:root {
      --bg-deep: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
      --accent: #ffd700;
      --text-display: #fff;
      --text-body: #2d3748;
      --text-accent: #1e3c72;
      --bg-solid: #fff;
      --max-reading-width: 720px;
      --max-content-width: 1200px;
      --radius: 16px;
      --shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
      --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }

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

    body {
      font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      background: var(--bg-deep);
      color: var(--text-display);
      line-height: 1.6;
      overflow-x: hidden;
    }

    .hero-section {
      min-height: 100vh;
      display: flex;
      flex-direction: column;
      padding: 20px;
      padding-bottom: 20px;
      position: relative;
    }

    .hero-header {
      text-align: center;
      padding: 15px 0 20px;
    }

    .hero-header h1 {
      font-size: clamp(1.75rem, 5vw, 2.5rem);
      font-weight: 300;
      letter-spacing: -0.5px;
      margin-bottom: 8px;
      background: linear-gradient(135deg, var(--accent) 0%, #fff 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .hero-header p {
      font-size: clamp(0.9rem, 2.5vw, 1.1rem);
      color: rgba(255, 255, 255, 0.9);
    }

    .hero-header a {
      color: var(--accent);
      text-decoration: none;
      font-weight: 600;
      transition: opacity 0.3s;
    }

    .hero-header a:hover {
      opacity: 0.8;
    }

    .breathing-zone {
      flex: 1;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 15px;
      max-width: 600px;
      width: 100%;
      margin: 0 auto;
    }

    .taiji-container {
      position: relative;
      width: min(60vw, 280px);
      height: min(60vw, 280px);
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .progress-ring {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      transform: rotate(-90deg);
    }

    .progress-ring-circle {
      fill: none;
      stroke: var(--accent);
      stroke-width: 3;
      stroke-linecap: round;
      filter: drop-shadow(0 0 12px rgba(255, 215, 0, 0.5));
      transition: stroke-dashoffset 0.1s linear;
    }

    .taiji-symbol {
      position: relative;
      width: 70%;
      height: 70%;
      filter: drop-shadow(0 0 15px rgba(255, 215, 0, 0.3));
      transition: transform 0.1s ease-out, opacity 0.1s ease-out;
    }

    .breath-status {
      font-size: clamp(1.5rem, 4vw, 2rem);
      font-weight: 300;
      letter-spacing: 1px;
      text-transform: uppercase;
      text-align: center;
      text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    }

    .breath-timer {
      font-size: clamp(2.5rem, 8vw, 3.5rem);
      font-weight: 200;
      color: var(--accent);
      text-shadow: 0 0 20px rgba(255, 215, 0, 0.4);
    }

    .cycle-counter {
      font-size: 1rem;
      opacity: 0.8;
    }

    .control-panel {
      display: flex;
      gap: 10px;
      flex-wrap: wrap;
      justify-content: center;
      width: 100%;
      margin-top: 10px;
    }

    .control-btn {
      padding: 10px 18px;
      background: rgba(255, 255, 255, 0.1);
      border: 1px solid rgba(255, 215, 0, 0.3);
      color: var(--text-display);
      border-radius: 12px;
      cursor: pointer;
      font-size: 0.9rem;
      font-weight: 500;
      backdrop-filter: blur(10px);
      transition: var(--transition);
      white-space: nowrap;
    }

    .control-btn:hover:not(:disabled) {
      background: rgba(255, 215, 0, 0.2);
      border-color: var(--accent);
      transform: translateY(-2px);
    }

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

    .pattern-selector {
      display: flex;
      gap: 8px;
      justify-content: center;
      flex-wrap: wrap;
      margin-top: 8px;
      margin-bottom: 10px;
    }

    .pattern-btn {
      padding: 8px 16px;
      background: rgba(255, 255, 255, 0.08);
      border: 1px solid rgba(255, 215, 0, 0.2);
      border-radius: 20px;
      cursor: pointer;
      font-size: 0.85rem;
      color: rgba(255, 255, 255, 0.7);
      transition: var(--transition);
    }

    .pattern-btn.active {
      background: rgba(255, 215, 0, 0.2);
      color: var(--accent);
      border-color: var(--accent);
    }

    .scroll-indicator {
      position: absolute;
      bottom: -20px;
      left: 50%;
      transform: translateX(-50%);
      text-align: center;
      cursor: pointer;
      animation: bounce 2s infinite;
      z-index: 10;
      transition: opacity 0.3s;
    }

    .scroll-indicator-text {
      font-size: 0.85rem;
      color: rgba(255, 255, 255, 0.9);
      margin-bottom: 5px;
      text-transform: uppercase;
      letter-spacing: 1px;
      font-weight: 600;
    }

    .scroll-arrow {
      width: 28px;
      height: 28px;
      border: 2px solid var(--accent);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto;
      color: var(--accent);
      font-size: 1.1rem;
      background: rgba(30, 60, 114, 0.8);
      backdrop-filter: blur(10px);
    }

    @keyframes bounce {
      0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
      }
      40% {
        transform: translateX(-50%) translateY(-10px);
      }
      60% {
        transform: translateX(-50%) translateY(-5px);
      }
    }

    .content-wrapper {
      background: var(--bg-solid);
      color: var(--text-body);
      border-radius: 20px 20px 0 0;
      margin-top: 40px;
    }

    .content-container {
      max-width: var(--max-reading-width);
      margin: 0 auto;
      padding: 50px 30px;
    }

    .wide-container {
      max-width: var(--max-content-width);
      margin: 0 auto;
      padding: 50px 30px;
    }

    .section-title {
      font-size: clamp(1.75rem, 4vw, 2.5rem);
      font-weight: 300;
      color: var(--text-accent);
      margin-bottom: 30px;
      text-align: center;
      position: relative;
      padding-bottom: 15px;
    }

    .section-title::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 60px;
      height: 3px;
      background: var(--accent);
    }

    .subsection-title {
      font-size: clamp(1.3rem, 3vw, 1.75rem);
      font-weight: 600;
      color: var(--text-accent);
      margin: 40px 0 20px;
      padding-bottom: 12px;
      border-bottom: 2px solid var(--accent);
    }

    p {
      margin-bottom: 20px;
      line-height: 1.8;
      font-size: 1.05rem;
    }

    .highlight {
      background: linear-gradient(120deg, var(--accent) 0%, #9ef01a 100%);
      background-repeat: no-repeat;
      background-size: 100% 0.3em;
      background-position: 0 85%;
      padding: 0.1em 0.2em;
      font-weight: 600;
    }

    .data-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 25px;
      margin: 40px 0;
    }

    .data-card {
      background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
      padding: 30px;
      border-radius: 16px;
      border-left: 5px solid var(--accent);
      transition: transform 0.3s, box-shadow 0.3s;
    }

    .data-card:hover {
      transform: translateY(-5px);
      box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
    }

    .data-card h3 {
      margin-bottom: 15px;
      color: var(--text-accent);
      font-size: 1.3rem;
    }

    .data-card p {
      font-size: 1rem;
      margin-bottom: 0;
    }

    .data-metric {
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--accent);
      margin: 15px 0;
    }

    .comparison-table {
      width: 100%;
      margin: 30px 0;
      border-collapse: collapse;
      background: white;
      border-radius: 12px;
      overflow: hidden;
      box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    }

    .comparison-table th,
    .comparison-table td {
      padding: 18px;
      text-align: left;
      border-bottom: 1px solid #e2e8f0;
    }

    .comparison-table th {
      background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
      color: white;
      font-weight: 600;
      font-size: 1.1rem;
    }

    .comparison-table tr:hover {
      background: #f8f9fa;
    }

    .cta-section {
      background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
      color: white;
      padding: 60px 30px;
      text-align: center;
      margin: 50px 0;
    }

    .cta-section h2 {
      font-size: clamp(1.75rem, 4vw, 2.5rem);
      margin-bottom: 20px;
    }

    .cta-section p {
      font-size: 1.2rem;
      margin-bottom: 30px;
      opacity: 0.95;
    }

    .cta-btn {
      display: inline-block;
      padding: 18px 40px;
      background: var(--accent);
      color: var(--text-accent);
      text-decoration: none;
      border-radius: 30px;
      font-weight: 700;
      font-size: 1.1rem;
      transition: var(--transition);
      box-shadow: 0 8px 20px rgba(255, 215, 0, 0.3);
    }

    .cta-btn:hover {
      transform: translateY(-3px);
      box-shadow: 0 12px 30px rgba(255, 215, 0, 0.4);
    }

    ul, ol {
      margin: 20px 0 20px 25px;
    }

    .breath-tool li {
      margin-bottom: 12px;
      padding-left: 8px;
      position: relative;
      line-height: 1.7;
    }

    ul li::before {
      content: "•";
      color: var(--accent);
      font-weight: bold;
      position: absolute;
      left: -18px;
    }

    .tip-box {
      margin-top: 30px;
      padding: 20px;
      background: #f8f9fa;
      border-left: 5px solid var(--accent);
      border-radius: 8px;
    }

    .breath-tool footer {
      background: rgba(0, 0, 0, 0.2);
      color: rgba(255, 255, 255, 0.7);
      text-align: center;
      padding: 30px 20px;
      font-size: 0.9rem;
    }

    .breath-tool footer a {
      color: var(--accent);
      text-decoration: none;
    }

    @media (max-width: 768px) {
      .content-container,
      .wide-container {
        padding: 30px 20px;
      }

      .data-grid {
        grid-template-columns: 1fr;
      }

      .comparison-table th,
      .comparison-table td {
        padding: 12px;
        font-size: 0.9rem;
      }

      .hero-section {
        min-height: auto;
        padding-bottom: 20px;
      }

      .hero-header {
        padding: 10px 0 15px;
      }

      .breathing-zone {
        gap: 12px;
      }

      .taiji-container {
        width: min(55vw, 240px);
        height: min(55vw, 240px);
      }

      .control-panel {
        gap: 8px;
      }

      .control-btn {
        padding: 9px 14px;
        font-size: 0.85rem;
        flex: 1;
        min-width: auto;
      }

      .pattern-selector {
        margin-top: 10px;
        margin-bottom: 8px;
      }

      .scroll-indicator {
        bottom: -25px;
      }
    }

    @media (max-width: 480px) {
      .control-btn {
        font-size: 0.85rem;
        padding: 10px 12px;
      }

      .pattern-btn {
        padding: 6px 12px;
        font-size: 0.8rem;
      }
    }

    @media (orientation: landscape) and (max-height: 600px) {
      .hero-section {
        min-height: auto;
        padding: 10px 15px 15px;
      }

      .hero-header {
        padding: 8px 0 12px;
      }

      .hero-header h1 {
        font-size: 1.5rem;
      }

      .breathing-zone {
        gap: 8px;
      }

      .taiji-container {
        width: min(35vh, 180px);
        height: min(35vh, 180px);
      }

      .control-panel {
        margin-top: 8px;
      }

      .pattern-selector {
        margin-top: 6px;
      }

      .scroll-indicator {
        bottom: -30px;
      }
    }