:root {
    --opn-bg: #f7f8fa;
    --opn-panel: #ffffff;
    --opn-panel-soft: #fbfbfc;
    --opn-border: #dfe3e8;
    --opn-text: #1f2933;
    --opn-muted: #6b7280;
    --opn-accent: #2563eb;
    --opn-danger: #b91c1c;
    --opn-shadow: 0 18px 42px rgba(15, 23, 42, .08);
}

[data-theme="dark"] {
    --opn-bg: #111827;
    --opn-panel: #182230;
    --opn-panel-soft: #141c28;
    --opn-border: #2f3a4a;
    --opn-text: #eef2f7;
    --opn-muted: #a7b0bd;
    --opn-accent: #7aa2ff;
    --opn-danger: #f87171;
    --opn-shadow: 0 18px 42px rgba(0,0,0,.24);
}

* { box-sizing: border-box; }
body { margin: 0; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; background: var(--opn-bg); color: var(--opn-text); }
a { color: inherit; text-decoration: none; }

.opn-install { min-height: 100vh; display: grid; place-items: center; padding: 24px; }
.opn-install-card { width: min(560px, 100%); background: var(--opn-panel); border: 1px solid var(--opn-border); box-shadow: var(--opn-shadow); padding: 30px; border-radius: 4px; }
.opn-brand { display: flex; justify-content: space-between; align-items: baseline; font-weight: 700; letter-spacing: -.02em; margin-bottom: 22px; }
.opn-brand span { color: var(--opn-muted); font-size: 13px; font-weight: 500; }
h1 { margin: 0 0 12px; font-size: 28px; letter-spacing: -.03em; }
.opn-muted { color: var(--opn-muted); line-height: 1.55; }
label { display: block; font-size: 13px; color: var(--opn-muted); margin: 14px 0; }
input, textarea, select { width: 100%; border: 1px solid var(--opn-border); background: var(--opn-panel); color: var(--opn-text); border-radius: 3px; padding: 11px 12px; font: inherit; outline: none; }
input:focus, textarea:focus, select:focus { border-color: var(--opn-accent); box-shadow: 0 0 0 2px rgba(37, 99, 235, .12); }
hr { border: 0; border-top: 1px solid var(--opn-border); margin: 22px 0; }
code { background: var(--opn-panel-soft); border: 1px solid var(--opn-border); padding: 2px 5px; border-radius: 3px; }
.opn-alert { border-left: 3px solid var(--opn-danger); background: rgba(185, 28, 28, .08); padding: 11px 12px; margin: 12px 0; color: var(--opn-text); }
.opn-button, button, .opn-toolbar-button { cursor: pointer; border: 1px solid var(--opn-border); background: var(--opn-panel); color: var(--opn-text); border-radius: 3px; padding: 9px 12px; font: inherit; }
.opn-button { display: inline-block; background: var(--opn-accent); border-color: var(--opn-accent); color: white; font-weight: 650; margin-top: 10px; }

.opn-app-shell { overflow: hidden; }
.opn-app { height: 100vh; display: grid; grid-template-columns: 340px 1fr; background: var(--opn-bg); }
.opn-sidebar { background: var(--opn-panel); border-right: 1px solid var(--opn-border); min-width: 0; display: flex; flex-direction: column; }
.opn-sidebar-head { height: 60px; border-bottom: 1px solid var(--opn-border); display: flex; align-items: center; justify-content: space-between; padding: 0 14px 0 18px; }
.opn-sidebar-head strong { font-size: 18px; letter-spacing: -.02em; }
.opn-sidebar-head span { display: block; font-size: 12px; color: var(--opn-muted); margin-top: 2px; }
.opn-icon-button { width: 34px; height: 34px; display: inline-grid; place-items: center; padding: 0; font-size: 20px; }
.opn-icon-button.active, .opn-toolbar-button.active { border-color: var(--opn-accent); color: var(--opn-accent); background: rgba(37, 99, 235, .08); }
.opn-search-wrap { padding: 12px; border-bottom: 1px solid var(--opn-border); }
.opn-list { overflow: auto; flex: 1; }
.opn-note-row { padding: 13px 16px; border-bottom: 1px solid var(--opn-border); cursor: pointer; background: var(--opn-panel); }
.opn-note-row:hover, .opn-note-row.active { background: var(--opn-panel-soft); }
.opn-note-title { font-weight: 650; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; margin-bottom: 5px; }
.opn-note-snippet { color: var(--opn-muted); font-size: 13px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.opn-pin-mark { color: var(--opn-accent); margin-right: 6px; }

.opn-editor-pane { display: flex; flex-direction: column; min-width: 0; }
.opn-editor-toolbar { height: 60px; border-bottom: 1px solid var(--opn-border); background: var(--opn-panel); display: flex; align-items: center; gap: 8px; padding: 0 12px; }
.opn-toolbar-button { font-size: 13px; }
.opn-toolbar-button.danger { color: var(--opn-danger); }
.opn-save-state { margin-left: auto; color: var(--opn-muted); font-size: 13px; }
.opn-editor-area { position: relative; flex: 1; min-height: 0; }
#opn-body { height: 100%; border: 0; border-radius: 0; resize: none; padding: 34px min(8vw, 84px); font-size: 18px; line-height: 1.68; background: var(--opn-panel); box-shadow: none; }
#opn-body:focus { box-shadow: none; }
.opn-rendered { height: 100%; overflow: auto; padding: 34px min(8vw, 84px); background: var(--opn-panel); font-size: 18px; line-height: 1.68; }
.opn-rendered h1, .opn-rendered h2, .opn-rendered h3 { letter-spacing: -.03em; }
.hidden { display: none !important; }
.opn-mobile-only { display: none; }

@media (max-width: 760px) {
    .opn-app { grid-template-columns: 1fr; }
    .opn-sidebar { position: fixed; z-index: 20; inset: 0 auto 0 0; width: 86vw; transform: translateX(-100%); transition: transform .18s ease; box-shadow: var(--opn-shadow); }
    .opn-app.sidebar-open .opn-sidebar { transform: translateX(0); }
    .opn-mobile-only { display: inline-grid; }
    #opn-body, .opn-rendered { padding: 22px; font-size: 16px; }
    .opn-editor-toolbar { overflow-x: auto; }
    .opn-save-state { margin-left: 0; }
}

.opn-system-body { min-height: 100vh; background: var(--opn-bg); padding: 28px; }
.opn-system-wrap { max-width: 1120px; margin: 0 auto; }
.opn-system-header { display: flex; align-items: flex-start; justify-content: space-between; gap: 18px; margin-bottom: 18px; }
.opn-system-header .opn-brand { margin-bottom: 10px; }
.opn-system-actions { display: flex; gap: 8px; flex-wrap: wrap; }
.opn-system-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; margin-bottom: 16px; }
.opn-system-card { background: var(--opn-panel); border: 1px solid var(--opn-border); border-radius: 4px; box-shadow: var(--opn-shadow); padding: 20px; }
.opn-system-card h2 { margin: 0 0 12px; font-size: 18px; letter-spacing: -.02em; }
.opn-system-card h3 { margin: 0 0 10px; font-size: 15px; letter-spacing: -.01em; }
.opn-wide-card { margin-bottom: 18px; }
.opn-detected-packages { margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--opn-border); }
.opn-status-list { margin: 0; }
.opn-status-list div { display: flex; justify-content: space-between; gap: 18px; padding: 10px 0; border-bottom: 1px solid var(--opn-border); }
.opn-status-list div:last-child { border-bottom: 0; }
.opn-status-list dt { color: var(--opn-muted); }
.opn-status-list dd { margin: 0; font-weight: 650; text-align: right; }
.opn-path-code { display: block; margin: 10px 0 14px; padding: 11px 12px; overflow-x: auto; }
.opn-mini-note { margin-top: 12px; border-left: 3px solid var(--opn-accent); background: rgba(37, 99, 235, .08); padding: 11px 12px; color: var(--opn-text); }
.opn-package-list { display: grid; gap: 10px; }
.opn-package-row { display: flex; align-items: center; justify-content: space-between; gap: 18px; border: 1px solid var(--opn-border); background: var(--opn-panel-soft); padding: 14px; border-radius: 4px; }
.opn-package-row p { margin: 6px 0; }
.opn-size-label { color: var(--opn-muted); font-size: 12px; }
.opn-alert-good { border-left-color: #15803d; background: rgba(21, 128, 61, .10); }
button:disabled, .opn-button:disabled { opacity: .45; cursor: not-allowed; }

@media (max-width: 760px) {
    .opn-system-body { padding: 16px; }
    .opn-system-header, .opn-package-row { flex-direction: column; align-items: stretch; }
    .opn-system-grid { grid-template-columns: 1fr; }
    .opn-status-list div { flex-direction: column; gap: 4px; }
    .opn-status-list dd { text-align: left; }
}


.opn-upload-form {
    margin: 18px 0 12px;
    padding: 14px;
    border: 1px solid var(--opn-border);
    background: var(--opn-panel-soft);
    border-radius: 3px;
}
.opn-upload-form label {
    display: block;
    font-weight: 700;
    margin-bottom: 10px;
}
.opn-upload-row {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 10px;
    align-items: stretch;
}
.opn-upload-row input[type=file] {
    width: 100%;
    min-width: 0;
    padding: 10px;
    border: 1px solid var(--opn-border);
    border-radius: 3px;
    background: var(--opn-panel);
}
.opn-upload-button {
    min-width: 118px;
    justify-content: center;
    white-space: nowrap;
}
@media (max-width: 560px) {
    .opn-upload-row { grid-template-columns: 1fr; }
    .opn-upload-button { width: 100%; }
}

/* v0.5 Tags foundation */
.opn-tag-panel {
    border-bottom: 1px solid var(--opn-border);
    padding: 10px 12px 12px;
    background: var(--opn-panel);
}
.opn-tag-panel-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    margin-bottom: 8px;
    color: var(--opn-muted);
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: .04em;
}
.opn-tag-clear {
    padding: 3px 7px;
    font-size: 12px;
    border-radius: 3px;
}
.opn-tags-list {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    max-height: 112px;
    overflow: auto;
}
.opn-tags-empty {
    color: var(--opn-muted);
    font-size: 13px;
}
.opn-tag-filter {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 5px 8px;
    font-size: 13px;
    line-height: 1.2;
    border-radius: 3px;
    background: var(--opn-panel-soft);
}
.opn-tag-filter small {
    color: var(--opn-muted);
    font-size: 11px;
}
.opn-tag-filter.active {
    border-color: var(--opn-accent);
    color: var(--opn-accent);
    background: rgba(37, 99, 235, .08);
}
.opn-row-tags {
    display: flex;
    gap: 5px;
    flex-wrap: wrap;
    margin-top: 8px;
}
.opn-tag-badge {
    display: inline-block;
    max-width: 110px;
    padding: 2px 6px;
    border: 1px solid var(--opn-border);
    border-radius: 3px;
    color: var(--opn-muted);
    font-size: 11px;
    line-height: 1.35;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    background: var(--opn-panel-soft);
}
.opn-editor-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    min-height: 54px;
    padding: 9px 14px;
    border-bottom: 1px solid var(--opn-border);
    background: var(--opn-panel);
}
.opn-editor-meta label {
    width: auto;
    margin: 0;
    color: var(--opn-muted);
    font-size: 13px;
    font-weight: 700;
}
#opn-tags-input {
    margin: 0;
    flex: 1;
    min-width: 0;
    box-shadow: none;
    background: var(--opn-panel-soft);
}
#opn-tags-input:disabled {
    opacity: .55;
}
.opn-editor-pane {
    min-height: 0;
}
@media (max-width: 760px) {
    .opn-tags-list { max-height: 88px; }
    .opn-editor-meta { align-items: stretch; flex-direction: column; gap: 6px; }
}

/* v0.6 Tags UI / System Header Hotfix */
.opn-editor-toolbar {
    gap: 6px;
}
.opn-icon-label {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    min-height: 34px;
    padding: 7px 10px;
    line-height: 1;
}
.opn-icon-label span {
    display: inline-block;
    min-width: 16px;
    text-align: center;
    font-size: 15px;
    line-height: 1;
}
.opn-icon-label em {
    font-style: normal;
    font-size: 12px;
}
.opn-save-state {
    min-width: 86px;
    text-align: right;
}
.opn-brand-system {
    display: block;
    justify-content: initial;
    margin-bottom: 10px;
}
.opn-system-actions {
    align-items: center;
    gap: 14px;
}
.opn-action-divider {
    width: 1px;
    height: 30px;
    background: var(--opn-border);
    display: inline-block;
}
.opn-back-button {
    padding-left: 13px;
    padding-right: 13px;
}
.opn-logout-button {
    color: var(--opn-muted);
}
.opn-tag-panel {
    padding-left: 14px;
    padding-right: 14px;
}
.opn-tag-panel-head {
    font-size: 13px;
    text-transform: none;
    letter-spacing: 0;
}
.opn-tag-clear {
    padding: 4px 8px;
    font-size: 12px;
    color: var(--opn-accent);
    border-color: rgba(37, 99, 235, .35);
    background: rgba(37, 99, 235, .08);
}
.opn-tags-list {
    gap: 7px;
    padding: 1px 0 2px;
}
.opn-tag-filter {
    min-height: 30px;
    padding: 6px 10px;
    gap: 7px;
    max-width: 100%;
}
.opn-tag-filter span {
    display: inline-block;
    max-width: 150px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.opn-tag-filter small {
    padding-left: 4px;
    border-left: 1px solid var(--opn-border);
}
.opn-editor-meta {
    padding-left: 18px;
    padding-right: 18px;
}
#opn-tags-input {
    padding-left: 13px;
    padding-right: 13px;
}
@media (max-width: 760px) {
    .opn-icon-label em { display: none; }
    .opn-icon-label { min-width: 34px; justify-content: center; }
    .opn-save-state { min-width: auto; text-align: left; }
    .opn-system-actions { width: 100%; justify-content: space-between; }
    .opn-action-divider { display: none; }
}


/* v0.8 Tag Manager + monochrome line icons */
.opn-icon-button svg,
.opn-icon-label svg {
    width: 17px;
    height: 17px;
    stroke: currentColor;
    stroke-width: 1.8;
    fill: none;
    stroke-linecap: round;
    stroke-linejoin: round;
    flex: 0 0 auto;
}
.opn-icon-button svg { width: 18px; height: 18px; }
.opn-icon-label {
    color: var(--opn-text);
}
.opn-icon-label.danger,
.opn-toolbar-button.danger {
    color: var(--opn-danger);
}
.opn-icon-label em {
    font-size: 13px;
}
.opn-tags-list {
    gap: 7px;
    max-height: 128px;
}
.opn-tag-filter {
    border: 1px solid var(--opn-border);
    background: var(--opn-panel-soft);
}
.opn-tag-filter.active {
    border-color: var(--opn-accent);
}
.opn-tag-manager-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
}
.opn-tag-manager-table th,
.opn-tag-manager-table td {
    padding: 10px 8px;
    border-bottom: 1px solid var(--opn-border);
    text-align: left;
    vertical-align: middle;
}
.opn-tag-manager-table th {
    color: var(--opn-muted);
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: .04em;
}
.opn-tag-manager-table td:last-child,
.opn-tag-manager-table th:last-child {
    text-align: right;
}
.opn-tag-manager-table form {
    margin: 0;
}
.opn-button-danger {
    color: var(--opn-danger);
    border-color: rgba(185, 28, 28, .35);
    background: var(--opn-panel);
}
.opn-button-danger:hover,
.opn-button-danger:focus {
    background: rgba(185, 28, 28, .08);
}
.opn-system-subgrid {
    display: grid;
    gap: 16px;
    margin-bottom: 16px;
}
@media (max-width: 760px) {
    .opn-tag-manager-table,
    .opn-tag-manager-table tbody,
    .opn-tag-manager-table tr,
    .opn-tag-manager-table td {
        display: block;
        width: 100%;
    }
    .opn-tag-manager-table thead { display: none; }
    .opn-tag-manager-table tr { padding: 10px 0; border-bottom: 1px solid var(--opn-border); }
    .opn-tag-manager-table td { border-bottom: 0; padding: 4px 0; }
    .opn-tag-manager-table td:last-child { text-align: left; padding-top: 8px; }
}


/* v0.9 Instant tag delete + refined native line icons */
.opn-icon-button,
.opn-icon-label {
    color: var(--opn-text);
}
.opn-icon-button svg,
.opn-icon-label svg {
    width: 16px;
    height: 16px;
    stroke-width: 1.65;
    opacity: .92;
}
.opn-icon-button:hover svg,
.opn-icon-label:hover svg,
.opn-icon-label:focus svg {
    opacity: 1;
}
.opn-icon-label {
    gap: 7px;
    min-height: 34px;
    padding: 7px 11px;
}
.opn-icon-label em {
    font-size: 13px;
    letter-spacing: -.01em;
}
.opn-icon-label.danger svg,
.opn-toolbar-button.danger svg {
    color: var(--opn-text);
}
.opn-toolbar-button.danger em,
.opn-toolbar-button.danger {
    color: var(--opn-danger);
}
.opn-tag-manager-table .opn-button-danger {
    padding: 7px 10px;
    font-size: 13px;
}
.opn-tag-manager-note {
    margin-top: -4px;
    margin-bottom: 14px;
}

/* v0.10 System tabs + in-place tag delete */
.opn-system-tabs {
    display: flex;
    align-items: stretch;
    gap: 0;
    margin: 12px 0 16px;
    border: 1px solid var(--opn-border);
    background: var(--opn-panel-soft);
    border-radius: 4px;
    padding: 4px;
    box-shadow: 0 10px 24px rgba(15, 23, 42, .04);
}
.opn-system-tab {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 36px;
    padding: 8px 14px;
    border-radius: 3px;
    color: var(--opn-muted);
    font-weight: 650;
    font-size: 14px;
}
.opn-system-tab:hover,
.opn-system-tab:focus {
    color: var(--opn-text);
    background: var(--opn-panel);
}
.opn-system-tab.active {
    color: var(--opn-text);
    background: var(--opn-panel);
    border: 1px solid var(--opn-border);
    box-shadow: 0 6px 16px rgba(15, 23, 42, .05);
}
.opn-system-notice-wrap:empty {
    display: none;
}
.opn-tag-delete-form .opn-button-danger:disabled {
    opacity: .55;
}
@media (max-width: 760px) {
    .opn-system-tabs { width: 100%; }
    .opn-system-tab { flex: 1; }
}


/* v0.12 Upload row alignment hotfix */
.opn-upload-row {
    grid-template-columns: minmax(0, 1fr) 150px;
    gap: 8px;
    align-items: stretch;
}
.opn-upload-row input[type=file],
.opn-upload-row .opn-upload-button {
    height: 48px;
    min-height: 48px;
    margin: 0;
}
.opn-upload-row input[type=file] {
    display: block;
    padding: 9px 10px;
    line-height: 28px;
}
.opn-upload-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 150px;
    min-width: 150px;
    padding: 0 16px;
    line-height: 1;
}
@media (max-width: 560px) {
    .opn-upload-row { grid-template-columns: 1fr; }
    .opn-upload-button { width: 100%; min-width: 0; }
}


/* v0.13 UI polish + note type foundation */
.opn-editor-toolbar {
    min-height: 62px;
    height: 62px;
    padding: 0 18px;
    gap: 10px;
}
.opn-toolbar-button,
.opn-icon-button {
    transition: border-color .15s ease, background .15s ease, color .15s ease, opacity .15s ease;
}
.opn-icon-label {
    min-height: 38px;
    padding: 8px 12px;
    border-color: var(--opn-border);
    background: var(--opn-panel-soft);
}
.opn-icon-label:hover,
.opn-icon-button:hover {
    background: var(--opn-panel);
    border-color: color-mix(in srgb, var(--opn-border) 55%, var(--opn-text));
}
.opn-icon-label svg,
.opn-icon-button svg {
    stroke-linecap: round;
    stroke-linejoin: round;
}
.opn-editor-meta-structured {
    display: grid;
    grid-template-columns: 170px minmax(0, 1fr);
    gap: 14px;
    min-height: 64px;
    padding: 10px 18px;
}
.opn-meta-field {
    display: flex;
    align-items: center;
    gap: 10px;
    min-width: 0;
}
.opn-meta-field label {
    flex: 0 0 auto;
}
.opn-tags-field input,
.opn-note-type-field select {
    height: 40px;
}
.opn-note-type-field select {
    min-width: 112px;
    padding: 8px 26px 8px 10px;
    background: var(--opn-panel-soft);
    color: var(--opn-text);
    border: 1px solid var(--opn-border);
    border-radius: 3px;
    font: inherit;
    font-size: 13px;
}
.opn-row-meta {
    display: flex;
    gap: 5px;
    flex-wrap: wrap;
    margin-top: 8px;
    align-items: center;
}
.opn-type-badge {
    display: inline-flex;
    align-items: center;
    min-height: 19px;
    padding: 2px 6px;
    border: 1px solid var(--opn-border);
    border-radius: 3px;
    color: var(--opn-muted);
    background: var(--opn-panel-soft);
    font-size: 11px;
    line-height: 1.25;
    font-weight: 650;
}
#opn-body[data-note-type="code"] {
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
    font-size: 15px;
    line-height: 1.75;
    tab-size: 4;
}
#opn-body[data-note-type="plain"] {
    line-height: 1.62;
}
#opn-body[data-note-type="task"] {
    line-height: 1.7;
}
.opn-status-list div dt,
.opn-status-list div dd {
    word-break: break-word;
}
@media (max-width: 760px) {
    .opn-editor-meta-structured {
        grid-template-columns: 1fr;
        align-items: stretch;
    }
    .opn-meta-field {
        align-items: stretch;
        flex-direction: column;
        gap: 6px;
    }
    .opn-note-type-field select {
        width: 100%;
    }
}

/* v0.14 task note editor + demo data manager */
.opn-task-tools {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    border-bottom: 1px solid var(--opn-border);
    background: var(--opn-panel-soft);
    min-height: 50px;
}
.opn-task-tools.hidden { display: none; }
.opn-task-tools .opn-toolbar-button {
    min-height: 34px;
    padding: 7px 10px;
    font-size: 13px;
}
.opn-task-help {
    color: var(--opn-muted);
    font-size: 13px;
    line-height: 1.35;
}
.opn-task-help code {
    padding: 1px 4px;
    border: 1px solid var(--opn-border);
    border-radius: 3px;
    background: var(--opn-panel);
    color: var(--opn-text);
}
.opn-task-preview-line {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    margin: 4px 0;
    line-height: 1.5;
}
.opn-task-preview-line input[type="checkbox"] {
    width: 17px;
    height: 17px;
    margin-top: 3px;
    flex: 0 0 auto;
}
.opn-task-preview-line span {
    min-width: 0;
}
.opn-demo-actions {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
    margin: 16px 0 18px;
}
.opn-demo-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 10px;
}
.opn-demo-grid > div {
    border: 1px solid var(--opn-border);
    border-radius: 3px;
    background: var(--opn-panel-soft);
    padding: 12px;
    min-height: 82px;
}
.opn-demo-grid strong,
.opn-demo-grid span {
    display: block;
}
.opn-demo-grid strong {
    margin-bottom: 6px;
    color: var(--opn-text);
}
.opn-demo-grid span {
    color: var(--opn-muted);
    font-size: 13px;
    line-height: 1.4;
}
@media (max-width: 900px) {
    .opn-demo-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 560px) {
    .opn-task-tools { align-items: stretch; flex-direction: column; }
    .opn-task-tools .opn-toolbar-button { width: 100%; justify-content: center; }
    .opn-demo-grid { grid-template-columns: 1fr; }
}

/* v0.15 Compact Sidebar + Slim Tags Navigation */
.opn-slim-nav {
    border-bottom: 1px solid var(--opn-border);
    background: var(--opn-panel);
    padding: 8px 10px;
}
.opn-nav-row,
.opn-tag-row {
    width: 100%;
    min-height: 30px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    border: 0;
    background: transparent;
    color: var(--opn-text);
    border-radius: 3px;
    padding: 6px 8px;
    font-size: 13px;
    text-align: left;
    cursor: pointer;
}
.opn-nav-row:hover,
.opn-tag-row:hover,
.opn-nav-row.active,
.opn-tag-row.active {
    background: var(--opn-panel-soft);
}
.opn-active-tag-row {
    color: var(--opn-accent);
    font-weight: 650;
    margin-bottom: 6px;
}
.opn-tag-panel {
    border: 0;
    padding: 4px 0 0;
    background: transparent;
}
.opn-tag-panel-head {
    list-style: none;
    cursor: pointer;
    user-select: none;
    min-height: 28px;
    display: flex;
    align-items: center;
    padding: 5px 8px;
    margin: 2px 0 4px;
    color: var(--opn-muted);
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: .04em;
}
.opn-tag-panel-head::-webkit-details-marker { display: none; }
.opn-tag-panel-head::after {
    content: '▾';
    margin-left: auto;
    font-size: 11px;
    color: var(--opn-muted);
}
.opn-tag-panel:not([open]) .opn-tag-panel-head::after { content: '▸'; }
.opn-tag-search {
    height: 32px;
    padding: 6px 8px;
    margin: 0 0 6px;
    font-size: 13px;
    background: var(--opn-panel-soft);
}
.opn-tags-list,
.opn-tags-slim-list {
    display: grid;
    gap: 1px;
    max-height: 150px;
    overflow: auto;
    padding: 0;
}
.opn-tag-filter,
.opn-tag-row {
    min-height: 30px;
    max-width: none;
    padding: 6px 8px;
    border: 0;
    background: transparent;
}
.opn-tag-row span {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.opn-tag-row small {
    border: 0;
    padding: 0;
    min-width: 18px;
    text-align: right;
    color: var(--opn-muted);
    font-size: 12px;
}
.opn-tags-empty {
    display: block;
    padding: 7px 8px;
    color: var(--opn-muted);
    font-size: 12px;
}
.opn-note-row,
.opn-note-row-compact {
    padding: 10px 14px;
}
.opn-note-title {
    margin-bottom: 3px;
    font-size: 14px;
    line-height: 1.25;
}
.opn-note-snippet {
    font-size: 12.5px;
    line-height: 1.35;
}
.opn-row-meta,
.opn-row-meta-text {
    margin-top: 4px;
    color: var(--opn-muted);
    font-size: 11.5px;
    line-height: 1.3;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.opn-type-badge,
.opn-tag-badge {
    display: none;
}
.opn-pin-mark {
    margin-right: 5px;
    font-size: 10px;
}
@media (max-width: 760px) {
    .opn-tags-list,
    .opn-tags-slim-list { max-height: 118px; }
    .opn-note-row,
    .opn-note-row-compact { padding: 10px 13px; }
}

/* v0.16 Archive view + sidebar navigation polish */
.opn-sidebar-head {
    gap: 10px;
}
.opn-slim-nav {
    padding-top: 7px;
    padding-bottom: 7px;
}
.opn-nav-row {
    min-height: 29px;
}
.opn-nav-row small {
    color: var(--opn-muted);
    font-size: 11px;
    font-weight: 600;
}
.opn-nav-row.active {
    font-weight: 650;
    border-left: 2px solid var(--opn-accent);
    padding-left: 6px;
}
.opn-tag-panel {
    margin-top: 4px;
    padding-top: 6px;
    border-top: 1px solid var(--opn-border);
}
.opn-editor-toolbar #opn-archive em,
.opn-editor-toolbar #opn-restore em {
    min-width: 48px;
}

/* v0.17 Revision History Browser */
.opn-editor-pane {
    position: relative;
}
.opn-history-panel {
    position: absolute;
    z-index: 12;
    top: 62px;
    right: 0;
    bottom: 0;
    width: min(390px, 42vw);
    background: var(--opn-panel);
    border-left: 1px solid var(--opn-border);
    box-shadow: -18px 0 34px rgba(15, 23, 42, .08);
    display: flex;
    flex-direction: column;
}
.opn-history-head {
    min-height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 14px 16px;
    border-bottom: 1px solid var(--opn-border);
    background: var(--opn-panel-soft);
}
.opn-history-head strong,
.opn-history-head span {
    display: block;
}
.opn-history-head strong {
    font-size: 15px;
    letter-spacing: -.01em;
}
.opn-history-head span {
    margin-top: 3px;
    color: var(--opn-muted);
    font-size: 12px;
}
.opn-history-list {
    overflow: auto;
    padding: 10px;
}
.opn-history-row {
    border: 1px solid var(--opn-border);
    background: var(--opn-panel);
    border-radius: 3px;
    padding: 12px;
    margin-bottom: 10px;
}
.opn-history-row-head {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 12px;
}
.opn-history-row-head strong {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-size: 13px;
}
.opn-history-row-head small {
    color: var(--opn-muted);
    font-size: 11px;
    white-space: nowrap;
}
.opn-history-row p {
    margin: 8px 0 10px;
    color: var(--opn-muted);
    font-size: 12.5px;
    line-height: 1.45;
}
.opn-history-row-actions {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 8px;
}
.opn-history-row-actions span {
    margin-right: auto;
    color: var(--opn-muted);
    font-size: 11px;
    font-weight: 650;
}
.opn-history-row-actions .opn-toolbar-button,
.opn-history-row-actions .opn-button {
    margin-top: 0;
    min-height: 30px;
    padding: 6px 9px;
    font-size: 12px;
}
.opn-history-empty {
    color: var(--opn-muted);
    font-size: 13px;
    line-height: 1.5;
    padding: 14px;
    border: 1px dashed var(--opn-border);
    background: var(--opn-panel-soft);
    border-radius: 3px;
}
@media (max-width: 980px) {
    .opn-history-panel { width: min(420px, 55vw); }
}
@media (max-width: 760px) {
    .opn-history-panel {
        top: 62px;
        left: 0;
        right: 0;
        width: 100%;
    }
}