:root {
    /* DARK THEME DEFAULTS */
    --bg: #0f1320;
    --bg-2: #101626;
    --surface: rgba(255, 255, 255, 0.06);
    --surface-strong: rgba(12, 18, 40, .72);
    --border: rgba(140, 170, 255, .18);

    --text: #f5f8ff;
    --muted: #b8c2e6;

    --accent: #78a6ff;
    --accent-2: #66e6d2;
    --green: #35d49f;
    --amber: #ffd166;
    --red: #ff6b7c;

    --radius-sm: 10px;
    --radius-md: 14px;
    --radius-lg: 18px;

    --shadow-1: 0 6px 20px rgba(0, 0, 0, .25);
    --shadow-2: 0 14px 40px rgba(0, 0, 0, .35);

    --blur: 14px;
    --speed-fast: .15s;
    --speed: .25s;

    --font: system-ui, -apple-system, Segoe UI, Roboto, Inter,
      "Helvetica Neue", Arial, "Noto Sans", "Apple Color Emoji", "Segoe UI Emoji";

    --nav-h: 72px;
  }

  /* LIGHT THEME OVERRIDES */
  html[data-theme="light"] {
    --bg: #f7f8fd;
    --bg-2: #eef2ff;
    --surface: rgba(255, 255, 255, 0.65);
    --surface-strong: rgba(255, 255, 255, 0.95);
    --border: rgba(23, 32, 58, 0.12);

    --text: #0f1428;
    --muted: #4c567c;

    --accent: #4b82ff;
    --accent-2: #35c7a3;

    --shadow-1: 0 6px 18px rgba(23, 32, 58, .10);
    --shadow-2: 0 18px 40px rgba(23, 32, 58, .14);
  }

  /* ===== NAVBAR CORE (same on every page) ===== */

  .nav {
    top: 0;
    height: var(--nav-h);
    background: var(--surface-strong);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(var(--blur)) saturate(140%);
    flex-shrink: 0;
  }

  .nav-inner {
    width: min(1120px, 92%);
    margin: 0 auto;
    height: 100%;
    display: flex;
    align-items: center;
    gap: 14px;
  }

  .brand {
    display: flex;
    gap: 12px;
    align-items: center;
    text-decoration: none;
    color: var(--text);
    font-weight: 900;
    letter-spacing: .2px;
  }

  .logo {
    width: 38px;
    height: 38px;
    border-radius: 12px;
    background: linear-gradient(180deg, #6ea3ff, #4b82ff);
    box-shadow: 0 10px 22px rgba(76, 130, 255, .22);
    overflow: hidden;
  }

  .nav-links {
    display: flex;
    gap: 16px;
    align-items: center;
    margin-left: 24px;
  }

  .nav-link {
    padding: 8px 16px;
    border-radius: 10px;
    text-decoration: none;
    cursor: pointer;
    color: var(--text);
    font-weight: 600;
    transition: background-color .15s, color .15s;
  }

  .nav-link:hover {
    background-color: rgba(255, 255, 255, 0.1);
  }

  .nav-link.active {
    background-color: rgba(120, 166, 255, 0.2);
    color: var(--accent);
  }

  .spacer {
    flex: 1;
  }

  .theme-btn,
  .cta {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    height: 40px;
    border-radius: 12px;
    padding: 0 18px;
    color: #000;
    background: gold;
    position: relative;
    overflow: hidden;
    z-index: 1;
  }

  .cta.glow::before {
    content: "";
    position: absolute;
    inset: -3px;
    border-radius: 14px;
    padding: 2px;
    background: linear-gradient(130deg, #ffd700, #ff8c00, #ffe066, #fcb900);
    background-size: 300% 300%;
    animation: borderGlow 4s ease infinite;
    z-index: -1;
  }

  @keyframes borderGlow {
    0% {
      background-position: 0% 50%;
    }

    50% {
      background-position: 100% 50%;
    }

    100% {
      background-position: 0% 50%;
    }
  }

  .theme-btn {
    width: 40px;
    border: 1px solid var(--border);
    background: rgba(255, 255, 255, .08);
    color: var(--text);
    cursor: pointer;
    padding: 0;
  }

  .cta {
    padding: 0 22px;
    background: linear-gradient(180deg, #35d49f, #18b98a);
    color: #061a11;
    font-weight: 900;
    text-decoration: none;
    border: 0;
    box-shadow: 0 10px 24px rgba(24, 185, 138, .22);
    isolation: isolate;
    will-change: transform;
  }

  .cta::after {
    content: "";
    position: absolute;
    inset: -2px;
    z-index: -1;
    border-radius: 14px;
    background: radial-gradient(220px 120px at var(--bx, 50%) 50%,
        rgba(53, 212, 159, .38),
        transparent 60%);
    transition: .08s linear;
  }

  /* MOBILE MENU */

  .mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text);
    font-size: 24px;
    cursor: pointer;
    padding: 8px;
    margin-right: 10px;
  }

  .mobile-menu {
    position: fixed;
    top: var(--nav-h);
    left: 0;
    width: 100%;
    background: var(--surface-strong);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(var(--blur)) saturate(140%);
    padding: 20px;
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition:
      transform 0.3s ease,
      opacity 0.3s ease,
      visibility 0.3s;
    z-index: 9;
  }

  .mobile-menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .mobile-nav-links {
    display: flex;
    flex-direction: column;
    gap: 16px;
  }

  .mobile-nav-link {
    padding: 12px 16px;
    border-radius: 10px;
    text-decoration: none;
    color: var(--text);
    font-weight: 600;
    transition: background-color .15s, color .15s;
  }

  .mobile-nav-link:hover,
  .mobile-nav-link.active {
    background-color: rgba(120, 166, 255, 0.2);
    color: var(--accent);
  }

  a {
    color: var(--accent);
  }

  @media (max-width: 1100px) {
    .nav-links {
      display: none;
    }

    .mobile-menu-btn {
      display: block;
    }
  }