:root {
        --bg-color: #1c1c1e;
        --card-bg: rgba(44, 44, 46, 0.6);
        --card-border: rgba(255, 255, 255, 0.08);
        --accent-color: #d4b483;
        --text-main: #f2f2f7;
        --text-sub: #aeaeb2;
      }

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

      body {
        font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN",
          "Hiragino Sans", Meiryo, sans-serif;
        background-color: var(--bg-color);
        background-image: radial-gradient(
          circle at 50% 0%,
          #2c2c2e 0%,
          #1c1c1e 80%
        );
        min-height: 100vh;
        display: flex;
        align-items: center;
        justify-content: center;
        padding: 2rem;
        overflow-x: hidden;
        color: var(--text-main);
      }

      .container {
        max-width: 1200px;
        width: 100%;
        display: flex;
        justify-content: center;
      }

      .slider-section {
        width: 100%;
        max-width: 1000px;
        display: flex;
        flex-direction: column;
        align-items: center;
      }

      /* Slider Area */
      .slider-wrapper {
        position: relative;
        perspective: 1200px;
        width: 100%;
        display: flex;
        flex-direction: column;
        align-items: center;
      }

      .slider-container {
        position: relative;
        height: 500px;
        width: 100%;
        max-width: 800px;
        margin: 0 auto;
        display: flex;
        justify-content: center;
      }

      .slide-card {
        position: absolute;
        top: 0;
        left: 50%;
        margin-left: -160px;
        width: 320px;
        height: 460px;
        will-change: transform, opacity;
        cursor: pointer;
        transform-style: preserve-3d;
      }

      /* Glassmorphism Card Style - Refined */
      .card-inner {
        background: var(--card-bg);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        border: 1px solid var(--card-border);
        border-radius: 4px;
        height: 100%;
        padding: 3rem 2.5rem;
        display: flex;
        flex-direction: column;
        box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2),
          inset 0 1px 0 rgba(255, 255, 255, 0.1);
        transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
        backface-visibility: hidden;
      }

      .slide-card.active .card-inner {
        background: rgba(58, 58, 60, 0.7);
        box-shadow: 0 30px 60px rgba(0, 0, 0, 0.3),
          inset 0 1px 0 rgba(255, 255, 255, 0.15);
        border-color: rgba(212, 180, 131, 0.3);
      }

      .card-header {
        display: flex;
        align-items: center;
        gap: 1rem;
        margin-bottom: 1rem;
      }

      .card-number {
        font-family: "Georgia", serif;
        color: var(--accent-color);
        font-size: 1.1rem;
        font-style: italic;
      }

      .card-line {
        flex: 1;
        height: 1px;
        background: rgba(255, 255, 255, 0.1);
      }

      .card-title {
        font-size: 1.8rem;
        font-weight: 500;
        color: var(--text-main);
        margin-bottom: 2rem;
        line-height: 1.4;
        white-space: pre-line;
        letter-spacing: 0.05em;
      }

      .card-illustration {
        flex: 1;
        display: flex;
        align-items: flex-start;
        justify-content: flex-start;
        margin-bottom: 2rem;
      }

      .card-illustration svg {
        width: 48px;
        height: 48px;
        stroke: var(--text-main);
        stroke-width: 1;
        fill: none;
        opacity: 0.8;
        transition: all 0.3s ease;
      }

      .slide-card.active .card-illustration svg {
        stroke: var(--accent-color);
        opacity: 1;
        transform: scale(1.1);
      }

      .card-description {
        color: var(--text-sub);
        font-size: 0.9rem;
        line-height: 1.8;
        letter-spacing: 0.02em;
      }

      /* Controls Layout */
      .slider-controls {
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: center;
        gap: 3rem;
        width: 100%;
        margin-top: 2.5rem;
      }

      .slider-indicators {
        display: flex;
        gap: 1.5rem;
        align-items: center;
      }

      .indicator {
        width: auto;
        height: auto;
        background: transparent;
        border: none;
        color: var(--text-sub);
        font-family: "Georgia", serif;
        font-size: 1rem;
        cursor: pointer;
        transition: all 0.3s ease;
        padding: 0.5rem;
        position: relative;
      }

      /* アクティブ時の下線 */
      .indicator::after {
        content: "";
        position: absolute;
        bottom: 0;
        left: 50%;
        width: 0;
        height: 1px;
        background: var(--accent-color);
        transition: all 0.3s ease;
        transform: translateX(-50%);
      }

      .indicator.active {
        color: var(--accent-color);
        font-style: italic;
      }

      .indicator.active::after {
        width: 80%;
      }

      .indicator:hover:not(.active) {
        color: var(--text-main);
      }

      .nav-btn {
        width: 48px;
        height: 48px;
        border-radius: 50%;
        border: 1px solid rgba(255, 255, 255, 0.1);
        background: transparent;
        cursor: pointer;
        display: flex;
        align-items: center;
        justify-content: center;
        transition: all 0.3s ease;
        color: var(--text-sub);
      }

      .nav-btn:hover {
        border-color: var(--accent-color);
        color: var(--accent-color);
        background: rgba(212, 180, 131, 0.05);
      }

      .nav-btn svg {
        width: 20px;
        height: 20px;
      }

      @media (max-width: 768px) {
        .slider-container {
          height: 480px;
        }
        .slide-card {
          width: 280px;
          height: 420px;
          margin-left: -140px;
        }
        .card-inner {
          padding: 2rem;
        }
        .slider-controls {
          gap: 1.5rem;
        }
      }