/* ─── LAYOUT: App Shell, Topbar, Nav, Pages, Cards, Stats ─────────────── */
  /* MAIN APP */
  #app { display: none; flex-direction: column; min-height: 100vh; padding-bottom: 80px; }
  #app.visible { display: flex; }

  /* TOP BAR */
  .topbar {
    display: flex; align-items: center; justify-content: space-between;
    padding: 16px 20px 12px;
    position: sticky; top: 0; z-index: 50;
    background: rgba(10,10,15,0.92);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
  }
  .topbar-logo {
    font-family: var(--font-display);
    font-size: 20px; font-weight: 800;
    letter-spacing: -0.5px;
  }
  .topbar-logo span { color: var(--accent); font-weight: 400; }
  .topbar-week {
    font-family: var(--font-mono);
    font-size: 11px; color: var(--text3);
    letter-spacing: 1px;
  }
  .topbar-reset {
    background: var(--surface2);
    border: 1px solid var(--border);
    color: var(--text3);
    font-size: 11px; font-family: var(--font-mono);
    padding: 6px 10px; border-radius: 6px;
    cursor: pointer;
    transition: color 0.2s;
  }
  .topbar-reset:hover { color: var(--accent2); border-color: var(--accent2); }

  /* BOTTOM NAV */
  .bottom-nav {
    position: fixed; bottom: 0; left: 0; right: 0; z-index: 50;
    background: rgba(17,17,24,0.96);
    backdrop-filter: blur(16px);
    border-top: 1px solid var(--border);
    display: flex;
    padding: 8px 0 max(8px, env(safe-area-inset-bottom));
  }
  .nav-item {
    flex: 1; display: flex; flex-direction: column;
    align-items: center; gap: 4px;
    padding: 6px 0; cursor: pointer;
    opacity: 0.4;
    transition: opacity 0.2s;
    border: none; background: none; color: var(--text);
  }
  .nav-item.active { opacity: 1; }
  .nav-item svg { width: 22px; height: 22px; }
  .nav-item span { font-size: 10px; font-family: var(--font-mono); letter-spacing: 0.5px; }
  .nav-item.active span { color: var(--accent); }

  /* PAGES */
  .page { display: none; padding: 20px; flex-direction: column; gap: 20px; }
  .page.active { display: flex; }

  /* CARDS */
  .card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    position: relative; overflow: hidden;
  }
  .card-label {
    font-family: var(--font-mono);
    font-size: 11px; color: var(--text3);
    letter-spacing: 2px; text-transform: uppercase;
    margin-bottom: 8px;
  }
  .card-value {
    font-family: var(--font-display);
    font-size: 36px; font-weight: 800;
    letter-spacing: -1px;
    line-height: 1;
  }
  .card-sub {
    font-size: 13px; color: var(--text2);
    margin-top: 4px;
    font-family: var(--font-mono);
  }
  .card-accent-bar {
    position: absolute; top: 0; left: 0; right: 0;
    height: 2px;
  }

  /* STAT GRID */
  .stat-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
  .stat-mini {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 14px 16px;
  }
  .stat-mini-label {
    font-family: var(--font-mono);
    font-size: 10px; color: var(--text3);
    letter-spacing: 1.5px; text-transform: uppercase;
    margin-bottom: 6px;
  }
  .stat-mini-value {
    font-family: var(--font-display);
    font-size: 24px; font-weight: 700;
    letter-spacing: -0.5px;
  }
  .stat-mini-unit { font-size: 13px; font-weight: 400; color: var(--text2); margin-left: 2px; }
  .stat-mini-change { font-size: 11px; font-family: var(--font-mono); margin-top: 4px; }
  .green { color: var(--accent); }
  .red { color: var(--accent2); }
  .yellow { color: var(--accent3); }
  .blue { color: var(--accent4); }

  /* PROGRESS BAR */
  .prog-bar-wrap { margin-top: 14px; }
  .prog-bar-labels { display: flex; justify-content: space-between; margin-bottom: 6px; }
  .prog-bar-labels span { font-family: var(--font-mono); font-size: 11px; color: var(--text3); }
  .prog-bar-track {
    height: 6px; background: var(--surface3);
    border-radius: 99px; overflow: hidden;
  }
  .prog-bar-fill {
    height: 100%; border-radius: 99px;
    background: linear-gradient(90deg, var(--accent), #4dffa3);
    transition: width 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
  }

  /* CHART CARD */
  .chart-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
  }
  .chart-header {
    display: flex; justify-content: space-between;
    align-items: flex-start; margin-bottom: 16px;
  }
  .chart-title {
    font-family: var(--font-display);
    font-size: 16px; font-weight: 700;
  }
  .chart-badge {
    font-family: var(--font-mono);
    font-size: 10px; letter-spacing: 1px;
    padding: 4px 8px; border-radius: 4px;
    text-transform: uppercase;
  }
  .chart-wrap { position: relative; height: 160px; }

  /* ALERT CARD */
  .alert-card {
    border-radius: var(--radius-sm);
    padding: 14px 16px;
    display: flex; gap: 12px; align-items: flex-start;
  }
  .alert-card .alert-icon { font-size: 20px; flex-shrink: 0; }
  .alert-card .alert-title { font-family: var(--font-display); font-size: 14px; font-weight: 700; margin-bottom: 3px; }
  .alert-card .alert-text { font-size: 13px; line-height: 1.4; color: var(--text2); }
  .alert-green { background: rgba(124,255,196,0.08); border: 1px solid rgba(124,255,196,0.2); }
  .alert-yellow { background: rgba(255,196,107,0.08); border: 1px solid rgba(255,196,107,0.2); }
  .alert-red { background: rgba(255,107,107,0.08); border: 1px solid rgba(255,107,107,0.2); }
  .alert-blue { background: rgba(107,184,255,0.08); border: 1px solid rgba(107,184,255,0.2); }

  /* INPUT FORM */
  .form-section-label {
    font-family: var(--font-display);
    font-size: 18px; font-weight: 800;
    letter-spacing: -0.3px;
  }
  .form-section-sub { font-size: 13px; color: var(--text3); font-family: var(--font-mono); margin-top: 2px; }
  .input-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
  }
  .input-row {
    display: flex; align-items: center;
    padding: 14px 18px;
    border-bottom: 1px solid var(--border);
    gap: 12px;
  }
  .input-row:last-child { border-bottom: none; }
  .input-row-label { flex: 1; }
  .input-row-label .lbl { font-size: 14px; font-weight: 500; }
  .input-row-label .sub { font-size: 11px; color: var(--text3); font-family: var(--font-mono); margin-top: 2px; }
  .input-row input[type="number"] {
    background: var(--surface3);
    border: 1px solid var(--border2);
    color: var(--text);
    font-family: var(--font-display);
    font-size: 17px; font-weight: 700;
    width: 100px; text-align: right;
    padding: 9px 11px;
    border-radius: var(--radius-sm);
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
  }
  .input-row input[type="number"]:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(124,255,196,0.1);
  }
  .input-row .unit-lbl {
    font-size: 12px; color: var(--text3);
    font-family: var(--font-mono); width: 30px;
  }

  /* DAILY STEPS GRID */
  .day-grid { display: grid; grid-template-columns: repeat(7, 1fr); gap: 6px; margin-top: 4px; }
  .day-cell { display: flex; flex-direction: column; align-items: center; gap: 4px; }
  .day-cell .d-label { font-size: 9px; color: var(--text3); font-family: var(--font-mono); text-transform: uppercase; }
  .day-cell input {
    width: 100%; background: var(--surface3);
    border: 1px solid var(--border);
    color: var(--text); text-align: center;
    font-family: var(--font-display); font-size: 12px; font-weight: 600;
    padding: 8px 2px; border-radius: 8px;
    outline: none;
    transition: border-color 0.2s;
  }
  .day-cell input:focus { border-color: var(--accent); }

  /* DAILY WEIGHT GRID */
  .weight-grid { display: grid; grid-template-columns: repeat(7, 1fr); gap: 6px; margin-top: 4px; }
  .weight-cell { display: flex; flex-direction: column; align-items: center; gap: 4px; }
  .weight-cell .d-label { font-size: 9px; color: var(--text3); font-family: var(--font-mono); text-transform: uppercase; }
  .weight-cell input {
    width: 100%; background: var(--surface3);
    border: 1px solid var(--border);
    color: var(--text); text-align: center;
    font-family: var(--font-display); font-size: 12px; font-weight: 600;
    padding: 8px 2px; border-radius: 8px;
    outline: none;
    transition: border-color 0.2s;
  }
  .weight-cell input:focus { border-color: var(--accent); }

  /* SAVE BUTTON */
  .save-btn {
    background: var(--accent);
    color: #000;
    font-family: var(--font-display);
    font-size: 16px; font-weight: 700;
    padding: 16px;
    border: none; border-radius: var(--radius);
    cursor: pointer; width: 100%;
    transition: opacity 0.2s, transform 0.1s;
    letter-spacing: 0.5px;
  }
  .save-btn:active { transform: scale(0.98); opacity: 0.9; }
  .save-success {
    text-align: center; font-family: var(--font-mono);
    font-size: 12px; color: var(--accent); letter-spacing: 1px;
    padding: 8px; display: none;
  }

  /* PHASE BADGE */
  .phase-badge {
    display: inline-flex; align-items: center; gap: 8px;
    background: var(--surface2);
    border: 1px solid var(--border2);
    border-radius: 99px;
    padding: 6px 14px;
    font-family: var(--font-mono);
    font-size: 11px; letter-spacing: 1px;
    text-transform: uppercase;
  }
  .phase-dot { width: 7px; height: 7px; border-radius: 50%; }

  /* INSIGHTS PAGE */
  .insight-week-label {
    font-family: var(--font-display);
    font-size: 22px; font-weight: 800;
    letter-spacing: -0.5px;
  }
  .insight-summary {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
  }
  .insight-summary p {
    font-size: 15px; line-height: 1.6; color: var(--text2);
  }
  .insight-summary strong { color: var(--text); font-weight: 600; }

  .reco-list { display: flex; flex-direction: column; gap: 8px; }
  .reco-item {
    display: flex; align-items: center; gap: 12px;
    background: var(--surface2);
    border-radius: var(--radius-sm);
    padding: 12px 14px;
    border-left: 3px solid var(--accent);
    font-size: 14px;
  }
  .reco-item.warn { border-left-color: var(--accent3); }
  .reco-item.danger { border-left-color: var(--accent2); }
  .reco-item.info { border-left-color: var(--accent4); }

  /* HISTORY TABLE */
  .hist-row {
    display: flex; align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
    gap: 8px;
  }
  .hist-row:last-child { border-bottom: none; }
  .hist-wk {
    font-family: var(--font-mono); font-size: 11px;
    color: var(--text3); width: 48px; flex-shrink: 0;
  }
  .hist-weight {
    font-family: var(--font-display); font-weight: 700;
    font-size: 16px; flex: 1;
  }
  .hist-waist { font-size: 12px; color: var(--text2); font-family: var(--font-mono); }
  .hist-change {
    font-size: 12px; font-family: var(--font-mono);
    font-weight: 600; text-align: right; width: 60px;
  }

  /* BF ESTIMATE */
  .bf-card {
    background: linear-gradient(135deg, #111118 0%, #1a1a25 100%);
    border: 1px solid var(--border2);
    border-radius: var(--radius);
    padding: 20px;
  }
  .bf-main {
    font-family: var(--font-display);
    font-size: 48px; font-weight: 800;
    letter-spacing: -2px;
    line-height: 1;
  }
  .bf-main span { font-size: 24px; font-weight: 500; color: var(--text2); }

  /* Scrollbar */
  ::-webkit-scrollbar { width: 4px; }
  ::-webkit-scrollbar-track { background: transparent; }
  ::-webkit-scrollbar-thumb { background: var(--surface3); border-radius: 2px; }

  /* ONTRACK indicator */
  .track-pill {
    display: inline-flex; align-items: center; gap: 6px;
    padding: 5px 12px; border-radius: 99px;
    font-family: var(--font-mono); font-size: 11px;
    letter-spacing: 1px; text-transform: uppercase;
    font-weight: 600;
  }
  .track-pill.ahead { background: rgba(124,255,196,0.15); color: var(--accent); }
  .track-pill.ontarget { background: rgba(107,184,255,0.15); color: var(--accent4); }
  .track-pill.behind { background: rgba(255,107,107,0.15); color: var(--accent2); }
  .track-pill::before { content: '●'; font-size: 8px; }

  /* Empty state */
  .empty-state {
    text-align: center; padding: 40px 20px;
    color: var(--text3); font-family: var(--font-mono);
    font-size: 12px; letter-spacing: 1px;
  }
  .empty-state .big { font-size: 32px; margin-bottom: 12px; }

  /* Chart empty state */
  .chart-empty-state {
    height: 160px; display: flex; align-items: center; justify-content: center;
    text-align: center;
    font-family: var(--font-mono); font-size: 12px;
    color: var(--text3); line-height: 1.6; padding: 0 20px;
  }
  .chart-empty-state strong { color: var(--text2); }

  /* Insights empty state */
  .insights-empty-state {
    display: flex; flex-direction: column; align-items: center;
    padding: 20px 12px; text-align: center; gap: 6px;
  }
  .ies-icon { font-size: 28px; }
  .ies-title { font-family: var(--font-display); font-size: 15px; font-weight: 700; color: var(--text); }
  .ies-desc { font-family: var(--font-mono); font-size: 11px; color: var(--text3); line-height: 1.6; }
  .ies-desc strong { color: var(--text2); }
  
  /* Neck input note */
  .note-text { font-size: 11px; color: var(--text3); font-family: var(--font-mono); margin-top: 6px; line-height: 1.5; }
  
  /* QUICK STATS STRIP */
  /* QUICK STATS STRIP */
  .log-stats-strip {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px 18px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px 20px;
    position: relative;
    overflow: hidden;
  }
  .log-stats-strip::before {
    content: '';
    position: absolute; top: 0; left: 0; right: 0; height: 2px;
    background: linear-gradient(90deg, var(--accent), #4dffa3, var(--accent4));
  }
  .lss-item { display: flex; flex-direction: column; gap: 3px; }
  .lss-label {
    font-family: var(--font-mono);
    font-size: 9px; color: var(--text3);
    letter-spacing: 2px; text-transform: uppercase;
  }
  .lss-value {
    font-family: var(--font-display);
    font-size: 20px; font-weight: 800;
    letter-spacing: -0.5px; line-height: 1;
  }
  .lss-value .lss-unit { font-size: 12px; font-weight: 400; color: var(--text2); margin-left: 2px; }
  .lss-sub { font-size: 10px; font-family: var(--font-mono); color: var(--text3); }
  .lss-phase {
    grid-column: 1 / -1;
    display: flex; align-items: center; gap: 8px;
    padding-top: 10px;
    border-top: 1px solid var(--border);
    margin-top: 2px;
  }
  .lss-phase-dot { width: 6px; height: 6px; border-radius: 50%; flex-shrink: 0; }
  .lss-phase-name {
    font-family: var(--font-mono);
    font-size: 11px; letter-spacing: 1px; text-transform: uppercase;
    flex: 1;
  }
  .lss-phase-wk { font-family: var(--font-mono); font-size: 10px; color: var(--text3); }