/* ══════════════════════════════════════════════════
   PatternScale — The Stretch Fabric Grading Calculator
   Design: Tape-measure yellow + charcoal — fashion atelier
   ══════════════════════════════════════════════════ */

:root {
    --clr-bg:          #141216;
    --clr-surface-1:   #1c1920;
    --clr-surface-2:   #25222a;
    --clr-border:      #38333f;
    --clr-text:        #ede8f2;
    --clr-text-muted:  #8c849a;
    --clr-accent:      #fbbf24;
    --clr-accent-glow: rgba(251, 191, 36, 0.12);
    --radius:          10px;
    --font-sans:       'DM Sans', 'Inter', system-ui, sans-serif;
    --font-mono:       'JetBrains Mono', monospace;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body { font-family: var(--font-sans); background: var(--clr-bg); color: var(--clr-text); line-height: 1.6; min-height: 100vh; }
.container { width: 100%; max-width: 1100px; margin: 0 auto; padding: 0 1rem; }

.site-header { background: linear-gradient(135deg, #1c1920 0%, #141216 100%); border-bottom: 2px solid var(--clr-accent); padding: 2rem 0 1.5rem; text-align: center; }
.header-inner { display: flex; flex-direction: column; align-items: center; gap: 0.4rem; }
.brand { display: flex; align-items: center; gap: 0.6rem; }
.brand-icon { font-size: 2.2rem; }
.brand-name { font-family: var(--font-sans); font-size: 2rem; font-weight: 700; color: var(--clr-text); }
.brand-accent { color: var(--clr-accent); }
.brand-tagline { font-size: 0.82rem; font-weight: 600; color: var(--clr-accent); text-transform: uppercase; letter-spacing: 1.5px; }
.brand-subtitle { font-size: 0.82rem; color: var(--clr-text-muted); max-width: 520px; }

.privacy-badge { display: inline-flex; align-items: center; gap: 0.5rem; background: var(--clr-accent-glow); border: 1px solid var(--clr-accent); border-radius: 99px; padding: 0.35rem 1rem; font-size: 0.75rem; color: var(--clr-accent); margin: 1.5rem auto; width: fit-content; }
.badge-icon { font-size: 0.9rem; }

/* ── Tab Nav ── */
.tab-nav { display: flex; justify-content: center; gap: 0.5rem; margin-bottom: 1rem; }
.tab-btn { padding: 0.5rem 1.2rem; font-size: 0.85rem; font-weight: 600; background: var(--clr-surface-1); color: var(--clr-text-muted); border: 1px solid var(--clr-border); border-radius: 99px; cursor: pointer; transition: all 0.2s; }
.tab-btn.active { background: var(--clr-accent-glow); color: var(--clr-accent); border-color: var(--clr-accent); }
.tab-content { display: none; }
.tab-content.active { display: block; }

.app-grid { display: grid; grid-template-columns: 1fr; gap: 1.5rem; }
@media (min-width: 768px) { .app-grid { grid-template-columns: 380px 1fr; } }

.panel { background: var(--clr-surface-1); border: 1px solid var(--clr-border); border-radius: var(--radius); padding: 1.5rem; }
.panel-title { font-size: 1.25rem; font-weight: 700; color: var(--clr-accent); margin-bottom: 1.2rem; }

.input-group { margin-bottom: 1rem; }
.input-group label { display: block; font-size: 0.8rem; font-weight: 500; color: var(--clr-text-muted); margin-bottom: 0.3rem; }
.input-group input, .input-group select { width: 100%; padding: 0.6rem 0.8rem; font-size: 0.95rem; background: var(--clr-surface-2); color: var(--clr-text); border: 1px solid var(--clr-border); border-radius: 6px; font-family: var(--font-mono); transition: border-color 0.2s; }
.input-group input:focus, .input-group select:focus { outline: none; border-color: var(--clr-accent); }

.btn-calculate { width: 100%; padding: 0.8rem; font-size: 1rem; font-weight: 700; background: linear-gradient(135deg, var(--clr-accent), #f59e0b); color: #141216; border: none; border-radius: 8px; cursor: pointer; transition: transform 0.15s, box-shadow 0.2s; }
.btn-calculate:hover { transform: translateY(-1px); box-shadow: 0 6px 20px rgba(251, 191, 36, 0.3); }

.summary-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0.8rem; margin-bottom: 1.5rem; }
.summary-card { background: var(--clr-surface-2); border: 1px solid var(--clr-border); border-radius: 8px; padding: 0.8rem; text-align: center; }
.summary-card--highlight { border-color: var(--clr-accent); background: var(--clr-accent-glow); }
.summary-label { display: block; font-size: 0.7rem; color: var(--clr-text-muted); text-transform: uppercase; letter-spacing: 0.8px; }
.summary-value { display: block; font-family: var(--font-mono); font-size: 1.4rem; font-weight: 700; color: var(--clr-text); margin-top: 0.25rem; }
.summary-card--highlight .summary-value { color: var(--clr-accent); }

/* ── Fraction Reference ── */
.fraction-table { margin-top: 1rem; }
.section-subtitle { font-size: 1rem; font-weight: 600; color: var(--clr-text); margin-bottom: 0.5rem; }
.fraction-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(100px, 1fr)); gap: 0.4rem; }
.frac-cell { background: var(--clr-surface-2); border: 1px solid var(--clr-border); border-radius: 6px; padding: 0.4rem; text-align: center; font-family: var(--font-mono); font-size: 0.75rem; }
.frac-cell .frac-label { color: var(--clr-text-muted); font-size: 0.65rem; }
.frac-cell .frac-decimal { color: var(--clr-accent); font-weight: 600; }

.ad-slot { display: flex; align-items: center; justify-content: center; border: 2px dashed var(--clr-border); color: var(--clr-text-muted); font-size: 0.7rem; margin: 1rem auto; border-radius: 6px; }
.ad-slot--mobile { width: 320px; height: 50px; }
.ad-slot--desktop { display: none; width: 728px; height: 90px; }
@media (min-width: 768px) { .ad-slot--mobile { display: none; } .ad-slot--desktop { display: flex; } }
.site-footer { text-align: center; padding: 2rem 0; color: var(--clr-text-muted); font-size: 0.75rem; border-top: 1px solid var(--clr-border); margin-top: 3rem; }

/* ═══════════════ AFFILIATE & SEO ═══════════════ */
.seo-card {
    background: var(--clr-surface-1);
    border: 1px solid var(--clr-border);
    border-radius: var(--radius);
    padding: 1.5rem;
    margin: 2rem 0;
}
.seo-card h2 {
    color: var(--clr-text);
    margin-bottom: 0.5rem;
    font-size: 1.25rem;
}
.seo-card p {
    color: var(--clr-text-muted);
    line-height: 1.6;
}
.affiliate-gear a {
    color: var(--clr-accent);
    font-weight: 600;
    text-decoration: none;
}
.affiliate-gear a:hover {
    color: var(--clr-text);
    text-decoration: underline;
}