
        page-break-after: always;
        box-shadow: none !important;
        border: none !important;
        margin: 0 auto !important;

        box-sizing: border-box !important;
        overflow: hidden !important;
        page-break-inside: avoid !important;
    }

    /* When a paper or the container is set to landscape in the app, the
       printed pages should also be landscape. The app toggles either
       .a4-paper.landscape or #paper-container.landscape; handle both. */
    .a4-paper.landscape,
    #paper-container.landscape .a4-paper {
        width: 297mm !important;
        height: 210mm !important;
    }

    .a4-paper:last-child {
        page-break-after: auto;
    }

    .text-block {
        border-color: transparent !important;
    }
}

/* Heading-based indentation */
:root {
  --indent-level-1: 1em; /* After H1 */
  --indent-level-2: 2em; /* After H2 */
  --indent-level-3: 3em; /* After H3, H4, etc. */
}

.indent-level-1 {
  padding-top: calc(var(--block-padding-vertical) + var(--indent-level-1));
}

.indent-level-2 {
  padding-top: calc(var(--block-padding-vertical) + var(--indent-level-2));
}

.indent-level-3 {
  padding-top: calc(var(--block-padding-vertical) + var(--indent-level-3));
}