:root {
  --bg: #07080b;
  --surface: #0d0f14;
  --text: #e9eef5;
  --muted: #7a8899;
  --border: #1a2230;
  --accent: #7dd3fc;
  --accent2: rgba(125, 211, 252, 0.1);
  --green: #34d399;
  --warn: #fbbf24;
  --bad: #fb7185;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: radial-gradient(ellipse at top, rgba(125,211,252,0.06), transparent 60%), var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}
.wrap { max-width: 740px; margin: 0 auto; padding: 24px 16px 60px; }

/* Header */
.hdr { text-align: center; padding-bottom: 20px; border-bottom: 1px solid var(--border); margin-bottom: 20px; }
.brand { font-size: 11px; letter-spacing: 0.2em; text-transform: uppercase; color: var(--muted); margin-bottom: 4px; }
.hdr h1 { font-size: 24px; font-weight: 600; }
.hdr .subtitle { font-size: 13px; color: var(--muted); margin-top: 4px; }

/* Cards */
.card { background: linear-gradient(180deg, rgba(255,255,255,0.03), rgba(255,255,255,0.01)); border: 1px solid var(--border); border-radius: 12px; padding: 20px; margin-bottom: 16px; }
.card h2 { font-size: 13px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); margin-bottom: 12px; display: flex; align-items: center; gap: 8px; }
.card p { color: var(--muted); font-size: 14px; margin-bottom: 10px; line-height: 1.65; }
.card.intro p:last-of-type { margin-bottom: 16px; }

/* Logic list (replaces generic ul in card body) */
.logic-list { list-style: none; margin: 8px 0 12px 0; }
.logic-list li { font-size: 13px; color: var(--text); padding: 8px 0 8px 20px; border-bottom: 1px solid var(--border); position: relative; line-height: 1.6; }
.logic-list li::before { content: "\2022"; color: var(--accent); position: absolute; left: 4px; }
.logic-list li:last-child { border-bottom: none; }
.logic-list li strong { color: var(--text); }

/* Flow steps */
.flow { display: flex; align-items: center; gap: 8px; margin: 16px 0; flex-wrap: wrap; }
.flow-step { display: flex; align-items: center; gap: 8px; background: var(--accent2); border: 1px solid rgba(125,211,252,0.2); border-radius: 8px; padding: 8px 12px; font-size: 13px; }
.flow-step .num { background: var(--accent); color: var(--bg); width: 20px; height: 20px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 11px; font-weight: 700; }
.arrow { color: var(--muted); font-size: 14px; }

/* Lanes */
.lanes { display: flex; flex-direction: column; gap: 12px; }
.lane { background: rgba(0,0,0,0.2); border: 1px solid var(--border); border-radius: 10px; padding: 14px; }
.lane-hd { display: flex; align-items: center; gap: 10px; margin-bottom: 8px; }
.lane-letter { background: var(--accent); color: var(--bg); width: 24px; height: 24px; border-radius: 6px; display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: 12px; }
.lane strong { font-size: 15px; }
.lane p { font-size: 13px; margin-bottom: 10px; line-height: 1.6; }
.tag { font-size: 11px; color: var(--muted); background: rgba(255,255,255,0.05); padding: 2px 6px; border-radius: 4px; margin-left: 8px; }
.tag-ok { color: var(--green); background: rgba(52,211,153,0.1); }
.tag-bad { color: var(--bad); background: rgba(251,113,133,0.1); }

/* Rules */
.rules ul { list-style: none; margin: 0 0 12px 0; }
.rules li { font-size: 13px; color: var(--text); padding: 8px 0; border-bottom: 1px solid var(--border); display: flex; align-items: baseline; gap: 8px; line-height: 1.6; }
.rules li::before { content: "\2713"; color: var(--green); font-size: 12px; flex-shrink: 0; }
.rules li strong { color: var(--text); }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; padding: 10px 16px; background: rgba(255,255,255,0.04); border: 1px solid var(--border); border-radius: 8px; color: var(--text); font-size: 13px; font-weight: 600; cursor: pointer; text-decoration: none; }
.btn:hover { border-color: var(--accent); background: var(--accent2); }
.btn.primary { background: var(--accent2); border-color: rgba(125,211,252,0.3); }
.btn.small { padding: 6px 10px; font-size: 12px; }
.btn.accept { color: var(--green); }
.btn.reject { color: var(--bad); }
.btn-row { display: flex; gap: 10px; flex-wrap: wrap; }

/* Calculator */
.calc-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 12px; margin-bottom: 16px; }
.calc-input label { font-size: 11px; color: var(--muted); display: flex; align-items: center; gap: 4px; margin-bottom: 4px; }
.input-row { display: flex; align-items: center; gap: 6px; }
.input-row input { flex: 1; min-width: 0; }
.input-row .unit { font-size: 12px; color: var(--muted); white-space: nowrap; }
input, textarea, select { width: 100%; background: rgba(0,0,0,0.3); border: 1px solid var(--border); border-radius: 8px; padding: 10px 12px; color: var(--text); font-size: 14px; }
input:focus, textarea:focus, select:focus { outline: none; border-color: var(--accent); }
textarea { min-height: 100px; resize: vertical; }

/* Results */
.results { background: rgba(0,0,0,0.2); border: 1px solid var(--border); border-radius: 10px; padding: 14px; margin-bottom: 14px; }
.result-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 12px; }
.result-row:last-child { margin-bottom: 0; }
.result-row.highlight { background: var(--accent2); border-radius: 8px; padding: 12px; margin: -4px -4px 12px -4px; }
.result-label { font-size: 11px; color: var(--muted); margin-bottom: 2px; }
.result-value { font-size: 18px; font-weight: 700; }
.result-value.accent { color: var(--green); }

/* Insight box */
.insight { font-size: 13px; color: var(--muted); background: rgba(52, 211, 153, 0.08); border: 1px solid rgba(52, 211, 153, 0.2); border-radius: 8px; padding: 12px; line-height: 1.65; margin-top: 12px; }
.insight strong { color: var(--green); }
.insight span { color: var(--text); font-weight: 600; }

/* Logic chain (vertical flow on green-steel page) */
.chain { display: flex; flex-direction: column; gap: 0; margin-bottom: 16px; }
.chain-step { display: flex; gap: 12px; padding: 12px; background: rgba(0,0,0,0.15); border: 1px solid var(--border); border-radius: 8px; }
.chain-num { background: var(--accent); color: var(--bg); width: 28px; height: 28px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 13px; font-weight: 700; flex-shrink: 0; margin-top: 2px; }
.chain-body strong { display: block; font-size: 14px; color: var(--text); margin-bottom: 2px; }
.chain-body p { font-size: 13px; margin: 0; }
.chain-arrow { text-align: center; color: var(--accent); font-size: 16px; padding: 2px 0; opacity: 0.5; }

/* Allocation grid (where steel goes) */
.alloc-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 10px; }
.alloc { background: rgba(0,0,0,0.2); border: 1px solid var(--border); border-radius: 8px; padding: 10px 12px; }
.alloc strong { display: block; font-size: 13px; margin-bottom: 2px; }
.alloc-qty { display: block; font-size: 15px; font-weight: 700; color: var(--accent); margin-bottom: 4px; }
.alloc .muted { font-size: 11px; line-height: 1.4; }

/* Data table */
.data-table { width: 100%; border-collapse: collapse; margin: 12px 0; font-size: 13px; }
.data-table th { text-align: left; color: var(--muted); font-size: 11px; text-transform: uppercase; letter-spacing: 0.05em; padding: 6px 10px; border-bottom: 1px solid var(--border); }
.data-table td { padding: 8px 10px; border-bottom: 1px solid rgba(255,255,255,0.04); color: var(--text); }
.data-table tbody tr:hover { background: rgba(125,211,252,0.04); }

/* Vertical grid */
.vertical-grid { display: flex; flex-direction: column; gap: 6px; }
.vert-item { display: flex; align-items: center; gap: 10px; padding: 8px 10px; border-radius: 6px; background: rgba(0,0,0,0.15); border: 1px solid transparent; }
.vert-item.active { border-color: rgba(52,211,153,0.3); background: rgba(52,211,153,0.06); }
.vert-item.sub { padding-left: 36px; }
.vert-icon { color: var(--accent); font-size: 10px; flex-shrink: 0; }
.vert-icon.sm { color: var(--muted); font-size: 8px; }
.vert-item strong { font-size: 13px; }
.vert-status { display: block; font-size: 11px; color: var(--muted); }

/* Uses grid (legacy compat) */
.uses-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 10px; }
.use { background: rgba(0,0,0,0.2); border: 1px solid var(--border); border-radius: 8px; padding: 10px 12px; }
.use strong { display: block; font-size: 13px; margin-bottom: 2px; }
.use .muted { font-size: 11px; }

/* Integration cards */
.integration { display: flex; flex-direction: column; gap: 10px; }
.int-item { background: rgba(0,0,0,0.2); border: 1px solid var(--border); border-radius: 8px; padding: 12px; }
.int-item.bad { border-color: rgba(251,113,133,0.25); background: rgba(251,113,133,0.04); }
.int-hd { display: flex; align-items: center; justify-content: space-between; margin-bottom: 6px; }
.int-item p { font-size: 13px; margin: 0; line-height: 1.6; }

/* Form */
.field { margin-bottom: 14px; }
.field label { display: flex; align-items: center; gap: 6px; font-size: 12px; color: var(--muted); margin-bottom: 6px; }
.field.inline { display: inline-flex; flex-direction: column; margin-right: 12px; }
.field.inline select { width: auto; min-width: 120px; }
.hint { font-size: 11px; color: var(--muted); margin-top: 4px; display: block; }
.submit-row { display: flex; align-items: center; gap: 12px; margin-top: 16px; }
.status { font-size: 13px; color: var(--green); }

/* Lane tabs */
.lane-tabs { display: flex; gap: 8px; margin-bottom: 14px; }
.lane-tab { flex: 1; padding: 10px; background: rgba(0,0,0,0.2); border: 1px solid var(--border); border-radius: 8px; color: var(--muted); font-size: 13px; font-weight: 600; cursor: pointer; }
.lane-tab:hover { color: var(--text); }
.lane-tab.on { background: var(--accent2); border-color: rgba(125,211,252,0.3); color: var(--accent); }
.lane-prompt { background: rgba(0,0,0,0.2); border: 1px solid var(--border); border-radius: 8px; padding: 12px; font-size: 13px; color: var(--muted); line-height: 1.6; }
.lane-prompt strong { color: var(--text); }
.hidden { display: none; }

/* Notice */
.notice { background: rgba(251, 191, 36, 0.08); border-color: rgba(251, 191, 36, 0.2); }
.notice p { margin-bottom: 6px; }

/* Submissions list */
.sub-list { display: flex; flex-direction: column; gap: 12px; }
.sub-item { background: rgba(0,0,0,0.2); border: 1px solid var(--border); border-radius: 10px; padding: 14px; }
.sub-hd { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 8px; flex-wrap: wrap; gap: 4px; }
.sub-date { font-size: 12px; color: var(--muted); }
.sub-body { font-size: 13px; margin-bottom: 8px; }
.sub-int { font-size: 12px; color: var(--muted); margin-bottom: 8px; }
.sub-actions { display: flex; gap: 8px; }
.count { font-size: 12px; color: var(--muted); font-weight: normal; }
.filter-row { display: flex; flex-wrap: wrap; align-items: flex-end; gap: 12px; }

/* Tooltips */
.q { display: inline-flex; align-items: center; justify-content: center; width: 16px; height: 16px; border-radius: 50%; border: 1px solid var(--border); font-size: 10px; color: var(--muted); cursor: pointer; background: rgba(255,255,255,0.02); }
.q:hover { background: var(--accent2); border-color: var(--accent); color: var(--accent); }

/* Modal */
.modal { display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.8); align-items: center; justify-content: center; padding: 20px; z-index: 100; }
.modal.on { display: flex; }
.modal-box { background: var(--surface); border: 1px solid var(--border); border-radius: 14px; padding: 20px; max-width: 600px; width: 100%; max-height: 80vh; overflow-y: auto; }
.modal-box h3 { font-size: 16px; margin-bottom: 12px; }
.modal-box p { font-size: 13px; color: var(--muted); margin-bottom: 8px; line-height: 1.6; }
.modal-box hr { border: none; border-top: 1px solid var(--border); margin: 12px 0; }
.modal-box ul { list-style: none; margin: 8px 0; }
.modal-box li { font-size: 13px; color: var(--muted); padding: 4px 0 4px 16px; position: relative; line-height: 1.6; }
.modal-box li::before { content: "\2022"; position: absolute; left: 0; color: var(--accent); }
.modal-box .btn { margin-top: 12px; }

/* Nav & footer */
.nav-links { display: flex; justify-content: space-between; padding: 16px 0; border-top: 1px solid var(--border); margin-top: 8px; }
.nav-links a { font-size: 13px; color: var(--muted); text-decoration: none; }
.nav-links a:hover { color: var(--accent); }
footer { text-align: center; font-size: 12px; color: var(--muted); margin-top: 20px; }

/* CTA */
.cta { text-align: center; }
.cta h2 { justify-content: center; }
.cta p { text-align: center; }
.cta .btn-row { justify-content: center; }

.muted { color: var(--muted); }

@media (max-width: 600px) {
  .result-row { grid-template-columns: 1fr; }
  .calc-grid { grid-template-columns: 1fr 1fr; }
  .flow { flex-direction: column; align-items: stretch; }
  .arrow { display: none; }
  .alloc-grid { grid-template-columns: 1fr; }
  .data-table { font-size: 12px; }
  .data-table th, .data-table td { padding: 6px; }
}


/* Badge + receipts */
.badge-status { font-size: 12px; color: var(--muted); margin-top: 8px; }
.badge-status span { color: var(--text); font-weight: 600; }
.receipt-list { list-style: none; padding-left: 0; margin-top: 10px; }
.receipt-list li { border-left: 2px solid var(--border); padding-left: 12px; margin-bottom: 12px; color: var(--muted); font-size: 13px; }
.receipt-meta { margin-top: 6px; font-size: 12px; color: var(--muted); }

/* ══════════════════════════════════════════
   VERTICAL CHALLENGE v3 ADDITIONS
   ══════════════════════════════════════════ */

/* Vertical grid */
.vertical-grid { display: flex; flex-direction: column; gap: 4px; }
.vert-item { display: flex; align-items: center; gap: 10px; padding: 7px 10px; border-radius: 6px; background: rgba(0,0,0,0.15); border: 1px solid transparent; }
.vert-item.filled { opacity: 0.6; }
.vert-item.open { border-color: rgba(251,191,36,0.4); background: rgba(251,191,36,0.08); opacity: 1; }
.vert-item.active { border-color: rgba(52,211,153,0.3); background: rgba(52,211,153,0.06); opacity: 1; }
.vert-item.sub { padding-left: 36px; }
.vert-icon { color: var(--accent); font-size: 10px; flex-shrink: 0; }
.vert-icon.sm { color: var(--muted); font-size: 8px; }
.vert-icon.open-icon { color: var(--warn); font-size: 12px; }
.vert-item strong { font-size: 13px; }
.vert-status { display: block; font-size: 11px; color: var(--muted); }
.vert-item.open .vert-status { color: var(--warn); font-weight: 600; }

/* Exemplar cards */
.exemplar-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.exemplar-card { display: block; background: rgba(0,0,0,0.2); border: 1px solid var(--border); border-radius: 10px; padding: 14px; text-decoration: none; color: var(--text); transition: border-color 0.15s; }
.exemplar-card:hover { border-color: var(--accent); }
.exemplar-card.highlight { border-color: rgba(251,191,36,0.3); background: rgba(251,191,36,0.04); }
.exemplar-card.highlight:hover { border-color: var(--warn); }
.exemplar-card strong { display: block; font-size: 15px; margin-bottom: 6px; }
.exemplar-card span { display: block; font-size: 12px; color: var(--muted); line-height: 1.5; margin-bottom: 4px; }
.exemplar-card .exemplar-label { color: var(--accent); font-weight: 600; margin-top: 8px; }
.exemplar-card.highlight .exemplar-label { color: var(--warn); }

/* Logic chain */
.chain { display: flex; flex-direction: column; gap: 0; margin-bottom: 16px; }
.chain-step { display: flex; gap: 12px; padding: 12px; background: rgba(0,0,0,0.15); border: 1px solid var(--border); border-radius: 8px; }
.chain-num { background: var(--accent); color: var(--bg); width: 28px; height: 28px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 13px; font-weight: 700; flex-shrink: 0; margin-top: 2px; }
.chain-body { flex: 1; }
.chain-body strong { display: block; font-size: 14px; color: var(--text); margin-bottom: 2px; }
.chain-body p { font-size: 13px; margin: 0; }
.chain-arrow { text-align: center; color: var(--accent); font-size: 16px; padding: 2px 0; opacity: 0.5; }

/* Logic list */
.logic-list { list-style: none; margin: 8px 0 12px 0; }
.logic-list li { font-size: 13px; color: var(--text); padding: 8px 0 8px 20px; border-bottom: 1px solid var(--border); position: relative; line-height: 1.6; }
.logic-list li::before { content: "\2022"; color: var(--accent); position: absolute; left: 4px; }
.logic-list li:last-child { border-bottom: none; }

/* Data tables */
.data-table { width: 100%; border-collapse: collapse; margin: 8px 0; font-size: 13px; }
.data-table th { text-align: left; color: var(--muted); font-size: 11px; text-transform: uppercase; letter-spacing: 0.05em; padding: 6px 10px; border-bottom: 1px solid var(--border); }
.data-table td { padding: 7px 10px; border-bottom: 1px solid rgba(255,255,255,0.04); color: var(--text); }
.data-table tbody tr:hover { background: rgba(125,211,252,0.04); }

/* Insight box */
.insight { font-size: 13px; color: var(--muted); background: rgba(52,211,153,0.08); border: 1px solid rgba(52,211,153,0.2); border-radius: 8px; padding: 12px; line-height: 1.65; }
.insight strong { color: var(--green); }
.insight span { color: var(--text); font-weight: 600; }

/* Integration items */
.integration { display: flex; flex-direction: column; gap: 10px; }
.int-item { background: rgba(0,0,0,0.2); border: 1px solid var(--border); border-radius: 8px; padding: 12px; }
.int-item.bad { border-color: rgba(251,113,133,0.25); background: rgba(251,113,133,0.04); }
.int-hd { display: flex; align-items: center; justify-content: space-between; margin-bottom: 6px; }
.int-item p { font-size: 13px; margin: 0; line-height: 1.6; }

/* Allocation grid */
.alloc-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 10px; }
.alloc { background: rgba(0,0,0,0.2); border: 1px solid var(--border); border-radius: 8px; padding: 10px 12px; }
.alloc strong { display: block; font-size: 13px; margin-bottom: 2px; }
.alloc-qty { display: block; font-size: 15px; font-weight: 700; color: var(--accent); margin-bottom: 4px; }
.alloc .muted { font-size: 11px; line-height: 1.4; }

/* Urban Mine calc blocks */
.um-calc { }
.um-block { background: rgba(0,0,0,0.15); border: 1px solid var(--border); border-radius: 10px; padding: 14px; }
.um-block h3 { font-size: 14px; color: var(--text); margin-bottom: 10px; }

/* Receipt list */
.receipt-list { list-style: none; margin: 0; }
.receipt-list li { padding: 8px 0; border-bottom: 1px solid var(--border); }
.receipt-list li strong { font-size: 13px; display: block; }
.receipt-meta { font-size: 11px; color: var(--muted); margin-top: 2px; }

/* Subtitle */
.hdr .subtitle { font-size: 13px; color: var(--muted); margin-top: 4px; }

/* Sub title in submissions */
.sub-title { font-size: 13px; margin-bottom: 4px; }

/* Tag variants */
.tag-ok { color: var(--green); background: rgba(52,211,153,0.1); }
.tag-bad { color: var(--bad); background: rgba(251,113,133,0.1); }

@media (max-width: 600px) {
  .exemplar-row { grid-template-columns: 1fr; }
  .alloc-grid { grid-template-columns: 1fr; }
}