:root {
  --bg: #07111f;
  --panel: #0c1b2e;
  --panel-2: #11243b;
  --ink: #f5fbff;
  --muted: #91a6bb;
  --blue: #2f91ff;
  --cyan: #33e0c1;
  --orange: #ffad46;
  --line: rgba(157, 190, 220, .18);
  --paper: #f5f9fc;
  --dark-ink: #102033;
  --radius: 24px;
  --shadow: 0 28px 80px rgba(0, 0, 0, .32);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: radial-gradient(circle at 80% 8%, rgba(47,145,255,.16), transparent 30rem), radial-gradient(circle at 8% 36%, rgba(51,224,193,.08), transparent 26rem), var(--bg); font-family: Inter, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif; line-height: 1.7; }
body::before { content: ""; position: fixed; z-index: -1; inset: 0; background-image: linear-gradient(rgba(255,255,255,.025) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.025) 1px, transparent 1px); background-size: 56px 56px; mask-image: linear-gradient(to bottom, #000, transparent 78%); }
a { color: inherit; }
img { max-width: 100%; display: block; }
button, input, select { font: inherit; }
button, a, input, select { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 3px solid var(--cyan); outline-offset: 4px; }
.container { width: min(1160px, calc(100% - 36px)); margin-inline: auto; }
.skip-link { position: fixed; z-index: 200; left: 14px; top: -70px; padding: 10px 16px; border-radius: 10px; color: var(--dark-ink); background: var(--cyan); font-weight: 800; transition: top .2s; }
.skip-link:focus { top: 14px; }
h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 22px; max-width: 850px; font-size: clamp(46px, 7.4vw, 88px); line-height: .98; letter-spacing: -.062em; }
h2 { margin-bottom: 16px; font-size: clamp(32px, 4.8vw, 54px); line-height: 1.08; letter-spacing: -.045em; }
h3 { margin-bottom: 9px; font-size: 20px; line-height: 1.35; }
.lead { max-width: 680px; color: var(--muted); font-size: clamp(17px, 2vw, 20px); }
.eyebrow { display: inline-flex; align-items: center; gap: 9px; margin: 0 0 15px; color: var(--cyan); font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 11px; font-weight: 800; letter-spacing: .15em; text-transform: uppercase; }
.eyebrow::before { content: ""; width: 26px; height: 2px; background: var(--cyan); box-shadow: 0 0 18px var(--cyan); }
.muted { color: var(--muted); }
.site-header { position: sticky; z-index: 70; top: 0; border-bottom: 1px solid var(--line); background: rgba(7,17,31,.82); backdrop-filter: blur(20px); }
.nav { min-height: 76px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 11px; text-decoration: none; font-weight: 900; font-size: 19px; }
.brand img { width: 46px; height: 46px; border-radius: 14px; box-shadow: 0 8px 26px rgba(47,145,255,.24); }
.brand small { display: block; margin-top: -4px; color: var(--cyan); font-family: ui-monospace, monospace; font-size: 9px; letter-spacing: .15em; }
.nav-links { display: flex; align-items: center; gap: 26px; }
.nav-links a { color: var(--muted); text-decoration: none; font-size: 14px; font-weight: 700; }
.nav-links a:hover, .nav-links a[aria-current="page"] { color: #fff; }
.nav-cta { min-height: 44px; padding: 9px 18px; display: inline-flex; align-items: center; border-radius: 12px; color: var(--dark-ink) !important; background: var(--cyan); }
.menu-button { display: none; min-width: 44px; min-height: 44px; border: 1px solid var(--line); border-radius: 12px; color: #fff; background: var(--panel); font-weight: 800; }
.hero { position: relative; overflow: hidden; padding: 92px 0 70px; }
.hero::after { content: ""; position: absolute; width: 650px; height: 650px; right: -400px; top: -230px; border: 110px solid rgba(47,145,255,.06); border-radius: 50%; }
.hero-grid { position: relative; z-index: 1; display: grid; grid-template-columns: 1.05fr .95fr; align-items: center; gap: 70px; }
.hero h1 span { color: transparent; background: linear-gradient(100deg, var(--blue), var(--cyan)); -webkit-background-clip: text; background-clip: text; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin: 30px 0 22px; }
.button { min-height: 52px; padding: 13px 22px; display: inline-flex; align-items: center; justify-content: center; gap: 9px; border: 1px solid var(--line); border-radius: 14px; color: #fff; background: var(--panel); text-decoration: none; font-size: 15px; font-weight: 850; cursor: pointer; transition: transform .2s, border-color .2s, box-shadow .2s; }
.button:hover { transform: translateY(-2px); border-color: rgba(51,224,193,.7); }
.button.primary { border-color: transparent; color: var(--dark-ink); background: linear-gradient(110deg, var(--blue), var(--cyan)); box-shadow: 0 14px 38px rgba(47,145,255,.23); }
.button.light { color: var(--dark-ink); background: #fff; }
.microcopy { color: var(--muted); font-size: 12px; }
.trust-row { display: flex; flex-wrap: wrap; gap: 9px; }
.chip { padding: 7px 12px; border: 1px solid var(--line); border-radius: 99px; color: #c3d2df; background: rgba(12,27,46,.62); font-size: 11px; font-weight: 700; }
.compression-visual { position: relative; min-height: 510px; display: grid; place-items: center; }
.app-window { position: relative; z-index: 2; width: min(480px, 92vw); overflow: hidden; border: 1px solid rgba(130,185,233,.28); border-radius: 28px; background: rgba(12,27,46,.92); box-shadow: var(--shadow); transform: rotate(2deg); }
.window-bar { height: 48px; padding: 0 18px; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--line); font-family: ui-monospace, monospace; font-size: 10px; color: var(--muted); }
.window-dots { display: flex; gap: 6px; }
.window-dots i { width: 8px; height: 8px; display: block; border-radius: 50%; background: #37506a; }
.window-dots i:first-child { background: var(--orange); }
.window-body { padding: 28px; }
.compare-head { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.compare-head b { font-size: 20px; }
.saving { padding: 5px 10px; border-radius: 99px; color: var(--dark-ink); background: var(--cyan); font-size: 11px; font-weight: 900; }
.file-preview { height: 210px; margin: 22px 0; position: relative; overflow: hidden; border: 1px solid rgba(255,255,255,.14); border-radius: 20px; background: linear-gradient(145deg, #122e50, #1b867f); box-shadow: inset 0 0 0 1px rgba(255,255,255,.04); }
.file-preview img { width: 100%; height: 100%; display: block; object-fit: cover; object-position: center; transition: transform .6s ease; }
.app-window:hover .file-preview img { transform: scale(1.035); }
.file-preview::before { content: ""; position: absolute; z-index: 1; inset: 0; background: linear-gradient(180deg, transparent 42%, rgba(5,15,27,.78)); pointer-events: none; }
.file-preview::after { content: "OFFICIAL SAMPLE / OPTIMIZED"; position: absolute; z-index: 2; left: 20px; bottom: 17px; font-family: ui-monospace, monospace; font-size: 11px; font-weight: 800; letter-spacing: .1em; text-shadow: 0 2px 10px rgba(0,0,0,.55); }
.meter { height: 8px; overflow: hidden; border-radius: 99px; background: #20344a; }
.meter span { width: 76%; height: 100%; display: block; border-radius: inherit; background: linear-gradient(90deg, var(--blue), var(--cyan)); }
.size-row { margin-top: 18px; display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 16px; }
.size-box { padding: 14px; border: 1px solid var(--line); border-radius: 15px; background: rgba(255,255,255,.025); }
.size-box small { display: block; color: var(--muted); font-size: 10px; }
.size-box strong { font-family: ui-monospace, monospace; font-size: 21px; }
.size-box:last-child strong { color: var(--cyan); }
.flow-arrow { color: var(--blue); font-size: 22px; }
.float-stat { position: absolute; z-index: 3; padding: 12px 15px; border: 1px solid var(--line); border-radius: 14px; background: rgba(8,21,36,.9); box-shadow: var(--shadow); backdrop-filter: blur(14px); font-family: ui-monospace, monospace; font-size: 11px; font-weight: 800; }
.float-stat.one { left: 0; top: 14%; color: var(--cyan); }
.float-stat.two { right: 0; bottom: 12%; color: var(--orange); }
.section { padding: 92px 0; }
.section.light { color: var(--dark-ink); background: var(--paper); }
.section-head { max-width: 760px; margin-bottom: 40px; }
.section.light .lead, .section.light .muted { color: #63768a; }
.tool-shell { overflow: hidden; border: 1px solid var(--line); border-radius: 32px; background: var(--panel); box-shadow: var(--shadow); }
.tool-head { padding: 25px 28px; display: flex; align-items: center; justify-content: space-between; gap: 20px; border-bottom: 1px solid var(--line); }
.tool-head h2 { margin: 0; font-size: 24px; letter-spacing: -.025em; }
.privacy-pill { padding: 7px 12px; border: 1px solid rgba(51,224,193,.3); border-radius: 99px; color: var(--cyan); font-size: 11px; font-weight: 800; }
.tool-grid { display: grid; grid-template-columns: 1.1fr .9fr; }
.drop-zone { min-height: 390px; margin: 28px; padding: 32px; display: grid; place-items: center; text-align: center; border: 2px dashed #31506c; border-radius: 24px; background: radial-gradient(circle, rgba(47,145,255,.12), transparent 62%); cursor: pointer; transition: border-color .2s, background .2s; }
.drop-zone:hover, .drop-zone.is-dragging { border-color: var(--cyan); background: rgba(51,224,193,.07); }
.drop-zone input { position: absolute; width: 1px; height: 1px; opacity: 0; pointer-events: none; }
.upload-mark { width: 74px; height: 74px; margin: 0 auto 22px; display: grid; place-items: center; border: 1px solid rgba(51,224,193,.42); border-radius: 22px; color: var(--cyan); background: rgba(51,224,193,.08); font-size: 34px; }
.drop-zone h3 { font-size: 24px; }
.drop-zone p { margin-bottom: 22px; color: var(--muted); }
.controls { padding: 28px; border-left: 1px solid var(--line); background: rgba(255,255,255,.018); }
.control { margin-bottom: 24px; }
.control label, .control legend { margin-bottom: 9px; display: flex; align-items: center; justify-content: space-between; gap: 12px; color: #d9e7f2; font-size: 13px; font-weight: 800; }
.control fieldset { margin: 0; padding: 0; border: 0; }
.control output { color: var(--cyan); font-family: ui-monospace, monospace; }
.control select { width: 100%; min-height: 48px; padding: 0 13px; border: 1px solid var(--line); border-radius: 12px; color: #fff; background: #0a1728; }
.control input[type="range"] { width: 100%; accent-color: var(--cyan); }
.control-note { color: var(--muted); font-size: 11px; }
.process-button { width: 100%; }
.status-line { min-height: 24px; margin: 14px 0 0; color: var(--muted); text-align: center; font-size: 12px; }
.results { display: none; padding: 0 28px 28px; }
.results.is-visible { display: block; }
.results-summary { padding: 18px 20px; display: flex; align-items: center; justify-content: space-between; gap: 18px; border: 1px solid rgba(51,224,193,.26); border-radius: 18px; background: rgba(51,224,193,.06); }
.results-summary strong { color: var(--cyan); font-size: 20px; }
.result-list { margin-top: 14px; display: grid; gap: 10px; }
.result-item { padding: 13px; display: grid; grid-template-columns: 54px 1fr auto; align-items: center; gap: 13px; border: 1px solid var(--line); border-radius: 14px; background: rgba(255,255,255,.025); }
.result-item img { width: 54px; height: 54px; object-fit: cover; border-radius: 10px; }
.result-item b { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: 13px; }
.result-item small { color: var(--muted); font-size: 10px; }
.result-download { min-height: 40px; padding: 8px 13px; border-radius: 10px; color: var(--dark-ink); background: var(--cyan); text-decoration: none; font-size: 12px; font-weight: 900; }
.feature-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.feature-card { min-height: 270px; padding: 28px; border: 1px solid #dce5ed; border-radius: var(--radius); background: #fff; box-shadow: 0 14px 40px rgba(16,32,51,.06); }
.feature-icon { width: 50px; height: 50px; margin-bottom: 48px; display: grid; place-items: center; border-radius: 15px; color: #fff; background: linear-gradient(140deg, var(--blue), #176bc8); font-family: ui-monospace, monospace; font-weight: 900; }
.feature-card:nth-child(2) .feature-icon, .feature-card:nth-child(4) .feature-icon { color: var(--dark-ink); background: var(--cyan); }
.feature-card p { margin: 0; color: #68798a; font-size: 14px; }
.workflow { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; counter-reset: step; }
.step { min-height: 250px; padding: 28px; border-top: 1px solid var(--line); counter-increment: step; }
.step::before { content: "0" counter(step); display: block; margin-bottom: 34px; color: var(--cyan); font-family: ui-monospace, monospace; font-size: 40px; font-weight: 300; }
.step p { color: var(--muted); font-size: 14px; }
.format-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.format-card { padding: 30px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--panel); }
.format-tag { margin-bottom: 42px; display: flex; align-items: center; justify-content: space-between; gap: 10px; font-family: ui-monospace, monospace; }
.format-tag strong { color: var(--cyan); font-size: 22px; }
.format-tag span { color: var(--muted); font-size: 10px; }
.format-card p { color: var(--muted); font-size: 14px; }
.cta-panel { padding: clamp(34px, 6vw, 70px); display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 30px; border: 1px solid rgba(51,224,193,.24); border-radius: 32px; background: linear-gradient(135deg, rgba(47,145,255,.18), rgba(51,224,193,.1)); }
.cta-panel h2 { margin-bottom: 8px; }
.faq-list { max-width: 860px; }
details { padding: 22px 0; border-bottom: 1px solid var(--line); }
summary { cursor: pointer; list-style: none; display: flex; align-items: center; justify-content: space-between; gap: 20px; font-weight: 800; }
summary::after { content: "+"; color: var(--cyan); font-size: 24px; }
details[open] summary::after { content: "−"; }
details p { margin: 14px 38px 0 0; color: var(--muted); font-size: 14px; }
.page-hero { padding: 80px 0 48px; text-align: center; }
.page-hero h1, .page-hero .lead { margin-inline: auto; }
.page-hero .actions { justify-content: center; }
.breadcrumb { margin: 0 auto 24px; display: flex; align-items: center; justify-content: center; gap: 9px; color: var(--muted); font-size: 13px; }
.breadcrumb a { color: var(--cyan); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; text-underline-offset: 4px; }
.download-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.download-card { padding: 34px; border: 1px solid var(--line); border-radius: var(--radius); background: linear-gradient(145deg, var(--panel-2), var(--panel)); }
.platform { margin-bottom: 30px; color: var(--cyan); font-family: ui-monospace, monospace; font-size: 42px; font-weight: 300; }
.download-card ul { padding-left: 20px; color: var(--muted); }
.download-card .button { width: 100%; margin-top: 16px; }
.guide-layout { display: grid; grid-template-columns: 270px 1fr; gap: 54px; align-items: start; }
.guide-nav { position: sticky; top: 105px; padding: 22px; border: 1px solid var(--line); border-radius: 18px; background: var(--panel); }
.guide-nav strong { display: block; margin-bottom: 8px; }
.guide-nav a { padding: 8px 0; display: block; color: var(--muted); text-decoration: none; font-size: 13px; }
.article-card { margin-bottom: 18px; padding: clamp(26px, 4vw, 44px); border: 1px solid var(--line); border-radius: var(--radius); background: var(--panel); }
.article-card ol, .article-card ul { padding-left: 22px; color: var(--muted); }
.article-card table { width: 100%; border-collapse: collapse; font-size: 14px; }
.article-card th, .article-card td { padding: 14px; border-bottom: 1px solid var(--line); text-align: left; }
.article-card th { color: var(--cyan); }
.notice { padding: 17px 19px; border-left: 4px solid var(--cyan); border-radius: 0 14px 14px 0; color: #bed0de; background: rgba(51,224,193,.07); }
.footer { padding: 58px 0 112px; border-top: 1px solid var(--line); }
.footer-grid { display: grid; grid-template-columns: 1fr auto; align-items: end; gap: 30px; }
.footer p { max-width: 680px; color: var(--muted); font-size: 12px; }
.footer-links { display: flex; gap: 18px; font-size: 13px; font-weight: 700; }
.friend-links { grid-column: 1 / -1; padding: 18px 20px; display: flex; flex-wrap: wrap; align-items: center; gap: 12px; border: 1px solid var(--line); border-radius: 18px; background: rgba(255,255,255,.025); }
.friend-links strong { color: #dcecff; font-size: 13px; }
.friend-links a { padding: 7px 12px; border: 1px solid rgba(51,224,193,.26); border-radius: 99px; color: var(--cyan); background: rgba(51,224,193,.06); text-decoration: none; font-size: 13px; font-weight: 800; }
.friend-links a:hover { border-color: rgba(51,224,193,.72); background: rgba(51,224,193,.12); }
.sticky-download { position: fixed; z-index: 90; left: 50%; bottom: 16px; width: min(700px, calc(100% - 24px)); padding: 10px 11px 10px 18px; display: flex; align-items: center; justify-content: space-between; gap: 14px; border: 1px solid rgba(51,224,193,.3); border-radius: 18px; color: #fff; background: rgba(7,17,31,.94); box-shadow: 0 18px 60px rgba(0,0,0,.45); backdrop-filter: blur(18px); opacity: 0; transform: translate(-50%, 28px); pointer-events: none; transition: .3s; }
.sticky-download.is-visible { opacity: 1; transform: translate(-50%, 0); pointer-events: auto; }
.sticky-download b { display: block; font-size: 14px; }
.sticky-download span { color: var(--muted); font-size: 11px; }
.sticky-download .button { min-height: 44px; padding: 9px 17px; white-space: nowrap; }
.promo-tool-float { position: fixed; z-index: 82; right: 18px; top: 42%; width: 172px; transform: translateY(-50%); }
.promo-tool-float a { position: relative; min-height: 168px; padding: 18px; display: flex; flex-direction: column; justify-content: space-between; gap: 14px; overflow: hidden; border: 1px solid rgba(255,173,70,.38); border-radius: 20px; color: #fff; background: linear-gradient(150deg, rgba(17,36,59,.96), rgba(47,145,255,.22) 54%, rgba(255,173,70,.14)); box-shadow: 0 20px 54px rgba(0,0,0,.36); text-decoration: none; backdrop-filter: blur(16px); transition: transform .2s, border-color .2s, box-shadow .2s; }
.promo-tool-float a::before { content: ""; position: absolute; width: 86px; height: 86px; right: -32px; top: -28px; border-radius: 50%; background: radial-gradient(circle, rgba(255,173,70,.42), transparent 68%); pointer-events: none; }
.promo-tool-float a:hover { transform: translateX(-4px); border-color: rgba(255,173,70,.75); box-shadow: 0 24px 64px rgba(0,0,0,.42); }
.promo-tool-badge { width: fit-content; padding: 5px 9px; border-radius: 99px; color: var(--dark-ink); background: var(--orange); font-size: 11px; font-weight: 900; }
.promo-tool-float strong { position: relative; font-size: 18px; line-height: 1.25; }
.promo-tool-float small { position: relative; color: #c7d8e8; font-size: 12px; }
@media (max-width: 900px) {
  .menu-button { display: block; }
  .nav-links { display: none; position: absolute; inset: 76px 18px auto; padding: 18px; align-items: stretch; flex-direction: column; gap: 7px; border: 1px solid var(--line); border-radius: 18px; background: var(--panel); box-shadow: var(--shadow); }
  .nav-links.is-open { display: flex; }
  .nav-links a { padding: 10px; }
  .hero-grid, .tool-grid, .guide-layout { grid-template-columns: 1fr; }
  .controls { border-left: 0; border-top: 1px solid var(--line); }
  .guide-nav { display: none; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 620px) {
  .container { width: min(100% - 24px, 1160px); }
  h1 { font-size: 48px; }
  .hero { padding: 56px 0 48px; }
  .section { padding: 66px 0; }
  .compression-visual { min-height: 460px; }
  .app-window { width: 310px; }
  .window-body { padding: 20px; }
  .file-preview { height: 170px; }
  .float-stat.one { left: 0; top: 4%; }
  .float-stat.two { right: 0; bottom: 2%; }
  .tool-head { align-items: flex-start; flex-direction: column; }
  .drop-zone { min-height: 330px; margin: 14px; padding: 22px; }
  .controls, .results { padding: 22px; }
  .results-summary { align-items: flex-start; flex-direction: column; }
  .result-item { grid-template-columns: 44px 1fr; }
  .result-item img { width: 44px; height: 44px; }
  .result-download { grid-column: 1 / 3; text-align: center; }
  .feature-grid, .workflow, .format-grid, .download-grid { grid-template-columns: 1fr; }
  .feature-card { min-height: auto; }
  .feature-icon { margin-bottom: 30px; }
  .cta-panel { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .article-card { overflow-x: auto; }
  .sticky-download { bottom: 8px; }
  .sticky-download span { display: none; }
  .promo-tool-float { right: 10px; top: auto; bottom: 82px; width: 138px; transform: none; }
  .promo-tool-float a { min-height: auto; padding: 12px; border-radius: 16px; gap: 8px; }
  .promo-tool-badge { font-size: 10px; }
  .promo-tool-float strong { font-size: 15px; }
  .promo-tool-float small { display: none; }
}
@media (prefers-reduced-motion: reduce) { * { scroll-behavior: auto !important; transition: none !important; } }