/* ═══════════════════════════════════════════════════════════════
   TBS Straddle Backtest — Premium Dark Theme
   ═══════════════════════════════════════════════════════════════ */

/* ── CSS Tokens ──────────────────────────────────────────────── */
:root {
    /* surfaces */
    --bg-deep:        #f0f4f8;
    --bg-body:        #f8fafc;
    --bg-card:        rgba(255, 255, 255, 0.9);
    --bg-card-solid:  #ffffff;
    --bg-sidebar:     rgba(255, 255, 255, 0.95);
    --bg-hover:       rgba(99, 102, 241, 0.08);
    --bg-input:       rgba(0, 0, 0, 0.03);

    /* borders */
    --border:         rgba(0, 0, 0, 0.08);
    --border-hover:   rgba(99, 102, 241, 0.4);
    --border-input:   rgba(0, 0, 0, 0.15);

    /* accents */
    --accent:         #4f46e5;
    --accent-light:   #6366f1;
    --accent-glow:    rgba(79, 70, 229, 0.15);
    --violet:         #7c3aed;
    --emerald:        #059669;
    --emerald-soft:   rgba(5, 150, 105, 0.12);
    --red:            #dc2626;
    --red-soft:       rgba(220, 38, 38, 0.12);
    --amber:          #d97706;
    --amber-soft:     rgba(217, 119, 6, 0.12);
    --cyan:           #0891b2;
    --gold:           #d97706;

    /* text */
    --text-primary:   #0f172a;
    --text-secondary: #334155;
    --text-muted:     #64748b;
    --text-inverse:   #ffffff;

    /* misc */
    --radius:         12px;
    --radius-sm:      8px;
    --radius-lg:      16px;
    --shadow:         0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-lg:      0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
    --glass-blur:     blur(20px);
    --transition:     0.25s cubic-bezier(0.4, 0, 0.2, 1);

    /* layout */
    --sidebar-w:      280px;
}

/* ── Reset ───────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 14px; scroll-behavior: smooth; }
body {
    font-family: 'Inter', -apple-system, sans-serif;
    background: var(--bg-body);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
}

/* subtle grid background */
body::before {
    content: '';
    position: fixed; inset: 0;
    background-image:
        radial-gradient(circle at 25% 25%, rgba(79,70,229,0.06) 0%, transparent 50%),
        radial-gradient(circle at 75% 75%, rgba(124,58,237,0.05) 0%, transparent 50%);
    pointer-events: none; z-index: 0;
}

/* ── Scrollbar ───────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--text-muted); border-radius: 8px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-secondary); }

/* ── Loading Overlay ─────────────────────────────────────────── */
.loader-overlay {
    position: fixed; inset: 0; z-index: 9999;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: var(--glass-blur);
    display: flex; align-items: center; justify-content: center;
    opacity: 1; transition: opacity 0.4s;
}
.loader-overlay.hidden { opacity: 0; pointer-events: none; }
.loader-content { text-align: center; }
.loader-spinner {
    width: 48px; height: 48px; margin: 0 auto 16px;
    border: 3px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}
.loader-spinner.small { width: 24px; height: 24px; margin: 0; border-width: 2px; }
.loader-text { color: var(--text-secondary); font-weight: 500; }
@keyframes spin { to { transform: rotate(360deg); } }

.inline-loader {
    display: flex; align-items: center; gap: 12px;
    padding: 20px; color: var(--text-secondary);
    font-weight: 500;
}

/* ── Sidebar ─────────────────────────────────────────────────── */
.sidebar {
    position: fixed; top: 0; left: 0; bottom: 0;
    width: var(--sidebar-w);
    background: var(--bg-sidebar);
    backdrop-filter: var(--glass-blur);
    border-right: 1px solid var(--border);
    display: flex; flex-direction: column;
    z-index: 100;
    overflow-y: auto;
}

.sidebar-brand {
    display: flex; align-items: center; gap: 12px;
    padding: 24px 20px 20px;
    border-bottom: 1px solid var(--border);
}
.brand-icon {
    font-size: 28px;
    width: 44px; height: 44px;
    display: grid; place-items: center;
    background: linear-gradient(135deg, var(--accent), var(--violet));
    border-radius: var(--radius);
    box-shadow: 0 4px 20px var(--accent-glow);
}
.brand-title {
    font-size: 1.15rem; font-weight: 700;
    background: linear-gradient(135deg, var(--text-primary), var(--accent-light));
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.brand-sub { font-size: 0.75rem; color: var(--text-muted); font-weight: 400; }

.sidebar-section { padding: 20px; border-bottom: 1px solid var(--border); }

/* ── Inputs ──────────────────────────────────────────────────── */
.input-label {
    display: block; font-size: 0.75rem; font-weight: 600;
    color: var(--text-secondary); text-transform: uppercase;
    letter-spacing: 0.05em; margin-bottom: 6px; margin-top: 14px;
}
.input-label:first-child { margin-top: 0; }

.input-select, .input-text {
    width: 100%; padding: 10px 12px;
    background: var(--bg-input); color: var(--text-primary);
    border: 1px solid var(--border-input); border-radius: var(--radius-sm);
    font-family: inherit; font-size: 0.9rem;
    transition: border-color var(--transition), box-shadow var(--transition);
    outline: none;
}
.input-select:focus, .input-text:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}
.input-select option { background: var(--bg-card-solid); color: var(--text-primary); }

/* ── Buttons ─────────────────────────────────────────────────── */
.btn-primary {
    width: 100%; margin-top: 20px; padding: 12px;
    background: linear-gradient(135deg, var(--accent), var(--violet));
    color: #fff; font-weight: 600; font-size: 0.95rem;
    border: none; border-radius: var(--radius-sm);
    cursor: pointer;
    display: flex; align-items: center; justify-content: center; gap: 8px;
    transition: transform var(--transition), box-shadow var(--transition);
    box-shadow: 0 4px 20px var(--accent-glow);
}
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 6px 28px var(--accent-glow); }
.btn-primary:active { transform: translateY(0); }
.btn-primary:disabled {
    opacity: 0.5; cursor: not-allowed; transform: none;
    box-shadow: none;
}
.btn-icon { font-size: 0.85rem; }

.btn-secondary {
    padding: 10px 20px;
    background: var(--bg-input); color: var(--text-primary);
    border: 1px solid var(--border-input); border-radius: var(--radius-sm);
    font-family: inherit; font-size: 0.85rem; font-weight: 500;
    cursor: pointer; transition: all var(--transition);
}
.btn-secondary:hover { border-color: var(--accent); background: var(--bg-hover); }
.btn-secondary.active {
    background: linear-gradient(135deg, var(--accent), var(--violet));
    border-color: transparent; color: #fff;
}

/* ── Navigation ──────────────────────────────────────────────── */
.sidebar-nav { padding: 16px 12px; flex: 1; }
.nav-heading {
    font-size: 0.65rem; font-weight: 700; color: var(--text-muted);
    text-transform: uppercase; letter-spacing: 0.1em;
    padding: 0 8px 8px; margin-bottom: 4px;
}
.nav-btn {
    width: 100%; padding: 10px 12px;
    display: flex; align-items: center; gap: 10px;
    background: transparent; color: var(--text-secondary);
    border: none; border-radius: var(--radius-sm);
    font-family: inherit; font-size: 0.88rem; font-weight: 500;
    cursor: pointer; transition: all var(--transition);
    text-align: left; margin-bottom: 2px;
}
.nav-btn:hover { background: var(--bg-hover); color: var(--text-primary); }
.nav-btn.active {
    background: var(--bg-hover); color: var(--accent-light);
    box-shadow: inset 3px 0 0 var(--accent);
}
.nav-icon { font-size: 1rem; width: 20px; text-align: center; }

.sidebar-footer {
    padding: 16px 20px;
    border-top: 1px solid var(--border);
}
.data-badge {
    display: flex; align-items: center; gap: 8px;
    font-size: 0.75rem; color: var(--text-muted);
}
.badge-dot {
    width: 8px; height: 8px; border-radius: 50%;
    background: var(--emerald);
    box-shadow: 0 0 8px var(--emerald);
    animation: pulse-dot 2s infinite;
}
@keyframes pulse-dot {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

/* ── Main ────────────────────────────────────────────────────── */
.main {
    margin-left: var(--sidebar-w);
    padding: 28px 32px;
    min-height: 100vh;
    position: relative; z-index: 1;
}

/* ── Welcome ─────────────────────────────────────────────────── */
.welcome-section {
    display: flex; align-items: center; justify-content: center;
    min-height: 70vh;
}
.welcome-card {
    text-align: center; max-width: 560px;
    padding: 48px;
    background: var(--bg-card);
    backdrop-filter: var(--glass-blur);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    animation: fadeUp 0.6s ease-out;
}
.welcome-icon { font-size: 56px; margin-bottom: 20px; }
.welcome-card h2 {
    font-size: 1.6rem; font-weight: 700; margin-bottom: 12px;
    background: linear-gradient(135deg, var(--text-primary), var(--accent-light));
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.welcome-card p { color: var(--text-secondary); line-height: 1.6; }
.welcome-features {
    display: flex; flex-wrap: wrap; gap: 8px;
    justify-content: center; margin-top: 24px;
}
.feature-chip {
    display: flex; align-items: center; gap: 6px;
    padding: 6px 14px;
    background: var(--bg-input); border: 1px solid var(--border);
    border-radius: 100px; font-size: 0.8rem;
    color: var(--text-secondary);
}

@keyframes fadeUp {
    from { opacity: 0; transform: translateY(20px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* ── Cards ───────────────────────────────────────────────────── */
.card {
    background: var(--bg-card);
    backdrop-filter: var(--glass-blur);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    margin-bottom: 24px;
    overflow: hidden;
    animation: fadeUp 0.5s ease-out both;
    transition: border-color var(--transition);
}
.card:hover { border-color: var(--border-hover); }
.card-header {
    padding: 18px 24px;
    border-bottom: 1px solid var(--border);
    display: flex; align-items: center; justify-content: space-between;
}
.card-header h3 {
    font-size: 1rem; font-weight: 600;
    display: flex; align-items: center; gap: 10px;
}
.sort-hint { font-size: 0.75rem; color: var(--text-muted); font-weight: 400; }
.sl-badge {
    font-size: 0.7rem; padding: 3px 10px;
    background: var(--accent-glow); color: var(--accent-light);
    border-radius: 100px; font-weight: 600;
}

/* ── Chart container ─────────────────────────────────────────── */
.chart-container { padding: 20px 24px; position: relative; height: 360px; }
.chart-container.chart-tall { height: 440px; }

/* ── Metric cards ────────────────────────────────────────────── */
.metrics-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
    margin-bottom: 24px;
}
.metric-card {
    padding: 20px 22px;
    background: var(--bg-card);
    backdrop-filter: var(--glass-blur);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: all var(--transition);
    animation: fadeUp 0.5s ease-out both;
}
.metric-card:hover {
    transform: translateY(-3px);
    border-color: var(--border-hover);
    box-shadow: var(--shadow-lg);
}
.metric-label {
    font-size: 0.7rem; font-weight: 600;
    color: var(--text-muted); text-transform: uppercase;
    letter-spacing: 0.08em; margin-bottom: 8px;
}
.metric-value {
    font-size: 1.75rem; font-weight: 800;
    font-family: 'JetBrains Mono', monospace;
    line-height: 1;
}
.metric-sub {
    font-size: 0.75rem; color: var(--text-muted);
    margin-top: 6px;
}

.metric-card.green .metric-value { color: var(--emerald); }
.metric-card.green { border-left: 3px solid var(--emerald); }
.metric-card.red .metric-value { color: var(--red); }
.metric-card.red { border-left: 3px solid var(--red); }
.metric-card.blue .metric-value { color: var(--accent-light); }
.metric-card.blue { border-left: 3px solid var(--accent); }
.metric-card.amber .metric-value { color: var(--amber); }
.metric-card.amber { border-left: 3px solid var(--amber); }
.metric-card.cyan .metric-value { color: var(--cyan); }
.metric-card.cyan { border-left: 3px solid var(--cyan); }

/* ── Tables ──────────────────────────────────────────────────── */
.table-wrap { overflow-x: auto; padding: 0 0 8px; }
.data-table {
    width: 100%; border-collapse: collapse;
    font-size: 0.82rem;
}
.data-table th {
    padding: 12px 16px; text-align: left;
    font-weight: 600; color: var(--text-secondary);
    text-transform: uppercase; font-size: 0.68rem;
    letter-spacing: 0.06em;
    background: rgba(255,255,255,0.02);
    border-bottom: 1px solid var(--border);
    position: sticky; top: 0; z-index: 2;
    white-space: nowrap;
}
.data-table td {
    padding: 10px 16px;
    border-bottom: 1px solid var(--border);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    white-space: nowrap;
    transition: background var(--transition);
}
.data-table tbody tr:hover td { background: var(--bg-hover); }
.data-table .positive { color: var(--emerald); }
.data-table .negative { color: var(--red); }
.data-table .highlight-row td {
    background: var(--accent-glow);
    font-weight: 600;
}

/* ── Basket controls ─────────────────────────────────────────── */
.basket-controls {
    display: flex; gap: 10px; margin-bottom: 20px;
}

/* ── Grid layouts ────────────────────────────────────────────── */
.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 20px;
    margin-bottom: 24px;
}

/* ── Responsive ──────────────────────────────────────────────── */
@media (max-width: 900px) {
    :root { --sidebar-w: 0px; }
    .sidebar { transform: translateX(-100%); }
    .main { margin-left: 0; padding: 20px 16px; }
    .metrics-row { grid-template-columns: repeat(2, 1fr); }
    .grid-3 { grid-template-columns: 1fr; }
}