:root {
      --bg: #0b0f14;
      --panel: #121824;
      --accent: #4f7cff;
      --text: #e6eaf0;
      --muted: #9aa4b2;
    }

    :root.theme-light {
      --bg: #f6f7fb;
      --panel: #ffffff;
      --text: #111827;
      --muted: #5f6675;
    }

    * { box-sizing: border-box; }

    body {
      margin: 0;
      font-family: 'Inter', system-ui, sans-serif;
      background: var(--bg);
      color: var(--text);
      overflow-x: hidden;
    }

    body::before {
      content: "";
      position: fixed;
      inset: -20vh -20vw;
      background:
        radial-gradient(900px 500px at 20% 10%, rgba(79,124,255,0.28), transparent 55%),
        radial-gradient(700px 420px at 80% 20%, rgba(57,217,138,0.14), transparent 60%),
        radial-gradient(900px 520px at 60% 90%, rgba(255,107,107,0.12), transparent 62%);
      filter: blur(18px);
      opacity: 0.9;
      animation: drift 14s ease-in-out infinite alternate;
      z-index: -2;
      pointer-events: none;
    }

    .theme-light body::before {
      background:
        radial-gradient(900px 500px at 20% 10%, rgba(79,124,255,0.16), transparent 55%),
        radial-gradient(700px 420px at 80% 20%, rgba(57,217,138,0.10), transparent 60%),
        radial-gradient(900px 520px at 60% 90%, rgba(255,107,107,0.08), transparent 62%);
      opacity: 0.6;
    }

    @keyframes drift {
      from { transform: translate3d(-1.2%, -0.8%, 0) scale(1); }
      to   { transform: translate3d( 1.2%,  0.9%, 0) scale(1.02); }
    }

    /* NAV */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      height: 100vh;
      width: 280px;
      background: linear-gradient(180deg, rgba(18,24,36,0.98), rgba(11,15,22,0.96));
      padding: 26px 24px 48px;
      border-right: 1px solid rgba(255,255,255,0.06);
      box-shadow: 18px 0 60px rgba(0,0,0,0.45);
      transform: translateX(0);
      transition: transform 0.35s ease;
      z-index: 1000;
    }

    .theme-light .nav {
      background: linear-gradient(180deg, rgba(255,255,255,0.98), rgba(244,246,252,0.96));
      border-right: 1px solid rgba(0,0,0,0.08);
      box-shadow: 12px 0 36px rgba(0,0,0,0.12);
    }

    .nav.open { transform: translateX(0); }

    .nav-title {
      margin-top: 0;
      font-weight: 700;
      letter-spacing: 0.6px;
      font-size: 1.4rem;
      margin-bottom: 24px;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .nav a {
      display: flex;
      align-items: center;
      gap: 14px;
      margin: 12px 0;
      padding: 12px 14px;
      border-radius: 12px;
      color: var(--text);
      text-decoration: none;
      font-weight: 500;
      transition: background 0.25s, color 0.25s, transform 0.15s;
    }

    .nav a:hover {
      background: rgba(79, 124, 255, 0.15);
      color: var(--accent);
      transform: translateX(4px);
    }

    .nav a.active {
      background: rgba(79, 124, 255, 0.2);
      color: #d7e2ff;
      box-shadow: inset 0 0 0 1px rgba(79, 124, 255, 0.35);
    }

    .theme-light .nav a {
      color: #1f2937;
    }

    .theme-light .nav a.active {
      color: #0f172a;
      background: rgba(79,124,255,0.18);
      box-shadow: inset 0 0 0 1px rgba(79,124,255,0.28);
    }

    .icon {
      font-size: 1.2rem;
      width: 22px;
      text-align: center;
    }

    .hamburger,
    .overlay {
      display: none;
    }

    .hamburger {
      position: fixed;
      top: 20px;
      left: 20px;
      font-size: 28px;
      cursor: pointer;
      z-index: 1100;
      user-select: none;
      transition: left 0.35s ease;
    }

    .hamburger.open { left: 300px; }

    .overlay {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.55);
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.35s ease;
      z-index: 900;
    }

    .overlay.show {
      opacity: 1;
      pointer-events: auto;
    }

    .main {
      min-height: 100vh;
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      padding: 120px 24px 140px;
      text-align: center;
      margin-left: 280px;
      width: calc(100% - 280px);
    }

    .card {
      background: linear-gradient(145deg, #141b2e, #0f1524);
      border-radius: 22px;
      padding: 48px 42px;
      max-width: 560px;
      box-shadow: 0 30px 80px rgba(0,0,0,0.45);
      border: 1px solid rgba(255,255,255,0.06);
    }

    .theme-light .card {
      background: linear-gradient(145deg, #ffffff, #eef2f7);
      border: 1px solid rgba(0,0,0,0.08);
      box-shadow: 0 16px 36px rgba(0,0,0,0.12);
    }

    .card h1 {
      margin-top: 0;
      font-size: 2.2rem;
      margin-bottom: 10px;
    }

    .card p {
      color: var(--muted);
      font-size: 1.05rem;
      margin-bottom: 24px;
    }

    .theme-light .card p {
      color: #4b5563;
    }

    .card a {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 12px 18px;
      border-radius: 12px;
      background: #4f7cff;
      color: white;
      font-weight: 700;
      text-decoration: none;
    }

    /* Bottom nav */
    .bottom-nav {
      position: fixed;
      left: 12px;
      right: 12px;
      bottom: 14px;
      padding: 10px 12px;
      border-radius: 22px;
      background: rgba(12,16,26,0.92);
      border: 1px solid rgba(255,255,255,0.08);
      box-shadow: 0 16px 50px rgba(0,0,0,0.45);
      display: none;
      justify-content: space-around;
      gap: 8px;
      z-index: 1200;
      backdrop-filter: blur(8px);
    }

    .theme-light .bottom-nav {
      background: rgba(255,255,255,0.95);
      border: 1px solid rgba(0,0,0,0.08);
      box-shadow: 0 12px 32px rgba(0,0,0,0.12);
    }

    .bottom-nav a {
      flex: 1;
      text-decoration: none;
      color: var(--muted);
      font-weight: 700;
      font-size: 0.75rem;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 4px;
      padding: 8px 6px;
      border-radius: 14px;
      transition: background 0.2s ease, color 0.2s ease, transform 0.2s ease;
    }

    .bottom-nav a .icon {
      font-size: 1.15rem;
    }

    .bottom-nav a.active {
      color: var(--text);
      background: rgba(79,124,255,0.22);
      box-shadow: inset 0 0 0 1px rgba(79,124,255,0.4);
      transform: translateY(-1px);
    }

    .theme-light .bottom-nav a {
      color: #5f6675;
    }

    .theme-light .bottom-nav a.active {
      color: #0f172a;
    }

    @media (min-width: 821px) {
      .nav {
        transform: translateX(0);
      }

      .hamburger,
      .overlay {
        display: none;
      }

      .main {
        margin-left: 280px;
        width: calc(100% - 280px);
      }
    }

    @media (max-width: 820px) {
      .nav,
      .overlay,
      .hamburger {
        display: none;
      }

      body {
        padding-bottom: 120px;
      }

      .main {
        padding: 120px 20px 180px;
        margin-left: 0;
        width: 100%;
      }

      .bottom-nav {
        display: flex;
      }
    }
  
    @media (max-width: 540px) {
      .bottom-nav a span:not(.icon) {
        display: none;
      }

      .bottom-nav a {
        font-size: 0;
        gap: 0;
      }

      .bottom-nav a .icon {
        font-size: 1.25rem;
      }
    }