/* =============================================================
   Bitertools — Premium SaaS Utility Tools
   style.css  |  Shared across all pages
   -------------------------------------------------------------
   Sections:
   1.  CSS Variables & Theme (light -> dark scroll transition)
   2.  Base & Resets
   3.  Layout helpers
   4.  Buttons
   5.  Header / Navigation (glassmorphism, sticky)
   6.  Hero + 3D Sphere
   7.  Cards & Sections
   8.  Tool Hub / Working Tool
   9.  Statistics, Testimonials, FAQ
   10. Forms (contact / newsletter)
   11. Footer
   12. Animations & Utilities
   13. Responsive breakpoints
   ============================================================= */

/* -------------------------------------------------------------
   1. CSS VARIABLES & THEME
   The --theme (0 = light, 1 = dark) is driven by JS on scroll.
   Colors are interpolated in JS and written to these vars.
   ------------------------------------------------------------- */
:root {
  /* Brand */
  --brand: #2563EB;
  --brand-600: #1D4ED8;
  --brand-400: #60A5FA;
  --brand-glow: rgba(37, 99, 235, 0.45);

  /* Dynamic theme colors (updated by script.js on scroll) */
  --bg: #ffffff;
  --bg-alt: #f4f7ff;
  --surface: rgba(255, 255, 255, 0.72);
  --surface-solid: #ffffff;
  --text: #0b1220;
  --text-muted: #4b5670;
  --border: rgba(15, 23, 42, 0.10);
  --shadow: rgba(23, 42, 89, 0.12);
  --header-bg: rgba(255, 255, 255, 0.65);

  /* Static tokens */
  --radius: 18px;
  --radius-sm: 12px;
  --radius-lg: 26px;
  --maxw: 1200px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --t-fast: 0.2s;
  --t: 0.35s;
  --font: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

/* -------------------------------------------------------------
   2. BASE & RESETS
   ------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  overflow-x: hidden;
  transition: background var(--t) linear, color var(--t) linear;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

h1, h2, h3, h4 { line-height: 1.15; margin: 0 0 .5em; font-weight: 800; letter-spacing: -0.02em; }
h1 { font-size: clamp(2.2rem, 5vw, 3.6rem); }
h2 { font-size: clamp(1.7rem, 3.5vw, 2.6rem); }
h3 { font-size: clamp(1.15rem, 2vw, 1.4rem); }
p { margin: 0 0 1rem; color: var(--text-muted); }

::selection { background: var(--brand); color: #fff; }

/* -------------------------------------------------------------
   3. LAYOUT HELPERS
   ------------------------------------------------------------- */
.container { width: min(100% - 2.5rem, var(--maxw)); margin-inline: auto; }
.section { padding: clamp(3.5rem, 8vw, 6.5rem) 0; position: relative; }
.section-head { max-width: 720px; margin: 0 auto 3rem; text-align: center; }
.section-head p { font-size: 1.05rem; }
.eyebrow {
  display: inline-block; font-size: .8rem; font-weight: 700; letter-spacing: .12em;
  text-transform: uppercase; color: var(--brand);
  background: var(--brand-glow); padding: .35rem .8rem; border-radius: 999px; margin-bottom: 1rem;
}
.grid { display: grid; gap: 1.5rem; }
.text-gradient {
  background: linear-gradient(120deg, var(--brand-400), var(--brand) 50%, #7c3aed);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

/* -------------------------------------------------------------
   4. BUTTONS
   ------------------------------------------------------------- */
.btn {
  --_bg: var(--brand);
  position: relative; display: inline-flex; align-items: center; gap: .55rem;
  font-weight: 700; font-size: .98rem; padding: .85rem 1.5rem; border-radius: 999px;
  border: 1px solid transparent; cursor: pointer; overflow: hidden;
  transition: transform var(--t-fast) var(--ease), box-shadow var(--t) var(--ease), background var(--t);
  will-change: transform;
}
.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--brand-400), var(--brand) 55%, var(--brand-600));
  box-shadow: 0 10px 24px -8px var(--brand-glow), inset 0 1px 0 rgba(255,255,255,.25);
}
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 18px 38px -10px var(--brand-glow); }
.btn-ghost {
  color: var(--text); background: var(--surface); border-color: var(--border);
  backdrop-filter: blur(8px);
}
.btn-ghost:hover { transform: translateY(-3px); border-color: var(--brand); color: var(--brand); }
.btn:active { transform: translateY(-1px) scale(.98); }

/* Ripple (spawned by JS) */
.ripple {
  position: absolute; border-radius: 50%; transform: scale(0);
  background: rgba(255,255,255,.55); pointer-events: none; animation: ripple .6s ease-out;
}
@keyframes ripple { to { transform: scale(4); opacity: 0; } }

/* -------------------------------------------------------------
   5. HEADER / NAVIGATION
   ------------------------------------------------------------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  transition: background var(--t), box-shadow var(--t), backdrop-filter var(--t);
}
.site-header.scrolled {
  background: var(--header-bg);
  -webkit-backdrop-filter: blur(16px) saturate(160%);
  backdrop-filter: blur(16px) saturate(160%);
  box-shadow: 0 8px 30px -12px var(--shadow);
  border-bottom: 1px solid var(--border);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 74px; gap: 1rem; }

.brand { display: flex; align-items: center; gap: .6rem; font-weight: 800; font-size: 1.25rem; letter-spacing: -.02em; }
.brand-logo {
  width: 34px; height: 34px; border-radius: 10px; flex: none;
  background: conic-gradient(from 140deg, var(--brand-400), #7c3aed, var(--brand), var(--brand-400));
  box-shadow: 0 6px 16px -6px var(--brand-glow), inset 0 0 8px rgba(255,255,255,.5);
  position: relative;
}
.brand-logo::after {
  content: ""; position: absolute; inset: 8px; border-radius: 6px;
  background: var(--bg); opacity: .55;
}
.brand span { color: var(--brand); }

.nav-links { display: flex; align-items: center; gap: .35rem; list-style: none; margin: 0; padding: 0; }
.nav-links a {
  position: relative; font-weight: 600; font-size: .95rem; padding: .5rem .8rem; border-radius: 8px;
  color: var(--text); transition: color var(--t-fast);
}
.nav-links a::after {
  content: ""; position: absolute; left: .8rem; right: .8rem; bottom: .3rem; height: 2px;
  background: var(--brand); border-radius: 2px; transform: scaleX(0); transform-origin: left;
  transition: transform var(--t) var(--ease);
}
.nav-links a:hover, .nav-links a.active { color: var(--brand); }
.nav-links a:hover::after, .nav-links a.active::after { transform: scaleX(1); }

.nav-cta { display: flex; align-items: center; gap: .6rem; }
.hamburger {
  display: none; width: 44px; height: 44px; border: 1px solid var(--border); border-radius: 12px;
  background: var(--surface); cursor: pointer; padding: 0; place-items: center;
}
.hamburger span, .hamburger span::before, .hamburger span::after {
  content: ""; display: block; width: 20px; height: 2px; background: var(--text); border-radius: 2px;
  transition: transform var(--t), opacity var(--t);
}
.hamburger span { position: relative; }
.hamburger span::before { position: absolute; top: -6px; }
.hamburger span::after { position: absolute; top: 6px; }
.hamburger.open span { background: transparent; }
.hamburger.open span::before { transform: translateY(6px) rotate(45deg); }
.hamburger.open span::after { transform: translateY(-6px) rotate(-45deg); }

/* -------------------------------------------------------------
   6. HERO + 3D SPHERE
   ------------------------------------------------------------- */
.hero { position: relative; padding: clamp(2.5rem, 6vw, 5rem) 0 clamp(3rem, 7vw, 6rem); overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1.1fr .9fr; align-items: center; gap: 3rem; }
.hero h1 { margin-bottom: 1.1rem; }
.hero-lead { font-size: 1.15rem; max-width: 34ch; }
.hero-actions { display: flex; flex-wrap: wrap; gap: .9rem; margin: 1.6rem 0 1.4rem; }

.trust { display: flex; align-items: center; gap: .8rem; flex-wrap: wrap; font-size: .85rem; color: var(--text-muted); }
.trust .stars { color: #f5a623; letter-spacing: 2px; }
.avatars { display: flex; }
.avatars i {
  width: 30px; height: 30px; border-radius: 50%; margin-left: -8px; border: 2px solid var(--bg);
  background: linear-gradient(135deg, var(--brand-400), #7c3aed); display: inline-block;
}

.hero-stats { display: flex; gap: 2rem; margin-top: 2.2rem; flex-wrap: wrap; }
.hero-stats .num { font-size: 1.8rem; font-weight: 800; color: var(--text); }
.hero-stats .lbl { font-size: .82rem; color: var(--text-muted); }

/* --- Sphere --- */
.sphere-stage {
  position: relative; display: grid; place-items: center; min-height: 420px;
  perspective: 900px;
}
.sphere-float { animation: floaty 6s ease-in-out infinite; }
.sphere {
  width: clamp(240px, 30vw, 360px); aspect-ratio: 1; border-radius: 50%;
  position: relative; transform-style: preserve-3d;
  /* continuous rotation applied inline / by keyframe with ~145deg perspective tilt */
  animation: spin 14s linear infinite, breathe 5s ease-in-out infinite;
  background:
    radial-gradient(circle at 32% 28%, #ffffff 0%, rgba(255,255,255,.0) 24%),
    conic-gradient(from 145deg at 50% 50%,
      #60a5fa, #7c3aed, #ec4899, #f59e0b, #22d3ee, #2563eb, #60a5fa);
  box-shadow:
    inset -28px -34px 60px rgba(0,0,0,.45),
    inset 24px 22px 50px rgba(255,255,255,.35),
    0 40px 80px -20px var(--brand-glow);
  will-change: transform;
  transform: rotateX(20deg) rotateZ(0deg);
}
/* glossy highlight */
.sphere::before {
  content: ""; position: absolute; top: 12%; left: 18%; width: 42%; height: 32%;
  background: radial-gradient(circle at 30% 30%, rgba(255,255,255,.9), rgba(255,255,255,0) 70%);
  border-radius: 50%; filter: blur(2px); transform: translateZ(1px);
}
/* soft glow ring */
.sphere::after {
  content: ""; position: absolute; inset: -14%; border-radius: 50%; z-index: -1;
  background: radial-gradient(circle, var(--brand-glow), transparent 62%);
  filter: blur(18px); animation: breathe 5s ease-in-out infinite;
}
/* ambient shadow under sphere */
.sphere-shadow {
  position: absolute; bottom: 6%; left: 50%; width: 55%; height: 34px; transform: translateX(-50%);
  background: radial-gradient(ellipse, rgba(23,42,89,.35), transparent 70%);
  filter: blur(10px); animation: shadowPulse 6s ease-in-out infinite;
}

@keyframes spin { to { transform: rotateX(20deg) rotateZ(360deg); } }
@keyframes floaty { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-16px); } }
@keyframes breathe { 0%,100% { transform: scale(1); } 50% { transform: scale(1.04); } }
@keyframes shadowPulse { 0%,100% { opacity:.55; width:55%; } 50% { opacity:.35; width:48%; } }

/* -------------------------------------------------------------
   7. CARDS & SECTIONS
   ------------------------------------------------------------- */
.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 1.6rem; box-shadow: 0 10px 30px -18px var(--shadow);
  -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px);
  transition: transform var(--t) var(--ease), box-shadow var(--t), border-color var(--t);
  position: relative; overflow: hidden;
}
.card::before { /* gradient border glow on hover */
  content: ""; position: absolute; inset: 0; border-radius: inherit; padding: 1px;
  background: linear-gradient(135deg, var(--brand-400), transparent 40%, #7c3aed);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor; mask-composite: exclude;
  opacity: 0; transition: opacity var(--t);
}
.card:hover { transform: translateY(-8px); box-shadow: 0 26px 50px -22px var(--brand-glow); border-color: transparent; }
.card:hover::before { opacity: 1; }
.card .ico {
  width: 48px; height: 48px; border-radius: 14px; display: grid; place-items: center; font-size: 1.4rem;
  background: var(--brand-glow); color: var(--brand); margin-bottom: 1rem;
}
.card h3 { color: var(--text); }
.card p { margin-bottom: 0; font-size: .95rem; }

.features-grid { grid-template-columns: repeat(3, 1fr); }
.why-grid { grid-template-columns: 1.1fr .9fr; align-items: center; gap: 3rem; }
.why-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 1.1rem; }
.why-list li { display: flex; gap: .9rem; align-items: flex-start; }
.why-list .tick {
  flex: none; width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center;
  background: var(--brand); color: #fff; font-size: .85rem; font-weight: 800; margin-top: 2px;
}
.why-list b { color: var(--text); display: block; }

.steps-grid { grid-template-columns: repeat(3, 1fr); counter-reset: step; }
.step { position: relative; }
.step .n {
  font-size: 2.4rem; font-weight: 800; color: var(--brand); opacity: .35; line-height: 1;
}
.benefits-grid { grid-template-columns: repeat(4, 1fr); }

/* -------------------------------------------------------------
   8. TOOL HUB / WORKING TOOL
   ------------------------------------------------------------- */
.tools-grid { grid-template-columns: repeat(4, 1fr); }
.tool-card { text-align: left; cursor: pointer; }
.tool-card .badge {
  position: absolute; top: 1rem; right: 1rem; font-size: .68rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: .06em; padding: .25rem .55rem; border-radius: 999px;
  background: var(--brand); color: #fff;
}
.tool-card .badge.soon { background: var(--border); color: var(--text-muted); }

.tool-app {
  background: var(--surface-solid); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: clamp(1.4rem, 3vw, 2.4rem); box-shadow: 0 30px 60px -30px var(--shadow); margin-top: 2.5rem;
}
.tool-tabs { display: flex; gap: .5rem; flex-wrap: wrap; margin-bottom: 1.4rem; }
.tool-tab {
  font-weight: 700; font-size: .9rem; padding: .55rem 1rem; border-radius: 999px; cursor: pointer;
  border: 1px solid var(--border); background: transparent; color: var(--text-muted); transition: all var(--t-fast);
}
.tool-tab.active { background: var(--brand); color: #fff; border-color: var(--brand); }
.tool-io textarea, .tool-io input[type="text"] {
  width: 100%; border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 1rem;
  font: inherit; font-size: 1rem; background: var(--bg); color: var(--text); resize: vertical;
  transition: border-color var(--t-fast), box-shadow var(--t-fast);
}
.tool-io textarea { min-height: 150px; }
.tool-io textarea:focus, .tool-io input:focus { outline: none; border-color: var(--brand); box-shadow: 0 0 0 4px var(--brand-glow); }
.tool-controls { display: flex; flex-wrap: wrap; gap: .6rem; margin: 1rem 0; }
.tool-controls .btn { padding: .6rem 1.1rem; font-size: .9rem; }
.tool-stats { display: flex; flex-wrap: wrap; gap: 1.4rem; margin-top: 1rem; }
.tool-stats .stat b { font-size: 1.5rem; color: var(--brand); display: block; }
.tool-stats .stat span { font-size: .8rem; color: var(--text-muted); }
.tool-output {
  margin-top: 1rem; padding: 1rem; border-radius: var(--radius-sm); background: var(--bg-alt);
  border: 1px dashed var(--border); min-height: 60px; white-space: pre-wrap; word-break: break-word;
  color: var(--text); font-size: .95rem;
}
.hidden { display: none !important; }

/* -------------------------------------------------------------
   9. STATISTICS / TESTIMONIALS / FAQ
   ------------------------------------------------------------- */
.stats-band { grid-template-columns: repeat(4, 1fr); text-align: center; }
.stats-band .num { font-size: clamp(2rem, 4vw, 3rem); font-weight: 800; color: var(--brand); }
.stats-band .lbl { color: var(--text-muted); font-size: .9rem; }

.testi-grid { grid-template-columns: repeat(3, 1fr); }
.testi p { color: var(--text); font-size: 1rem; }
.testi .who { display: flex; align-items: center; gap: .7rem; margin-top: 1rem; }
.testi .who i {
  width: 40px; height: 40px; border-radius: 50%;
  background: linear-gradient(135deg, var(--brand-400), #7c3aed); flex: none;
}
.testi .who b { color: var(--text); display: block; font-size: .92rem; }
.testi .who span { font-size: .8rem; color: var(--text-muted); }

.faq { max-width: 780px; margin-inline: auto; }
.faq-item { border: 1px solid var(--border); border-radius: var(--radius-sm); margin-bottom: .8rem; background: var(--surface); overflow: hidden; }
.faq-q {
  width: 100%; text-align: left; background: none; border: 0; cursor: pointer; font: inherit;
  font-weight: 700; color: var(--text); padding: 1.1rem 1.3rem; display: flex; justify-content: space-between; gap: 1rem;
}
.faq-q .plus { color: var(--brand); transition: transform var(--t); flex: none; }
.faq-item.open .plus { transform: rotate(45deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height var(--t) var(--ease); }
.faq-a p { padding: 0 1.3rem 1.1rem; margin: 0; }

/* CTA band */
.cta-band {
  text-align: center; border-radius: var(--radius-lg); padding: clamp(2.5rem, 6vw, 4.5rem) 1.5rem;
  background: linear-gradient(135deg, var(--brand), var(--brand-600) 60%, #4c1d95); color: #fff;
  box-shadow: 0 40px 80px -30px var(--brand-glow); position: relative; overflow: hidden;
}
.cta-band h2, .cta-band p { color: #fff; }
.cta-band p { opacity: .9; }
.cta-band .btn-ghost { background: rgba(255,255,255,.14); color: #fff; border-color: rgba(255,255,255,.3); }

/* Updates */
.updates-grid { grid-template-columns: repeat(3, 1fr); }
.update .tag { font-size: .72rem; font-weight: 700; color: var(--brand); text-transform: uppercase; letter-spacing: .08em; }
.update time { font-size: .8rem; color: var(--text-muted); }

/* -------------------------------------------------------------
   10. FORMS
   ------------------------------------------------------------- */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.field { display: flex; flex-direction: column; gap: .4rem; margin-bottom: 1rem; }
.field.full { grid-column: 1 / -1; }
.field label { font-weight: 600; font-size: .88rem; color: var(--text); }
.field input, .field textarea {
  border: 1px solid var(--border); border-radius: var(--radius-sm); padding: .8rem 1rem; font: inherit;
  background: var(--bg); color: var(--text); transition: border-color var(--t-fast), box-shadow var(--t-fast);
}
.field textarea { min-height: 140px; resize: vertical; }
.field input:focus, .field textarea:focus { outline: none; border-color: var(--brand); box-shadow: 0 0 0 4px var(--brand-glow); }
.form-note { font-size: .85rem; }

.contact-grid { grid-template-columns: 1.2fr .8fr; gap: 2.5rem; align-items: start; }
.info-row { display: flex; gap: .8rem; align-items: flex-start; margin-bottom: 1.2rem; }
.info-row .ico { flex: none; width: 42px; height: 42px; border-radius: 12px; background: var(--brand-glow); color: var(--brand); display: grid; place-items: center; }
.info-row b { color: var(--text); display: block; }
.map-placeholder {
  height: 220px; border-radius: var(--radius); margin-top: 1rem; border: 1px solid var(--border);
  background: linear-gradient(135deg, var(--bg-alt), var(--brand-glow)); display: grid; place-items: center;
  color: var(--text-muted); font-weight: 600;
}

/* Legal / article pages */
.article { max-width: 820px; margin-inline: auto; }
.article h2 { margin-top: 2.2rem; }
.article h3 { margin-top: 1.6rem; color: var(--text); }
.article p, .article li { color: var(--text-muted); }
.article ul { padding-left: 1.2rem; }
.article li { margin-bottom: .5rem; }
.updated { font-size: .85rem; color: var(--text-muted); }

/* -------------------------------------------------------------
   11. FOOTER
   ------------------------------------------------------------- */
.site-footer {
  background: #05070d; color: #c7cfe0; padding: clamp(3rem, 6vw, 4.5rem) 0 1.5rem; position: relative;
  overflow: hidden; border-top: 1px solid rgba(255,255,255,.06);
}
.footer-particles { position: absolute; inset: 0; pointer-events: none; overflow: hidden; }
.footer-particles i {
  position: absolute; width: 4px; height: 4px; border-radius: 50%;
  background: var(--brand-400); opacity: .5; animation: rise linear infinite;
}
@keyframes rise { from { transform: translateY(20px); opacity: 0; } 20% { opacity: .6; } to { transform: translateY(-260px); opacity: 0; } }

.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.3fr; gap: 2rem; position: relative; z-index: 1; }
.footer-grid h4 { color: #fff; font-size: 1rem; margin-bottom: 1.1rem; }
.footer-brand p { color: #93a0bd; font-size: .92rem; max-width: 30ch; }
.footer-brand .brand { color: #fff; margin-bottom: .9rem; }
.footer-links { list-style: none; margin: 0; padding: 0; display: grid; gap: .6rem; }
.footer-links a { color: #93a0bd; font-size: .92rem; position: relative; width: fit-content; transition: color var(--t-fast); }
.footer-links a::after { content:""; position:absolute; left:0; bottom:-2px; height:1px; width:100%; background: var(--brand-400); transform: scaleX(0); transform-origin:left; transition: transform var(--t) var(--ease); }
.footer-links a:hover { color: #fff; }
.footer-links a:hover::after { transform: scaleX(1); }

.socials { display: flex; gap: .6rem; margin-top: 1.2rem; }
.socials a {
  width: 40px; height: 40px; border-radius: 12px; display: grid; place-items: center; color: #cbd5e1;
  background: rgba(255,255,255,.06); border: 1px solid rgba(255,255,255,.08);
  transition: transform var(--t) var(--ease), background var(--t), color var(--t);
}
.socials a:hover { transform: translateY(-4px) scale(1.05); color: #fff; }
.socials a.fb:hover { background: #1877F2; }
.socials a.ig:hover { background: linear-gradient(45deg,#f09433,#e6683c,#dc2743,#cc2366,#bc1888); }
.socials a.x:hover  { background: #000; }
.socials a.li:hover { background: #0A66C2; }
.socials svg { width: 18px; height: 18px; fill: currentColor; }

.newsletter { display: flex; gap: .5rem; margin-top: .5rem; }
.newsletter input {
  flex: 1; min-width: 0; border: 1px solid rgba(255,255,255,.12); background: rgba(255,255,255,.05);
  color: #fff; border-radius: 999px; padding: .7rem 1rem; font: inherit;
}
.newsletter input::placeholder { color: #7c88a6; }
.newsletter input:focus { outline: none; border-color: var(--brand-400); }

.footer-bottom {
  margin-top: 2.5rem; padding-top: 1.3rem; border-top: 1px solid rgba(255,255,255,.08);
  display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; align-items: center;
  font-size: .85rem; color: #7c88a6; position: relative; z-index: 1;
}

.to-top {
  position: fixed; right: 20px; bottom: 20px; width: 46px; height: 46px; border-radius: 50%; z-index: 90;
  background: linear-gradient(135deg, var(--brand-400), var(--brand-600)); color: #fff; border: 0; cursor: pointer;
  display: grid; place-items: center; box-shadow: 0 12px 26px -8px var(--brand-glow);
  opacity: 0; visibility: hidden; transform: translateY(12px); transition: all var(--t) var(--ease);
}
.to-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.to-top:hover { transform: translateY(-3px) scale(1.06); }

/* -------------------------------------------------------------
   12. ANIMATIONS & UTILITIES
   ------------------------------------------------------------- */
[data-reveal] { opacity: 0; transform: translateY(28px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
[data-reveal].in { opacity: 1; transform: none; }
[data-reveal].d1 { transition-delay: .08s; }
[data-reveal].d2 { transition-delay: .16s; }
[data-reveal].d3 { transition-delay: .24s; }
[data-reveal].d4 { transition-delay: .32s; }

.mt-1 { margin-top: .5rem; } .mt-2 { margin-top: 1rem; } .mt-3 { margin-top: 1.5rem; }
.center { text-align: center; }
.muted { color: var(--text-muted); }

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; }
  html { scroll-behavior: auto; }
}

/* -------------------------------------------------------------
   13. RESPONSIVE
   ------------------------------------------------------------- */
@media (max-width: 980px) {
  .hero-grid { grid-template-columns: 1fr; text-align: center; }
  .hero-lead { margin-inline: auto; }
  .hero-actions, .hero-stats, .trust { justify-content: center; }
  .sphere-stage { order: -1; min-height: 340px; }
  .why-grid, .contact-grid { grid-template-columns: 1fr; }
  .features-grid, .tools-grid, .benefits-grid, .stats-band, .testi-grid, .steps-grid, .updates-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 760px) {
  .nav-links {
    position: fixed; inset: 74px 0 auto 0; flex-direction: column; align-items: stretch; gap: 0;
    background: var(--header-bg); -webkit-backdrop-filter: blur(18px); backdrop-filter: blur(18px);
    padding: 1rem 1.25rem 1.5rem; border-bottom: 1px solid var(--border);
    transform: translateY(-140%); transition: transform var(--t) var(--ease); box-shadow: 0 20px 40px -20px var(--shadow);
  }
  .nav-links.open { transform: translateY(0); }
  .nav-links a { padding: .9rem .5rem; }
  .nav-links a::after { display: none; }
  .hamburger { display: grid; }
  .nav-cta .btn:not(.hamburger) { display: none; }
  .form-grid { grid-template-columns: 1fr; }
}

@media (max-width: 560px) {
  .features-grid, .tools-grid, .benefits-grid, .stats-band, .testi-grid, .steps-grid, .updates-grid, .footer-grid { grid-template-columns: 1fr; }
  .hero-stats { gap: 1.2rem; }
  .footer-bottom { flex-direction: column; text-align: center; }
}