/* ── Core 9UY Design Tokens ──────────────────────────────────────────── */
:root {
  --bg:              #0a0a0a;
  --bg-panel:        rgba(17, 24, 39, 0.55);
  --bg-panel-deep:   rgba(9, 13, 22, 0.8);
  --fg:              #d4d4d8;
  --accent:          #10b981;   /* green */
  --accent-blue:     #3b82f6;
  --danger:          #ef4444;
  --warning:         #f59e0b;
  --border:          #1f2937;
  --border-hover:    #374151;
  --text-muted:      #9ca3af;

  /* diff-specific */
  --diff-add-bg:     rgba(16,  185, 129, 0.12);
  --diff-add-gutter: rgba(16,  185, 129, 0.25);
  --diff-add-text:   #10b981;
  --diff-del-bg:     rgba(239,  68,  68, 0.12);
  --diff-del-gutter: rgba(239,  68,  68, 0.25);
  --diff-del-text:   #ef4444;
  --diff-hunk-bg:    rgba(59, 130, 246, 0.08);
  --diff-hunk-text:  #6b7280;
  --diff-ctx-text:   #d1d5db;
}

/* ── Reset / Base ─────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }

body {
    background-color: var(--bg);
    color: var(--fg);
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
                 "Liberation Mono", "Courier New", monospace;
    margin: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background-image:
        linear-gradient(rgba(255,255,255,0.025) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.025) 1px, transparent 1px);
    background-size: 30px 30px;
    -webkit-font-smoothing: antialiased;
    font-size: 14px;
}

/* ── Scanline ─────────────────────────────────────────────────────────── */
.scanline {
    position: fixed;
    inset: 0;
    background: linear-gradient(to bottom, rgba(255,255,255,0) 50%, rgba(0,0,0,0.14) 50%);
    background-size: 100% 4px;
    pointer-events: none;
    z-index: 100;
    opacity: 0.18;
}

/* ── Header ───────────────────────────────────────────────────────────── */
.app-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.875rem 1.5rem;
    border-bottom: 1px solid var(--border);
    position: relative;
    z-index: 10;
    flex-shrink: 0;
}

.back-link, .feedback-link {
    color: var(--text-muted);
    transition: color 0.2s;
    text-decoration: none;
    display: flex;
    align-items: center;
}
.back-link:hover, .feedback-link:hover { color: #fff; }

.app-title {
    font-size: 1.0625rem;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: #fff;
    margin: 0;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.status-indicator {
    font-size: 0.6rem;
    color: rgba(16,185,129,.8);
    text-transform: uppercase;
    letter-spacing: -.04em;
}
.status-indicator.error  { color: rgba(239,68,68,.8); }
.status-indicator.active { animation: blink 1.8s infinite; }
@keyframes blink { 0%,100%{opacity:1} 50%{opacity:.35} }

/* ── Main Container ───────────────────────────────────────────────────── */
.app-container {
    flex: 1;
    width: 100%;
    max-width: 1600px;
    margin: 0 auto;
    padding: 1.25rem 1.5rem 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    position: relative;
    z-index: 10;
}

/* ── Editors Row ──────────────────────────────────────────────────────── */
.editors-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    flex-shrink: 0;
}

@media (max-width: 700px) {
    .editors-row { grid-template-columns: 1fr; }
}

/* ── Editor Panel ─────────────────────────────────────────────────────── */
.editor-panel {
    background: var(--bg-panel);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    transition: border-color 0.25s;
    min-height: 220px;
}
.editor-panel:focus-within { border-color: var(--border-hover); }

.panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.5rem 0.875rem;
    background: rgba(0,0,0,0.25);
    border-bottom: 1px solid var(--border);
    gap: 0.5rem;
    flex-shrink: 0;
}

.panel-label {
    display: flex;
    align-items: center;
    gap: 0.375rem;
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
}
.panel-label i { width: 13px; height: 13px; }

.panel-actions {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.editor-panel textarea {
    flex: 1;
    background: transparent;
    color: #e5e7eb;
    border: none;
    padding: 0.875rem 1rem;
    font-family: inherit;
    font-size: 0.8125rem;
    line-height: 1.55;
    resize: none;
    outline: none;
    white-space: pre;
    tab-size: 2;
    min-height: 160px;
}
.editor-panel textarea::placeholder { color: #374151; }

/* drag-over highlight */
.editor-panel textarea.drag-over {
    background: rgba(16, 185, 129, 0.06);
}

.panel-footer {
    padding: 0.25rem 0.875rem;
    background: rgba(0,0,0,0.18);
    border-top: 1px solid var(--border);
    flex-shrink: 0;
}

.char-count {
    font-size: 0.65rem;
    color: var(--border-hover);
}

/* ── Toolbar ──────────────────────────────────────────────────────────── */
.diff-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    flex-wrap: wrap;
    flex-shrink: 0;
}

.toolbar-left, .toolbar-right {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.toolbar-divider {
    width: 1px;
    height: 1.1rem;
    background: var(--border);
    margin: 0 0.25rem;
}

/* ── Icon Buttons ─────────────────────────────────────────────────────── */
.icon-button {
    background: transparent;
    color: var(--fg);
    border: 1px solid transparent;
    border-radius: 0.375rem;
    padding: 0.3125rem 0.5rem;
    font-family: inherit;
    font-size: 0.7rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    transition: all 0.18s;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    line-height: 1;
    user-select: none;
}
.icon-button:hover {
    background: rgba(255,255,255,0.05);
    border-color: var(--border-hover);
    color: #fff;
}
.icon-button:active { transform: scale(0.97); }
.icon-button i { width: 13px; height: 13px; }

.icon-button.primary {
    background: rgba(16,185,129,0.12);
    border-color: rgba(16,185,129,0.35);
    color: var(--accent);
}
.icon-button.primary:hover {
    background: rgba(16,185,129,0.2);
    border-color: var(--accent);
    color: #fff;
}

/* Treat label like button for file inputs */
label.icon-button { cursor: pointer; }
.file-input-hidden {
    position: absolute;
    width: 0; height: 0;
    opacity: 0;
    pointer-events: none;
}

/* ── Mode Group ───────────────────────────────────────────────────────── */
.mode-label {
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
}

.mode-group {
    display: flex;
    border: 1px solid var(--border);
    border-radius: 0.375rem;
    overflow: hidden;
}

.mode-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-family: inherit;
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    padding: 0.3rem 0.65rem;
    cursor: pointer;
    transition: all 0.18s;
    line-height: 1;
}
.mode-btn + .mode-btn { border-left: 1px solid var(--border); }
.mode-btn:hover { color: #fff; background: rgba(255,255,255,0.04); }
.mode-btn.active {
    background: rgba(16,185,129,0.15);
    color: var(--accent);
}

/* ── Checkboxes ───────────────────────────────────────────────────────── */
.check-label {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--text-muted);
    cursor: pointer;
    user-select: none;
    transition: color 0.18s;
}
.check-label:hover { color: #fff; }
.check-label input[type="checkbox"] {
    accent-color: var(--accent);
    width: 11px;
    height: 11px;
    cursor: pointer;
}

/* ── Stats Pill ───────────────────────────────────────────────────────── */
.stats-pill {
    font-size: 0.65rem;
    color: var(--text-muted);
    letter-spacing: 0.04em;
    display: flex;
    align-items: center;
    gap: 0.6rem;
}
.stats-pill .stat-add  { color: var(--accent); }
.stats-pill .stat-del  { color: var(--danger); }
.stats-pill .stat-same { color: var(--text-muted); }

/* ── Output Panel ─────────────────────────────────────────────────────── */
.output-panel {
    background: var(--bg-panel);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    overflow: hidden;
    flex: 1;
    min-height: 260px;
    display: flex;
    flex-direction: column;
}

.output-placeholder {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    color: var(--text-muted);
}
.output-placeholder p {
    font-size: 0.8rem;
    margin: 0;
}
.output-placeholder kbd {
    background: rgba(255,255,255,0.07);
    border: 1px solid var(--border-hover);
    border-radius: 0.25rem;
    padding: 0.1em 0.4em;
    font-family: inherit;
    font-size: 0.75em;
}

/* ── Diff Output ──────────────────────────────────────────────────────── */
.diff-output {
    flex: 1;
    overflow: auto;
    font-size: 0.8125rem;
    line-height: 1.55;
}

/* ── Unified Diff ─────────────────────────────────────────────────────── */
.diff-table {
    width: 100%;
    border-collapse: collapse;
    table-layout: fixed;
}

.diff-table .gutter {
    width: 40px;
    min-width: 40px;
    padding: 0 0.5rem;
    text-align: right;
    color: var(--border-hover);
    font-size: 0.7rem;
    user-select: none;
    vertical-align: top;
    white-space: nowrap;
}
.diff-table .sign {
    width: 22px;
    min-width: 22px;
    padding: 0 0.25rem;
    text-align: center;
    font-weight: 700;
    user-select: none;
    vertical-align: top;
}
.diff-table .content {
    padding: 0 0.75rem 0 0.25rem;
    white-space: pre-wrap;
    word-break: break-all;
    vertical-align: top;
}

/* unified: single gutter + sign */
.diff-row { transition: background 0.1s; }
.diff-row.add    { background: var(--diff-add-bg); }
.diff-row.del    { background: var(--diff-del-bg); }
.diff-row.hunk   { background: var(--diff-hunk-bg); }
.diff-row.ctx    {}

.diff-row.add .gutter  { border-left: 2px solid var(--diff-add-gutter); color: var(--diff-add-text); }
.diff-row.del .gutter  { border-left: 2px solid var(--diff-del-gutter); color: var(--diff-del-text); }
.diff-row.hunk .gutter { border-left: 2px solid rgba(59,130,246,0.3); }
.diff-row.ctx  .gutter { border-left: 2px solid transparent; }

.diff-row.add .sign  { color: var(--diff-add-text); }
.diff-row.del .sign  { color: var(--diff-del-text); }
.diff-row.hunk .sign { color: var(--diff-hunk-text); }

.diff-row.add  .content { color: var(--diff-ctx-text); }
.diff-row.del  .content { color: var(--diff-ctx-text); }
.diff-row.hunk .content { color: var(--diff-hunk-text); font-style: italic; }
.diff-row.ctx  .content { color: #9ca3af; }

/* ── Split Diff ──────────────────────────────────────────────────────── */
.split-table {
    width: 100%;
    border-collapse: collapse;
    table-layout: fixed;
}
.split-table .split-gutter {
    width: 36px;
    min-width: 36px;
    padding: 0 0.4rem;
    text-align: right;
    color: var(--border-hover);
    font-size: 0.7rem;
    user-select: none;
    white-space: nowrap;
    vertical-align: top;
}
.split-table .split-content {
    padding: 0 0.6rem;
    white-space: pre-wrap;
    word-break: break-all;
    vertical-align: top;
}
.split-divider {
    width: 1px;
    background: var(--border);
    padding: 0;
}
.split-row td { line-height: 1.55; }
.split-row .left-add  { background: var(--diff-add-bg); }
.split-row .left-del  { background: var(--diff-del-bg); }
.split-row .right-add { background: var(--diff-add-bg); }
.split-row .right-del { background: var(--diff-del-bg); }
.split-row .hunk-cell { background: var(--diff-hunk-bg); color: var(--diff-hunk-text); font-style: italic; }
.split-row .split-gutter.add { border-left: 2px solid var(--diff-add-gutter); color: var(--diff-add-text); }
.split-row .split-gutter.del { border-left: 2px solid var(--diff-del-gutter); color: var(--diff-del-text); }
.split-row .split-gutter.ctx { border-left: 2px solid transparent; }
.split-row .split-gutter.hunk { border-left: 2px solid rgba(59,130,246,0.3); }

/* Inline character-level highlight */
.diff-ins-char { background: rgba(16,185,129,0.35); border-radius: 2px; }
.diff-del-char { background: rgba(239,68,68,0.35); border-radius: 2px; }

/* ── Identical Banner ─────────────────────────────────────────────────── */
.identical-banner {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 2.5rem 1rem;
    color: var(--accent);
}
.identical-banner i { width: 28px; height: 28px; }
.identical-banner p { margin: 0; font-size: 0.875rem; }

/* ── Scrollbars ───────────────────────────────────────────────────────── */
::-webkit-scrollbar          { width: 7px; height: 7px; }
::-webkit-scrollbar-track    { background: transparent; }
::-webkit-scrollbar-thumb    { background: var(--border-hover); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: #4b5563; }