/*
  Classic ribbon skin: owner-requested look inspired by 2013-era desktop mail (flat white surfaces, one blue,
  ribbon tabs, bottom navigation, coloured status bar). Applies when <html data-skin="classic">.
  The ribbon and bottom navigation are hidden in the default instrument-panel skin.
*/

.ribbon, .classic-nav { display: none; }

/* ---------- Tokens: White (light) ---------- */
:root[data-skin="classic"] {
    color-scheme: light;
    --base: #ffffff;
    --panel: #ffffff;
    --panel-2: #f4f4f4;
    --raised: #ffffff;
    --hair: #e1e1e1;
    --hair-strong: #c6c6c6;
    --text: #262626;
    --text-2: #444444;
    --muted: #666666;
    --signal: #0072c6;
    --signal-ink: #ffffff;
    --signal-soft: #cde6f7;
    --signal-line: #0072c6;
    --ok: #107c10;
    --warn: #a05a00;
    --fault: #c50f1f;
    --fault-soft: rgba(197, 15, 31, 0.07);
    --ok-soft: rgba(16, 124, 16, 0.08);
    --selection: #cde6f7;
    --hover: #e5f1fb;
    --focus: #0072c6;
    --brand-bar: #0072c6;
    --brand-bar-ink: #ffffff;
    --ribbon-hover-border: #92c0e0;
    --shadow-float: 0 3px 10px rgba(0, 0, 0, 0.18), 0 0 0 1px #c6c6c6;
    --reader-bg: #ffffff;
    --font-ui: "Segoe UI", "Segoe UI Web (West European)", -apple-system, "Helvetica Neue", Arial, sans-serif;
    --font-light: "Segoe UI Light", "Segoe UI", -apple-system, "Helvetica Neue", Arial, sans-serif;
    --font-mono: Consolas, "Cascadia Mono", ui-monospace, monospace;
    --r-1: 0px;
    --r-2: 0px;
}

/* ---------- Tokens: Dark Gray ---------- */
:root[data-skin="classic"][data-theme="dark"] {
    color-scheme: dark;
    --base: #1f1f1f;
    --panel: #262626;
    --panel-2: #2f2f2f;
    --raised: #333333;
    --hair: #3d3d3d;
    --hair-strong: #555555;
    --text: #f0f0f0;
    --text-2: #d6d6d6;
    --muted: #a8a8a8;
    --signal: #5aa9e6;
    --signal-ink: #0b1a28;
    --signal-soft: #1d3a52;
    --signal-line: #5aa9e6;
    --ok: #6ccb5f;
    --warn: #f0a640;
    --fault: #ff8a8a;
    --fault-soft: rgba(255, 138, 138, 0.1);
    --ok-soft: rgba(108, 203, 95, 0.1);
    --selection: #1d3a52;
    --hover: #333f4a;
    --focus: #5aa9e6;
    --brand-bar: #0f5a96;
    --brand-bar-ink: #ffffff;
    --ribbon-hover-border: #4f7fa6;
    --shadow-float: 0 3px 12px rgba(0, 0, 0, 0.5), 0 0 0 1px #555555;
    --reader-bg: #ffffff;
}

@media (prefers-color-scheme: dark) {
    :root[data-skin="classic"]:not([data-theme="light"]) {
        color-scheme: dark;
        --base: #1f1f1f;
        --panel: #262626;
        --panel-2: #2f2f2f;
        --raised: #333333;
        --hair: #3d3d3d;
        --hair-strong: #555555;
        --text: #f0f0f0;
        --text-2: #d6d6d6;
        --muted: #a8a8a8;
        --signal: #5aa9e6;
        --signal-ink: #0b1a28;
        --signal-soft: #1d3a52;
        --signal-line: #5aa9e6;
        --ok: #6ccb5f;
        --warn: #f0a640;
        --fault: #ff8a8a;
        --fault-soft: rgba(255, 138, 138, 0.1);
        --ok-soft: rgba(108, 203, 95, 0.1);
        --selection: #1d3a52;
        --hover: #333f4a;
        --focus: #5aa9e6;
        --brand-bar: #0f5a96;
        --brand-bar-ink: #ffffff;
        --ribbon-hover-border: #4f7fa6;
        --shadow-float: 0 3px 12px rgba(0, 0, 0, 0.5), 0 0 0 1px #555555;
        --reader-bg: #ffffff;
    }
}

/* ---------- Shared component restyling ---------- */
[data-skin="classic"] body { font-size: 13.5px; }
[data-skin="classic"] h1, [data-skin="classic"] .thread-subject, [data-skin="classic"] .deck-hero .greeting,
[data-skin="classic"] .doc-title-input, [data-skin="classic"] .backstage-main h1 {
    font-family: var(--font-light);
    font-weight: 300;
}
[data-skin="classic"] h1 { font-size: 24px; }
[data-skin="classic"] .thread-subject { font-size: 24px; }

[data-skin="classic"] .readout {
    border: 0;
    padding: 0;
    font-family: var(--font-ui);
    text-transform: uppercase;
    letter-spacing: 0.02em;
}
[data-skin="classic"] .readout b { font-weight: 600; }
[data-skin="classic"] .num, [data-skin="classic"] .mono:not(textarea):not(pre):not(code),
[data-skin="classic"] .msg .when, [data-skin="classic"] .nav-item .count, [data-skin="classic"] .meter-tile .v {
    font-family: var(--font-ui);
}
[data-skin="classic"] .meter-tile .v { font-family: var(--font-light); font-weight: 300; font-size: 28px; }

[data-skin="classic"] .label { letter-spacing: 0.02em; }

[data-skin="classic"] .btn { background: var(--panel); }
[data-skin="classic"] .btn:hover { background: var(--hover); border-color: var(--ribbon-hover-border); }
[data-skin="classic"] .btn-primary { background: var(--signal); border-color: var(--signal); color: var(--signal-ink); }
[data-skin="classic"] .btn-primary:hover { background: var(--signal); filter: brightness(1.08); }
[data-skin="classic"] .btn-ghost { background: transparent; }

[data-skin="classic"] .segmented { border: 0; gap: 2px; }
[data-skin="classic"] .segmented button { border: 0; background: none; font-size: 13px; padding: 2px 8px; }
[data-skin="classic"] .segmented button.active { color: var(--signal); background: none; box-shadow: none; font-weight: 600; }

[data-skin="classic"] .avatar { border-radius: 50%; border: 0; background: var(--signal-soft); color: var(--signal); font-family: var(--font-ui); }

/* Folder pane */
[data-skin="classic"] .mail-nav { background: var(--panel); }
[data-skin="classic"] .nav-group-title .label { text-transform: none; font-size: 13px; font-weight: 600; color: var(--text); letter-spacing: 0; }
[data-skin="classic"] .nav-item { font-size: 13.5px; color: var(--text); }
[data-skin="classic"] .nav-item .ico { color: var(--text-2); }
[data-skin="classic"] .nav-item.active { background: var(--selection); }
[data-skin="classic"] .nav-item.active::before { display: none; }
[data-skin="classic"] .nav-item .count, [data-skin="classic"] .nav-item .count.hot { color: var(--signal); font-weight: 600; }

/* Message list: unread mail gets the blue edge and blue subject */
[data-skin="classic"] .msg .dot { display: none; }
[data-skin="classic"] .msg.unread::after { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px; background: var(--signal); }
[data-skin="classic"] .msg.unread .subject { color: var(--signal); font-weight: 600; }
[data-skin="classic"] .msg.unread .when { color: var(--signal); }
[data-skin="classic"] .msg.selected { background: var(--selection); }
[data-skin="classic"] .msg.selected::before { display: none; }
[data-skin="classic"] .msg .from { font-size: 14px; }
[data-skin="classic"] .list-toolbar h2 { font-family: var(--font-light); font-weight: 300; font-size: 18px; }

/* Reading pane */
[data-skin="classic"] .letter { border-color: var(--hair); }
[data-skin="classic"] .letter-head .who .name { font-size: 15px; font-weight: 600; }

[data-skin="classic"] .tabs .active::after, [data-skin="classic"] .rail a.active::before { background: var(--signal); }

/* ---------- Desktop layout: ribbon on top, navigation at the bottom ---------- */
@media (min-width: 761px) {
    :root[data-skin="classic"] { --rail-w: 0px; --status-h: 24px; }

    [data-skin="classic"] .shell {
        grid-template-columns: minmax(0, 1fr);
        grid-template-rows: auto minmax(0, 1fr) auto var(--status-h);
    }

    [data-skin="classic"] .rail { display: none; }
    [data-skin="classic"] .main { grid-row: 2; }
    [data-skin="classic"] .ribbon { display: block; grid-row: 1; }
    [data-skin="classic"] .classic-nav { display: flex; grid-row: 3; }
    [data-skin="classic"] .statusbar {
        grid-row: 4;
        grid-column: 1;
        background: var(--brand-bar);
        color: var(--brand-bar-ink);
        border-top: 0;
        font-family: var(--font-ui);
        text-transform: uppercase;
        letter-spacing: 0.03em;
    }
    [data-skin="classic"] .statusbar a, [data-skin="classic"] .statusbar button { color: var(--brand-bar-ink); }
    [data-skin="classic"] .statusbar .kbd { color: var(--brand-bar-ink); border-color: rgba(255, 255, 255, 0.6); }
    [data-skin="classic"] .statusbar .lamp.ok { background: #9be59b; }

    /* New Email lives on the ribbon. */
    [data-skin="classic"] .mail-nav .compose-btn { display: none; }
    [data-skin="classic"] .mail-nav { padding-top: 4px; }

    [data-skin="classic"] .compose { bottom: calc(var(--status-h) + 46px); }
    [data-skin="classic"] .toasts { bottom: calc(var(--status-h) + 46px); }
}

/* ---------- Ribbon ---------- */
.ribbon {
    position: relative;
    z-index: 30;
    background: var(--panel);
    border-bottom: 1px solid var(--hair-strong);
    font-family: var(--font-ui);
    user-select: none;
}

.ribbon-tabs { display: flex; align-items: stretch; height: 27px; padding-right: 6px; }

.ribbon-file {
    background: var(--brand-bar);
    color: var(--brand-bar-ink);
    border: 0;
    padding: 0 20px;
    font: inherit;
    font-size: 12px;
    letter-spacing: 0.02em;
    cursor: pointer;
}
.ribbon-file:hover { filter: brightness(1.1); }

.ribbon-tab {
    position: relative;
    background: none;
    border: 1px solid transparent;
    border-bottom: 0;
    padding: 0 14px;
    font: inherit;
    font-size: 12px;
    letter-spacing: 0.02em;
    color: var(--text-2);
    cursor: pointer;
}
.ribbon-tab:hover { color: var(--signal); }
.ribbon-tab.active {
    color: var(--signal);
    background: var(--panel);
    border-color: var(--hair-strong);
    margin-bottom: -1px;
    z-index: 1;
}

.ribbon-context { align-self: center; font-size: 12px; color: var(--muted); padding: 0 12px; }

.ribbon-pin { background: none; border: 0; color: var(--muted); padding: 0 6px; cursor: pointer; }
.ribbon-pin:hover { color: var(--signal); }

.ribbon-body {
    display: flex;
    align-items: stretch;
    height: 96px;
    padding: 4px 4px 0;
    border-top: 1px solid var(--hair-strong);
    background: var(--panel);
    overflow-x: auto;
    overflow-y: hidden;
}
.ribbon-body.peek {
    position: absolute;
    left: 0;
    right: 0;
    top: 27px;
    box-shadow: var(--shadow-float);
}

.rgroup { display: flex; flex-direction: column; padding: 0 6px; border-right: 1px solid var(--hair); flex: 0 0 auto; }
.rgroup-items { display: flex; gap: 2px; flex: 1; align-items: flex-start; }
.rgroup-label { font-size: 11px; color: var(--muted); text-align: center; padding: 2px 0 4px; white-space: nowrap; }

.rbtn {
    background: none;
    border: 1px solid transparent;
    color: var(--text);
    font: inherit;
    font-size: 12px;
    cursor: pointer;
    text-decoration: none;
}
.rbtn:hover:not(:disabled) { background: var(--hover); border-color: var(--ribbon-hover-border); text-decoration: none; }
.rbtn:disabled { opacity: 0.4; cursor: default; }
.rbtn.on { background: var(--signal-soft); border-color: var(--ribbon-hover-border); }

.rbtn.big {
    display: flex;
    flex-direction: column;
    align-items: center;
    min-width: 54px;
    height: 70px;
    padding: 4px 6px 2px;
    line-height: 1.15;
    text-align: center;
    white-space: nowrap;
}
.rbtn.big .ico { width: 32px; height: 32px; margin-bottom: 3px; }
.rbtn .ico * { vector-effect: non-scaling-stroke; }
.rbtn.big .ico { stroke-width: 1.5px; }
.rbtn.primary .ico { color: var(--signal); }

.rbtn.small { display: flex; align-items: center; gap: 6px; height: 22px; padding: 0 6px; white-space: nowrap; }
.rstack { display: flex; flex-direction: column; gap: 1px; }

.ribbon .menu { top: 100%; left: 0; z-index: 70; }
.ribbon-scrim { position: fixed; inset: 0; z-index: 55; }

.ribbon-search { display: flex; height: 22px; border: 1px solid var(--hair-strong); background: var(--base); width: 190px; }
.ribbon-search input { flex: 1; min-width: 0; border: 0; background: transparent; padding: 0 6px; font: inherit; font-size: 12px; color: var(--text); }
.ribbon-search input:focus { outline: none; }
.ribbon-search:focus-within { border-color: var(--signal); }
.ribbon-search button { border: 0; background: none; color: var(--muted); cursor: pointer; padding: 0 5px; }

/* ---------- Bottom navigation ---------- */
.classic-nav {
    align-items: center;
    gap: 4px;
    height: 38px;
    padding: 0 10px;
    border-top: 1px solid var(--hair);
    background: var(--panel);
    font-family: var(--font-ui);
}
.classic-nav a { font-size: 15px; color: var(--text-2); padding: 4px 10px; text-decoration: none; }
.classic-nav a:hover { color: var(--signal); text-decoration: none; }
.classic-nav a.active { color: var(--signal); font-weight: 600; }

/* ---------- File backstage ---------- */
.backstage {
    position: fixed;
    inset: 0;
    z-index: 150;
    display: grid;
    grid-template-columns: 220px minmax(0, 1fr);
    background: var(--base);
    font-family: var(--font-ui);
}
.backstage-side { display: flex; flex-direction: column; background: var(--brand-bar); padding: 18px 0; }
.backstage-side a, .backstage-side button {
    display: block;
    width: 100%;
    color: var(--brand-bar-ink);
    background: none;
    border: 0;
    padding: 9px 28px;
    font: inherit;
    font-size: 15px;
    text-align: left;
    text-decoration: none;
    cursor: pointer;
}
.backstage-side a:hover, .backstage-side button:hover, .backstage-side .active { background: rgba(255, 255, 255, 0.16); text-decoration: none; }
.backstage-side .backstage-back {
    width: 38px;
    height: 38px;
    margin: 0 0 22px 24px;
    padding: 0;
    border: 2px solid var(--brand-bar-ink);
    border-radius: 50%;
    display: grid;
    place-items: center;
}
.backstage-main { padding: 34px 48px; overflow: auto; }
.backstage-main h1 { font-size: 34px; margin-bottom: 22px; }
.backstage-account { display: flex; gap: 14px; align-items: center; padding: 12px 0; border-bottom: 1px solid var(--hair); max-width: 640px; }

@media (max-width: 760px) {
    .backstage { grid-template-columns: minmax(0, 1fr); grid-template-rows: auto minmax(0, 1fr); }
    .backstage-side { flex-direction: row; overflow-x: auto; padding: 6px; }
    .backstage-side a, .backstage-side button { width: auto; padding: 10px 14px; white-space: nowrap; }
    .backstage-side .backstage-back { margin: 0 8px 0 4px; flex: 0 0 38px; }
    .backstage-main { padding: 20px 16px; }
}

.ribbon-body { scrollbar-width: thin; }


/* Menus must be able to drop below the ribbon, so the body never scrolls. On narrower windows the
   least essential groups are hidden instead, the way the desktop original collapses groups. */
.ribbon-body { overflow: visible; }
@media (max-width: 1180px) { .rgroup.opt { display: none; } }
@media (max-width: 900px) { .rgroup.opt2 { display: none; } }