/* Diff Checker */
.tool-interface { padding: var(--spacing-2xl) 0; }

/* Controls */
.diff-controls {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--color-background-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
}
.diff-control-group { display: flex; align-items: center; gap: var(--spacing-sm); }
.diff-control-group--actions { margin-left: auto; gap: var(--spacing-sm); flex-wrap: wrap; }
.diff-label { font-size: var(--font-size-sm); font-weight: 600; color: var(--color-text-light); white-space: nowrap; }
.diff-toggle-label { display: flex; align-items: center; gap: 6px; font-size: var(--font-size-sm); color: var(--color-text-light); cursor: pointer; white-space: nowrap; }
.diff-toggle-label input { accent-color: var(--color-primary); width: 14px; height: 14px; cursor: pointer; }

.seg-buttons { display: flex; border: 1px solid var(--color-border); border-radius: var(--radius-sm); overflow: hidden; }
.seg-btn {
    padding: 5px 14px;
    font-size: var(--font-size-sm);
    background: var(--color-background);
    border: none;
    cursor: pointer;
    color: var(--color-text-light);
    transition: all var(--transition-fast);
    border-right: 1px solid var(--color-border);
}
.seg-btn:last-child { border-right: none; }
.seg-btn.active { background: var(--color-primary); color: #fff; }
.seg-btn:hover:not(.active) { background: var(--color-background-alt); }

.btn-sm { padding: 5px 12px; font-size: var(--font-size-sm); }

/* Stats bar */
.diff-stats {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-md);
    font-size: var(--font-size-sm);
    font-weight: 600;
}
.stat { padding: 3px 12px; border-radius: 20px; }
.stat--added   { background: rgba(34,197,94,.15);  color: #15803d; }
.stat--removed { background: rgba(239,68,68,.12);  color: #b91c1c; }
.stat--changed { background: rgba(234,179,8,.15);  color: #a16207; }
.stat--same    { background: var(--color-background-alt); color: var(--color-text-light); }

/* Editor split */
.diff-editor-split {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}
.diff-pane { display: flex; flex-direction: column; }
.diff-pane-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-sm);
}
.diff-pane-label {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--color-text-light);
    text-transform: uppercase;
    letter-spacing: .05em;
}
.diff-paste-btn {
    font-size: 11px;
    padding: 2px 9px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    background: var(--color-background);
    color: var(--color-text-light);
    cursor: pointer;
    transition: all var(--transition-fast);
}
.diff-paste-btn:hover { border-color: var(--color-primary); color: var(--color-primary); }

.diff-textarea {
    width: 100%;
    min-height: 280px;
    padding: var(--spacing-md);
    font-family: 'JetBrains Mono', monospace;
    font-size: 13px;
    line-height: 1.6;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-background-alt);
    color: var(--color-text);
    resize: vertical;
    tab-size: 2;
}
.diff-textarea:focus { outline: none; border-color: var(--color-primary); }

/* Output */
.diff-output-wrap {
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    overflow: hidden;
    margin-bottom: var(--spacing-md);
}
.diff-output-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-background-alt);
    border-bottom: 1px solid var(--color-border);
}
.diff-output-title { font-size: var(--font-size-sm); font-weight: 700; flex: 1; }
.diff-legend { display: flex; gap: var(--spacing-md); font-size: 12px; }
.legend-added   { color: #15803d; font-weight: 600; }
.legend-removed { color: #b91c1c; font-weight: 600; }
.legend-changed { color: #a16207; font-weight: 600; }

.diff-output {
    font-family: 'JetBrains Mono', monospace;
    font-size: 12.5px;
    line-height: 1.55;
    overflow-x: auto;
    max-height: 600px;
    overflow-y: auto;
}

/* Line mode rows */
.diff-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    min-width: 0;
}
.diff-row:hover .diff-line { filter: brightness(1.05); }

.diff-line {
    display: flex;
    align-items: baseline;
    padding: 1px 0;
    min-width: 0;
    overflow: hidden;
}
.diff-line code {
    font-family: inherit;
    font-size: inherit;
    white-space: pre;
    flex: 1;
    min-width: 0;
    overflow-x: auto;
}
.diff-line--same  { background: transparent; }
.diff-line--del   { background: rgba(239,68,68,.10); }
.diff-line--add   { background: rgba(34,197,94,.10); }
.diff-line--empty { background: var(--color-background-alt); opacity: .4; }

.ln {
    display: inline-block;
    min-width: 38px;
    padding: 0 8px;
    text-align: right;
    color: var(--color-text-light);
    opacity: .6;
    font-size: 11px;
    user-select: none;
    flex-shrink: 0;
    border-right: 1px solid var(--color-border);
    margin-right: 8px;
}
.ln--empty { min-width: 38px; border-right: 1px solid var(--color-border); margin-right: 8px; }

.diff-sign {
    width: 14px;
    flex-shrink: 0;
    font-weight: 700;
    opacity: .7;
    user-select: none;
}
.diff-line--del  .diff-sign { color: #ef4444; }
.diff-line--add  .diff-sign { color: #22c55e; }

/* Inline word/char highlights within changed lines */
mark.diff-mark-del { background: rgba(239,68,68,.30); border-radius: 2px; padding: 0 1px; font-style: normal; }
mark.diff-mark-add { background: rgba(34,197,94,.30);  border-radius: 2px; padding: 0 1px; font-style: normal; }

/* Word / char inline mode */
.diff-inline-wrap {
    padding: var(--spacing-lg);
    white-space: pre-wrap;
    word-break: break-all;
}
.diff-same        { color: var(--color-text); }
.diff-add-inline  { background: rgba(34,197,94,.20);  color: #15803d; border-radius: 2px; }
.diff-del-inline  { background: rgba(239,68,68,.15);  color: #b91c1c; text-decoration: line-through; border-radius: 2px; }

.diff-identical { color: var(--color-text-light); padding: var(--spacing-xl); text-align: center; font-style: italic; }

/* Status / hint */
.status-message { padding: var(--spacing-sm) var(--spacing-md); border-radius: var(--radius-md); margin-top: var(--spacing-sm); min-height: 32px; font-size: var(--font-size-sm); }
.status-message.success { background: rgba(34,197,94,.12); color: #15803d; border: 1px solid rgba(34,197,94,.3); }
.status-message.error   { background: rgba(239,68,68,.10); color: #b91c1c; border: 1px solid rgba(239,68,68,.3); }

.diff-hint { font-size: var(--font-size-sm); color: var(--color-text-light); text-align: right; margin-top: var(--spacing-sm); }
.diff-hint kbd { display: inline-block; padding: 1px 5px; font-size: 11px; font-family: 'JetBrains Mono',monospace; border: 1px solid var(--color-border); border-radius: 3px; background: var(--color-background); }

/* Info section */
.info-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px,1fr)); gap: var(--spacing-xl); margin-top: var(--spacing-xl); }
.info-card { background: var(--color-background-alt); padding: var(--spacing-xl); border-radius: var(--radius-lg); }
.info-card h3 { margin-bottom: var(--spacing-md); color: var(--color-primary); }
.info-card ul { padding-left: var(--spacing-lg); display: flex; flex-direction: column; gap: 6px; }
.info-card li { font-size: var(--font-size-sm); color: var(--color-text-light); }
.related-tools { padding: var(--spacing-2xl) 0; }
.related-tools .tools-grid { display: grid; grid-template-columns: repeat(auto-fit,minmax(240px,1fr)); gap: var(--spacing-lg); margin-top: var(--spacing-xl); }
.visually-hidden { position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0; }

/* Responsive */
@media (max-width: 860px) {
    .diff-editor-split { grid-template-columns: 1fr; }
    .diff-row { grid-template-columns: 1fr; }
    .diff-line--empty { display: none; }
    .diff-output-header { flex-wrap: wrap; }
    .diff-legend { display: none; }
    .diff-control-group--actions { margin-left: 0; width: 100%; }
    .diff-controls { flex-direction: column; align-items: flex-start; }
}