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

    body {
      font-family: 'Rajdhani', sans-serif;
      background: #000;
      color: #00d4ff;
      min-height: 100vh;
      overflow-y: auto;
      overflow-x: hidden;
      -webkit-font-smoothing: antialiased;
    }

    /* ── HUD Container — CSS Grid layout ── */
    .hud-container {
      position: relative;
      display: grid;
      grid-template-columns: minmax(200px, 280px) 1fr minmax(200px, 280px);
      grid-template-rows: auto 1fr auto;
      grid-template-areas:
        "left-top    center    right-top"
        "left-mid    center    right-mid"
        "left-bottom center    right-bottom";
      min-height: 100vh;
      gap: 10px;
      padding: 15px;
      background: radial-gradient(ellipse at center, #001428 0%, #000a14 40%, #000 100%);
    }

    /* ── Scanline overlay ── */
    .scanlines {
      position: absolute;
      inset: 0;
      background: repeating-linear-gradient(
        0deg,
        rgba(0, 0, 0, 0.08) 0px,
        rgba(0, 0, 0, 0.08) 1px,
        transparent 1px,
        transparent 2px
      );
      pointer-events: none;
      z-index: 100;
    }

    /* ── Sweep scan effect ── */
    .scan-sweep {
      position: absolute;
      inset: 0;
      background: linear-gradient(
        180deg,
        transparent 0%,
        rgba(0, 212, 255, 0.03) 45%,
        rgba(0, 212, 255, 0.08) 50%,
        rgba(0, 212, 255, 0.03) 55%,
        transparent 100%
      );
      animation: sweep 4s ease-in-out infinite;
      pointer-events: none;
      z-index: 99;
    }
    @keyframes sweep {
      0%   { transform: translateY(-100%); }
      100% { transform: translateY(100%); }
    }

    /* ── Grid area assignments ── */
    .system-panel   { grid-area: left-top; }
    .alerts-panel   { grid-area: left-mid; align-self: center; }
    .ai-panel       { grid-area: left-bottom; align-self: end; }
    .center-area    { grid-area: center; }
    .datetime-panel { grid-area: right-top; }
    .network-panel  { grid-area: right-mid; align-self: center; }
    .analysis-panel { grid-area: right-bottom; align-self: end; }

    /* ── Center area — flexbox centering ── */
    .center-area {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      position: relative;
    }

    /* ── Main circular HUD ── */
    .main-circle {
      position: relative;
      width: min(500px, 60vmin);
      height: min(500px, 60vmin);
      cursor: pointer;
      z-index: 10;
    }

    .circle-ring {
      position: absolute;
      border: 2px solid rgba(0, 212, 255, 0.3);
      border-radius: 50%;
      animation: rotate 20s linear infinite;
      transition: border-color 0.4s, box-shadow 0.4s;
    }
    .ring-1 {
      inset: 0;
      border-color: rgba(0, 212, 255, 0.15);
      border-style: dashed;
    }
    .ring-2 {
      inset: 10%;
      animation-direction: reverse;
      animation-duration: 15s;
      border-top-color: #00d4ff;
      border-bottom-color: transparent;
    }
    .ring-3 {
      inset: 20%;
      animation-duration: 10s;
      border-left-color: #00d4ff;
      border-right-color: transparent;
    }
    .ring-4 {
      inset: 5%;
      animation-duration: 25s;
      border-color: rgba(0, 212, 255, 0.08);
    }

    .main-circle.clicked .circle-ring {
      border-color: rgba(0, 255, 136, 0.6);
      box-shadow: 0 0 15px rgba(0, 255, 136, 0.3);
    }

    @keyframes rotate {
      from { transform: rotate(0deg); }
      to   { transform: rotate(360deg); }
    }

    /* ── Arc reactor core ── */
    .arc-reactor {
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
      width: 30%;
      height: 30%;
      background: radial-gradient(circle, #00d4ff 0%, #0088aa 30%, transparent 70%);
      border-radius: 50%;
      box-shadow:
        0 0 30px #00d4ff,
        0 0 60px rgba(0, 212, 255, 0.4),
        inset 0 0 30px rgba(0, 212, 255, 0.5);
      animation: pulse 2s ease-in-out infinite;
    }
    .arc-reactor::before {
      content: '';
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
      width: 33%;
      height: 33%;
      background: #fff;
      border-radius: 50%;
      box-shadow: 0 0 20px #00d4ff;
    }

    .main-circle.clicked .arc-reactor {
      box-shadow:
        0 0 50px #00ff88,
        0 0 100px rgba(0, 255, 136, 0.4),
        inset 0 0 40px rgba(0, 255, 136, 0.5);
      background: radial-gradient(circle, #00ff88 0%, #00aa66 30%, transparent 70%);
    }

    @keyframes pulse {
      0%, 100% { opacity: 1; transform: translate(-50%, -50%) scale(1); }
      50%      { opacity: 0.8; transform: translate(-50%, -50%) scale(1.05); }
    }

    /* ── Panel base ── */
    .panel {
      position: relative;
      background: rgba(0, 12, 24, 0.85);
      border: 1px solid rgba(0, 212, 255, 0.3);
      padding: 0.9rem 1rem;
      font-family: 'Orbitron', sans-serif;
      backdrop-filter: blur(4px);
      -webkit-backdrop-filter: blur(4px);
      opacity: 0;
      transform: translateY(10px);
      animation: panelIn 0.6s forwards;
      transition: border-color 0.3s, box-shadow 0.3s;
    }
    .panel:hover {
      border-color: rgba(0, 212, 255, 0.7);
      box-shadow: 0 0 20px rgba(0, 212, 255, 0.15);
    }
    .panel::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      height: 2px;
      background: linear-gradient(90deg, transparent, #00d4ff, transparent);
    }

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

    .panel-title {
      font-size: 0.65rem;
      color: #00d4ff;
      margin-bottom: 0.7rem;
      letter-spacing: 3px;
      text-transform: uppercase;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .panel-title::before {
      content: '';
      display: inline-block;
      width: 6px;
      height: 6px;
      background: #00d4ff;
      border-radius: 1px;
      animation: blink 2s infinite;
    }

    /* ── System status panel ── */
    .system-panel {
      animation-delay: 0.1s;
    }

    .status-item {
      display: flex;
      justify-content: space-between;
      margin-bottom: 0.3rem;
      font-size: 0.8rem;
      font-weight: 500;
    }
    .status-label {
      opacity: 0.7;
      letter-spacing: 1px;
    }
    .status-value {
      color: #00ff88;
      font-weight: 700;
      font-variant-numeric: tabular-nums;
    }
    .status-value.warning { color: #ffaa00; }
    .status-value.critical { color: #ff3344; }

    .progress-bar {
      height: 3px;
      background: rgba(0, 212, 255, 0.15);
      margin-bottom: 0.6rem;
      border-radius: 2px;
      overflow: hidden;
    }
    .progress-fill {
      height: 100%;
      background: linear-gradient(90deg, #00d4ff, #00ff88);
      transition: width 0.8s ease;
      border-radius: 2px;
    }
    .progress-fill.warning {
      background: linear-gradient(90deg, #ffaa00, #ff6600);
    }
    .progress-fill.critical {
      background: linear-gradient(90deg, #ff3344, #ff0000);
    }

    /* ── Date/time panel ── */
    .datetime-panel {
      text-align: right;
      animation-delay: 0.2s;
    }
    .time-display {
      font-size: 2.6rem;
      font-weight: 700;
      text-shadow: 0 0 20px rgba(0, 212, 255, 0.6);
      line-height: 1;
      letter-spacing: 2px;
    }
    .time-seconds {
      font-size: 1.2rem;
      opacity: 0.6;
      font-weight: 400;
    }
    .date-display {
      font-size: 0.85rem;
      opacity: 0.6;
      margin-top: 0.3rem;
      letter-spacing: 1px;
    }
    .timezone-display {
      font-size: 0.65rem;
      opacity: 0.4;
      margin-top: 0.15rem;
      font-family: 'Rajdhani', sans-serif;
    }

    /* ── AI status panel ── */
    .ai-panel {
      animation-delay: 0.3s;
    }
    .ai-status {
      display: flex;
      align-items: center;
      gap: 0.8rem;
    }
    .ai-avatar {
      width: 44px;
      height: 44px;
      background: radial-gradient(circle, #00d4ff, transparent);
      border-radius: 50%;
      animation: pulse 2s infinite;
      flex-shrink: 0;
      cursor: pointer;
    }
    .ai-avatar:hover {
      box-shadow: 0 0 25px #00d4ff;
    }
    .ai-text {
      flex: 1;
      min-width: 0;
    }
    .ai-name {
      font-size: 1rem;
      font-weight: 700;
      letter-spacing: 2px;
    }
    .ai-message {
      font-size: 0.8rem;
      opacity: 0.7;
      font-family: 'Rajdhani', sans-serif;
      min-height: 1.2em;
      white-space: nowrap;
      overflow: hidden;
    }

    /* typing cursor */
    .typing-cursor::after {
      content: '\2588';
      animation: cursorBlink 0.7s step-end infinite;
      margin-left: 1px;
      color: #00d4ff;
    }
    @keyframes cursorBlink {
      0%, 100% { opacity: 1; }
      50%      { opacity: 0; }
    }

    /* ── Analysis panel ── */
    .analysis-panel {
      animation-delay: 0.4s;
    }
    .chart-bars {
      display: flex;
      align-items: flex-end;
      gap: 3px;
      height: 70px;
    }
    .chart-bar {
      flex: 1;
      background: linear-gradient(to top, #00d4ff, rgba(0, 212, 255, 0.2));
      border-radius: 1px 1px 0 0;
      transition: height 0.6s ease;
      cursor: pointer;
      position: relative;
    }
    .chart-bar:hover {
      background: linear-gradient(to top, #00ff88, rgba(0, 255, 136, 0.3));
      box-shadow: 0 0 8px rgba(0, 255, 136, 0.4);
    }

    /* ── Alerts panel ── */
    .alerts-panel {
      animation-delay: 0.5s;
    }
    .alert-item {
      padding: 0.45rem 0.6rem;
      margin-bottom: 0.4rem;
      background: rgba(0, 212, 255, 0.06);
      border-left: 3px solid #00d4ff;
      font-size: 0.72rem;
      font-family: 'Rajdhani', sans-serif;
      font-weight: 500;
      letter-spacing: 0.5px;
      cursor: pointer;
      transition: all 0.3s;
    }
    .alert-item:hover {
      background: rgba(0, 212, 255, 0.15);
      padding-left: 0.8rem;
    }
    .alert-item.warning {
      border-color: #ffaa00;
      background: rgba(255, 170, 0, 0.06);
    }
    .alert-item.success {
      border-color: #00ff88;
      background: rgba(0, 255, 136, 0.06);
    }
    .alert-dismissed {
      opacity: 0.3;
      text-decoration: line-through;
    }

    /* ── Network panel ── */
    .network-panel {
      animation-delay: 0.6s;
    }
    .network-node {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      margin-bottom: 0.45rem;
      font-size: 0.75rem;
      font-weight: 500;
      letter-spacing: 1px;
      cursor: pointer;
      transition: color 0.3s;
    }
    .network-node:hover {
      color: #fff;
    }
    .node-dot {
      width: 7px;
      height: 7px;
      border-radius: 50%;
      background: #00ff88;
      animation: blink 2s infinite;
      flex-shrink: 0;
      box-shadow: 0 0 6px rgba(0, 255, 136, 0.4);
    }
    .node-dot.offline {
      background: #ff3344;
      animation: none;
      box-shadow: 0 0 6px rgba(255, 51, 68, 0.4);
    }
    .node-latency {
      margin-left: auto;
      font-size: 0.6rem;
      opacity: 0.5;
      font-variant-numeric: tabular-nums;
    }
    @keyframes blink {
      0%, 100% { opacity: 1; }
      50%      { opacity: 0.3; }
    }

    /* ── Voice command button ── */
    .voice-btn {
      position: relative;
      margin-top: 20px;
      width: 56px;
      height: 56px;
      border-radius: 50%;
      background: rgba(0, 212, 255, 0.1);
      border: 2px solid rgba(0, 212, 255, 0.5);
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.3rem;
      transition: all 0.3s;
      z-index: 20;
    }
    .voice-btn:hover {
      background: rgba(0, 212, 255, 0.25);
      box-shadow: 0 0 30px rgba(0, 212, 255, 0.3);
      border-color: #00d4ff;
    }
    .voice-btn.active {
      background: #00d4ff;
      border-color: #00d4ff;
      animation: voicePulse 0.6s infinite;
    }
    .voice-btn.active::after {
      content: '';
      position: absolute;
      inset: -8px;
      border: 2px solid rgba(0, 212, 255, 0.4);
      border-radius: 50%;
      animation: ripple 1s infinite;
    }
    @keyframes voicePulse {
      0%, 100% { transform: scale(1); }
      50%      { transform: scale(1.08); }
    }
    @keyframes ripple {
      0%   { transform: scale(1); opacity: 1; }
      100% { transform: scale(1.5); opacity: 0; }
    }

    /* ── Chat log & input ── */
    .chat-log {
      max-height: 120px;
      overflow-y: auto;
      margin-top: 0.5rem;
      font-size: 0.72rem;
      font-family: 'Rajdhani', sans-serif;
      scrollbar-width: thin;
      scrollbar-color: rgba(0,212,255,0.3) transparent;
    }
    .chat-log::-webkit-scrollbar { width: 3px; }
    .chat-log::-webkit-scrollbar-thumb { background: rgba(0,212,255,0.3); border-radius: 2px; }
    .chat-entry {
      padding: 0.2rem 0;
      border-bottom: 1px solid rgba(0,212,255,0.08);
      line-height: 1.3;
    }
    .chat-entry.user-msg { color: #aaddff; }
    .chat-entry.user-msg::before { content: '> '; opacity: 0.5; }
    .chat-entry.jarvis-msg { color: #00ff88; }
    .chat-entry.jarvis-msg::before { content: 'J: '; opacity: 0.5; }
    .chat-input-area {
      display: flex;
      gap: 0.3rem;
      margin-top: 0.4rem;
      align-items: center;
    }
    .chat-input {
      flex: 1;
      background: rgba(0,212,255,0.08);
      border: 1px solid rgba(0,212,255,0.3);
      color: #00d4ff;
      font-family: 'Rajdhani', sans-serif;
      font-size: 0.8rem;
      padding: 0.35rem 0.5rem;
      outline: none;
      border-radius: 2px;
    }
    .chat-input:focus {
      border-color: #00d4ff;
      box-shadow: 0 0 8px rgba(0,212,255,0.15);
    }
    .chat-input::placeholder {
      color: rgba(0,212,255,0.3);
    }
    .chat-send-btn {
      background: rgba(0,212,255,0.15);
      border: 1px solid rgba(0,212,255,0.4);
      color: #00d4ff;
      cursor: pointer;
      padding: 0.35rem 0.5rem;
      font-size: 0.75rem;
      border-radius: 2px;
      transition: all 0.3s;
    }
    .chat-send-btn:hover {
      background: rgba(0,212,255,0.3);
      border-color: #00d4ff;
    }
    .voice-unsupported {
      opacity: 0.3;
      cursor: not-allowed;
      pointer-events: none;
    }

    /* ── Boot sequence ── */
    .boot-screen {
      position: absolute;
      inset: 0;
      background: #000;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      z-index: 1000;
      transition: opacity 1s ease-out;
    }
    .boot-screen.hidden {
      opacity: 0;
      pointer-events: none;
    }
    .boot-text {
      font-family: 'Orbitron', sans-serif;
      font-size: 0.85rem;
      margin: 0.25rem;
      opacity: 0;
      animation: bootFadeIn 0.4s forwards;
      letter-spacing: 2px;
    }
    .boot-text.success { color: #00ff88; }
    .boot-progress {
      width: 200px;
      height: 2px;
      background: rgba(0, 212, 255, 0.2);
      margin-top: 1rem;
      border-radius: 1px;
      overflow: hidden;
      opacity: 0;
      animation: bootFadeIn 0.4s 2.4s forwards;
    }
    .boot-progress-fill {
      height: 100%;
      background: #00d4ff;
      width: 0%;
      animation: bootLoad 1s 2.5s forwards ease-out;
    }
    @keyframes bootFadeIn {
      to { opacity: 1; }
    }
    @keyframes bootLoad {
      to { width: 100%; }
    }

    /* ── Ad area ── */
    .ad-area {
      grid-column: 1 / -1;
      justify-self: center;
      margin: 10px auto;
    }

    /* ── Footer ── */
    .footer {
      grid-column: 1 / -1;
      justify-self: center;
      font-family: 'Rajdhani', sans-serif;
      font-size: 0.65rem;
      letter-spacing: 2px;
      opacity: 0.2;
      color: #00d4ff;
      z-index: 50;
      transition: opacity 0.3s;
      white-space: normal;
      text-align: center;
      padding-bottom: 10px;
    }
    .footer:hover {
      opacity: 0.5;
    }

    /* ── Click-ripple effect on main circle ── */
    .click-ripple {
      position: absolute;
      border: 2px solid rgba(0, 212, 255, 0.6);
      border-radius: 50%;
      pointer-events: none;
      animation: clickRipple 0.8s forwards;
    }
    @keyframes clickRipple {
      0%   { width: 0; height: 0; opacity: 1; }
      100% { width: 300px; height: 300px; opacity: 0; margin-top: -150px; margin-left: -150px; }
    }

    /* ── Particle burst on interaction ── */
    .particle {
      position: absolute;
      width: 3px;
      height: 3px;
      background: #00d4ff;
      border-radius: 50%;
      pointer-events: none;
      z-index: 200;
    }

    /* ── Mobile responsiveness: tablet ── */
    @media (max-width: 768px) {
      .hud-container {
        grid-template-columns: 1fr;
        grid-template-rows: auto;
        grid-template-areas: none;
        gap: 10px;
        padding: 10px;
      }

      /* Reset all grid areas for single-column flow */
      .system-panel,
      .alerts-panel,
      .ai-panel,
      .center-area,
      .datetime-panel,
      .network-panel,
      .analysis-panel,
      .ad-area,
      .footer {
        grid-area: auto;
        align-self: auto;
      }

      /* Order: center first, then panels */
      .center-area    { order: 0; }
      .system-panel   { order: 1; }
      .datetime-panel { order: 2; }
      .alerts-panel   { order: 3; }
      .network-panel  { order: 4; }
      .ai-panel       { order: 5; }
      .analysis-panel { order: 6; }
      .ad-area        { order: 7; }
      .footer         { order: 8; }

      .main-circle {
        width: min(300px, 50vmin);
        height: min(300px, 50vmin);
      }

      .datetime-panel {
        text-align: left;
      }

      .time-display {
        font-size: 1.8rem;
      }
    }

    /* ── Mobile responsiveness: small phones ── */
    @media (max-width: 375px) {
      .hud-container {
        padding: 6px;
        gap: 6px;
      }

      .panel {
        padding: 0.6rem 0.7rem;
      }

      .panel-title {
        font-size: 0.55rem;
        letter-spacing: 1.5px;
        margin-bottom: 0.4rem;
      }

      .status-item {
        font-size: 0.7rem;
      }

      .time-display {
        font-size: 1.2rem;
      }

      .time-seconds {
        font-size: 0.8rem;
      }

      .date-display {
        font-size: 0.7rem;
      }

      .ai-name { font-size: 0.85rem; }
      .ai-message { font-size: 0.7rem; }
      .ai-avatar { width: 34px; height: 34px; }

      .voice-btn {
        width: 46px;
        height: 46px;
        font-size: 1.1rem;
      }

      .main-circle {
        width: min(240px, 45vmin);
        height: min(240px, 45vmin);
      }

      .alert-item {
        font-size: 0.68rem;
        padding: 0.35rem 0.5rem;
      }

      .network-node {
        font-size: 0.7rem;
      }

      .chart-bars {
        height: 50px;
      }

      .footer {
        font-size: 0.6rem;
        letter-spacing: 1px;
      }

      .boot-text { font-size: 0.65rem; }
    }

    /* ── Touch target improvements for mobile ── */
    @media (max-width: 600px) {
      .alert-item { padding: 0.6rem 0.8rem; font-size: 0.75rem; min-height: 44px; display: flex; align-items: center; }
      .network-node { font-size: 0.8rem; min-height: 44px; display: flex; align-items: center; }
      .chat-input { font-size: 0.85rem; min-height: 44px; padding: 0.5rem 0.7rem; }
      .chat-send-btn { min-width: 44px; min-height: 44px; padding: 0.5rem; font-size: 1rem; }
    }

    /* 접근성: 모션 감소 설정 */
    @media (prefers-reduced-motion: reduce) {
      *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
      }
      .scanlines, .scan-sweep { display: none !important; }
      .boot-screen { display: none !important; }
    }