:root {
  color-scheme: dark;
  --bg: #07111f;
  --bg-deep: #040b15;
  --surface: #0b192b;
  --surface-2: #10243a;
  --surface-3: #142c46;
  --line: rgba(139, 177, 212, .15);
  --line-strong: rgba(77, 215, 255, .32);
  --text: #d8e5f2;
  --muted: #849ab0;
  --faint: #60778d;
  --accent: #4dd7ff;
  --accent-2: #70a5ff;
  --success: #59dfb1;
  --danger: #ff7c91;
  --shadow: 0 30px 80px rgba(0, 0, 0, .32);
  --radius: 26px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; min-width: 320px; overflow-x: hidden; background: var(--bg); color: var(--text); font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; font-size: 16px; line-height: 1.55; }
button, select, input { font: inherit; }
button, a, label { -webkit-tap-highlight-color: transparent; }
a { color: inherit; text-decoration: none; }
svg { width: 1.25rem; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
[hidden] { display: none !important; }

.ambient { position: absolute; border-radius: 999px; pointer-events: none; filter: blur(5px); opacity: .8; }
.ambient-one { top: 110px; left: -250px; width: 640px; height: 640px; background: radial-gradient(circle, rgba(36, 153, 255, .15), transparent 70%); }
.ambient-two { top: 160px; right: -180px; width: 540px; height: 540px; background: radial-gradient(circle, rgba(57, 220, 255, .11), transparent 70%); }

.side-ad { display: none; }

@media (min-width: 1500px) {
  .side-ad { position: absolute; z-index: 2; top: 190px; width: clamp(120px, calc((100vw - 1180px) / 2 - 40px), 160px); height: min(600px, calc(100vh - 230px)); min-height: 420px; display: flex; flex-direction: column; color: #405569; text-align: center; }
  .side-ad-left { left: 20px; }
  .side-ad-right { right: 20px; }
  .side-ad .adsbygoogle { width: 100%; min-height: 420px; flex: 1; }
}

.site-header { position: relative; z-index: 5; max-width: 1180px; height: 84px; margin: 0 auto; padding: 0 24px; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid rgba(139, 177, 212, .09); }
.brand { display: inline-flex; align-items: center; gap: 11px; font-size: 1.08rem; font-weight: 750; letter-spacing: -.03em; }
.brand > span:last-child > span { color: var(--accent); }
.brand-mark { width: 34px; height: 34px; border: 1px solid var(--line-strong); border-radius: 10px; display: inline-flex; align-items: center; justify-content: center; gap: 2px; background: linear-gradient(145deg, rgba(77, 215, 255, .13), rgba(55, 115, 210, .05)); box-shadow: inset 0 0 18px rgba(77, 215, 255, .06); }
.brand-mark span { width: 2px; border-radius: 2px; background: var(--accent); box-shadow: 0 0 8px rgba(77, 215, 255, .75); }
.brand-mark span:nth-child(1), .brand-mark span:nth-child(5) { height: 8px; opacity: .6; }
.brand-mark span:nth-child(2), .brand-mark span:nth-child(4) { height: 14px; }
.brand-mark span:nth-child(3) { height: 20px; }
.site-header nav { display: flex; align-items: center; gap: 34px; color: var(--muted); font-size: .9rem; }
.site-header nav a, .header-action { transition: color .2s ease, border-color .2s ease, background .2s ease; }
.site-header nav a:hover, .site-header nav a:focus-visible { color: var(--text); }
.header-action { padding: 9px 16px; border: 1px solid var(--line); border-radius: 10px; color: #a9bed2; font-size: .86rem; }
.header-action:hover, .header-action:focus-visible { color: var(--accent); border-color: var(--line-strong); background: rgba(77, 215, 255, .05); }

main { position: relative; z-index: 1; }
.hero-shell { width: min(1180px, calc(100% - 48px)); min-height: 690px; margin: 0 auto; padding: 80px 0 70px; display: grid; grid-template-columns: minmax(0, .92fr) minmax(460px, 1.08fr); align-items: center; gap: 84px; }
.eyebrow, .step-label { margin: 0 0 18px; color: var(--accent); font-size: .72rem; font-weight: 800; letter-spacing: .15em; text-transform: uppercase; }
.eyebrow { display: inline-flex; align-items: center; gap: 9px; }
.eyebrow > span { width: 7px; height: 7px; border-radius: 99px; background: var(--accent); box-shadow: 0 0 14px var(--accent); }
.hero-copy h1 { margin: 0; max-width: 620px; font-size: clamp(3rem, 5vw, 5rem); line-height: .98; letter-spacing: -.065em; font-weight: 680; }
.hero-copy h1 em, .formats-copy h2 em { color: var(--accent); font-style: normal; font-weight: inherit; }
.hero-copy > p { max-width: 530px; margin: 28px 0 0; color: var(--muted); font-size: 1.08rem; }
.trust-row { margin-top: 34px; display: flex; flex-wrap: wrap; gap: 11px 20px; color: #a2b7cb; font-size: .82rem; }
.trust-row span { display: inline-flex; align-items: center; gap: 7px; }
.trust-row svg { width: 16px; color: var(--accent); }

.converter-card { position: relative; padding: 28px; border: 1px solid var(--line); border-radius: var(--radius); background: linear-gradient(155deg, rgba(16, 36, 58, .97), rgba(7, 19, 34, .97)); box-shadow: var(--shadow), inset 0 1px 0 rgba(255, 255, 255, .035); }
.converter-card::before { content: ""; position: absolute; inset: -1px; z-index: -1; border-radius: inherit; background: linear-gradient(135deg, rgba(77, 215, 255, .25), transparent 35%, rgba(112, 165, 255, .12)); filter: blur(12px); opacity: .35; }
.converter-heading { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 20px; }
.converter-heading .step-label { margin-bottom: 4px; }
.converter-heading h2 { margin: 0; font-size: 1.28rem; letter-spacing: -.025em; }
.secure-badge { display: inline-flex; align-items: center; gap: 7px; padding: 6px 10px; border: 1px solid rgba(89, 223, 177, .18); border-radius: 99px; color: #8fdbc3; background: rgba(89, 223, 177, .06); font-size: .72rem; }
.secure-badge span { width: 6px; height: 6px; border-radius: 99px; background: var(--success); box-shadow: 0 0 8px rgba(89, 223, 177, .6); }
.dropzone { min-height: 205px; padding: 32px 20px; border: 1px dashed rgba(119, 165, 202, .32); border-radius: 18px; background: rgba(4, 12, 23, .37); display: flex; flex-direction: column; align-items: center; justify-content: center; cursor: pointer; text-align: center; transition: border-color .2s ease, background .2s ease, transform .2s ease; }
.dropzone:hover, .dropzone:focus-visible, .dropzone.is-dragging { outline: none; border-color: var(--accent); background: rgba(25, 82, 116, .18); transform: translateY(-1px); }
.upload-icon { width: 50px; height: 50px; margin-bottom: 15px; border: 1px solid rgba(77, 215, 255, .24); border-radius: 14px; display: grid; place-items: center; color: var(--accent); background: rgba(77, 215, 255, .08); }
.dropzone strong { font-size: 1rem; }
.dropzone > span:not(.upload-icon) { margin-top: 2px; color: var(--muted); font-size: .86rem; }
.dropzone small { margin-top: 15px; color: var(--faint); font-size: .72rem; }
.file-card { min-height: 86px; padding: 14px; border: 1px solid var(--line-strong); border-radius: 16px; background: rgba(77, 215, 255, .055); display: flex; align-items: center; gap: 14px; }
.file-type { width: 54px; height: 54px; flex: 0 0 auto; border-radius: 12px; display: grid; place-items: center; background: linear-gradient(145deg, #1f628a, #143955); color: #bdefff; font-size: .56rem; font-weight: 900; letter-spacing: .07em; }
.file-info { min-width: 0; flex: 1; display: flex; flex-direction: column; }
.file-info strong { overflow: hidden; white-space: nowrap; text-overflow: ellipsis; font-size: .9rem; }
.file-info span { color: var(--muted); font-size: .75rem; }
.icon-button { width: 40px; height: 40px; border: 0; border-radius: 10px; display: grid; place-items: center; color: var(--muted); background: transparent; cursor: pointer; }
.icon-button:hover, .icon-button:focus-visible { color: var(--danger); background: rgba(255, 124, 145, .08); }
.settings { margin-top: 18px; display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.settings label { color: var(--muted); font-size: .72rem; font-weight: 700; letter-spacing: .03em; }
.select-wrap { position: relative; display: block; margin-top: 6px; }
.select-wrap select { width: 100%; height: 48px; padding: 0 40px 0 13px; appearance: none; border: 1px solid var(--line); border-radius: 11px; outline: 0; color: #c9d8e6; background: rgba(5, 14, 25, .58); font-size: .82rem; cursor: pointer; }
.select-wrap select:hover, .select-wrap select:focus-visible { border-color: var(--line-strong); }
.select-wrap svg { position: absolute; width: 16px; right: 13px; top: 16px; color: var(--faint); pointer-events: none; }
.primary-button { width: 100%; min-height: 54px; margin-top: 16px; padding: 0 18px; border: 0; border-radius: 13px; display: flex; justify-content: center; align-items: center; gap: 11px; color: #03131e; background: linear-gradient(110deg, #4dd7ff, #79b6ff); box-shadow: 0 10px 28px rgba(42, 166, 219, .2); font-weight: 800; cursor: pointer; transition: transform .2s ease, box-shadow .2s ease, filter .2s ease; }
.primary-button:hover:not(:disabled), .primary-button:focus-visible:not(:disabled) { transform: translateY(-1px); box-shadow: 0 14px 32px rgba(42, 166, 219, .3); filter: brightness(1.05); }
.primary-button:active:not(:disabled) { transform: translateY(1px); }
.primary-button:disabled { color: #546878; background: #14283b; box-shadow: none; cursor: not-allowed; }
.primary-button svg { width: 18px; }
.converter-note { margin: 16px 0 0; display: flex; justify-content: center; align-items: center; gap: 7px; color: var(--faint); font-size: .69rem; text-align: center; }
.converter-note svg { width: 14px; color: #7fa5bb; }
.progress-panel, .result-panel { margin-top: 18px; padding: 18px; border: 1px solid var(--line); border-radius: 15px; background: rgba(4, 12, 23, .42); }
.progress-copy { display: flex; align-items: center; justify-content: space-between; gap: 12px; font-size: .84rem; }
.progress-copy span { color: var(--accent); font-variant-numeric: tabular-nums; }
.progress-track { height: 6px; margin: 13px 0 10px; overflow: hidden; border-radius: 99px; background: #14283b; }
.progress-track span { display: block; width: 0; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--accent), var(--accent-2)); box-shadow: 0 0 12px rgba(77, 215, 255, .6); transition: width .16s ease; }
.progress-panel p { margin: 0; color: var(--faint); font-size: .7rem; }
.text-button { margin: 8px 0 0; padding: 0; border: 0; color: var(--muted); background: transparent; font-size: .73rem; text-decoration: underline; cursor: pointer; }
.result-panel { display: flex; align-items: center; gap: 12px; border-color: rgba(89, 223, 177, .2); background: rgba(89, 223, 177, .05); }
.result-icon { width: 39px; height: 39px; flex: 0 0 auto; border-radius: 11px; display: grid; place-items: center; color: var(--success); background: rgba(89, 223, 177, .1); }
.result-panel > div { min-width: 0; flex: 1; display: flex; flex-direction: column; }
.result-panel strong { font-size: .85rem; }
.result-panel div span { color: var(--muted); font-size: .7rem; }
.download-button { min-height: 38px; padding: 0 12px; border: 1px solid rgba(89, 223, 177, .22); border-radius: 9px; display: inline-flex; align-items: center; gap: 6px; color: #92e7cc; background: rgba(89, 223, 177, .07); font-size: .75rem; font-weight: 700; }
.download-button svg { width: 15px; }

.ad-slot { width: min(880px, calc(100% - 48px)); min-height: 90px; margin: 12px auto 0; color: #405569; text-align: center; }
.ad-slot-between { margin: 0 auto; }
.ad-label { display: block; margin-bottom: 4px; font-size: .55rem; line-height: 1.4; letter-spacing: .19em; }
.ad-slot .adsbygoogle { width: 100%; min-height: 90px; }

.section { width: min(1120px, calc(100% - 48px)); margin: 0 auto; padding: 130px 0; }
.section-intro { max-width: 570px; margin: 0 auto 55px; text-align: center; }
.section-intro .step-label, .formats-copy .step-label, .privacy-band .step-label { margin-bottom: 12px; }
.section h2, .privacy-band h2 { margin: 0; font-size: clamp(2rem, 3.4vw, 3rem); line-height: 1.1; letter-spacing: -.045em; }
.section-intro > p:last-child { margin: 15px 0 0; color: var(--muted); }
.steps-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.steps-grid article { position: relative; min-height: 250px; padding: 29px; overflow: hidden; border: 1px solid var(--line); border-radius: 20px; background: linear-gradient(145deg, rgba(14, 31, 51, .78), rgba(7, 17, 31, .72)); }
.steps-grid article::after { content: ""; position: absolute; right: -45px; bottom: -50px; width: 140px; height: 140px; border-radius: 99px; background: radial-gradient(circle, rgba(77, 215, 255, .08), transparent 65%); }
.step-number { position: absolute; top: 22px; right: 25px; color: rgba(135, 163, 187, .18); font-size: 2rem; font-weight: 800; }
.step-icon { width: 48px; height: 48px; margin-bottom: 32px; border-radius: 13px; display: grid; place-items: center; color: var(--accent); background: rgba(77, 215, 255, .07); }
.steps-grid h3 { margin: 0; font-size: 1.08rem; }
.steps-grid p { margin: 9px 0 0; color: var(--muted); font-size: .88rem; }

.formats { display: grid; grid-template-columns: 1fr .83fr; align-items: center; gap: 100px; }
.formats-copy > p:not(.step-label) { max-width: 520px; margin: 19px 0 30px; color: var(--muted); }
.formats-copy ul { margin: 0; padding: 0; display: grid; gap: 9px; list-style: none; }
.formats-copy li { min-height: 72px; padding: 12px 14px; border: 1px solid var(--line); border-radius: 14px; display: flex; align-items: center; gap: 13px; background: rgba(12, 27, 45, .58); }
.formats-copy li > span { width: 48px; height: 44px; flex: 0 0 auto; border-radius: 10px; display: grid; place-items: center; color: var(--accent); background: rgba(77, 215, 255, .08); font-size: .68rem; font-weight: 900; }
.formats-copy li div { min-width: 0; flex: 1; display: flex; flex-direction: column; }
.formats-copy li strong { font-size: .84rem; }
.formats-copy li small { color: var(--muted); font-size: .7rem; }
.formats-copy li > b { padding: 4px 7px; border-radius: 99px; color: #7edebf; background: rgba(89, 223, 177, .07); font-size: .57rem; text-transform: uppercase; }
.sound-visual { position: relative; min-height: 420px; overflow: hidden; border: 1px solid var(--line); border-radius: 28px; display: grid; place-items: center; background: radial-gradient(circle at 50% 46%, rgba(27, 112, 166, .22), transparent 46%), linear-gradient(145deg, rgba(13, 31, 51, .87), rgba(5, 13, 24, .87)); }
.sound-visual::before { content: ""; position: absolute; width: 330px; height: 330px; border: 1px solid rgba(77, 215, 255, .09); border-radius: 50%; box-shadow: 0 0 0 52px rgba(77, 215, 255, .025), 0 0 0 104px rgba(77, 215, 255, .02); }
.disc { position: absolute; width: 170px; height: 170px; border: 1px solid rgba(77, 215, 255, .22); border-radius: 50%; background: repeating-radial-gradient(circle, rgba(77, 215, 255, .08) 0 1px, transparent 2px 9px); box-shadow: inset 0 0 45px rgba(77, 215, 255, .06), 0 0 60px rgba(0, 0, 0, .25); }
.disc span { position: absolute; inset: 38%; border-radius: 50%; background: var(--accent); box-shadow: 0 0 24px rgba(77, 215, 255, .6); }
.wave-bars { position: relative; z-index: 2; height: 110px; display: flex; align-items: center; gap: 6px; }
.wave-bars i { width: 4px; height: var(--h); border-radius: 9px; background: linear-gradient(var(--accent), var(--accent-2)); box-shadow: 0 0 10px rgba(77, 215, 255, .45); }
.visual-label { position: absolute; bottom: 25px; color: #506b82; font-size: .6rem; font-weight: 800; letter-spacing: .18em; }

.privacy-band { width: min(1180px, calc(100% - 48px)); margin: 25px auto; padding: 54px 60px; border: 1px solid rgba(77, 215, 255, .17); border-radius: 26px; display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 36px; background: linear-gradient(110deg, rgba(13, 45, 68, .76), rgba(9, 26, 44, .74)); }
.privacy-icon { width: 72px; height: 72px; border-radius: 20px; display: grid; place-items: center; color: var(--accent); background: rgba(77, 215, 255, .08); box-shadow: inset 0 0 24px rgba(77, 215, 255, .06); }
.privacy-icon svg { width: 31px; }
.privacy-band h2 { font-size: clamp(1.65rem, 3vw, 2.45rem); }
.privacy-band > div:nth-child(2) > p:last-child { max-width: 630px; margin: 13px 0 0; color: var(--muted); font-size: .86rem; }
.privacy-points { display: grid; gap: 12px; color: #a7becf; font-size: .78rem; }
.privacy-points span { display: flex; align-items: center; gap: 9px; white-space: nowrap; }
.privacy-points i { width: 6px; height: 6px; border-radius: 99px; background: var(--success); box-shadow: 0 0 8px rgba(89, 223, 177, .5); }

.faq { padding-bottom: 120px; }
.faq-list { max-width: 800px; margin: 0 auto; border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary { min-height: 72px; padding: 0 5px; display: flex; align-items: center; justify-content: space-between; gap: 16px; color: #c5d5e4; font-weight: 650; cursor: pointer; list-style: none; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary svg { width: 18px; color: var(--muted); transition: transform .2s ease; }
.faq details[open] summary svg { transform: rotate(180deg); }
.faq details p { margin: -4px 40px 24px 5px; color: var(--muted); font-size: .88rem; }

footer { width: min(1180px, calc(100% - 48px)); margin: 0 auto; padding: 54px 0 24px; border-top: 1px solid var(--line); display: grid; grid-template-columns: 1fr auto; align-items: start; gap: 35px; color: var(--muted); }
.footer-brand p { margin: 11px 0 0; font-size: .78rem; }
.footer-links { max-width: 560px; display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 12px 24px; }
.footer-links a, .footer-links button { padding: 0; border: 0; color: var(--muted); background: transparent; font-size: .76rem; cursor: pointer; }
.footer-links a:hover, .footer-links button:hover { color: var(--accent); }
.footer-bottom { grid-column: 1 / -1; padding-top: 22px; border-top: 1px solid rgba(139, 177, 212, .08); display: flex; justify-content: space-between; color: #53697e; font-size: .68rem; }

dialog { width: min(560px, calc(100% - 32px)); padding: 32px; border: 1px solid var(--line-strong); border-radius: 20px; color: var(--text); background: #0c1b2d; box-shadow: var(--shadow); }
dialog::backdrop { background: rgba(2, 7, 13, .76); backdrop-filter: blur(8px); }
dialog h2 { margin: 0 0 18px; font-size: 1.7rem; letter-spacing: -.04em; }
dialog p:not(.step-label) { color: var(--muted); font-size: .88rem; }
.dialog-close { position: absolute; top: 13px; right: 15px; width: 38px; height: 38px; border: 0; border-radius: 10px; color: var(--muted); background: rgba(255,255,255,.03); font-size: 1.4rem; cursor: pointer; }
.toast { position: fixed; left: 50%; bottom: 24px; z-index: 20; max-width: calc(100% - 32px); padding: 11px 16px; border: 1px solid var(--line-strong); border-radius: 11px; color: #cbeaf5; background: #10263a; box-shadow: var(--shadow); font-size: .8rem; transform: translate(-50%, 25px); opacity: 0; pointer-events: none; transition: opacity .25s ease, transform .25s ease; }
.toast.show { transform: translate(-50%, 0); opacity: 1; }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; animation-duration: .01ms !important; } }

@media (max-width: 960px) {
  .hero-shell { grid-template-columns: 1fr; gap: 48px; padding-top: 65px; }
  .hero-copy { max-width: 700px; text-align: center; margin: 0 auto; }
  .hero-copy > p { margin-left: auto; margin-right: auto; }
  .trust-row { justify-content: center; }
  .converter-card { width: min(620px, 100%); margin: 0 auto; }
  .formats { grid-template-columns: 1fr; gap: 50px; }
  .formats-copy { max-width: 660px; }
  .sound-visual { min-height: 380px; }
  .privacy-band { grid-template-columns: auto 1fr; }
  .privacy-points { grid-column: 2; grid-template-columns: repeat(3, auto); }
}

@media (max-width: 700px) {
  .site-header { height: 72px; }
  .site-header nav { display: none; }
  .hero-shell { width: min(100% - 32px, 620px); padding: 54px 0 48px; }
  .hero-copy h1 { font-size: clamp(2.65rem, 13vw, 4.2rem); }
  .hero-copy > p { font-size: .98rem; }
  .trust-row { display: grid; justify-items: start; width: fit-content; margin-left: auto; margin-right: auto; }
  .converter-card { padding: 20px; border-radius: 21px; }
  .dropzone { min-height: 190px; }
  .settings { grid-template-columns: 1fr; }
  .result-panel { align-items: flex-start; flex-wrap: wrap; }
  .result-panel > div { width: calc(100% - 55px); }
  .download-button { width: 100%; justify-content: center; }
  .ad-slot { width: calc(100% - 32px); }
  .section { width: calc(100% - 32px); padding: 90px 0; }
  .steps-grid { grid-template-columns: 1fr; }
  .steps-grid article { min-height: 220px; }
  .privacy-band { width: calc(100% - 32px); padding: 30px 24px; grid-template-columns: 1fr; gap: 20px; }
  .privacy-icon { width: 58px; height: 58px; }
  .privacy-points { grid-column: auto; grid-template-columns: 1fr; }
  footer { width: calc(100% - 32px); grid-template-columns: 1fr; }
  .footer-links { justify-content: flex-start; }
  .footer-bottom { flex-direction: column; gap: 6px; }
}

@media (max-width: 390px) {
  .header-action { display: none; }
  .converter-card { padding: 17px; }
  .converter-heading { align-items: center; }
  .secure-badge { padding: 5px 8px; }
  .dropzone { padding-left: 12px; padding-right: 12px; }
}