/* =========================================================
   ToolHub — Landing page
   Style: dark, aurora gradients, glassmorphism, bold type
   ========================================================= */

:root {
  --bg: #08080d;
  --bg-soft: #0d0d15;
  --surface: rgba(255, 255, 255, 0.035);
  --surface-2: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.09);
  --border-strong: rgba(255, 255, 255, 0.16);
  --text: #f4f4f8;
  --text-soft: #b9b9c6;
  --text-mute: #7b7b8a;

  --violet: #8b5cf6;
  --blue: #3b82f6;
  --teal: #2dd4bf;
  --orange: #fb923c;
  --pink: #f472b6;

  --radius: 22px;
  --radius-sm: 14px;
  --radius-pill: 999px;
  --maxw: 1160px;

  --shadow: 0 20px 60px -20px rgba(0, 0, 0, 0.7);
  --font: "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }

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

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 16px;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  /* Sticky footer: keep the footer at the bottom of the viewport on short pages */
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}
main { flex: 1 0 auto; }

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 22px;
}
.container--narrow { max-width: 760px; }

/* ---------- Aurora background ---------- */
.aurora {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  background:
    radial-gradient(1200px 600px at 50% -10%, rgba(139, 92, 246, 0.10), transparent 60%),
    var(--bg);
}
.aurora__blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.55;
  will-change: transform;
}
.aurora__blob--1 { width: 520px; height: 520px; top: -160px; left: -120px;
  background: radial-gradient(circle, rgba(139,92,246,0.65), transparent 70%);
  animation: float1 20s ease-in-out infinite; }
.aurora__blob--2 { width: 560px; height: 560px; top: -120px; right: -160px;
  background: radial-gradient(circle, rgba(59,130,246,0.55), transparent 70%);
  animation: float2 24s ease-in-out infinite; }
.aurora__blob--3 { width: 500px; height: 500px; top: 44%; left: -180px;
  background: radial-gradient(circle, rgba(45,212,191,0.35), transparent 70%);
  animation: float1 26s ease-in-out infinite reverse; }
.aurora__blob--4 { width: 620px; height: 620px; bottom: -220px; right: -120px;
  background: radial-gradient(circle, rgba(244,114,182,0.35), transparent 70%);
  animation: float2 30s ease-in-out infinite; }

.aurora__grain {
  position: absolute; inset: 0;
  opacity: 0.5;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.35'/%3E%3C/svg%3E");
  mix-blend-mode: overlay;
}

@keyframes float1 { 0%,100% { transform: translate(0,0); } 50% { transform: translate(40px, 50px); } }
@keyframes float2 { 0%,100% { transform: translate(0,0); } 50% { transform: translate(-50px, 40px); } }

@media (prefers-reduced-motion: reduce) {
  .aurora__blob { animation: none; }
  html { scroll-behavior: auto; }
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 13px 26px;
  border-radius: var(--radius-pill);
  font-weight: 600; font-size: 15px;
  border: 1px solid transparent;
  transition: transform .18s ease, box-shadow .25s ease, background .25s ease, border-color .25s ease;
  white-space: nowrap;
}
.btn--sm { padding: 9px 18px; font-size: 14px; }
.btn--primary {
  color: #0a0a10;
  background: linear-gradient(180deg, #ffffff, #e9e9f2);
  box-shadow: 0 10px 30px -10px rgba(255,255,255,0.35);
}
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 16px 40px -12px rgba(255,255,255,0.45); }
.btn--ghost {
  color: var(--text);
  background: var(--surface);
  border-color: var(--border-strong);
  backdrop-filter: blur(8px);
}
.btn--ghost:hover { background: var(--surface-2); transform: translateY(-2px); }

/* ---------- Header ---------- */
.header {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(14px);
  background: rgba(8, 8, 13, 0.55);
  border-bottom: 1px solid transparent;
  transition: background .3s ease, border-color .3s ease;
}
.header.scrolled { background: rgba(8, 8, 13, 0.82); border-color: var(--border); }
.header__inner { display: flex; align-items: center; justify-content: space-between; height: 68px; gap: 16px; }

.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; font-size: 19px; letter-spacing: -0.02em; }
.brand__mark {
  display: grid; place-items: center;
  width: 34px; height: 34px; border-radius: 10px;
  color: #fff;
  background: linear-gradient(135deg, var(--violet), var(--blue));
  box-shadow: 0 6px 18px -6px rgba(139,92,246,0.7);
}
.brand__mark svg { width: 19px; height: 19px; }
.brand__name span { color: var(--text-soft); }

.nav { display: flex; gap: 6px; }
.nav__link {
  padding: 8px 14px; border-radius: var(--radius-pill);
  color: var(--text-soft); font-size: 15px; font-weight: 500;
  transition: color .2s ease, background .2s ease;
}
.nav__link:hover { color: var(--text); background: var(--surface); }

.header__actions { display: flex; align-items: center; gap: 10px; }
.lang-toggle {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 8px 13px; border-radius: var(--radius-pill);
  background: var(--surface); border: 1px solid var(--border);
  color: var(--text-soft); font-size: 14px; font-weight: 600;
  transition: color .2s ease, background .2s ease, border-color .2s;
}
.lang-toggle svg { width: 16px; height: 16px; }
.lang-toggle:hover { color: var(--text); border-color: var(--border-strong); background: var(--surface-2); }

.menu-btn { display: none; flex-direction: column; gap: 5px; width: 40px; height: 40px;
  align-items: center; justify-content: center; background: var(--surface);
  border: 1px solid var(--border); border-radius: 11px; }
.menu-btn span { width: 18px; height: 2px; background: var(--text); border-radius: 2px; transition: transform .25s, opacity .25s; }
.menu-btn.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-btn.open span:nth-child(2) { opacity: 0; }
.menu-btn.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero { padding: 96px 0 60px; text-align: center; }
.hero__inner { display: flex; flex-direction: column; align-items: center; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 7px 16px; border-radius: var(--radius-pill);
  background: var(--surface); border: 1px solid var(--border);
  color: var(--text-soft); font-size: 13px; font-weight: 600; letter-spacing: 0.02em;
  backdrop-filter: blur(8px);
}
.hero__title {
  margin: 26px 0 0;
  font-size: clamp(2.6rem, 8vw, 5.3rem);
  line-height: 1.02; font-weight: 800; letter-spacing: -0.035em;
}
.hero__title span { display: block; }
.hero__title--grad {
  background: linear-gradient(100deg, #fff 10%, #b7a9ff 40%, #7fb0ff 70%, #67e8f9 95%);
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.hero__desc { margin: 26px auto 0; max-width: 620px; color: var(--text-soft); font-size: clamp(1rem, 2.4vw, 1.18rem); }
.hero__cta { margin-top: 34px; display: flex; gap: 14px; flex-wrap: wrap; justify-content: center; }

.stats {
  margin-top: 62px; width: 100%;
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 1px; overflow: hidden;
  background: var(--border);
  border: 1px solid var(--border); border-radius: var(--radius);
  backdrop-filter: blur(10px);
}
.stats__item { background: rgba(13,13,21,0.6); padding: 26px 18px; text-align: center; }
.stats__num { display: block; font-size: clamp(1.4rem, 4vw, 2.1rem); font-weight: 800; letter-spacing: -0.02em; }
.stats__label { display: block; margin-top: 4px; color: var(--text-mute); font-size: 13px; font-weight: 500; }

/* ---------- Ads ---------- */
.ad {
  position: relative;
  display: grid; place-items: center;
  border: 1px dashed var(--border-strong); border-radius: var(--radius-sm);
  background: repeating-linear-gradient(45deg, rgba(255,255,255,0.015) 0 12px, transparent 12px 24px);
  color: var(--text-mute); font-size: 13px; font-weight: 500;
}
.ad--leaderboard { margin: 8px 0 0; min-height: 92px; }
.ad--rect { margin: 12px 0; min-height: 250px; }
.ad__tag {
  position: absolute; top: 8px; left: 12px;
  font-size: 10px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--text-mute);
}
.ad::after { content: "AdSense"; opacity: 0.35; }

/* ==========================================================================
   TẠM ẨN QUẢNG CÁO cho lần chạy đầu (thu hút người dùng trước).
   => Khi muốn bật lại AdSense: XOÁ đúng 1 dòng dưới đây là hiện lại toàn bộ slot.
   ========================================================================== */
.ad { display: none !important; }

/* ---------- Sections ---------- */
.section { padding: 84px 0; }
.section__head { text-align: center; max-width: 640px; margin: 0 auto 52px; }
.pill {
  display: inline-block; padding: 6px 14px; border-radius: var(--radius-pill);
  background: var(--surface); border: 1px solid var(--border);
  color: var(--text-soft); font-size: 12.5px; font-weight: 600; letter-spacing: 0.02em;
}
.section__title { margin: 18px 0 0; font-size: clamp(2rem, 5.5vw, 3.2rem); font-weight: 800; letter-spacing: -0.03em; line-height: 1.05; }
.section__sub { margin: 14px 0 0; color: var(--text-soft); font-size: 1.05rem; }

/* ---------- Tools grid ---------- */
.tools { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.tool {
  position: relative; overflow: hidden;
  padding: 28px 26px 26px;
  border: 1px solid var(--border); border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(255,255,255,0.05), rgba(255,255,255,0.015));
  backdrop-filter: blur(12px);
  display: flex; flex-direction: column;
  transition: transform .25s ease, border-color .25s ease, box-shadow .3s ease;
}
.tool::before {
  content: ""; position: absolute; inset: 0; opacity: 0; pointer-events: none;
  transition: opacity .35s ease;
  background: radial-gradient(340px 200px at 80% -10%, var(--glow, rgba(139,92,246,0.4)), transparent 70%);
}
.tool[data-glow="violet"] { --glow: rgba(139,92,246,0.35); }
.tool[data-glow="blue"]   { --glow: rgba(59,130,246,0.35); }
.tool[data-glow="teal"]   { --glow: rgba(45,212,191,0.30); }
.tool[data-glow="orange"] { --glow: rgba(251,146,60,0.30); }
.tool[data-glow="pink"]   { --glow: rgba(244,114,182,0.32); }
.tool[data-glow="grey"]   { --glow: rgba(255,255,255,0.10); }
.tool:hover { transform: translateY(-5px); border-color: var(--border-strong); box-shadow: var(--shadow); }
.tool:hover::before { opacity: 1; }

.tool__top { display: flex; align-items: flex-start; justify-content: space-between; margin-bottom: 22px; }
.tool__icon {
  display: grid; place-items: center; width: 52px; height: 52px; border-radius: 15px;
  background: var(--surface-2); border: 1px solid var(--border-strong); color: var(--text);
}
.tool__icon svg { width: 25px; height: 25px; }
.tool__num { font-size: 2.2rem; font-weight: 800; color: rgba(255,255,255,0.10); letter-spacing: -0.03em; line-height: 1; }
.tool__title { margin: 0 0 8px; font-size: 1.22rem; font-weight: 700; letter-spacing: -0.01em; }
.tool__desc { margin: 0 0 22px; color: var(--text-soft); font-size: 0.96rem; flex: 1; }
.tool__link {
  display: inline-flex; align-items: center; gap: 7px; align-self: flex-start;
  padding: 10px 18px; border-radius: var(--radius-pill);
  background: var(--surface-2); border: 1px solid var(--border-strong);
  color: var(--text); font-size: 14px; font-weight: 600;
  transition: gap .2s ease, background .2s ease, transform .2s;
}
.tool__link svg { width: 16px; height: 16px; }
.tool__link:hover { gap: 11px; background: rgba(255,255,255,0.12); }

.tool--soon { align-items: flex-start; justify-content: center; }
.tool__badge {
  align-self: flex-start; padding: 7px 14px; border-radius: var(--radius-pill);
  background: var(--surface); border: 1px dashed var(--border-strong);
  color: var(--text-mute); font-size: 13px; font-weight: 600;
}

/* ---------- Features ---------- */
.features { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.feature {
  padding: 28px 24px; border: 1px solid var(--border); border-radius: var(--radius);
  background: var(--surface); backdrop-filter: blur(10px);
  transition: transform .25s ease, border-color .25s ease;
}
.feature:hover { transform: translateY(-4px); border-color: var(--border-strong); }
.feature__icon {
  display: grid; place-items: center; width: 50px; height: 50px; border-radius: 14px;
  margin-bottom: 18px; color: #fff;
  background: linear-gradient(135deg, rgba(139,92,246,0.9), rgba(59,130,246,0.9));
  box-shadow: 0 10px 24px -10px rgba(99,102,241,0.7);
}
.feature__icon svg { width: 24px; height: 24px; }
.feature__title { margin: 0 0 8px; font-size: 1.1rem; font-weight: 700; }
.feature__desc { margin: 0; color: var(--text-soft); font-size: 0.94rem; }

/* ---------- FAQ ---------- */
.faq { display: flex; flex-direction: column; gap: 12px; }
.faq__item {
  border: 1px solid var(--border); border-radius: var(--radius-sm);
  background: var(--surface); backdrop-filter: blur(8px);
  overflow: hidden; transition: border-color .2s ease;
}
.faq__item[open] { border-color: var(--border-strong); }
.faq__q {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 18px 22px; font-weight: 600; font-size: 1.02rem; list-style: none; user-select: none;
}
.faq__q::-webkit-details-marker { display: none; }
.faq__chev { width: 20px; height: 20px; flex-shrink: 0; color: var(--text-mute); transition: transform .25s ease; }
.faq__item[open] .faq__chev { transform: rotate(180deg); }
.faq__a { margin: 0; padding: 0 22px 20px; color: var(--text-soft); font-size: 0.98rem; }

/* ---------- Footer ---------- */
.footer {
  position: relative; margin-top: 40px;
  flex-shrink: 0;
  border-top: 1px solid var(--border-strong);
  background:
    radial-gradient(700px 300px at 80% 0%, rgba(59,130,246,0.16), transparent 70%),
    radial-gradient(600px 260px at 15% 20%, rgba(139,92,246,0.14), transparent 70%),
    #0b0b12;
}
.footer__inner { display: grid; grid-template-columns: 1.4fr 2fr; gap: 40px; padding-top: 62px; padding-bottom: 40px; }
.footer__tag { margin: 18px 0 22px; color: var(--text-soft); font-size: 0.96rem; max-width: 320px; }
.socials { display: flex; gap: 10px; }
.social {
  display: grid; place-items: center; width: 40px; height: 40px; border-radius: 11px;
  background: var(--surface); border: 1px solid var(--border); color: var(--text-soft);
  transition: color .2s ease, background .2s ease, transform .2s ease, border-color .2s;
}
.social svg { width: 18px; height: 18px; }
.social:hover { color: var(--text); background: var(--surface-2); border-color: var(--border-strong); transform: translateY(-2px); }

.footer__cols { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.footer__h { margin: 0 0 16px; font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.1em; color: var(--text-mute); font-weight: 700; }
.footer__col a { display: block; padding: 6px 0; color: var(--text-soft); font-size: 0.95rem; transition: color .2s ease; }
.footer__col a:hover { color: var(--text); }

.footer__bottom {
  display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 12px;
  padding-top: 24px; padding-bottom: 30px; margin-top: 12px;
  border-top: 1px solid var(--border);
  color: var(--text-mute); font-size: 0.88rem;
}

/* ---------- Toast ---------- */
.toast {
  position: fixed; left: 50%; bottom: 28px; transform: translateX(-50%) translateY(20px);
  padding: 13px 22px; border-radius: var(--radius-pill);
  background: rgba(20,20,30,0.92); border: 1px solid var(--border-strong);
  color: var(--text); font-size: 14px; font-weight: 500;
  box-shadow: var(--shadow); backdrop-filter: blur(10px);
  opacity: 0; pointer-events: none; transition: opacity .25s ease, transform .25s ease; z-index: 100;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .tools, .features, .steps { grid-template-columns: repeat(2, 1fr); }
  .footer__inner { grid-template-columns: 1fr; gap: 34px; }
}

@media (max-width: 720px) {
  .nav {
    position: fixed; inset: 68px 0 auto; flex-direction: column; gap: 4px;
    padding: 16px 22px 22px; background: rgba(8,8,13,0.96); backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--border);
    transform: translateY(-120%); transition: transform .3s ease; z-index: 40;
  }
  .nav.open { transform: translateY(0); }
  .nav__link { padding: 12px 14px; font-size: 16px; }
  .menu-btn { display: flex; }
  .header__actions .btn--sm { display: none; }

  .hero { padding: 64px 0 40px; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .section { padding: 60px 0; }
  .features, .steps { grid-template-columns: 1fr; }
  .footer__cols { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 480px) {
  .tools { grid-template-columns: 1fr; }
  .cta-card { padding: 44px 22px; }
  .footer__bottom { flex-direction: column; align-items: flex-start; }
}

/* =========================================================
   Mobile performance
   The aurora (4 large blur(90px) blobs animated forever) plus many
   backdrop-filter layers and a blend-mode grain force the GPU to
   re-render huge Gaussian blurs every frame — this heats phones and
   drains battery even when idle. On small screens we FREEZE the
   aurora and drop live blur; the look stays close, the GPU rests.
   ========================================================= */
@media (max-width: 860px) {
  /* Freeze the moving blur so it composites once instead of every frame. */
  .aurora__blob { animation: none; will-change: auto; filter: blur(55px); opacity: 0.4; }
  .aurora__grain { display: none; } /* full-screen mix-blend-mode is costly */

  /* backdrop-filter re-blurs everything behind on each repaint/scroll — drop it.
     The elements keep their own translucent background, so they still read as cards. */
  .header, .nav, .btn--ghost, .eyebrow, .stats, .tool, .feature, .faq__item, .toast {
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
  }
  /* No backdrop blur on mobile → the sticky header must be fully opaque,
     otherwise content scrolling behind it shows through. */
  .header, .header.scrolled { background: #08080d; }
}