:root {
        --bg: #0f1117;
        --surface: #1a1d27;
        --surface-2: #242836;
        --border: #2e3348;
        --text: #e4e6f0;
        --text-muted: #8b8fa3;
        --primary: #6366f1;
        --primary-hover: #818cf8;
        --green: #22c55e;
        --green-hover: #16a34a;
        --red: #ef4444;
        --red-hover: #dc2626;
        --amber: #f59e0b;
        --cyan: #06b6d4;
        --radius: 12px;
        --radius-sm: 8px;
        --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
      }

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

      body {
        font-family:
          "Inter",
          -apple-system,
          sans-serif;
        background: var(--bg);
        color: var(--text);
        min-height: 100vh;
        display: flex;
        align-items: center;
        justify-content: center;
      }

      .app {
        width: 100%;
        max-width: 440px;
        padding: 20px;
      }

      /* ── Header ───────────────────────────── */
      .header {
        text-align: center;
        margin-bottom: 24px;
      }

      .header h1 {
        font-size: 20px;
        font-weight: 700;
        letter-spacing: -0.3px;
      }

      .header .badge {
        display: inline-block;
        margin-top: 6px;
        font-size: 11px;
        color: var(--text-muted);
        background: var(--surface);
        padding: 3px 10px;
        border-radius: 20px;
        border: 1px solid var(--border);
      }

      /* ── Cards ────────────────────────────── */
      .card {
        background: var(--surface);
        border: 1px solid var(--border);
        border-radius: var(--radius);
        padding: 20px;
        margin-bottom: 16px;
        box-shadow: var(--shadow);
      }

      .card-title {
        font-size: 11px;
        font-weight: 600;
        text-transform: uppercase;
        letter-spacing: 1px;
        color: var(--text-muted);
        margin-bottom: 14px;
      }

      /* ── Forms ────────────────────────────── */
      .input-group {
        display: flex;
        gap: 8px;
      }

      input[type="text"] {
        flex: 1;
        background: var(--surface-2);
        border: 1px solid var(--border);
        border-radius: var(--radius-sm);
        padding: 10px 14px;
        font-size: 13px;
        font-family: "Inter", sans-serif;
        color: var(--text);
        outline: none;
        transition: border-color 0.2s;
      }

      input[type="text"]:focus {
        border-color: var(--primary);
      }

      input[type="text"]::placeholder {
        color: var(--text-muted);
      }

      /* ── Buttons ──────────────────────────── */
      .btn {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        gap: 6px;
        font-family: "Inter", sans-serif;
        font-size: 13px;
        font-weight: 600;
        padding: 10px 18px;
        border: none;
        border-radius: var(--radius-sm);
        cursor: pointer;
        transition: all 0.15s ease;
        white-space: nowrap;
      }

      .btn:disabled {
        opacity: 0.4;
        cursor: not-allowed;
      }

      .btn-primary {
        background: var(--primary);
        color: #fff;
      }

      .btn-primary:hover:not(:disabled) {
        background: var(--primary-hover);
      }

      .btn-green {
        background: var(--green);
        color: #fff;
      }

      .btn-green:hover:not(:disabled) {
        background: var(--green-hover);
      }

      .btn-red {
        background: var(--red);
        color: #fff;
      }

      .btn-red:hover:not(:disabled) {
        background: var(--red-hover);
      }

      .btn-ghost {
        background: var(--surface-2);
        color: var(--text);
        border: 1px solid var(--border);
      }

      .btn-ghost:hover:not(:disabled) {
        background: var(--border);
      }

      .btn-ghost.active {
        background: var(--primary);
        border-color: var(--primary);
        color: #fff;
      }

      .btn-sm {
        padding: 8px 12px;
        font-size: 12px;
      }

      .btn-icon {
        width: 44px;
        height: 44px;
        padding: 0;
        border-radius: 50%;
        font-size: 18px;
      }

      .btn-icon.btn-lg {
        width: 56px;
        height: 56px;
        font-size: 22px;
      }

      /* ── Status Indicators ────────────────── */
      .status-bar {
        display: flex;
        align-items: center;
        gap: 8px;
        padding: 10px 14px;
        background: var(--surface-2);
        border-radius: var(--radius-sm);
        font-size: 13px;
        margin-bottom: 12px;
      }

      .status-dot {
        width: 8px;
        height: 8px;
        border-radius: 50%;
        background: var(--text-muted);
        flex-shrink: 0;
      }

      .status-dot.online {
        background: var(--green);
        box-shadow: 0 0 6px var(--green);
      }

      .status-dot.error {
        background: var(--red);
        box-shadow: 0 0 6px var(--red);
      }

      .status-dot.warning {
        background: var(--amber);
        box-shadow: 0 0 6px var(--amber);
      }

      /* ── Call UI ──────────────────────────── */
      .call-info {
        text-align: center;
        padding: 16px 0;
      }

      .call-info .caller-name {
        font-size: 22px;
        font-weight: 700;
        margin-bottom: 4px;
      }

      .call-info .call-status {
        font-size: 13px;
        color: var(--text-muted);
      }

      .call-info .call-timer {
        font-size: 28px;
        font-weight: 600;
        font-variant-numeric: tabular-nums;
        margin-top: 8px;
        color: var(--green);
      }

      .call-controls {
        display: flex;
        justify-content: center;
        gap: 16px;
        margin-top: 20px;
      }

      .call-controls .btn-icon {
        position: relative;
      }

      .call-controls .btn-label {
        position: absolute;
        bottom: -20px;
        left: 50%;
        transform: translateX(-50%);
        font-size: 10px;
        color: var(--text-muted);
        white-space: nowrap;
      }

      .call-actions {
        display: flex;
        justify-content: center;
        gap: 24px;
        margin-top: 36px;
      }

      /* ── DTMF Pad ─────────────────────────── */
      .dtmf-pad {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 8px;
        margin-top: 12px;
      }

      .dtmf-pad .btn {
        font-size: 18px;
        font-weight: 600;
        padding: 14px;
      }

      /* ── Incoming Banner ──────────────────── */
      .incoming-banner {
        position: fixed;
        top: 20px;
        left: 50%;
        transform: translateX(-50%);
        background: var(--surface);
        border: 1px solid var(--primary);
        border-radius: var(--radius);
        padding: 16px 20px;
        box-shadow: 0 8px 32px rgba(99, 102, 241, 0.25);
        z-index: 100;
        display: none;
        min-width: 340px;
        animation: slideDown 0.3s ease;
      }

      @keyframes slideDown {
        from {
          opacity: 0;
          transform: translateX(-50%) translateY(-20px);
        }

        to {
          opacity: 1;
          transform: translateX(-50%) translateY(0);
        }
      }

      .incoming-banner .caller {
        font-size: 15px;
        font-weight: 600;
        margin-bottom: 4px;
      }

      .incoming-banner .sub {
        font-size: 12px;
        color: var(--text-muted);
        margin-bottom: 12px;
      }

      .incoming-banner .actions {
        display: flex;
        gap: 8px;
      }

      .incoming-banner .actions .btn {
        flex: 1;
      }

      /* ── Log Panel ────────────────────────── */
      .log-panel {
        background: var(--surface-2);
        border-radius: var(--radius-sm);
        padding: 12px;
        max-height: 180px;
        overflow-y: auto;
        font-size: 11px;
        font-family: "SF Mono", "Fira Code", monospace;
        line-height: 1.6;
        color: var(--text-muted);
      }

      .log-panel::-webkit-scrollbar {
        width: 4px;
      }

      .log-panel::-webkit-scrollbar-thumb {
        background: var(--border);
        border-radius: 2px;
      }

      .log-entry .time {
        color: var(--text-muted);
        opacity: 0.6;
      }

      .log-entry.error {
        color: var(--red);
      }

      .log-entry.success {
        color: var(--green);
      }

      .log-entry.warn {
        color: var(--amber);
      }

      .log-entry.info {
        color: var(--cyan);
      }

      /* ── Agent List ───────────────────────── */
      .agent-list {
        display: flex;
        flex-wrap: wrap;
        gap: 8px;
      }

      .agent-tag {
        display: inline-flex;
        align-items: center;
        gap: 6px;
        padding: 4px 10px;
        background: var(--surface-2);
        border-radius: 20px;
        font-size: 12px;
      }

      /* ── Utilities ────────────────────────── */
      .hidden {
        display: none !important;
      }

      .flex-center {
        display: flex;
        align-items: center;
        justify-content: center;
      }

      .mt-12 {
        margin-top: 12px;
      }

      .mt-8 {
        margin-top: 8px;
      }

      .text-center {
        text-align: center;
      }

      .text-muted {
        color: var(--text-muted);
        font-size: 12px;
      }

      /* ── Media elements (hidden audio) ────── */
      audio {
        display: none;
      }

      /* ── Transfer input ───────────────────── */
      .transfer-row {
        display: flex;
        gap: 8px;
        margin-top: 12px;
      }