/* ═══════════════════════════════════════════════════════════════
   ResinRatio — The Epoxy Volume & Mix Calculator
   Bespoke theme: Deep resin blue/teal with glossy highlights
   ═══════════════════════════════════════════════════════════════ */

:root {
    --bg-primary: #0a0f14;
    --bg-surface: #121a22;
    --bg-hover: #1a2530;
    --bg-input: #0e1820;
    --text-primary: #e8f4f8;
    --text-secondary: #a0bcc8;
    --text-muted: #5e8090;
    --accent: #06b6d4;
    --accent-hover: #0891b2;
    --accent-glow: rgba(6, 182, 212, 0.15);
    --accent-glow-strong: rgba(6, 182, 212, 0.3);
    --border: rgba(160, 188, 200, 0.1);
    --border-hover: rgba(6, 182, 212, 0.4);
    --success: #22c55e;
    --success-bg: rgba(34, 197, 94, 0.12);
    --warning: #f59e0b;
    --warning-bg: rgba(245, 158, 11, 0.12);
    --error: #ef4444;
    --error-bg: rgba(239, 68, 68, 0.12);
    --resin-blue: #38bdf8;
    --hardener-amber: #f59e0b;
    --colorant-pink: #ec4899;
    --radius: 12px;
    --radius-sm: 8px;
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.4);
    --transition: 0.2s ease;
}

[data-theme="light"] {
    --bg-primary: #f0f9ff;
    --bg-surface: #ffffff;
    --bg-hover: #e0f2fe;
    --bg-input: #f0f9ff;
    --text-primary: #0c4a6e;
    --text-secondary: #1e6b8a;
    --text-muted: #5e8090;
    --border: rgba(12, 74, 110, 0.1);
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-secondary);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 1rem; }

/* ── Header ── */
.site-header {
    background: linear-gradient(135deg, #0c1820 0%, #0a0f14 100%);
    border-bottom: 1px solid var(--border);
    padding: 2rem 0 1.5rem;
    text-align: center;
}
.header-inner { display: flex; flex-direction: column; align-items: center; gap: 0.25rem; }
.brand { display: flex; align-items: center; gap: 0.75rem; }
.brand-icon { font-size: 2rem; }
.brand-name { font-family: 'Outfit', sans-serif; font-weight: 800; font-size: clamp(1.8rem, 5vw, 2.5rem); color: var(--text-primary); letter-spacing: -0.02em; }
.brand-tagline { font-family: 'Outfit', sans-serif; font-weight: 600; font-size: 1rem; color: var(--accent); margin-top: 0.25rem; }
.brand-subtitle { font-size: 0.9rem; color: var(--text-muted); max-width: 520px; margin-top: 0.25rem; }

.privacy-badge { display: inline-flex; align-items: center; gap: 0.5rem; background: var(--accent-glow); border: 1px solid rgba(6, 182, 212, 0.2); border-radius: 999px; padding: 0.4rem 1rem; font-size: 0.8rem; font-weight: 500; color: var(--accent); margin: 1.5rem auto 1rem; text-align: center; width: fit-content; }

/* ── Grid ── */
.app-grid { display: grid; grid-template-columns: 1fr; gap: 1.5rem; margin-top: 1rem; }
@media (min-width: 768px) { .app-grid { grid-template-columns: 420px 1fr; } }

.panel { background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.5rem; box-shadow: var(--shadow); }
.panel-title { font-family: 'Outfit', sans-serif; font-weight: 700; font-size: 1.35rem; color: var(--text-primary); margin-bottom: 1.25rem; }

/* ── Inputs ── */
.input-group { margin-bottom: 1.25rem; }
.input-group--half { flex: 1; min-width: 0; }
.input-group--third { flex: 1; min-width: 0; }
.input-row { display: flex; gap: 1rem; margin-bottom: 1.25rem; }

label { display: block; font-size: 0.85rem; font-weight: 600; color: var(--text-primary); margin-bottom: 0.4rem; }
.optional-tag { font-weight: 400; color: var(--text-muted); font-size: 0.75rem; }

input[type="number"], select {
    width: 100%; padding: 0.65rem 0.85rem; background: var(--bg-input); border: 1px solid var(--border); border-radius: var(--radius-sm); color: var(--text-primary); font-family: 'JetBrains Mono', monospace; font-size: 0.95rem; transition: border-color var(--transition), box-shadow var(--transition); appearance: none;
}
select { font-family: 'Inter', sans-serif; font-size: 0.85rem; cursor: pointer; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%235e8090' d='M6 8L1 3h10z'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 0.75rem center; padding-right: 2rem; }
input:focus, select:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-glow); }
.input-hint { display: block; font-size: 0.75rem; color: var(--text-muted); margin-top: 0.3rem; }

/* ── Shape Selector ── */
.shape-selector { display: flex; gap: 0.75rem; }
.btn-shape { flex: 1; display: flex; flex-direction: column; align-items: center; gap: 0.3rem; padding: 0.75rem; background: var(--bg-hover); border: 1px solid var(--border); border-radius: var(--radius-sm); color: var(--text-secondary); cursor: pointer; transition: all var(--transition); font-family: 'Inter', sans-serif; font-size: 0.82rem; font-weight: 500; }
.btn-shape:hover { border-color: var(--accent); color: var(--accent); }
.btn-shape.active { background: var(--accent-glow-strong); border-color: var(--accent); color: var(--accent); }
.shape-icon { font-size: 1.4rem; }

/* ── Buttons ── */
.btn-calculate { width: 100%; padding: 0.85rem; font-size: 1rem; font-weight: 700; background: linear-gradient(135deg, var(--accent), var(--accent-hover)); border: none; border-radius: var(--radius-sm); color: #001a20; cursor: pointer; transition: all var(--transition); font-family: 'Inter', sans-serif; margin-top: 0.5rem; }
.btn-calculate:hover { transform: translateY(-1px); box-shadow: 0 4px 16px rgba(6, 182, 212, 0.35); }

.error-message { background: var(--error-bg); border: 1px solid rgba(239, 68, 68, 0.3); border-radius: var(--radius-sm); padding: 0.75rem 1rem; font-size: 0.85rem; color: var(--error); margin-bottom: 1rem; }
.hidden { display: none !important; }

/* ── Pot Life Banner ── */
.pot-life-banner { display: flex; align-items: center; gap: 0.75rem; padding: 0.85rem 1.1rem; border-radius: var(--radius-sm); margin-bottom: 1.25rem; font-weight: 600; font-size: 0.85rem; }
.pot-life-banner--ok { background: var(--success-bg); border: 1px solid rgba(34, 197, 94, 0.3); color: var(--success); }
.pot-life-banner--warn { background: var(--warning-bg); border: 1px solid rgba(245, 158, 11, 0.3); color: var(--warning); }
.pot-life-banner--danger { background: var(--error-bg); border: 1px solid rgba(239, 68, 68, 0.3); color: var(--error); }

/* ── Summary Grid ── */
.summary-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0.75rem; margin-bottom: 1.25rem; }
@media (min-width: 600px) { .summary-grid { grid-template-columns: repeat(3, 1fr); } }
.summary-card { background: var(--bg-hover); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 0.85rem 0.75rem; text-align: center; transition: border-color var(--transition); }
.summary-card:hover { border-color: var(--border-hover); }
.summary-card--highlight { border-color: var(--accent); background: var(--accent-glow); }
.summary-label { display: block; font-size: 0.7rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-muted); margin-bottom: 0.35rem; }
.summary-value { display: block; font-family: 'JetBrains Mono', monospace; font-size: 1.15rem; font-weight: 500; color: var(--text-primary); }

/* ── Layer Table ── */
.section-subtitle { font-family: 'Outfit', sans-serif; font-weight: 700; font-size: 1.1rem; color: var(--text-primary); margin-bottom: 0.75rem; }
.layer-table-wrap { overflow-x: auto; }
.layer-table { width: 100%; border-collapse: collapse; font-size: 0.85rem; }
.layer-table th { text-align: left; padding: 0.6rem 0.75rem; font-weight: 600; color: var(--text-muted); border-bottom: 1px solid var(--border); font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.05em; }
.layer-table td { padding: 0.6rem 0.75rem; border-bottom: 1px solid var(--border); color: var(--text-secondary); font-family: 'JetBrains Mono', monospace; font-size: 0.82rem; }

/* ── Volume Visualizer ── */
.volume-viz { background: var(--bg-input); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 1.25rem; min-height: 120px; }
.diagram-placeholder { color: var(--text-muted); font-size: 0.9rem; text-align: center; }
.diagram-placeholder strong { color: var(--accent); }

.viz-bar-container { display: flex; gap: 2px; height: 50px; border-radius: var(--radius-sm); overflow: hidden; margin-bottom: 0.75rem; }
.viz-bar { display: flex; align-items: center; justify-content: center; color: #fff; font-size: 0.72rem; font-weight: 700; font-family: 'JetBrains Mono', monospace; transition: width 0.5s ease; }
.viz-bar--resin { background: linear-gradient(135deg, #38bdf8, #0ea5e9); }
.viz-bar--hardener { background: linear-gradient(135deg, #f59e0b, #d97706); }
.viz-bar--colorant { background: linear-gradient(135deg, #ec4899, #db2777); }
.viz-legend { display: flex; gap: 1.25rem; flex-wrap: wrap; }
.viz-legend-item { display: flex; align-items: center; gap: 0.4rem; font-size: 0.78rem; color: var(--text-secondary); }
.viz-legend-swatch { width: 12px; height: 12px; border-radius: 3px; }

/* ── Export / Copy ── */
.export-row { display: flex; gap: 0.75rem; margin-bottom: 1.25rem; }
.btn-export { display: inline-flex; align-items: center; gap: 0.4rem; padding: 0.5rem 1rem; font-size: 0.8rem; font-weight: 600; background: var(--bg-hover); border: 1px solid var(--border); border-radius: var(--radius-sm); color: var(--text-secondary); cursor: pointer; transition: all var(--transition); }
.btn-export:hover { border-color: var(--accent); color: var(--accent); background: var(--accent-glow); }

/* ── How It Works ── */
.how-it-works { margin-top: 2.5rem; padding: 2rem 0; }
.how-title { text-align: center; margin-bottom: 1.5rem; }
.how-grid { display: grid; grid-template-columns: 1fr; gap: 1rem; }
@media (min-width: 600px) { .how-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 900px) { .how-grid { grid-template-columns: repeat(4, 1fr); } }
.how-card { background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.25rem; text-align: center; transition: border-color var(--transition), transform var(--transition); }
.how-card:hover { border-color: var(--border-hover); transform: translateY(-2px); }
.how-icon { font-size: 1.8rem; display: block; margin-bottom: 0.75rem; }
.how-card-title { font-family: 'Outfit', sans-serif; font-weight: 700; font-size: 1rem; color: var(--text-primary); margin-bottom: 0.5rem; }
.how-card p { font-size: 0.82rem; color: var(--text-muted); line-height: 1.5; }

/* ── SEO / Footer ── */
.seo-card { background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.5rem; margin-top: 1.5rem; }
.seo-card h2 { font-family: 'Outfit', sans-serif; font-weight: 700; font-size: 1.25rem; color: var(--text-primary); margin-bottom: 0.75rem; }
.seo-card p { font-size: 0.9rem; color: var(--text-secondary); line-height: 1.7; }
.seo-card strong { color: var(--text-primary); }

.site-footer { text-align: center; padding: 2rem 0; margin-top: 2rem; border-top: 1px solid var(--border); }
.footer-privacy { font-size: 0.82rem; font-weight: 500; color: var(--accent); margin-bottom: 0.4rem; }
.footer-disclaimer, .footer-copyright { font-size: 0.75rem; color: var(--text-muted); margin-bottom: 0.4rem; }
.footer-copyright strong { color: var(--text-secondary); }

.toast { position: fixed; bottom: 2rem; left: 50%; transform: translateX(-50%) translateY(100px); background: var(--bg-surface); border: 1px solid var(--accent); border-radius: var(--radius-sm); padding: 0.7rem 1.4rem; font-size: 0.85rem; font-weight: 500; color: var(--accent); box-shadow: 0 8px 32px rgba(0,0,0,0.4); opacity: 0; transition: all 0.3s ease; z-index: 1000; pointer-events: none; }
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

@media (max-width: 480px) { .input-row { flex-direction: column; gap: 0; } }