:root{
      --primary:#007BFF; --primary-dark:#0056b3;
      --secondary:#28a745; --accent:#ffc107; --danger:#dc3545; --warning:#fd7e14; --info:#17a2b8;

      --bg:#ffffff; --bg-2:#f8f9fa; --bg-3:#ffffffEE; --bg-hero-grad:linear-gradient(135deg,#007BFF 0%,#28a745 100%);
      --text:#212529; --text-2:#6c757d; --text-muted:#9097a3;

      --nav-bg:rgba(255,255,255,.92); --nav-border:rgba(0,0,0,.08); --nav-text:#111;
      --shadow-sm:0 2px 4px rgba(0,0,0,.08);
      --shadow-md:0 6px 20px rgba(0,0,0,.10);
      --shadow-lg:0 14px 40px rgba(0,0,0,.16);
      --radius-sm:8px; --radius-md:14px; --radius-lg:22px;
      --t-fast:.18s cubic-bezier(.4,0,.2,1);
      --t-slow:.35s cubic-bezier(.4,0,.2,1);
    }
    [data-theme="dark"]{
      --bg:#1a1a1a; --bg-2:#232425; --bg-3:#1e1f21;
      --text:#ffffff; --text-2:#c9c9c9; --text-muted:#9aa0a6;
      --nav-bg:rgba(28,28,30,.9); --nav-border:rgba(255,255,255,.08); --nav-text:#f1f1f1;
      --shadow-md:0 6px 20px rgba(0,0,0,.45); --shadow-lg:0 18px 50px rgba(0,0,0,.55);
    }

    /* ========== BASE ========== */
    *{margin:0;padding:0;box-sizing:border-box}
    html{scroll-behavior:smooth}
    body{font-family:'Inter',-apple-system,BlinkMacSystemFont,sans-serif;line-height:1.6;background:var(--bg);color:var(--text);overflow-x:hidden;transition:background var(--t-slow),color var(--t-slow)}
    .container{max-width:1200px;margin:0 auto;padding:0 20px}
    .text-center{text-align:center}
    .hidden{opacity:0;visibility:hidden}
    .visible{opacity:1;visibility:visible}
    .text-gradient{background:linear-gradient(135deg,#007BFF, #0056b3);-webkit-background-clip:text;-webkit-text-fill-color:transparent}

    /* ========== NAVBAR ========== */
  /* ========== NAVBAR ========== */
.navbar {
  position:fixed;
  inset:0 0 auto;
  z-index:1000;
  background:var(--nav-bg);
  backdrop-filter:saturate(140%) blur(16px);
  border-bottom:3px solid var(--nav-border);
  transition:box-shadow var(--t-slow),background var(--t-slow)
}
.navbar.scrolled{box-shadow:var(--shadow-sm)}
.nav-inner{display:flex;align-items:center;justify-content:space-between;padding:14px 20px}
.logo{display:flex;align-items:center;font-weight:800;font-size:1.25rem;color:var(--primary)}
.logo-img{height:50px;width:auto;margin-right:10px}
.logo-pulse{width:8px;height:8px;border-radius:999px;background:skyblue;margin-left:10px;animation:pulse 2s infinite}
@keyframes pulse{0%,100%{opacity:1;transform:scale(1)}50%{opacity:.35;transform:scale(1.5)}}

.nav-links{display:flex;gap:24px;align-items:center}
.nav-link{position:relative;text-decoration:none;color:var(--nav-text);font-weight:600;padding:8px 12px;border-radius:10px;transition:background var(--t-fast),color var(--t-fast)}
.nav-link:hover{background:rgba(0,123,255,.12);color:var(--primary)}
.nav-link::after{content:"";position:absolute;left:12px;right:12px;bottom:6px;height:2px;border-radius:2px;background:transparent;transition:background var(--t-fast),width var(--t-fast)}
.nav-link:hover::after{background:var(--primary)}

/* ========== NAVBAR (MOBILE) ========== */
@media (max-width:768px){
  .nav-inner{
    padding:22px 20px; /* increased vertical padding = taller navbar */
  }
}

    /* mobile toggle */
/* mobile toggle */
.mobile-toggle{display:none;width:42px;height:42px;border-radius:50%;align-items:center;justify-content:center;cursor:pointer;border:1px solid var(--nav-border);background:transparent;position:fixed;top:2px;right:18px;z-index:1002}
.mobile-toggle-bars{position:relative;width:20px;height:2px;background:var(--nav-text);transition:transform var(--t-slow),background var(--t-slow)}
.mobile-toggle-bars::before,.mobile-toggle-bars::after{content:"";position:absolute;left:0;width:20px;height:2px;background:var(--nav-text);transition:transform var(--t-slow),top var(--t-slow)}
.mobile-toggle-bars::before{top:-6px}.mobile-toggle-bars::after{top:6px}
.mobile-toggle.active .mobile-toggle-bars{background:transparent}
.mobile-toggle.active .mobile-toggle-bars::before{top:0;transform:rotate(45deg)}
.mobile-toggle.active .mobile-toggle-bars::after{top:0;transform:rotate(-45deg)}

/* mobile drawer */
.nav-drawer{display:none;flex-direction:column;background:var(--nav-bg);border-top:1px solid var(--nav-border);box-shadow:var(--shadow-sm)}
.nav-drawer a{padding:12px 20px}
.nav-drawer.show{display:flex;animation:slideDown var(--t-slow)}
@keyframes slideDown{from{opacity:0;transform:translateY(-8px)}to{opacity:1;transform:translateY(0)}}

/* theme + back-to-top */
.theme-toggle,.back-to-top{position:fixed;z-index:1001;border:none;cursor:pointer;border-radius:999px;box-shadow:var(--shadow-sm);transition:transform var(--t-slow),box-shadow var(--t-slow)}
.theme-toggle{bottom:78px;right:18px;background:var(--primary);color:#fff;width:55px;height:55px;font-size:18px}
.theme-toggle:hover{transform:scale(1.08);box-shadow:var(--shadow-md)}

    .back-to-top{bottom:10px;right:28px;background:linear-gradient(135deg,#007BFF,#0056b3);color:#fff;width:55px;height:55px;font-size:18px;transform:translateY(120px)}
    .back-to-top.visible{transform:translateY(0)}
    .back-to-top:hover{transform:translateY(-6px) scale(1.05);box-shadow:var(--shadow-lg)}

    /* ========== HERO ========== */
    .hero{min-height:100vh;display:flex;align-items:center;position:relative;background:var(--bg-hero-grad);color:#fff;overflow:hidden}
    .hero-background{position:absolute;inset:0;opacity:.12;background-image:
      radial-gradient(circle at 20% 20%, rgba(255,255,255,0.4) 1px, transparent 1px),
      radial-gradient(circle at 80% 40%, rgba(255,255,255,0.3) 1px, transparent 1px),
      radial-gradient(circle at 40% 80%, rgba(255,255,255,0.35) 1px, transparent 1px);
      background-size:100px 100px, 150px 150px, 120px 120px;animation:float 20s linear infinite}
    @keyframes float{0%{transform:translateY(0)}100%{transform:translateY(-50px)}}
    .hero-content{position:relative;z-index:2;text-align:center;max-width:800px;margin:0 auto;padding:90px 0 40px}
    .hero-title{font-size:clamp(2.4rem,4.5vw,4rem);font-weight:800;line-height:1.15;margin-bottom:16px;text-shadow:2px 2px 4px rgba(0,0,0,.12)}
    .hero-description{font-size:1.15rem;opacity:.96;max-width:640px;margin:0 auto 28px}
    .cta-button{display:inline-block;padding:16px 34px;border-radius:999px;background:#fff;color:var(--primary);font-weight:700;text-decoration:none;transition:transform var(--t-slow),box-shadow var(--t-slow)}
    .cta-button:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg)}
    .interactive-button{position:relative;overflow:hidden;border:none;cursor:pointer}
    .button-ripple{position:absolute;top:50%;left:50%;width:0;height:0;border-radius:50%;background:rgba(0,0,0,.08);transform:translate(-50%,-50%);transition:width .6s,height .6s}
    .interactive-button:active .button-ripple{width:320px;height:320px}
    .hero-stats{display:flex;justify-content:center;gap:56px;margin-top:48px;flex-wrap:wrap}
    .stat-item{text-align:center}
    .stat-number{display:block;font-size:3rem;font-weight:800;text-shadow:2px 2px 4px rgba(0,0,0,.12)}
    .stat-label{opacity:.9;font-size:.9rem;letter-spacing:.08em;text-transform:uppercase}

    /* ========== FEATURES ========== */
    .features{padding:96px 0;background:var(--bg-2)}
    .section-title{font-size:2.4rem;font-weight:800;text-align:center;margin-bottom:46px;color:var(--text)}
    .features-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(320px,1fr));gap:32px;max-width:1200px;margin:0 auto}
    .feature-box{background:var(--bg-3);padding:28px;border-radius:var(--radius-lg);box-shadow:var(--shadow-sm);transition:transform var(--t-slow),box-shadow var(--t-slow);position:relative;overflow:hidden;border:1px solid var(--nav-border)}
    .feature-box:hover{transform:translateY(-8px);box-shadow:var(--shadow-lg)}
    .feature-icon-container{position:relative;margin-bottom:18px;border-radius:14px;overflow:hidden}
    .feature-img{width:100%;height:200px;object-fit:cover;display:block;transition:transform var(--t-slow)}
    .feature-overlay{position:absolute;inset:0;background:rgba(0,123,255,.96);display:flex;align-items:center;justify-content:center;opacity:0;transition:opacity var(--t-slow)}
    .feature-icon-container:hover .feature-overlay{opacity:1}
    .feature-icon-container:hover .feature-img{transform:scale(1.06)}
    .feature-learn-more{background:#fff;color:var(--primary);border:none;padding:12px 22px;border-radius:999px;font-weight:800;cursor:pointer}
    .feature-box h3{font-size:1.35rem;font-weight:800;color:var(--primary);margin:6px 0 10px}
    .feature-box p{color:var(--text-2)}

    /* ========== DEMO ========== */
    .demo-section{padding:96px 0;background:var(--bg)}
    .demo-card{display:grid;grid-template-columns:1fr 1fr;gap:52px;align-items:center;background:var(--bg-3);padding:52px;border-radius:var(--radius-lg);box-shadow:var(--shadow-md);border:1px solid var(--nav-border)}
    .demo-content h2{font-size:2.2rem;font-weight:800;margin-bottom:12px}
    .demo-content p{font-size:1.08rem;color:var(--text-2);margin-bottom:24px}
    .demo-link{display:inline-block;padding:14px 28px;border-radius:999px;background:linear-gradient(135deg,#007BFF,#0056b3);color:#fff;text-decoration:none;font-weight:800;box-shadow:var(--shadow-sm)}
    .demo-link:hover{transform:translateY(-2px);box-shadow:var(--shadow-md)}
    .code-preview{background:#1e1e1e;border-radius:14px;overflow:hidden;box-shadow:var(--shadow-lg)}
    .code-header{background:#2d2d2d;padding:14px 18px;display:flex;align-items:center}
    .code-dots{display:flex;gap:8px}
    .code-dots span{width:12px;height:12px;border-radius:50%}
    .code-dots span:nth-child(1){background:#ff5f56}
    .code-dots span:nth-child(2){background:#ffbd2e}
    .code-dots span:nth-child(3){background:#27ca3f}
    .code-content{padding:22px;font-family:'Fira Code','Monaco','Consolas',monospace;color:#f8f8f2;font-size:.95rem;line-height:1.6}
    .code-line{display:block;margin-bottom:8px}
    .code-line.highlight{background:rgba(255,255,255,.1);padding:4px 8px;border-radius:6px;border-left:3px solid #00ff88}

    /* ========== MODAL ========== */
    .modal{position:fixed;inset:0;background:rgba(0,0,0,.75);backdrop-filter:blur(8px);z-index:10000;display:flex;align-items:center;justify-content:center;opacity:0;visibility:hidden;transition:opacity var(--t-slow),visibility var(--t-slow)}
    .modal.active{opacity:1;visibility:visible}
    .modal-content{background:var(--bg-3);padding:32px;border-radius:20px;max-width:700px;width:92%;max-height:80vh;overflow:auto;position:relative;box-shadow:var(--shadow-lg);transform:scale(.96);transition:transform var(--t-slow)}
    .modal.active .modal-content{transform:scale(1)}
    .modal-close{position:absolute;top:16px;right:18px;font-size:28px;cursor:pointer;color:var(--text-muted);transition:color var(--t-fast),transform var(--t-fast)}
    .modal-close:hover{color:var(--danger);transform:scale(1.08)}

    /* ========== FOOTER ========== */
    .footer{background:var(--text);color:red;padding:36px 0;text-align:right}
    .footer a{color:red;opacity:.85;text-decoration:none}

    /* ========== SCROLL ANIMATIONS ========== */
    .animate-on-scroll{opacity:0;transform:translateY(28px);transition:opacity .8s cubic-bezier(.4,0,.2,1),transform .8s cubic-bezier(.4,0,.2,1)}
    .animate-on-scroll.visible{opacity:1;transform:translateY(0)}

    /* ========== RESPONSIVE ========== */
    @media(max-width:992px){.demo-card{grid-template-columns:1fr;gap:32px;padding:40px}}
    @media(max-width:768px){
      .nav-links{display:none}
      .mobile-toggle{display:flex}
      .theme-toggle{bottom:70px;right:20px;width:50px;height:50px}
      .back-to-top{bottom:20px;right:20px;width:50px;height:50px}
      .hero-content{padding-top:96px}
      .features{padding:72px 0}
      .demo-section{padding:72px 0}
    }
    @media(max-width:480px){
      .container{padding:0 16px}
      .hero-title{font-size:2.4rem}
      .section-title{font-size:2rem}
      .feature-box,.demo-card{padding:24px}
    }

    /* ========== ACCESSIBILITY & PRINT ========== */
    @media(prefers-reduced-motion:reduce){*{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}}
    @media print{.navbar,.theme-toggle,.back-to-top,.hero-background,.button-ripple{display:none!important}}