:root {
      --bg: #05080f;
      --bg-panel: #0a101c;
      --bg-elevated: #0e1624;
      --border: #1a2a3a;
      --border-glow: #00e5ff33;
      --cyan: #00e5ff;
      --cyan-dim: #00b8d4;
      --magenta: #ff2d95;
      --magenta-dim: #c2185b;
      --purple: #7c4dff;
      --text: #e0f7fa;
      --text-dim: #78909c;
      --success: #00e676;
      --danger: #ff5252;
      --grid: #0d1520;
    }

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

    body {
      font-family: 'Rajdhani', sans-serif;
      background: var(--bg);
      color: var(--text);
      min-height: 100vh;
      line-height: 1.5;
      overflow-x: hidden;
      background-image:
        linear-gradient(rgba(0, 229, 255, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 229, 255, 0.03) 1px, transparent 1px);
      background-size: 40px 40px;
    }

    /* Subtle scanline overlay */
    body::before {
      content: '';
      position: fixed;
      inset: 0;
      background: repeating-linear-gradient(
        0deg,
        transparent,
        transparent 2px,
        rgba(0, 0, 0, 0.12) 2px,
        rgba(0, 0, 0, 0.12) 4px
      );
      pointer-events: none;
      z-index: 1000;
      opacity: 0.4;
    }

    /* Ambient glow orbs */
    body::after {
      content: '';
      position: fixed;
      top: -20%;
      left: -10%;
      width: 50%;
      height: 50%;
      background: radial-gradient(circle, rgba(0, 229, 255, 0.08) 0%, transparent 70%);
      pointer-events: none;
      z-index: 0;
    }

    .container {
      position: relative;
      z-index: 1;
      max-width: 880px;
      margin: 0 auto;
      padding: 2rem 1.25rem 4rem;
    }

    /* ========== HEADER ========== */
    header {
      text-align: center;
      margin-bottom: 2.25rem;
      padding-bottom: 1.5rem;
      position: relative;
    }

    header::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 60%;
      height: 1px;
      background: linear-gradient(90deg, transparent, var(--cyan), transparent);
      box-shadow: 0 0 12px var(--cyan);
    }

    .logo {
      font-family: 'Orbitron', sans-serif;
      font-weight: 800;
      font-size: clamp(1.9rem, 5.5vw, 2.9rem);
      letter-spacing: 0.18em;
      background: linear-gradient(135deg, var(--cyan) 0%, #80deea 40%, var(--magenta) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      text-shadow: none;
      filter: drop-shadow(0 0 18px rgba(0, 229, 255, 0.45));
      margin-bottom: 0.4rem;
    }

    .tagline {
      font-family: 'Share Tech Mono', monospace;
      font-size: 0.8rem;
      color: var(--cyan-dim);
      letter-spacing: 0.35em;
      text-transform: uppercase;
      opacity: 0.9;
    }

    .tagline span {
      color: var(--magenta);
    }

    /* ========== TABS ========== */
    .main-tabs {
      display: flex;
      gap: 0.35rem;
      margin-bottom: 1.75rem;
      background: var(--bg-panel);
      padding: 0.35rem;
      border-radius: 4px;
      border: 1px solid var(--border);
      box-shadow: 0 0 0 1px rgba(0, 229, 255, 0.05), inset 0 0 20px rgba(0, 0, 0, 0.3);
    }

    .main-tab {
      flex: 1;
      padding: 0.8rem 0.4rem;
      background: transparent;
      border: none;
      color: var(--text-dim);
      font-family: 'Orbitron', sans-serif;
      font-size: 0.72rem;
      font-weight: 600;
      letter-spacing: 0.12em;
      cursor: pointer;
      border-radius: 3px;
      transition: all 0.25s ease;
      text-transform: uppercase;
      position: relative;
    }

    .main-tab:hover {
      color: var(--cyan);
      background: rgba(0, 229, 255, 0.06);
    }

    .main-tab.active {
      color: var(--bg);
      background: linear-gradient(135deg, var(--cyan) 0%, var(--cyan-dim) 100%);
      box-shadow: 0 0 20px rgba(0, 229, 255, 0.4), 0 0 40px rgba(0, 229, 255, 0.15);
    }

    /* ========== PANELS ========== */
    .panel {
      display: none;
      animation: panelIn 0.3s ease;
    }

    .panel.active {
      display: block;
    }

    @keyframes panelIn {
      from { opacity: 0; transform: translateY(10px); }
      to { opacity: 1; transform: translateY(0); }
    }

    .card {
      background: var(--bg-panel);
      border: 1px solid var(--border);
      border-radius: 6px;
      padding: 1.4rem 1.5rem;
      margin-bottom: 1.1rem;
      position: relative;
      box-shadow: 0 4px 24px rgba(0, 0, 0, 0.35);
    }

    .card::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      height: 1px;
      background: linear-gradient(90deg, transparent, rgba(0, 229, 255, 0.35), transparent);
    }

    .card-title {
      font-family: 'Orbitron', sans-serif;
      font-size: 0.78rem;
      font-weight: 600;
      color: var(--cyan);
      margin-bottom: 1.1rem;
      letter-spacing: 0.14em;
      text-transform: uppercase;
      display: flex;
      align-items: center;
      gap: 0.6rem;
    }

    .card-title::before {
      content: '';
      width: 8px;
      height: 8px;
      background: var(--cyan);
      box-shadow: 0 0 8px var(--cyan);
      clip-path: polygon(50% 0%, 100% 50%, 50% 100%, 0% 50%);
    }

    label {
      display: block;
      font-family: 'Share Tech Mono', monospace;
      font-size: 0.72rem;
      color: var(--text-dim);
      margin-bottom: 0.4rem;
      letter-spacing: 0.08em;
      text-transform: uppercase;
    }

    textarea, input[type="text"], select {
      width: 100%;
      background: var(--bg);
      border: 1px solid var(--border);
      border-radius: 4px;
      color: var(--text);
      font-family: 'Share Tech Mono', monospace;
      font-size: 0.95rem;
      padding: 0.85rem 1rem;
      resize: vertical;
      transition: border-color 0.2s, box-shadow 0.2s;
    }

    textarea:focus, input[type="text"]:focus, select:focus {
      outline: none;
      border-color: var(--cyan);
      box-shadow: 0 0 0 1px rgba(0, 229, 255, 0.25), 0 0 16px rgba(0, 229, 255, 0.1);
    }

    textarea {
      min-height: 100px;
    }

    textarea::placeholder, input::placeholder {
      color: #37474f;
    }

    .row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 1rem;
    }

    @media (max-width: 640px) {
      .row { grid-template-columns: 1fr; }
    }

    /* ========== CARRIER ========== */
    .carrier-section {
      margin-top: 0.5rem;
    }

    .carrier-options {
      display: flex;
      flex-wrap: wrap;
      gap: 0.45rem;
      margin-bottom: 0.9rem;
    }

    .carrier-btn {
      width: 46px;
      height: 46px;
      font-size: 1.4rem;
      background: var(--bg);
      border: 1px solid var(--border);
      border-radius: 4px;
      cursor: pointer;
      transition: all 0.2s;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .carrier-btn:hover {
      border-color: var(--cyan-dim);
      transform: scale(1.06);
      box-shadow: 0 0 12px rgba(0, 229, 255, 0.2);
    }

    .carrier-btn.selected {
      border-color: var(--cyan);
      background: rgba(0, 229, 255, 0.1);
      box-shadow: 0 0 14px rgba(0, 229, 255, 0.35);
    }

    .custom-carrier {
      margin-top: 0.5rem;
    }

    /* ========== BUTTONS ========== */
    .btn-row {
      display: flex;
      flex-wrap: wrap;
      gap: 0.65rem;
      margin-top: 1.15rem;
    }

    .btn {
      font-family: 'Orbitron', sans-serif;
      font-size: 0.72rem;
      font-weight: 600;
      letter-spacing: 0.1em;
      padding: 0.75rem 1.35rem;
      border-radius: 3px;
      border: none;
      cursor: pointer;
      transition: all 0.2s;
      text-transform: uppercase;
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--cyan) 0%, #00b8d4 100%);
      color: #021018;
      box-shadow: 0 0 18px rgba(0, 229, 255, 0.35);
    }

    .btn-primary:hover {
      filter: brightness(1.12);
      box-shadow: 0 0 28px rgba(0, 229, 255, 0.5);
      transform: translateY(-1px);
    }

    .btn-primary:active {
      transform: translateY(1px);
    }

    .btn-secondary {
      background: transparent;
      color: var(--cyan);
      border: 1px solid var(--border);
    }

    .btn-secondary:hover {
      border-color: var(--cyan);
      background: rgba(0, 229, 255, 0.08);
      box-shadow: 0 0 12px rgba(0, 229, 255, 0.15);
    }

    .btn-danger {
      background: transparent;
      color: var(--danger);
      border: 1px solid #4a2020;
    }

    .btn-danger:hover {
      background: rgba(255, 82, 82, 0.1);
      border-color: var(--danger);
    }

    /* ========== OUTPUT ========== */
    .output-box {
      background: var(--bg);
      border: 1px solid var(--border);
      border-radius: 4px;
      padding: 1.1rem;
      min-height: 76px;
      font-family: 'Share Tech Mono', monospace;
      font-size: 1.1rem;
      word-break: break-all;
      position: relative;
      margin-top: 0.35rem;
      color: var(--cyan);
    }

    .output-box .placeholder {
      color: #37474f;
      font-style: normal;
      font-size: 0.9rem;
    }

    .status {
      margin-top: 0.7rem;
      font-family: 'Share Tech Mono', monospace;
      font-size: 0.78rem;
      min-height: 1.25em;
      color: var(--text-dim);
      letter-spacing: 0.04em;
    }

    .status.success { color: var(--success); }
    .status.error { color: var(--danger); }

    /* ========== TOGGLES ========== */
    .toggle-row {
      display: flex;
      align-items: center;
      gap: 0.7rem;
      margin: 0.85rem 0;
      flex-wrap: wrap;
    }

    .toggle {
      position: relative;
      width: 44px;
      height: 24px;
      background: var(--bg);
      border-radius: 12px;
      border: 1px solid var(--border);
      cursor: pointer;
      transition: all 0.25s;
    }

    .toggle.on {
      background: rgba(0, 229, 255, 0.15);
      border-color: var(--cyan);
      box-shadow: 0 0 10px rgba(0, 229, 255, 0.25);
    }

    .toggle::after {
      content: '';
      position: absolute;
      top: 2px;
      left: 2px;
      width: 18px;
      height: 18px;
      background: var(--text-dim);
      border-radius: 50%;
      transition: all 0.25s;
    }

    .toggle.on::after {
      transform: translateX(20px);
      background: var(--cyan);
      box-shadow: 0 0 8px var(--cyan);
    }

    .toggle-label {
      font-family: 'Rajdhani', sans-serif;
      font-size: 0.92rem;
      font-weight: 500;
      color: var(--text);
    }

    /* ========== TELEGRAPH KEY ========== */
    .key-area {
      text-align: center;
      padding: 1.25rem 0 0.5rem;
    }

    .morse-key {
      width: 170px;
      height: 64px;
      background: linear-gradient(180deg, #0e2030 0%, #061018 100%);
      border: 2px solid var(--cyan);
      border-radius: 4px;
      box-shadow:
        0 0 20px rgba(0, 229, 255, 0.25),
        inset 0 0 20px rgba(0, 229, 255, 0.05);
      cursor: pointer;
      position: relative;
      transition: all 0.08s;
      margin: 0 auto 1.1rem;
      display: flex;
      align-items: center;
      justify-content: center;
      font-family: 'Orbitron', sans-serif;
      font-size: 0.85rem;
      font-weight: 700;
      letter-spacing: 0.2em;
      color: var(--cyan);
      user-select: none;
      -webkit-user-select: none;
    }

    .morse-key:hover {
      box-shadow: 0 0 30px rgba(0, 229, 255, 0.4), inset 0 0 25px rgba(0, 229, 255, 0.08);
    }

    .morse-key:active,
    .morse-key.pressed {
      transform: scale(0.96);
      background: linear-gradient(180deg, #0a3040 0%, #041820 100%);
      box-shadow:
        0 0 40px rgba(0, 229, 255, 0.55),
        inset 0 0 30px rgba(0, 229, 255, 0.15);
      color: #fff;
    }

    .key-hint {
      font-family: 'Share Tech Mono', monospace;
      font-size: 0.75rem;
      color: var(--text-dim);
      margin-bottom: 1rem;
      letter-spacing: 0.06em;
    }

    .morse-display {
      font-family: 'Share Tech Mono', monospace;
      font-size: 1.35rem;
      letter-spacing: 0.18em;
      min-height: 2.1em;
      padding: 0.7rem;
      background: var(--bg);
      border-radius: 4px;
      border: 1px solid var(--border);
      margin-bottom: 0.7rem;
      word-break: break-all;
      color: var(--cyan);
    }

    .sound-indicator {
      display: inline-block;
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background: #333;
      margin-right: 0.35rem;
      vertical-align: middle;
    }

    .sound-indicator.on {
      background: var(--success);
      box-shadow: 0 0 8px var(--success);
    }

    /* ========== CHART ========== */
    .chart-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(88px, 1fr));
      gap: 0.35rem;
      font-size: 0.78rem;
    }

    .chart-item {
      background: var(--bg);
      padding: 0.35rem 0.5rem;
      border-radius: 3px;
      border: 1px solid var(--border);
      display: flex;
      justify-content: space-between;
      font-family: 'Share Tech Mono', monospace;
    }

    .chart-item span:first-child {
      color: var(--cyan);
      font-weight: 700;
    }

    .chart-item span:last-child {
      color: var(--text-dim);
    }

    /* ========== ABOUT ========== */
    .about-text {
      font-size: 0.98rem;
      color: var(--text);
      opacity: 0.92;
      line-height: 1.65;
    }

    .about-text strong {
      color: var(--cyan);
      font-weight: 600;
    }

    .about-list {
      padding-left: 1.2rem;
      margin: 0.9rem 0;
      font-size: 0.95rem;
      opacity: 0.9;
    }

    .about-list li {
      margin-bottom: 0.55rem;
    }

    /* ========== FOOTER ========== */
    footer {
      text-align: center;
      margin-top: 2.75rem;
      padding-top: 1.4rem;
      border-top: 1px solid var(--border);
      font-family: 'Share Tech Mono', monospace;
      font-size: 0.7rem;
      color: var(--text-dim);
      letter-spacing: 0.18em;
    }

    footer span {
      color: var(--cyan-dim);
    }