@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;600;700&display=swap');

:root {
    --bg-dark: #0f0f10;
    --bg-card: #1b1b1d;
    --accent: #f5f6fa;
    --accent-hover: #a0a3a7;
    --text-light: #f5f6fa;
    --text-muted: #a0a3a7;
    --radius: 16px;
    --shadow: 0 10px 30px rgba(0,0,0,0.45);
    --ring: 0 0 0 3px rgba(255,255,255,.08) inset;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: 'Poppins', Arial, sans-serif;
    margin: 0; padding: 0;
    background: radial-gradient(1200px 800px at 20% -10%, #1b1b1d55, transparent),
                radial-gradient(900px 600px at 110% 10%, #11111166, transparent),
                var(--bg-dark);
    color: var(--text-light);
    line-height: 1.6;
}
.container { width: min(1200px, 92%); margin: 0 auto; }

.navbar {
    position: sticky; top: 0;
    backdrop-filter: blur(8px);
    background: rgba(17,17,17,0.6);
    border-bottom: 1px solid rgba(255,255,255,0.06);
}
.navbar-inner { display: flex; align-items: center; justify-content: space-between; padding: 14px 0; }
.brand { font-weight:700; letter-spacing:.5px; font-size:1.05rem; color:var(--text-light); text-decoration:none; }
.nav-links { display:flex; gap:24px; align-items:center; }
.nav-links a { color: var(--text-light); text-decoration:none; font-weight:600; opacity:.9; transition: opacity .25s, transform .25s; }
.nav-links a:hover { opacity:1; transform:translateY(-2px); }

header {
    background: linear-gradient(-45deg, #1b1b1d, #121212, #1a1a1a, #0f0f10);
    background-size: 400% 400%;
    animation: gradientMove 12s ease infinite;
    color: var(--text-light);
    padding: 96px 0 64px;
    text-align:center;
    box-shadow: var(--shadow);
    border-bottom: 1px solid rgba(255,255,255,0.06);
}
@keyframes gradientMove { 0% {background-position:0% 50%;} 50% {background-position:100% 50%;} 100% {background-position:0% 50%;} }

.hero-title {
    margin:0; font-size:clamp(2.6rem,5vw,4.2rem);
    letter-spacing:1px; line-height:1.05;
    background: linear-gradient(180deg,#fff,#b7b9be 60%,#7a7d84);
    -webkit-background-clip: text; background-clip: text; color: transparent;
    text-shadow: 0 20px 60px rgba(0,0,0,.6);
}
.hero-sub { margin: 14px auto 0; font-size:1.15rem; color: var(--text-muted); max-width:780px; }

.main-buttons, .category-buttons, .cta-row {
    display:flex; justify-content:center; gap:14px; margin:28px 0 6px; flex-wrap:wrap;
}
.main-button, .category-buttons button {
    background: rgba(255,255,255,0.08);
    color: var(--text-light);
    border: 1px solid rgba(255,255,255,0.18);
    backdrop-filter: blur(8px);
    padding:12px 26px; border-radius: var(--radius);
    font-size:1rem; font-weight:700; cursor:pointer;
    transition: all .3s ease; box-shadow: var(--ring), var(--shadow);
    text-decoration:none;
}
.main-button:hover, .category-buttons button:hover {
    background: rgba(255,255,255,0.22);
    transform: translateY(-4px) scale(1.03);
    box-shadow: 0 16px 32px rgba(0,0,0,0.55);
}

.promo a { color:var(--accent); text-decoration:none; border-bottom:1px dashed rgba(245,246,250,.55); }
.promo a:hover { border-bottom-style:solid; }

section.section { padding:54px 0 14px; }
.section-title { text-align:center; font-size:clamp(1.8rem,3vw,2.4rem); margin-bottom:22px; letter-spacing:.6px; }

.products { display:grid; grid-template-columns:repeat(auto-fit,minmax(260px,1fr)); gap:24px; }
.product, .review {
    background: var(--bg-card); border-radius: var(--radius);
    padding:20px; box-shadow: var(--shadow);
    text-align:center; border:1px solid rgba(255,255,255,0.06);
    transition: transform .4s ease, box-shadow .4s ease;
}
.product:hover { transform: translateY(-6px) rotateX(2deg) rotateY(-2deg); box-shadow:0 20px 40px rgba(0,0,0,0.6); }
.product img { width:100%; aspect-ratio:1/1; object-fit:cover; border-radius: calc(var(--radius)-4px); transition: transform .45s ease, box-shadow .3s ease; border:3px solid #a0a3a7; box-shadow:0 6px 20px rgba(0,0,0,0.45); }
.product img:hover { transform: scale(1.06); box-shadow: 0 10px 25px rgba(0,0,0,0.55); }
.product h3 { margin:14px 0 10px; font-size:1.1rem; }
.product a {
    display:inline-block; text-decoration:none; background: rgba(255,255,255,0.12);
    color: var(--text-light); padding:10px 18px; border-radius:12px; font-weight:700; margin-top:6px;
    border:1px solid rgba(255,255,255,0.2); transition: transform .25s, background .25s;
}
.product a:hover { background: rgba(255,255,255,0.25); transform: translateY(-2px); }

.reviews { display:grid; grid-template-columns:repeat(auto-fit,minmax(280px,1fr)); gap:24px; margin-top:8px; }
.stars { letter-spacing:2px; font-size:1.1rem; color:#ffd36b; }
.review b { color: var(--accent); }
.review:hover { transform: translateY(-6px); box-shadow:0 16px 30px rgba(0,0,0,.55); }

.faq {
    padding:40px; max-width:1000px; margin:40px auto;
    border-radius: var(--radius); box-shadow: var(--shadow);
    border:1px solid rgba(255,255,255,0.06); background: var(--bg-card);
}
.faq h2 { text-align:center; margin-bottom:24px; font-size:2rem; }
.faq-item { margin-bottom:18px; padding:18px; border-radius: var(--radius); border:1px solid rgba(255,255,255,0.06); background:#161616; }
.faq-item h3 { margin:0; font-size:1.1rem; cursor:pointer; }
.faq-item p { margin-top:8px; color: var(--text-muted); }

footer { text-align:center; padding:28px 20px 40px; background:#151515; color: var(--text-muted); border-top:1px solid rgba(255,255,255,0.06); }
footer img { width:48px; height:48px; opacity:.85; transition: opacity .3s, transform .3s; }
footer img:hover { opacity:1; transform:translateY(-2px); }

.fade-in { opacity:0; transform:translateY(22px); transition: all .8s cubic-bezier(.21,.61,.35,1); will-change:transform,opacity; }
.fade-in.visible { opacity:1; transform:translateY(0); }

@media (max-width:768px){
    .navbar-inner { padding:12px 0; }
    header { padding:72px 0 48px; }
    .hero-sub { font-size:1rem; }
    .faq { padding:22px; }
}

body[data-page="spreadsheet"] .product img {
    aspect-ratio: 1 / 1;
    object-fit: cover;
}

body[data-page="bb"] .product img {
    aspect-ratio: 4 / 3;
    object-fit: contain;
    background-color: #fff;
}

/* Back to main button */
body[data-page="bb"] button {
    position: fixed;
    top: 18px;
    left: 18px;
    z-index: 1000;

    font-family: 'Poppins', Arial, sans-serif;
    font-weight: 700;
    font-size: 0.9rem;

    background: rgba(255,255,255,0.1);
    color: var(--text-light);

    border: 1px solid rgba(255,255,255,0.25);
    border-radius: 12px;
    padding: 10px 16px;

    cursor: pointer;
    backdrop-filter: blur(8px);
    box-shadow: var(--shadow), var(--ring);

    transition: all 0.25s ease;
}

body[data-page="bb"] button:hover {
    background: rgba(255,255,255,0.25);
    transform: translateY(-2px);
}