/* TTSAI 4.0 · Quiet visual system. Deliberately no external UI framework. */
:root{--v4-bg:#0a1020;--v4-panel:#111b2e;--v4-panel2:#141f33;--v4-line:rgba(176,208,238,.12);--v4-muted:#a8b8cc;--v4-mint:#83edd4;--v4-ink:#f3f7ff}
body{background:#0b1121;background-image:radial-gradient(1000px 600px at 90% 0%,rgba(66,100,160,.105),transparent 78%);color:var(--v4-ink)}
.site-header{height:70px;background:rgba(10,16,31,.91);border-bottom:1px solid var(--v4-line);backdrop-filter:blur(18px)}
.nav-inner{gap:20px}.nav-links{gap:24px}.nav-links a{font-size:12.5px;font-weight:600;color:#acbbce}.nav-actions{gap:12px}.nav-actions .btn-primary{font-size:12px;padding:12px 17px;min-height:42px}.brand{font-size:20px}.brand img{width:38px;height:38px}
.btn-primary{background:linear-gradient(112deg,#73eacb,#a8e8e3);color:#082327;border:1px solid transparent;box-shadow:0 8px 28px #5fe7ce15}
.btn-primary:hover{box-shadow:0 10px 30px #5fe7ce30}.btn-outline{border:1px solid var(--v4-line);background:#ffffff06}.btn-outline:hover{background:#ffffff10}
:focus-visible{outline:2px solid #8bfbe0!important;outline-offset:3px}
/* New homepage */
.v4-main{overflow:hidden}.v4-hero{display:grid;grid-template-columns:minmax(0,1.04fr) minmax(345px,.9fr);gap:min(7vw,80px);align-items:center;min-height:590px;padding:78px 0 83px}
.v4-kicker{display:inline-flex;align-items:center;gap:8px;font-size:10px;letter-spacing:1.7px;font-weight:800;color:var(--v4-mint)}.v4-pulse{width:7px;height:7px;border-radius:50%;background:var(--v4-mint);box-shadow:0 0 0 6px #79edce18}
.v4-hero h1{font-size:clamp(38px,4.15vw,64px);line-height:1.18;letter-spacing:-2.8px;margin:21px 0 22px;font-weight:800}.v4-gradient{background:linear-gradient(96deg,#8ff3dc,#a9b9f8 85%);color:transparent;-webkit-background-clip:text;background-clip:text}
.v4-hero-text>p{font-size:15px;line-height:1.95;color:var(--v4-muted);max-width:575px;margin:0}.v4-hero-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:30px}.v4-hero-actions .btn{min-height:49px;padding:12px 22px;font-size:13px}
.v4-proof{margin-top:22px;display:flex;flex-wrap:wrap;gap:13px;color:#8fa6b8;font-size:11px}
.v4-demo{border:1px solid rgba(167,203,237,.17);border-radius:25px;background:linear-gradient(155deg,#19243b,#10192b);padding:26px;box-shadow:0 25px 70px #02071444;position:relative}
.v4-demo:before{content:'';height:1px;position:absolute;left:22px;right:22px;top:0;background:linear-gradient(90deg,transparent,#8ff4d89e,transparent)}.v4-demo-top{display:flex;align-items:center;gap:12px;margin-bottom:24px}.v4-demo-top div{flex:1;min-width:0}.v4-demo-top strong{display:block;font-size:14px}.v4-demo-top small{display:block;color:#97a7bf;font-size:10.5px;line-height:1.6;margin-top:3px}.v4-icon{width:42px;height:42px;display:grid;place-items:center;background:#1d3449;color:#7ef4d8;border-radius:13px;font-size:21px}.v4-live{font-size:9px;letter-spacing:1px;border-radius:22px;background:#234339;color:#9bf8d4;border:1px solid #365d4d;padding:5px 9px;font-weight:800}
.v4-demo-label{font-size:11px;color:#b8c7dc;display:block;font-weight:700;margin-bottom:9px}.v4-demo textarea,.v4-demo select{display:block;width:100%;border:1px solid #ffffff16;border-radius:14px;background:#0d1428;color:#eff7ff;font:inherit;resize:vertical;padding:15px;font-size:13px;line-height:1.85}.v4-demo select{min-height:45px;padding:10px 12px;cursor:pointer}.v4-demo textarea{min-height:116px}.v4-wave{height:66px;display:flex;align-items:center;justify-content:center;gap:4px;margin:17px 0 13px;overflow:hidden}.v4-wave i{width:4px;min-width:4px;height:var(--h,24px);border-radius:8px;background:linear-gradient(#9d9ff4,#67ecd3);opacity:.63;transition:height .4s ease}
.v4-wave i:nth-child(4n+1){--h:16px}.v4-wave i:nth-child(4n+2){--h:36px}.v4-wave i:nth-child(4n+3){--h:54px}.v4-wave i:nth-child(5n){--h:27px}.v4-demo.is-speaking .v4-wave i{animation:v4-eq .8s ease-in-out infinite alternate}.v4-demo.is-speaking .v4-wave i:nth-child(3n){animation-delay:-.3s;animation-duration:1.1s}.v4-demo.is-speaking .v4-wave i:nth-child(4n){animation-delay:-.7s;animation-duration:.65s}
@keyframes v4-eq{to{transform:scaleY(.23);opacity:.95}}.v4-demo-actions{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-top:18px}.v4-demo-actions span{font-size:10px;color:#9baeca}.v4-demo-actions .btn{font-size:12px;min-height:42px;padding:9px 17px}
.v4-section{padding:34px 0 82px}.v4-section-head{display:flex;justify-content:space-between;align-items:end;gap:30px;margin-bottom:28px}.v4-section-head h2,.v4-flow-content h2{font-size:clamp(26px,3.2vw,40px);letter-spacing:-1.3px;line-height:1.25;margin:13px 0 0}.v4-section-head>p{max-width:410px;color:var(--v4-muted);font-size:12px;line-height:1.9;margin:0}
.v4-tools{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.v4-tool{display:flex;flex-direction:column;min-height:266px;padding:26px;border:1px solid var(--v4-line);border-radius:19px;background:linear-gradient(160deg,#111b2e,#0e1728);transition:transform .25s,border-color .25s}.v4-tool:hover{transform:translateY(-4px);border-color:#76e4cc69}.v4-tool-ico{display:grid;place-items:center;width:44px;height:44px;background:#1d3c3b;color:#8ef2d9;border-radius:13px;font-size:23px;margin-bottom:19px}.v4-tool-ico.violet{color:#c0baff;background:#313151}.v4-tool-ico.amber{color:#efc99d;background:#3e302b}.v4-tool-type{font-size:9px;font-weight:800;letter-spacing:1.4px;color:#94a9ba}.v4-tool h3{font-size:18px;letter-spacing:-.6px;margin:6px 0 8px}.v4-tool p{font-size:12px;line-height:1.9;color:#a2b0c4;margin:0 0 18px}.v4-tool-link{margin-top:auto;font-size:11px;font-weight:800;color:var(--v4-mint)}
.v4-flow-section{border-top:1px solid var(--v4-line);border-bottom:1px solid var(--v4-line);background:#111a2b99;padding:37px 0}.v4-flow-content{display:flex;align-items:center;justify-content:space-between;gap:25px}.v4-flow-content h2{font-size:clamp(24px,3vw,35px)}.v4-flow-content p{font-size:12px;color:var(--v4-muted);margin:9px 0 0}.v4-flow-content .btn{font-size:12px;white-space:nowrap}
.v4-faq{padding:72px 0 100px;max-width:1120px}.v4-faq details{padding:16px 5px;border-bottom:1px solid var(--v4-line)}.v4-faq summary{font-size:13px;font-weight:700;cursor:pointer}.v4-faq details p{font-size:12px;max-width:900px;color:#a9b9cd;line-height:1.9}.v4-faq details[open] summary{color:var(--v4-mint)}
/* Compact studio */
.studio-page{padding:28px 0 80px;background-image:none}.studio-page:before{display:none}.studio-head{display:none!important}.v4-studio-ribbon{display:flex;align-items:center;justify-content:space-between;gap:22px;margin-bottom:20px}.v4-studio-ribbon h2{font-size:clamp(24px,3.4vw,34px);line-height:1.2;letter-spacing:-1.3px;margin:5px 0 6px}.v4-studio-ribbon p{font-size:11px;color:#9aabc3;margin:0}.v4-ribbon-actions{display:flex;gap:8px;flex-wrap:wrap;justify-content:flex-end}.v4-small-link{display:inline-flex;align-items:center;justify-content:center;border:1px solid #ffffff19;background:#ffffff07;color:#d4e4f7;border-radius:10px;padding:10px 12px;font:600 11px 'Be Vietnam Pro',sans-serif;white-space:nowrap;cursor:pointer}.v4-small-link:hover{background:#ffffff13}.v4-small-link[aria-pressed=true]{border-color:#80ebd2;background:#1b4844;color:#bdfdea}
.studio-grid{grid-template-columns:minmax(0,1.6fr) minmax(300px,.84fr);gap:16px}.studio-panel{background:#121c30;border:1px solid #ffffff18;border-radius:19px;box-shadow:none}.studio-panel .panel-pad{padding:22px}.studio-grid>aside{display:flex;flex-direction:column;gap:0}.studio-panel h3{letter-spacing:-.25px}.side-section{padding:20px!important}.studio-bottom{display:none!important}.studio-announcement{border-radius:12px!important;margin-bottom:18px!important}.studio-page .eyebrow{font-size:10px}.studio-page .mode-switch{gap:6px}.mode-switch button{font-size:11px!important;padding:10px!important}.control-grid{gap:11px}.control-grid .field-label{font-size:10px}.studio-muted,.studio-small-hint,.v3-vnote{font-size:10.5px!important;line-height:1.8!important}.studio-panel .text-area,.studio-panel textarea{line-height:1.8}.v3-voice-grid{max-height:480px;overflow:auto;scrollbar-width:thin}.v4-voice-folded .v3-voice-card:nth-child(n+7){display:none}.v4-expand-btn{width:100%;margin-top:11px;border:1px solid #ffffff20;color:#c7e7dc;background:#ffffff06;padding:11px;border-radius:11px;cursor:pointer;font-size:11px;font-weight:700}.v4-expand-btn:hover{border-color:#8fead5}.v3-filter{gap:7px}.v3-chips button{font-size:10px!important}.v3-voice-card{min-width:0!important}.v4-advanced{margin:13px 0;background:#0c1728;border:1px solid var(--v4-line);border-radius:12px}.v4-advanced summary{cursor:pointer;padding:12px 15px;color:#a9c1d1;font-size:11px;font-weight:700}.v4-advanced .advanced-options{padding:4px 15px 16px}.v4-focus .studio-grid{grid-template-columns:minmax(0,860px);justify-content:center}.v4-focus .studio-grid>aside{display:none}.v4-focus .studio-bottom{display:none}.v4-focus .studio-page{padding-top:25px}
/* Light mode honors existing theme choice */
html[data-theme=light] body{background:#f3f7f9;background-image:none;color:#13273a}html[data-theme=light] .site-header{background:#f7fbffec;border-color:#dbe4ed}html[data-theme=light] .v4-demo,html[data-theme=light] .v4-tool,html[data-theme=light] .studio-panel{background:#fff;border-color:#d9e2ed;color:#193146}html[data-theme=light] .v4-hero-text>p,html[data-theme=light] .v4-section-head>p,html[data-theme=light] .v4-tool p,html[data-theme=light] .v4-flow-content p{color:#52657a}html[data-theme=light] .v4-demo textarea,html[data-theme=light] .v4-demo select{background:#f4f7fc;color:#182d44;border-color:#d8e1eb}html[data-theme=light] .v4-flow-section{background:#eaf1f6;border-color:#d9e4eb}html[data-theme=light] .v4-small-link{color:#28526a;background:#e9f2f6;border-color:#d5e5ec}
/* Local Lab less ornamental; compact reliable first-use view */
.local-app{padding-top:22px!important}.local-hero{min-height:0!important;padding:24px 0 21px!important;display:block!important}.local-hero h1{font-size:clamp(30px,4vw,46px)!important;line-height:1.24!important;max-width:680px!important;letter-spacing:-1.5px!important}.local-hero p{max-width:760px!important;font-size:12px!important;line-height:1.85!important}.local-hero-badges{margin-top:14px!important}.local-orbit{display:none}.local-infobar{padding:11px 16px!important;margin:12px 0 19px!important}.local-layout{gap:15px}.local-main,.local-side{gap:15px}.local-panel{background:#121c30;border:1px solid var(--v4-line);padding:21px;border-radius:17px;box-shadow:none}.local-section-title span{font-size:13px!important}.local-section-title small{font-size:10px!important}.local-voice-card{background:#0e182a!important}.v4-library-link{display:block;padding:11px 12px;background:#203f42;color:#a3ffe5;border-radius:10px;text-align:center;font-weight:700;font-size:11px;margin:0 0 13px}.v4-local-backup{border:1px solid var(--v4-line);background:#111b2c;border-radius:14px;padding:16px}.v4-local-backup>summary{cursor:pointer;color:#b6ccdd;font-size:12px;font-weight:700}.v4-local-backup[open]>summary{margin-bottom:14px}.v4-local-backup .local-section-title{display:none}.v4-local-backup .local-backup-actions{display:flex;flex-wrap:wrap;gap:8px}
/* Local library with active search and backup */
.v4-library-page{padding:51px 0 90px;min-height:75vh}.v4-library-head{display:flex;justify-content:space-between;gap:35px;align-items:center}.v4-library-head h1{font-size:clamp(29px,4vw,47px);line-height:1.2;letter-spacing:-1.9px;margin:11px 0}.v4-library-head p{max-width:655px;font-size:12px;color:var(--v4-muted);line-height:1.9}.v4-library-actions{display:flex;gap:9px;flex-wrap:wrap;justify-content:flex-end}.v4-library-actions .btn{white-space:nowrap;font-size:11px;padding:11px 13px;cursor:pointer}.v4-library-overview{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:13px;margin:30px 0 24px}.v4-library-overview>div{background:#131d30;border:1px solid var(--v4-line);border-radius:15px;padding:22px}.v4-library-overview strong{display:block;font-size:28px;line-height:1.3;color:#b8f8e9}.v4-library-overview span{font-size:11px;color:#9baec5}.v4-library-toolbar{display:flex;align-items:center;gap:13px;margin-bottom:18px;flex-wrap:wrap}.v4-library-toolbar label{font-size:11px;color:#9baec5}.v4-library-toolbar input{flex:1 1 230px;min-width:200px;border:1px solid var(--v4-line);background:#121d30;border-radius:11px;color:var(--v4-ink);padding:12px;font-size:12px}.v4-library-filters{display:flex;flex-wrap:wrap;gap:6px}.v4-library-filters button{border:1px solid var(--v4-line);background:#ffffff07;color:#a8bdd1;border-radius:9px;padding:10px;font-size:10px;cursor:pointer}.v4-library-filters button.active{background:#234840;color:#a5ffe5;border-color:#558d7b}.v4-library-items{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.v4-library-item{padding:22px;background:#121c2e;border:1px solid var(--v4-line);border-radius:15px;min-width:0;display:flex;flex-direction:column;gap:8px}.v4-library-item h3{font-size:14px;margin:0;overflow-wrap:anywhere}.v4-library-item p{font-size:11px;color:#b1bfd1;line-height:1.7;margin:0;overflow-wrap:anywhere;display:-webkit-box;-webkit-box-orient:vertical;-webkit-line-clamp:3;overflow:hidden}.v4-library-item .v4-meta{color:#92a8b9;font-size:10px}.v4-library-item .v4-type{color:#7ef6d6;font-size:9px;letter-spacing:1px;font-weight:800}.v4-library-item .v4-item-actions{display:flex;gap:7px;flex-wrap:wrap;margin-top:auto;padding-top:6px}.v4-item-actions button{border:1px solid var(--v4-line);border-radius:9px;background:#1c2940;color:#d8edf6;padding:9px 11px;font-size:10px;cursor:pointer}.v4-item-actions button:hover{border-color:#74e9c8}.v4-item-actions .danger{color:#f0aaa5}.v4-library-status{color:#9cb1c3;font-size:11px;min-height:24px;margin-top:14px}.v4-empty{grid-column:1/-1;border:1px dashed #40556c;padding:40px 15px;border-radius:16px;color:#9fb4c6;text-align:center;font-size:12px}.v4-library-bottom{display:flex;gap:30px;justify-content:space-between;align-items:center;border-top:1px solid var(--v4-line);margin-top:40px;padding-top:22px}.v4-library-bottom p{max-width:750px;font-size:11px;line-height:1.9;color:#9daec0}.v4-library-bottom a{color:#8ef5dd;font-size:11px;white-space:nowrap}
@media(max-width:1060px){.nav-links{gap:14px}.nav-links a{font-size:11px}.v4-hero{grid-template-columns:minmax(0,1fr) minmax(300px,.91fr);gap:26px}.v4-hero h1{font-size:45px}.studio-grid{grid-template-columns:minmax(0,1fr) minmax(270px,.85fr)}}
@media(max-width:800px){.site-header{height:66px}.v4-hero{grid-template-columns:minmax(0,1fr);padding:38px 0 50px;gap:30px;min-height:0}.v4-hero h1{font-size:clamp(37px,8.5vw,53px)}.v4-demo{max-width:640px;width:100%;margin:auto}.v4-tools{grid-template-columns:1fr}.v4-tool{min-height:0;padding:20px}.v4-section-head{display:block}.v4-section-head>p{margin-top:15px}.v4-flow-content{align-items:flex-start;flex-direction:column}.v4-studio-ribbon{align-items:flex-start;flex-direction:column}.v4-ribbon-actions{justify-content:flex-start}.studio-grid{grid-template-columns:1fr}.v4-library-head{display:block}.v4-library-actions{justify-content:flex-start;margin-top:16px}.v4-library-overview{gap:7px}.v4-library-overview>div{padding:14px}.v4-library-overview strong{font-size:23px}.v4-library-overview span{font-size:9px}.v4-library-items{grid-template-columns:1fr}.v4-library-bottom{flex-direction:column;align-items:flex-start;gap:6px}}
@media(max-width:550px){.container{width:calc(100% - 30px)}.site-header .nav-actions .btn-primary{display:none}.site-header .brand{font-size:20px}.v4-hero h1{letter-spacing:-1.7px;font-size:clamp(34px,9vw,45px)}.v4-hero-text>p{font-size:12.5px}.v4-demo{padding:18px;border-radius:18px}.v4-demo-top{gap:9px}.v4-demo-actions{align-items:stretch;flex-direction:column}.v4-demo-actions .btn{width:100%}.v4-section{padding-bottom:49px}.v4-faq{padding:45px 0 66px}.v4-library-page{padding:32px 0 70px}.v4-library-toolbar{align-items:stretch}.v4-library-toolbar input{min-width:100%;flex:auto}.v4-library-filters{width:100%}.v4-library-filters button{flex:1}.v4-studio-ribbon h2{font-size:25px}.v4-studio-ribbon p{font-size:10px}.v4-ribbon-actions{gap:6px}.v4-small-link{font-size:10px;padding:9px}.studio-panel .panel-pad{padding:16px}.local-panel{padding:16px}.local-app{padding-top:8px!important}.local-hero h1{font-size:32px!important}}
@media(prefers-reduced-motion:reduce){.v4-demo.is-speaking .v4-wave i{animation:none}.v4-tool{transition:none}html{scroll-behavior:auto}}
/* Keep download/output available in focus mode; hide only nonessential side panels. */
.v4-focus .studio-grid{grid-template-columns:minmax(0,1.6fr) minmax(275px,.65fr);justify-content:stretch}
.v4-focus .studio-grid>aside{display:block}
.v4-focus .studio-grid>aside .side-section:not(:nth-child(2)){display:none}
@media(max-width:800px){.v4-focus .studio-grid{grid-template-columns:minmax(0,1fr)}}
.v4-ribbon-actions #api-state{font-size:10px!important;border:1px solid #ffffff1c;border-radius:10px;padding:9px 11px;background:#ffffff09;color:#acc5d5;white-space:normal}