:root {
    --bg: #FCFCFA;
    --surface: #FFFFFF;
    --ink: #0F1417;
    --ink-2: #2A3338;
    --muted: #6B7680;
    --muted-2: #9AA3AC;
    --line: #E6E4DE;
    --line-2: #D8D5CC;
    --accent: #0E5866;
    --accent-2: #2F8F9D;
    --accent-soft: #E8F1F3;
    --danger: #B63A1F;
    --danger-soft: rgba(182, 58, 31, 0.08);
    --ok: #2D6A4F;
    --warn: #A67C00;
    --serif: 'Newsreader', Georgia, serif;
    --sans: 'IBM Plex Sans', system-ui, sans-serif;
    --mono: 'IBM Plex Mono', ui-monospace, monospace;
}
body.dark {
    --bg: #0C0F11;
    --surface: #14181B;
    --ink: #ECEDE8;
    --ink-2: #C6CAC6;
    --muted: #8A938E;
    --muted-2: #5D6561;
    --line: #222728;
    --line-2: #2E3436;
    --accent: #5BB4BF;
    --accent-2: #7FD0DB;
    --accent-soft: rgba(91, 180, 191, 0.12);
    --danger: #E07A5F;
    --danger-soft: rgba(224, 122, 95, 0.12);
    --ok: #7FB99A;
    --warn: #D4B85A;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { background: var(--bg); color: var(--ink); font-family: var(--sans); font-size: 14px; line-height: 1.5; -webkit-font-smoothing: antialiased; }
body { min-height: 100vh; transition: background 0.3s, color 0.3s; }

.hidden { display: none !important; }

/* Top bar */
.topbar { display: flex; align-items: center; justify-content: space-between; padding: 14px 28px; border-bottom: 1px solid var(--line); background: var(--surface); position: sticky; top: 0; z-index: 10; }
.brand { display: flex; align-items: baseline; gap: 10px; }
.brand .mark { font-family: var(--serif); font-size: 22px; font-weight: 500; letter-spacing: -0.01em; color: var(--ink); }
.brand .mark em { font-style: italic; color: var(--accent); font-weight: 500; }
.brand .ver { font-family: var(--mono); font-size: 10px; letter-spacing: 0.08em; color: var(--muted); text-transform: uppercase; padding: 2px 6px; border: 1px solid var(--line-2); border-radius: 2px; }
.topbar-right { display: flex; align-items: center; gap: 18px; }
.topbar .status { font-family: var(--mono); font-size: 11px; color: var(--muted); }
.topbar .status .dot { display: inline-block; width: 6px; height: 6px; border-radius: 50%; background: var(--muted-2); margin-right: 6px; vertical-align: middle; }
.topbar .status.active .dot { background: var(--ok); }
.theme-toggle { background: none; border: 1px solid var(--line-2); color: var(--ink-2); font-family: var(--mono); font-size: 11px; letter-spacing: 0.06em; padding: 6px 10px; border-radius: 3px; cursor: pointer; text-transform: uppercase; }
.theme-toggle:hover { border-color: var(--accent); color: var(--accent); }

/* Layout */
.workbench { display: grid; grid-template-columns: 360px 1fr; min-height: calc(100vh - 57px); }
@media (max-width: 980px) { .workbench { grid-template-columns: 1fr; } }

/* Sidebar */
.sidebar { border-right: 1px solid var(--line); background: var(--surface); padding: 28px 24px; display: flex; flex-direction: column; gap: 28px; overflow-y: auto; }
.step { display: flex; flex-direction: column; gap: 10px; }
.step-head { display: flex; align-items: baseline; gap: 10px; padding-bottom: 8px; border-bottom: 1px solid var(--line); }
.step-num { font-family: var(--mono); font-size: 10px; color: var(--muted); letter-spacing: 0.12em; }
.step-title { font-family: var(--serif); font-size: 17px; font-weight: 500; letter-spacing: -0.01em; color: var(--ink); }
.step-title em { font-style: italic; color: var(--accent); }

/* Tabs */
.tabs { display: flex; border-bottom: 1px solid var(--line); }
.tab { flex: 1; background: none; border: none; font-family: var(--sans); font-size: 12px; color: var(--muted); padding: 8px 4px; cursor: pointer; border-bottom: 2px solid transparent; transition: all 0.15s; }
.tab:hover { color: var(--ink); }
.tab.active { color: var(--accent); border-bottom-color: var(--accent); font-weight: 500; }
.input-panel { display: none; margin-top: 10px; }
.input-panel.active { display: block; }

textarea.csv { width: 100%; min-height: 180px; background: var(--bg); color: var(--ink); border: 1px solid var(--line); border-radius: 3px; padding: 12px 14px; font-family: var(--mono); font-size: 12px; line-height: 1.7; resize: vertical; }
textarea.csv:focus { outline: none; border-color: var(--accent); }

.file-drop { display: block; border: 1.5px dashed var(--line-2); border-radius: 3px; padding: 28px 16px; text-align: center; font-size: 13px; color: var(--muted); cursor: pointer; transition: all 0.15s; }
.file-drop:hover { border-color: var(--accent); color: var(--accent); background: var(--accent-soft); }
.file-drop .icon { font-family: var(--mono); font-size: 18px; margin-bottom: 8px; color: var(--muted-2); }

/* Buttons */
.btn { font-family: var(--sans); font-size: 13px; font-weight: 500; padding: 9px 16px; border-radius: 3px; cursor: pointer; border: 1px solid transparent; transition: all 0.15s; }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--ink); }
.btn-ghost { background: none; color: var(--ink-2); border-color: var(--line-2); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn-sm { font-size: 11px; padding: 5px 10px; }
.row { display: flex; gap: 8px; align-items: center; }
.row.between { justify-content: space-between; }

/* Validation */
.validation { font-family: var(--mono); font-size: 11px; padding: 8px 10px; border-radius: 3px; border-left: 2px solid; margin-top: 10px; }
.validation.ok { background: var(--accent-soft); border-left-color: var(--accent); color: var(--accent); }
.validation.err { background: var(--danger-soft); border-left-color: var(--danger); color: var(--danger); }
.validation.warn { background: rgba(166,124,0,0.08); border-left-color: var(--warn); color: var(--warn); }
.validation ul { margin-top: 4px; padding-left: 18px; }

/* Fields */
.field { display: flex; flex-direction: column; gap: 6px; }
.field label { font-size: 11px; color: var(--muted); text-transform: uppercase; letter-spacing: 0.08em; }
.field input[type=number], .field select { background: var(--bg); color: var(--ink); border: 1px solid var(--line); border-radius: 3px; padding: 8px 10px; font-family: var(--mono); font-size: 13px; }
.field input:focus, .field select:focus { outline: none; border-color: var(--accent); }
.field-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }

/* Models */
.model-list { display: flex; flex-direction: column; gap: 6px; }
.model-item { display: flex; align-items: center; gap: 10px; padding: 8px 10px; border: 1px solid var(--line); border-radius: 3px; cursor: pointer; transition: all 0.15s; background: var(--surface); position: relative; }
.model-item:hover { border-color: var(--accent); }
.model-item.selected { border-color: var(--accent); background: var(--accent-soft); }
.model-item .swatch { width: 10px; height: 10px; border-radius: 2px; flex-shrink: 0; }
.model-item .name { font-size: 13px; color: var(--ink); flex: 1; font-weight: 500; }
.model-item .desc { font-family: var(--mono); font-size: 10px; color: var(--muted); }
.model-item input { position: absolute; opacity: 0; pointer-events: none; }
.model-item .check { width: 14px; height: 14px; border: 1px solid var(--line-2); border-radius: 2px; display: flex; align-items: center; justify-content: center; font-size: 10px; color: transparent; flex-shrink: 0; }
.model-item.selected .check { border-color: var(--accent); background: var(--accent); color: #fff; }

/* Run button */
.run-btn { width: 100%; padding: 14px; margin-top: 8px; background: var(--ink); color: var(--bg); border: none; border-radius: 3px; cursor: pointer; font-family: var(--sans); font-size: 13px; font-weight: 500; letter-spacing: 0.02em; display: flex; align-items: center; justify-content: center; gap: 10px; transition: background 0.15s; }
.run-btn:hover:not(:disabled) { background: var(--accent); }
.run-btn:disabled { opacity: 0.4; cursor: not-allowed; }
.run-btn .kbd { font-family: var(--mono); font-size: 10px; padding: 2px 5px; border: 1px solid rgba(255,255,255,0.2); border-radius: 2px; opacity: 0.6; }

/* Main */
.main { padding: 40px 48px 80px; overflow-y: auto; background: var(--bg); }
@media (max-width: 980px) { .main { padding: 28px 24px; } }
.main-head { display: flex; justify-content: space-between; align-items: flex-end; padding-bottom: 20px; margin-bottom: 28px; border-bottom: 1px solid var(--line); gap: 20px; }
.main-title { font-family: var(--serif); font-size: 34px; font-weight: 500; letter-spacing: -0.02em; line-height: 1.1; color: var(--ink); }
.main-title em { font-style: italic; color: var(--accent); }
.main-sub { font-family: var(--mono); font-size: 11px; color: var(--muted); letter-spacing: 0.06em; text-transform: uppercase; margin-top: 6px; }
.run-meta { text-align: right; font-family: var(--mono); font-size: 11px; color: var(--muted); line-height: 1.7; }
.run-meta .tag { color: var(--accent); }

/* Empty + Loading */
.empty { display: flex; flex-direction: column; align-items: center; justify-content: center; min-height: 400px; gap: 16px; color: var(--muted); border: 1px dashed var(--line-2); border-radius: 4px; padding: 60px 40px; text-align: center; }
.empty .big { font-family: var(--serif); font-size: 28px; font-weight: 400; font-style: italic; color: var(--ink-2); letter-spacing: -0.01em; }
.empty .hint { font-family: var(--mono); font-size: 12px; letter-spacing: 0.04em; }

.loading-hero { min-height: 400px; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 20px; border: 1px solid var(--line); border-radius: 4px; background: var(--surface); }
.loading-hero .ring { width: 36px; height: 36px; border: 2px solid var(--line); border-top-color: var(--accent); border-radius: 50%; animation: spin 0.9s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.loading-hero .msg { font-family: var(--serif); font-size: 18px; font-style: italic; color: var(--ink-2); }
.loading-hero .progress { display: flex; gap: 20px; font-family: var(--mono); font-size: 11px; color: var(--muted); }
.loading-hero .progress .p { display: flex; align-items: center; gap: 6px; }
.loading-hero .progress .p .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--line-2); }
.loading-hero .progress .p.running .dot { background: var(--accent); animation: pulse 1s infinite; }
.loading-hero .progress .p.done .dot { background: var(--ok); }
.loading-hero .progress .p.failed .dot { background: var(--danger); }
@keyframes pulse { 50% { opacity: 0.3; } }

/* Headline block */
.headline-block { padding: 0 0 28px; border-bottom: 1px solid var(--line); margin-bottom: 28px; display: grid; grid-template-columns: 2fr 1fr; gap: 40px; align-items: end; }
@media (max-width: 820px) { .headline-block { grid-template-columns: 1fr; } }
.headline { font-family: var(--serif); font-size: 38px; font-weight: 500; letter-spacing: -0.025em; line-height: 1.1; color: var(--ink); text-wrap: pretty; }
.headline em { font-style: italic; color: var(--accent); font-weight: 600; }
.headline .pct { font-weight: 600; font-style: italic; color: var(--accent); }
.headline .pct.down { color: var(--danger); }
.numbers { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.num-item { border-top: 1px solid var(--ink); padding-top: 10px; }
.num-item .k { font-family: var(--mono); font-size: 10px; color: var(--muted); letter-spacing: 0.08em; text-transform: uppercase; }
.num-item .v { font-family: var(--serif); font-size: 26px; font-weight: 500; letter-spacing: -0.02em; margin-top: 4px; color: var(--ink); }
.num-item .v .unit { font-family: var(--mono); font-size: 12px; color: var(--muted); font-weight: 400; margin-left: 4px; letter-spacing: 0; }

/* Hero chart */
.hero-chart-wrap { background: var(--surface); border: 1px solid var(--line); border-radius: 4px; padding: 20px 20px 8px; margin-bottom: 28px; }
.chart-topline { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; }
.chart-legend { display: flex; gap: 18px; flex-wrap: wrap; }
.legend-item { display: flex; align-items: center; gap: 8px; font-family: var(--mono); font-size: 11px; color: var(--muted); }
.legend-item .sw { width: 16px; height: 2px; }
.legend-item .sw.dash { border-top: 2px dashed currentColor; height: 0; }

.section-label { font-family: var(--mono); font-size: 10px; color: var(--muted); letter-spacing: 0.12em; text-transform: uppercase; padding-bottom: 8px; margin-bottom: 16px; border-bottom: 1px solid var(--line); }

/* Model cards */
.model-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 16px; }
.model-card { background: var(--surface); border: 1px solid var(--line); border-radius: 4px; padding: 16px 18px; transition: border-color 0.15s; }
.model-card.best { border-color: var(--accent); }
.model-card.error { border-color: var(--danger); background: var(--danger-soft); }
.model-card .mhead { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 4px; }
.model-card .mname { font-family: var(--serif); font-size: 18px; font-weight: 500; letter-spacing: -0.01em; color: var(--ink); display: flex; align-items: center; gap: 8px; }
.model-card .mname .sw { width: 10px; height: 10px; border-radius: 2px; }
.model-card .mrank { font-family: var(--mono); font-size: 10px; color: var(--muted); letter-spacing: 0.08em; text-transform: uppercase; }
.model-card .mrank.best { color: var(--accent); }
.model-card .mmetrics { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; padding-top: 12px; margin-top: 12px; border-top: 1px solid var(--line); }
.mm { display: flex; flex-direction: column; gap: 2px; }
.mm .k { font-family: var(--mono); font-size: 10px; color: var(--muted); letter-spacing: 0.06em; text-transform: uppercase; }
.mm .v { font-family: var(--mono); font-size: 16px; font-weight: 500; color: var(--ink); }
.model-card .spark { height: 44px; margin-top: 10px; }
.model-card .err-text { font-family: var(--mono); font-size: 11px; color: var(--danger); margin-top: 8px; }

/* Forecast table */
.fc-table-wrap { background: var(--surface); border: 1px solid var(--line); border-radius: 4px; overflow: auto; margin-top: 16px; }
.fc-table { width: 100%; border-collapse: collapse; font-family: var(--mono); font-size: 12px; }
.fc-table th, .fc-table td { padding: 9px 14px; text-align: right; border-bottom: 1px solid var(--line); white-space: nowrap; }
.fc-table th:first-child, .fc-table td:first-child { text-align: left; color: var(--muted); }
.fc-table th { background: var(--bg); color: var(--muted); font-weight: 500; font-size: 10px; letter-spacing: 0.08em; text-transform: uppercase; }
.fc-table tr:last-child td { border-bottom: none; }
.fc-table tr:hover td { background: var(--accent-soft); }
.fc-table .delta.up { color: var(--accent); }
.fc-table .delta.down { color: var(--danger); }

/* AG Grid theme override (compact, fits sidebar) */
#ag-grid-container { border: 1px solid var(--line); border-radius: 3px; overflow: hidden; }
.ag-theme-quartz {
    --ag-background-color: var(--surface);
    --ag-header-background-color: var(--bg);
    --ag-odd-row-background-color: var(--surface);
    --ag-row-hover-color: var(--accent-soft);
    --ag-selected-row-background-color: var(--accent-soft);
    --ag-border-color: var(--line);
    --ag-row-border-color: var(--line);
    --ag-header-foreground-color: var(--muted);
    --ag-foreground-color: var(--ink);
    --ag-data-color: var(--ink);
    --ag-font-family: 'IBM Plex Mono', monospace;
    --ag-font-size: 12px;
    --ag-cell-horizontal-padding: 6px;
}
.ag-theme-quartz .ag-header-cell { font-size: 10px; text-transform: uppercase; letter-spacing: 0.08em; }
.ag-theme-quartz .ag-cell-focus { border: 1px solid var(--accent) !important; outline: none; }

/* Badges for model labels */
.badge { display: inline-block; padding: 2px 8px; border-radius: 10px;
         font-size: 0.75em; vertical-align: middle; }
.badge-premium { background: linear-gradient(45deg, #d4a017, #f1c40f); color: #222; }
.badge-default { background: #ccc; color: #333; }

.tier-chip {
    display: inline-block;
    padding: 2px 8px;
    margin-left: 8px;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.05em;
    border-radius: 3px;
    background: var(--accent, #888);
    color: #fff;
}
.tier-chip[data-tier="pro"] { background: var(--accent, #2b6cb0); }
.tier-chip[data-tier="free"] { background: var(--muted, #888); }

.sitefoot {
    display: flex; justify-content: space-between; align-items: center;
    padding: 18px 24px; margin-top: 32px;
    border-top: 1px solid var(--border, #2a2a2a);
    font-size: 13px; color: var(--muted, #888);
}
.sitefoot a { color: var(--muted, #888); text-decoration: none; margin: 0 4px; }
.sitefoot a:hover { color: var(--fg, #fff); }
.sitefoot-mark { font-weight: 600; margin-right: 12px; color: var(--fg, #fff); }
.sitefoot-version { font-family: 'IBM Plex Mono', monospace; font-size: 11px; opacity: 0.7; margin-left: 8px; }

/* Feedback widget */
.fb-btn {
    position: fixed; bottom: 20px; right: 20px;
    background: var(--accent, #2b6cb0); color: #fff; border: none;
    padding: 10px 16px; border-radius: 24px; cursor: pointer;
    font-size: 13px; font-weight: 600; box-shadow: 0 2px 8px rgba(0,0,0,0.2);
    z-index: 100;
}
.fb-modal { display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.5); z-index: 200; align-items: center; justify-content: center; }
.fb-modal.open { display: flex; }
.fb-card { background: var(--bg, #fff); padding: 24px; border-radius: 8px; width: 90%; max-width: 480px; }
.fb-card textarea, .fb-card input[type="email"] { width: 100%; margin: 8px 0; padding: 8px; box-sizing: border-box; }
.fb-actions { display: flex; gap: 8px; justify-content: flex-end; margin-top: 8px; }
.fb-status { margin-top: 8px; font-size: 13px; color: var(--muted, #888); }