:root{--type-note:.875rem;--type-ui:.9375rem;--type-body:1rem;--type-reading:1.0625rem;--type-h3:1.25rem;--type-h2:clamp(1.5rem,2.2vw,1.75rem);--type-h1:clamp(1.875rem,3.1vw,2.5rem)}
html{font-size:100%}body{font-size:var(--type-body);line-height:1.7}input,textarea,select,button{font-family:inherit}input,textarea,select{font-size:var(--type-body)}
.brand,.site-footer .brand{font-size:1.75rem;line-height:1.2;letter-spacing:-.04em}.header .tool-nav{font-size:var(--type-ui);line-height:1.5}
.download-page h1,.policy h1,.feedback-page h1{font-size:var(--type-h1);line-height:1.3;letter-spacing:-.025em}.download-page .tool-description{font-size:var(--type-reading);line-height:1.75}
.tool-tag,.section-caption,.tool-caption{font-size:var(--type-note);line-height:1.6;letter-spacing:.06em}.card-top,.card-top>div,.form-meta{font-size:var(--type-note);line-height:1.65}
.form-label,.result-actions label,.feedback-form label{font-size:var(--type-body);line-height:1.6}.input-wrap button{font-size:var(--type-note);line-height:1.5}.input-wrap button#clear,.modal-close{font-size:1.625rem;line-height:1}
.button-primary,.feedback-submit{font-size:var(--type-body);line-height:1.5}.form-help,.card-bottom,.field-error,.feedback-hint{font-size:var(--type-note);line-height:1.75}.guide-shortcut,.text-button,.change-link{font-size:var(--type-ui);line-height:1.6}
.guide h2,.policy h2{font-size:var(--type-h2);line-height:1.4;letter-spacing:-.02em}.guide h3{font-size:var(--type-h3);line-height:1.5;letter-spacing:-.01em}.guide p,.guide .guide-lead{font-size:var(--type-reading);line-height:1.8}.guide-toc,.guide-toc a{font-size:var(--type-body);line-height:1.75}.guide .guide-back a{font-size:var(--type-ui);line-height:1.6}.breadcrumbs,.policy .policy-date{font-size:var(--type-note);line-height:1.7}
.tool-faq .faq-list summary,.tool-faq .faq-list details p{font-size:var(--type-body);line-height:1.75}.faq-list summary{font-weight:600}.faq-list summary:after{font-size:1.5rem;line-height:1}.faq-support-text strong{font-size:var(--type-body);line-height:1.5}.faq-support-text>span,.tool-faq .faq-support>a{font-size:var(--type-note);line-height:1.65}
.platform-nav-panel>p,.platform-nav-link{font-size:var(--type-ui);line-height:1.6}.share-label{font-size:var(--type-note);line-height:1.6}.share-status{font-size:var(--type-note);line-height:1.6;color:#315d48}
.site-footer h2{font-size:var(--type-body);line-height:1.5}.site-footer .footer-intro p,.site-footer nav,.footer-reach>a,.footer-reach p,.footer-bottom{font-size:var(--type-note);line-height:1.8}.site-footer .footer-contact{font-size:var(--type-ui);line-height:1.8}
.status-message,.download-modal .status-message{font-size:var(--type-ui);line-height:1.75}.result-platform{font-size:var(--type-note);line-height:1.6;letter-spacing:.04em}.video-summary h2,.result h2{font-size:1.125rem;line-height:1.6;letter-spacing:0}.video-summary p,.result p,.download-modal .selected-quality,.download-modal .mode-help,.result .mode-help{font-size:var(--type-note);line-height:1.75}.result-actions select{font-size:var(--type-body);line-height:1.5}.modal-header h2{font-size:var(--type-h3);line-height:1.5;letter-spacing:-.01em}.download-modal #result-title{font-size:var(--type-body);line-height:1.65}.download-ad-slot span{font-size:var(--type-note);line-height:1.6;color:#596b84;letter-spacing:0}
.recent-intro,.recent-message,.recent-info p,.recent-info time,.recent-retry,.recent-clear,.recent-count{font-size:var(--type-note);line-height:1.65}.recent-info time{color:#596b84}.recent-info h3{font-size:var(--type-ui);line-height:1.6}.recent-count{min-width:24px}.recent-retry{white-space:normal}.support-shortcut{font-size:var(--type-note);line-height:1.5}
 
.card-top,.footer-bottom,.result-actions,.platform-nav-panel{flex-wrap:wrap}.result-actions>label,.result-top>div:last-child{min-width:0}.result-actions select{width:100%;max-width:100%}.result p,.video-summary p,.recent-info p,.feedback-success,.feedback-error{overflow-wrap:anywhere}.support-shortcut{max-width:calc(100vw - 24px)}.modal-header h2{overflow-wrap:anywhere}.modal-close{flex-shrink:0}
@media(max-width:760px){:root{--type-reading:1rem}.header .tool-nav{font-size:var(--type-note);flex-wrap:wrap}.tool-nav a{padding:9px 10px}.download-page h1,.policy h1,.feedback-page h1{font-size:1.875rem}.download-page .tool-description{font-size:var(--type-body)}.tool-tag{letter-spacing:.035em}.video-summary h2{font-size:var(--type-body)}.site-footer h2{font-size:var(--type-ui)}.platform-nav nav{flex-shrink:1;min-width:0;width:100%}.platform-nav-link{font-size:var(--type-ui);flex-wrap:wrap}.faq-support-text strong{font-size:var(--type-ui)}.recent-item{grid-template-columns:48px minmax(0,1fr)}.recent-retry{grid-column:2;justify-self:start}.recent-item img,.recent-image-fallback{width:48px}.footer-bottom>span{overflow-wrap:anywhere}}
@media(max-width:480px){.header .tool-nav{width:100%}.input-wrap{padding-left:10px;padding-right:10px;gap:8px}.input-wrap button{white-space:normal}.platform-nav-panel{padding-left:16px;padding-right:16px}.platform-nav-link{font-size:var(--type-note)}}

.guide .section-caption{font-size:var(--type-note);line-height:1.6;letter-spacing:.06em}
.guide h4{font-size:var(--type-reading);line-height:1.6;font-weight:650;letter-spacing:0;margin:24px 0 12px}.guide li{font-size:var(--type-reading);line-height:1.8;margin:0 0 10px}.guide ul{padding-left:24px;margin:12px 0 22px}
.guide ol{padding-left:24px;margin:12px 0 22px}.article-table{margin:20px 0 24px}.article-table table{width:100%;border-collapse:collapse;table-layout:fixed;font-size:var(--type-body);line-height:1.75}.article-table th,.article-table td{padding:12px 14px;border:1px solid #dce3ee;text-align:left;vertical-align:top;overflow-wrap:anywhere}.article-table th{font-weight:600;background:#f1f5fc}.article-table thead th{color:#243b5b}.article-table th:first-child{width:38%}@media(max-width:600px){.article-table th,.article-table td{padding:10px;font-size:var(--type-note)}}
.article-topics{margin:16px 0 0}.article-topic{border:1px solid #dce3ee;border-radius:10px;background:#fff;margin:0 0 10px;overflow:hidden}.article-topic summary{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:14px 16px;cursor:pointer;list-style:none;background:#f6f8fc}.article-topic summary::-webkit-details-marker{display:none}.guide .article-topic summary h4{font-size:var(--type-body);line-height:1.6;font-weight:600;margin:0;color:#243b5b}.article-topic summary .article-topic-toggle:after{content:'+';font-size:1.375rem;color:#315fb5}.article-topic[open] summary .article-topic-toggle:after{content:'−'}.article-topic[open] summary{border-bottom:1px solid #e5eaf2}.article-topic-body{padding:16px}.guide .article-topic-body p:last-child{margin-bottom:0}.article-topic summary:focus-visible{outline:3px solid #6b96ff;outline-offset:-3px}.article-topic summary:hover{background:#edf2fb}.article-topic summary .article-topic-toggle{flex-shrink:0}

.guide .article-topic summary h4{display:flex;align-items:center;justify-content:space-between;gap:16px;width:100%}

.source-article h3{margin-top:32px}.source-article h4{margin-top:24px}.source-article strong{font-weight:700}

.guide .guide-toc{padding:14px 18px;margin:20px 0 24px;line-height:1.5}
.guide .guide-toc ol{display:grid;gap:5px;margin:6px 0 0;padding-left:22px}
.guide .guide-toc li{margin:0;font-size:var(--type-body);line-height:1.5}
.guide .guide-toc a{display:inline-block;padding:2px 0;line-height:1.5;text-decoration:none}
.guide .guide-toc a:hover,.guide .guide-toc a:focus-visible{text-decoration:none}

.guide-images{display:grid;grid-template-columns:repeat(2,minmax(0,240px));justify-content:center;gap:24px;margin:24px 0}
.guide-images figure{margin:0;min-width:0}
.guide-images a{display:block;border-radius:12px;overflow:hidden;border:1px solid #dce5f3}
.guide-images img{display:block;width:100%;height:auto}
.guide-images figcaption{font-size:var(--type-small, .875rem);line-height:1.6;color:#52627b;margin-top:10px}
@media(max-width:480px){.guide-images{gap:12px;margin:20px 0}}

.guide-images-three{grid-template-columns:repeat(3,minmax(0,220px));gap:20px}
@media(max-width:600px){.guide-images-three{grid-template-columns:minmax(0,240px);gap:24px}}

@media(max-width:760px){
.header-shell{background:#142542;border-bottom:1px solid #253b5d;box-shadow:0 4px 18px #15254212}
.header{display:grid;grid-template-columns:minmax(0,1fr);justify-items:center;gap:10px;min-height:0;padding:12px 16px}
.header .brand{color:#fff;font-size:1.5rem;line-height:1.25;letter-spacing:-.035em;max-width:100%;min-width:0}
.header .brand-icon{width:32px;height:34px;flex-shrink:0;margin-right:8px;border-radius:10px;background:#315de0;box-shadow:none}
.header .brand-icon svg{width:22px;height:22px}
.header .brand-dot{color:#89aaff}
.header .tool-nav{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));width:100%;max-width:440px;gap:4px;padding:3px;border:0;border-radius:12px;background:#1a2f50;color:#ccd8eb;font-size:var(--type-ui);font-weight:600;line-height:1.4}
.header .tool-nav a{display:flex;align-items:center;justify-content:center;min-height:44px;padding:8px 6px;border-radius:9px;min-width:0;overflow-wrap:anywhere}
.header .tool-nav a:hover{background:#2a4267;color:#fff}
.header .tool-nav a[aria-current=page]{background:#fff;color:#234ea9;box-shadow:0 2px 6px #00000014}
.header .tool-nav a:focus-visible{outline:2px solid #89aaff;outline-offset:2px}
}

.mobile-tool-picker{display:none}
@media(max-width:760px){
.mobile-tool-picker:not([hidden]){display:block;position:fixed;right:12px;bottom:calc(72px + env(safe-area-inset-bottom));z-index:35}
.mobile-tool-toggle{display:grid;place-items:center;width:44px;height:44px;padding:0;border:1px solid #c5d3ee;border-radius:50%;background:#fff;color:#244dba;box-shadow:0 4px 20px #14254218;cursor:pointer}
.mobile-tool-toggle svg{width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:1.7}
.mobile-tool-toggle[aria-expanded=true]{background:#2855d5;color:#fff;border-color:#2855d5}
.mobile-tool-panel:not([hidden]){position:absolute;right:56px;bottom:0;display:grid;gap:3px;width:172px;padding:6px;border:1px solid #d3def0;border-radius:14px;background:#fff;box-shadow:0 5px 24px #14254224}
.mobile-tool-panel[hidden]{display:none}
.mobile-tool-panel a{display:flex;align-items:center;min-height:44px;padding:8px 14px;border-radius:9px;color:#334b6c;font-size:var(--type-ui);font-weight:600;text-decoration:none}
.mobile-tool-panel a:hover{background:#edf3ff;color:#234ea9}
.mobile-tool-panel a[aria-current=page]{background:#e9f0ff;color:#234ea9}
.mobile-tool-toggle:focus-visible,.mobile-tool-panel a:focus-visible{outline:2px solid #4775ec;outline-offset:2px}
.tool-picker-visible .support-shortcut{width:44px;height:44px;padding:0;justify-content:center;right:12px;bottom:calc(12px + env(safe-area-inset-bottom))}
.tool-picker-visible .support-shortcut span{display:none}
.tool-picker-visible .scroll-top{bottom:calc(132px + env(safe-area-inset-bottom))}
}

.guide-images-single{grid-template-columns:minmax(0,760px)}