/* Tab switcher */
    .calc-tabs {
      display: flex; gap: 8px; margin-bottom: 48px;
    }
    .calc-tab {
      padding: 11px 28px; border-radius: var(--r-full);
      font-size: 0.88rem; font-weight: 700;
      border: 2px solid var(--border);
      background: var(--white); color: var(--mid);
      cursor: none; transition: all 0.3s var(--bounce);
    }
    .calc-tab.active { background: var(--navy); color: white; border-color: var(--navy); }
    .calc-tab:hover:not(.active) { border-color: var(--navy); color: var(--navy); }

    /* Calculator layout */
    .calc-layout {
      display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: start;
    }
    .calc-panel {
      background: white; border: 1.5px solid var(--border); border-radius: var(--r-xl);
      padding: 40px;
    }
    .calc-panel-title {
      font-family: var(--font-head); font-size: 1.15rem; margin-bottom: 28px;
      color: var(--dark); display: flex; align-items: center; gap: 10px;
    }
    .calc-panel-title .lucide { width: 20px; height: 20px; color: var(--orange); }

    .calc-field { margin-bottom: 20px; }
    .calc-field label {
      display: block; font-size: 0.75rem; font-weight: 700;
      text-transform: uppercase; letter-spacing: 0.08em;
      color: var(--mid); margin-bottom: 8px;
    }
    .calc-input-wrap { position: relative; }
    .calc-input-prefix {
      position: absolute; left: 16px; top: 50%; transform: translateY(-50%);
      font-weight: 700; color: var(--muted); font-size: 0.95rem;
    }
    .calc-input {
      width: 100%; background: var(--light); border: 1.5px solid var(--border);
      border-radius: var(--r-md); padding: 14px 18px 14px 36px;
      font-family: var(--font-body); font-size: 1rem; font-weight: 600;
      color: var(--dark); transition: all 0.25s; outline: none;
    }
    .calc-input.no-prefix { padding-left: 18px; }
    .calc-input:focus { border-color: var(--orange); background: white; box-shadow: 0 0 0 4px rgba(196,83,26,0.08); }

    /* Results card */
    .results-card {
      background: var(--navy); border-radius: var(--r-xl); padding: 40px;
      position: sticky; top: 100px;
    }
    .results-title {
      font-family: var(--font-head); font-size: 1rem; color: rgba(255,255,255,0.6);
      text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 28px;
    }
    .roas-display {
      text-align: center; margin-bottom: 32px;
      padding: 28px; background: rgba(255,255,255,0.05);
      border-radius: var(--r-lg); border: 1px solid rgba(255,255,255,0.1);
    }
    .roas-label { font-size: 0.75rem; color: rgba(255,255,255,0.5); text-transform: uppercase; letter-spacing: 0.1em; margin-bottom: 8px; }
    .roas-value {
      font-family: var(--font-head); font-size: 4rem; color: var(--orange-light);
      line-height: 1; margin-bottom: 10px;
    }
    .roas-verdict {
      display: inline-block; padding: 6px 18px; border-radius: var(--r-full);
      font-size: 0.78rem; font-weight: 700;
    }
    .verdict-excellent { background: rgba(34,197,94,0.2); color: #4ade80; }
    .verdict-good { background: rgba(250,204,21,0.2); color: #fde047; }
    .verdict-needs-work { background: rgba(239,68,68,0.2); color: #fca5a5; }

    .metrics-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
    .metric-box {
      background: rgba(255,255,255,0.06); border-radius: var(--r-md); padding: 16px;
    }
    .metric-label { font-size: 0.7rem; color: rgba(255,255,255,0.45); text-transform: uppercase; letter-spacing: 0.07em; margin-bottom: 4px; }
    .metric-value { font-family: var(--font-head); font-size: 1.3rem; color: white; }
    .metric-box.highlight { background: rgba(196,83,26,0.2); }
    .metric-box.highlight .metric-value { color: var(--orange-light); }

    .calc-cta {
      margin-top: 28px; padding-top: 24px;
      border-top: 1px solid rgba(255,255,255,0.1);
      text-align: center;
    }
    .calc-cta p { font-size: 0.82rem; color: rgba(255,255,255,0.5); margin-bottom: 12px; }

    /* Mode panels */
    .calc-mode { display: none; }
    .calc-mode.active { display: block; }

    @media (max-width: 900px) {
      .calc-layout { grid-template-columns: 1fr; }
      .results-card { position: static; }
      .metrics-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 500px) {
      .metrics-grid { grid-template-columns: 1fr; }
    }