:root {
  --primary: #1d4ed8;
  --primary-light: #eff6ff;
  --success: #059669;
  --success-light: #f0fdf4;
  --warning: #b45309;
  --warning-light: #fffbeb;
  --danger: #dc2626;
  --danger-light: #fef2f2;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --border: #e2e8f0;
  --card-bg: #fff;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07);

  --band-24: #f59e0b;
  --band-5: #3b82f6;
  --band-6: #8b5cf6;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; -webkit-tap-highlight-color: transparent; }
html, body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif; background: #f8fafc; color: var(--text-primary); min-height: 100vh; }
a { color: var(--primary); text-decoration: none; }

/* ===== NAV ===== */
.top-nav {
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 0 20px;
  position: sticky; top: 0; z-index: 300;
}
.top-nav-inner { height: 52px; max-width: 1100px; margin: 0 auto; display: flex; align-items: center; gap: 12px; }
.nav-back { font-size: 0.82rem; font-weight: 600; color: var(--text-secondary); padding: 6px 12px; border: 1px solid var(--border); border-radius: 20px; white-space: nowrap; transition: all 0.15s; }
.nav-back:hover { color: var(--primary); border-color: var(--primary); }
.nav-title { font-size: 0.9rem; font-weight: 800; color: var(--text-primary); flex: 1; }

/* ===== HERO ===== */
.tool-hero {
  background: linear-gradient(135deg, #0f2d6b 0%, #1d4ed8 55%, #3b82f6 100%);
  color: #fff; padding: 28px 20px 24px; text-align: center;
}
.tool-hero h1 { font-size: 1.45rem; font-weight: 900; margin-bottom: 6px; }
.tool-hero p { font-size: 0.85rem; opacity: 0.88; line-height: 1.6; }
.hero-badges { display: flex; gap: 8px; justify-content: center; flex-wrap: wrap; margin-top: 12px; }
.hero-badge { background: rgba(255,255,255,0.15); border: 1px solid rgba(255,255,255,0.3); border-radius: 20px; padding: 4px 12px; font-size: 0.75rem; font-weight: 600; }

/* ===== WRAP ===== */
.tool-wrap { max-width: 1100px; margin: 0 auto; padding: 14px 12px 80px; display: flex; flex-direction: column; gap: 14px; }

/* ===== STATS ROW ===== */
.stats-row { display: flex; gap: 10px; }
.stat-card { flex: 1; background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 10px 14px; text-align: center; box-shadow: var(--shadow); }
.stat-num { font-size: 1.5rem; font-weight: 900; color: var(--primary); line-height: 1; }
.stat-label { font-size: 0.72rem; color: var(--text-muted); margin-top: 3px; font-weight: 600; }

/* ===== SCENARIO PICKER ===== */
.scenario-section { background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; }
.section-header { padding: 10px 16px; border-bottom: 1px solid var(--border); font-size: 0.85rem; font-weight: 800; color: var(--text-primary); display: flex; align-items: center; gap: 6px; }
.scenario-scroll { display: flex; gap: 8px; padding: 12px 14px; overflow-x: auto; -webkit-overflow-scrolling: touch; scrollbar-width: none; }
.scenario-scroll::-webkit-scrollbar { display: none; }
.scenario-btn {
  flex-shrink: 0; display: flex; flex-direction: column; align-items: center; gap: 4px;
  padding: 10px 14px; border: 2px solid var(--border); border-radius: 10px;
  background: var(--card-bg); cursor: pointer; transition: all 0.15s;
  min-width: 90px; text-align: center;
}
.scenario-btn:hover { border-color: var(--primary); }
.scenario-btn.active { border-color: var(--primary); background: var(--primary-light); }
.scenario-btn .sc-icon { font-size: 1.5rem; }
.scenario-btn .sc-name { font-size: 0.72rem; font-weight: 700; color: var(--text-secondary); white-space: nowrap; }
.scenario-btn.active .sc-name { color: var(--primary); }
.scenario-goal { padding: 8px 14px 12px; font-size: 0.78rem; color: var(--text-secondary); line-height: 1.6; border-top: 1px solid var(--border); background: #f8fafc; }
.scenario-goal strong { color: var(--text-primary); }

/* ===== MAIN TWO-COLUMN ===== */
.tool-main { display: grid; grid-template-columns: 1fr; gap: 14px; }
@media (min-width: 860px) { .tool-main { grid-template-columns: 3fr 2fr; } }

/* ===== FLOOR PANEL ===== */
.floor-panel { background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; }
.floor-toolbar { display: flex; gap: 6px; flex-wrap: wrap; padding: 10px 12px; background: #f8fafc; border-bottom: 1px solid var(--border); }
.fl-btn {
  font-size: 0.78rem; font-weight: 700; padding: 7px 12px; border-radius: 8px;
  border: 1.5px solid var(--border); background: var(--card-bg);
  color: var(--text-secondary); cursor: pointer; transition: all 0.15s;
  display: flex; align-items: center; gap: 4px; white-space: nowrap;
}
.fl-btn:hover { border-color: var(--primary); color: var(--primary); }
.fl-btn.active { background: var(--primary); color: #fff; border-color: var(--primary); }
.fl-btn.success { border-color: #6ee7b7; color: #059669; }
.fl-btn.success:hover { background: var(--success-light); }
.fl-btn.danger { border-color: #fca5a5; color: var(--danger); }
.fl-btn.danger:hover { background: var(--danger-light); }

/* Floor SVG container */
.floor-svg-wrap { position: relative; width: 100%; overflow: hidden; background: #94a3b8; }
.floor-svg-wrap svg { display: block; width: 100%; height: auto; cursor: default; }
.floor-svg-wrap.add-mode { cursor: crosshair; }

/* Legend */
.floor-legend { display: flex; gap: 10px; flex-wrap: wrap; padding: 8px 12px; border-top: 1px solid var(--border); background: #f8fafc; }
.legend-item { display: flex; align-items: center; gap: 5px; font-size: 0.7rem; color: var(--text-muted); font-weight: 600; }
.legend-dot { width: 12px; height: 12px; border-radius: 50%; flex-shrink: 0; }

/* ===== CONFIG PANEL ===== */
.config-panel { background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; display: flex; flex-direction: column; }

/* Tab bar */
.tab-bar { display: flex; border-bottom: 1px solid var(--border); overflow-x: auto; -webkit-overflow-scrolling: touch; scrollbar-width: none; background: #f8fafc; }
.tab-bar::-webkit-scrollbar { display: none; }
.tab-btn {
  flex-shrink: 0; padding: 10px 14px; font-size: 0.78rem; font-weight: 700;
  color: var(--text-muted); border: none; background: none; cursor: pointer;
  border-bottom: 2px solid transparent; transition: all 0.15s; white-space: nowrap;
}
.tab-btn.active { color: var(--primary); border-bottom-color: var(--primary); }
.tab-btn:hover:not(.active) { color: var(--text-secondary); }

.tab-pane { display: none; flex: 1; overflow-y: auto; }
.tab-pane.active { display: block; }
.tab-body { padding: 14px; }

/* AP config */
.ap-placeholder { padding: 30px 16px; text-align: center; color: var(--text-muted); font-size: 0.82rem; }
.ap-form { display: flex; flex-direction: column; gap: 10px; }
.form-row { display: flex; flex-direction: column; gap: 4px; }
.form-row label { font-size: 0.75rem; font-weight: 700; color: var(--text-secondary); }
.form-row input, .form-row select {
  font-size: 0.82rem; padding: 7px 10px; border: 1px solid var(--border);
  border-radius: 6px; background: #f8fafc; color: var(--text-primary);
  width: 100%; transition: border-color 0.15s;
}
.form-row input:focus, .form-row select:focus { outline: none; border-color: var(--primary); }
.form-row .hint { font-size: 0.7rem; color: var(--text-muted); }
.form-2col { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }

/* SSID panel */
.ssid-table { width: 100%; border-collapse: collapse; font-size: 0.78rem; }
.ssid-table th { background: #f8fafc; color: var(--text-muted); font-weight: 700; padding: 7px 8px; border-bottom: 1px solid var(--border); text-align: left; font-size: 0.7rem; white-space: nowrap; }
.ssid-table td { padding: 7px 8px; border-bottom: 1px solid var(--border); vertical-align: top; }
.ssid-table tr:last-child td { border-bottom: none; }
.ssid-table input, .ssid-table select { font-size: 0.75rem; padding: 4px 6px; border: 1px solid var(--border); border-radius: 4px; background: #f8fafc; width: 100%; }
.ssid-badge { display: inline-block; padding: 2px 7px; border-radius: 10px; font-size: 0.65rem; font-weight: 700; }
.ssid-badge.corp  { background: #eff6ff; color: var(--primary); }
.ssid-badge.guest { background: #f0fdf4; color: #059669; }
.ssid-badge.voice { background: #fdf4ff; color: #9333ea; }
.ssid-badge.iot   { background: #fff7ed; color: #ea580c; }

/* IP Calculator */
.ip-calc { display: flex; flex-direction: column; gap: 10px; }
.ip-row { display: flex; align-items: center; gap: 8px; font-size: 0.82rem; }
.ip-row label { width: 90px; font-weight: 700; color: var(--text-secondary); flex-shrink: 0; font-size: 0.75rem; }
.ip-row input, .ip-row select { flex: 1; font-size: 0.82rem; padding: 6px 8px; border: 1px solid var(--border); border-radius: 6px; }
.ip-result { background: #f8fafc; border: 1px solid var(--border); border-radius: 8px; padding: 12px 14px; font-size: 0.8rem; }
.ip-result-row { display: flex; justify-content: space-between; align-items: center; padding: 4px 0; border-bottom: 1px solid var(--border); }
.ip-result-row:last-child { border-bottom: none; padding-bottom: 0; }
.ip-result-row .key { color: var(--text-muted); font-weight: 600; }
.ip-result-row .val { font-weight: 800; }
.ip-result-row .val.ok { color: var(--success); }
.ip-result-row .val.warn { color: var(--warning); }
.ip-result-row .val.ng  { color: var(--danger); }
.bw-result { display: flex; flex-direction: column; gap: 6px; }
.bw-bar-wrap { height: 14px; background: var(--border); border-radius: 7px; overflow: hidden; margin-top: 4px; }
.bw-bar { height: 100%; border-radius: 7px; transition: width 0.4s; }

/* Security panel */
.sec-row { display: flex; align-items: flex-start; gap: 8px; padding: 8px 0; border-bottom: 1px solid var(--border); font-size: 0.8rem; }
.sec-row:last-child { border-bottom: none; }
.sec-icon { font-size: 1.1rem; flex-shrink: 0; margin-top: 1px; }
.sec-text { flex: 1; line-height: 1.6; }
.sec-text strong { font-weight: 700; }

/* ===== SCORE PANEL ===== */
.score-panel { background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; }
.score-header { padding: 12px 16px; font-size: 0.9rem; font-weight: 800; border-bottom: 1px solid var(--border); display: flex; align-items: center; gap: 8px; }
.score-body { padding: 16px; display: flex; flex-direction: column; gap: 12px; }
.score-top { display: flex; gap: 12px; align-items: center; }
.score-big { text-align: center; padding: 16px 24px; background: var(--primary-light); border-radius: var(--radius-sm); border: 2px solid #bfdbfe; flex-shrink: 0; }
.score-num { font-size: 2.8rem; font-weight: 900; color: var(--primary); line-height: 1; }
.score-denom { font-size: 1rem; color: var(--text-muted); font-weight: 600; }
.score-grade { font-size: 0.82rem; font-weight: 800; margin-top: 6px; }
.score-details { flex: 1; display: flex; flex-direction: column; gap: 6px; min-width: 0; }
.score-item { display: flex; align-items: flex-start; gap: 8px; padding: 8px 10px; border-radius: 8px; border: 1px solid var(--border); font-size: 0.78rem; background: #f8fafc; }
.score-item.pass { background: var(--success-light); border-color: #86efac; }
.score-item.fail { background: var(--danger-light); border-color: #fca5a5; }
.score-item.warn { background: var(--warning-light); border-color: #fde68a; }
.score-item-icon { font-size: 0.9rem; flex-shrink: 0; margin-top: 1px; }
.score-item-text { flex: 1; line-height: 1.5; color: var(--text-secondary); }
.score-item-text strong { color: var(--text-primary); }
.score-placeholder { text-align: center; color: var(--text-muted); font-size: 0.85rem; padding: 24px 0; }
.score-actions { display: flex; gap: 8px; flex-wrap: wrap; }
.score-actions button { font-size: 0.8rem; font-weight: 700; padding: 9px 16px; border-radius: 8px; cursor: pointer; transition: all 0.15s; border: 1.5px solid; }
.btn-score-main { background: var(--primary); color: #fff; border-color: var(--primary); }
.btn-score-main:hover { background: #1e40af; }
.btn-model { background: var(--card-bg); color: var(--text-secondary); border-color: var(--border); }
.btn-model:hover { border-color: var(--primary); color: var(--primary); }

/* Model answer overlay */
.model-panel { background: #fffbeb; border: 1px solid #fde68a; border-radius: var(--radius); padding: 16px; display: none; }
.model-panel.open { display: block; }
.model-panel h3 { font-size: 0.88rem; font-weight: 800; color: #92400e; margin-bottom: 8px; }
.model-list { display: flex; flex-direction: column; gap: 6px; }
.model-item { font-size: 0.8rem; color: #78350f; line-height: 1.6; padding: 6px 10px; background: rgba(255,255,255,0.6); border-radius: 6px; border-left: 3px solid #f59e0b; }

/* ===== EXPLAIN ACCORDION ===== */
.accordion { display: flex; flex-direction: column; gap: 8px; }
.accordion-item { background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.accordion-btn {
  width: 100%; padding: 13px 16px; font-size: 0.85rem; font-weight: 800;
  background: none; border: none; cursor: pointer; text-align: left;
  display: flex; align-items: center; justify-content: space-between; color: var(--text-primary);
  transition: background 0.15s;
}
.accordion-btn:hover { background: #f8fafc; }
.accordion-arrow { font-size: 0.75rem; color: var(--text-muted); transition: transform 0.2s; }
.accordion-item.open .accordion-arrow { transform: rotate(180deg); }
.accordion-body { display: none; padding: 0 16px 16px; font-size: 0.82rem; line-height: 1.8; color: var(--text-secondary); }
.accordion-item.open .accordion-body { display: block; }
.accordion-body h4 { font-size: 0.85rem; font-weight: 800; color: var(--text-primary); margin: 12px 0 6px; }
.accordion-body h4:first-child { margin-top: 0; }
.accordion-body ul { padding-left: 18px; }
.accordion-body ul li { margin-bottom: 5px; }
.accordion-body .highlight { background: var(--primary-light); border-left: 3px solid var(--primary); padding: 8px 12px; border-radius: 0 6px 6px 0; margin: 8px 0; font-size: 0.8rem; }
.accordion-body .warn-box { background: var(--warning-light); border-left: 3px solid #fbbf24; padding: 8px 12px; border-radius: 0 6px 6px 0; margin: 8px 0; }
.accordion-body code { font-family: monospace; background: #f1f5f9; padding: 1px 5px; border-radius: 4px; font-size: 0.78rem; color: var(--primary); }

/* ===== CONFLICT OVERLAY TEXT ===== */
.conflict-badge {
  font-size: 9px; font-weight: 900;
  fill: #dc2626; text-anchor: middle; dominant-baseline: middle;
  pointer-events: none;
}
.warning-label { fill: #b45309; font-size: 9px; font-weight: 700; text-anchor: middle; }

/* ===== TOAST ===== */
.toast {
  position: fixed; bottom: calc(20px + env(safe-area-inset-bottom)); left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: #1e293b; color: #fff; padding: 10px 20px; border-radius: 20px;
  font-size: 0.82rem; font-weight: 600; opacity: 0; transition: all 0.25s;
  z-index: 999; white-space: nowrap; pointer-events: none;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ===== AP INFO LABEL ===== */
.ap-info-label { font-size: 8.5px; fill: #475569; text-anchor: middle; pointer-events: none; font-weight: 600; }
.ap-name-label { font-size: 9.5px; fill: #1e293b; text-anchor: middle; font-weight: 800; pointer-events: none; }

/* ===== ROOM LABELS ===== */
.room-label { font-size: 11px; fill: #334155; font-weight: 700; text-anchor: middle; pointer-events: none; }
.room-icon  { font-size: 16px; text-anchor: middle; dominant-baseline: middle; pointer-events: none; }

/* ===== Dividers ===== */
.divider { height: 1px; background: var(--border); margin: 6px 0; }

/* Channel select colors */
.ch-24 { color: var(--band-24); }
.ch-5  { color: var(--band-5); }
.ch-6  { color: var(--band-6); }
.band-dot { display: inline-block; width: 8px; height: 8px; border-radius: 50%; margin-right: 4px; vertical-align: middle; }
.band-dot.b24 { background: var(--band-24); }
.band-dot.b5  { background: var(--band-5); }
.band-dot.b6  { background: var(--band-6); }