.tool-hero{padding:58px 0 38px;background:radial-gradient(circle at 85% 0,#e9e4ff 0,transparent 32%),linear-gradient(180deg,#fafbff,#fff)}
.tool-intro{text-align:center;max-width:840px;margin:0 auto 30px}
.tool-intro h1{font-size:clamp(35px,5vw,58px);line-height:1.12;letter-spacing:-.045em;margin:15px 0 14px}
.tool-intro h1 em{font-style:normal;color:var(--brand)}
.tool-intro p{margin:0 auto;color:var(--muted);font-size:18px;max-width:720px}
.trust-row{display:flex;justify-content:center;gap:18px;flex-wrap:wrap;margin-top:18px;color:#56637d;font-size:13px}
.trust-row span{display:flex;align-items:center;gap:6px}
.trust-row span:before{content:'✓';color:var(--accent);font-weight:900}
.converter-shell{background:#fff;border:1px solid #dce3f2;border-radius:24px;box-shadow:0 24px 70px rgba(31,43,91,.13);overflow:hidden}
.converter-toolbar{min-height:64px;padding:12px 16px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:15px;background:#fcfdff}
.tool-tabs,.tool-actions,.account-area{display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.format-option{border:1px solid var(--line);background:#fff;border-radius:9px;padding:8px 13px;color:#526078;font:inherit;font-size:14px;font-weight:700;cursor:pointer}
.format-option.active{border-color:#8d7af1;background:#f2efff;color:#4933b2}
.format-option small{font-weight:500;opacity:.72}
.tool-action{border:0;background:transparent;color:#5d6980;font:inherit;font-size:13px;padding:7px 9px;border-radius:8px;cursor:pointer}
.tool-action:hover{background:#f0f2f8;color:var(--ink)}
.account-status{font-size:13px;color:#59667e}
.account-status strong{color:var(--ink)}
.logout-button{display:none}
.logout-button.visible{display:inline-flex}
.editor-grid{display:grid;grid-template-columns:1fr 1fr;height:498px;min-height:0}
.editor-pane{min-width:0;display:flex;flex-direction:column}
.editor-pane:first-child{border-right:1px solid var(--line)}
.pane-heading{height:48px;display:flex;align-items:center;justify-content:space-between;padding:0 18px;border-bottom:1px solid var(--line);color:#4d5870;font-size:13px;font-weight:800;background:#fbfcff}
.pane-heading span:last-child{font-weight:500;color:#8a94a7}
#markdownInput,#latexInput{width:100%;height:450px;min-height:450px;max-height:450px;flex:0 0 450px;overflow-y:auto;border:0;resize:none;outline:0;padding:20px;font:14px/1.72 ui-monospace,SFMono-Regular,Consolas,"Liberation Mono",monospace;color:#18243a;background:#fff;tab-size:2}
#markdownInput::placeholder,#latexInput::placeholder{color:#99a3b5}
.preview{height:450px;min-height:450px;max-height:450px;flex:0 0 450px;padding:22px;overflow:auto;color:#26344e;background:#fff}
.preview-empty{color:#99a3b5;display:grid;place-items:center;min-height:390px;text-align:center}
.preview h1,.preview h2,.preview h3,.preview h4{line-height:1.35;color:#13213b;margin:1.1em 0 .55em}
.preview h1{font-size:30px;border-bottom:1px solid #e6eaf2;padding-bottom:9px;margin-top:0}
.preview h2{font-size:24px}.preview h3{font-size:19px}.preview p{margin:.7em 0}.preview ul,.preview ol{padding-left:24px}.preview blockquote{margin:14px 0;padding:9px 15px;border-left:4px solid #8d7af1;background:#f7f5ff;color:#536079}
.preview pre{overflow:auto;background:#151a2d;color:#eaf0ff;border-radius:11px;padding:15px;font:13px/1.65 ui-monospace,SFMono-Regular,Consolas,monospace}
.preview code{background:#f0f2f7;border-radius:5px;padding:2px 5px;font:13px ui-monospace,SFMono-Regular,Consolas,monospace}.preview pre code{background:transparent;padding:0}
.preview table{border-collapse:collapse;width:100%;margin:16px 0;font-size:14px}.preview th,.preview td{border:1px solid #dce3ef;padding:8px 10px;text-align:left}.preview th{background:#f5f7fb}.preview a{color:var(--brand);text-decoration:underline}.math-inline{font-family:"Cambria Math","Times New Roman",serif;font-style:italic;color:#2b3a59}
.latex-shortcuts{display:flex;align-items:center;gap:7px;overflow-x:auto;padding:9px 16px;border-bottom:1px solid var(--line);background:#fff}.latex-shortcuts span{font-size:12px;color:#7b869a;white-space:nowrap}.latex-shortcuts button{border:1px solid #dfe4ef;background:#f8f9fc;color:#3f4c65;border-radius:7px;padding:5px 9px;font:13px "Cambria Math","Times New Roman",serif;cursor:pointer;white-space:nowrap}.latex-shortcuts button:hover{border-color:#a99af3;background:#f2efff;color:#4933b2}.latex-preview{white-space:pre-wrap;display:block}.latex-preview .katex-display{margin:1.25em 0;overflow-x:auto;overflow-y:hidden;padding:4px 0}.latex-preview-note{white-space:normal;margin:0 0 16px;padding:9px 12px;border-radius:8px;background:#fff8e8;color:#8a6200;font:13px/1.5 Inter,"PingFang SC","Microsoft YaHei",sans-serif}.latex-preview-note.error{background:#fff1f2;color:#a73343}.preview-caption{font-size:12px;color:#8993a6;font-weight:500}
.converter-bottom{padding:14px 16px;border-top:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:14px;background:#fbfcff}
.converter-status{font-size:13px;color:#6a768d;min-height:24px;display:flex;align-items:center;gap:8px}
.converter-status.error{color:#c0394b}.converter-status.success{color:#087c5a}
.convert-button{border:0;min-width:168px;cursor:pointer;font:inherit}
.convert-button:disabled{opacity:.62;cursor:wait;transform:none}
.result-card{display:none;margin:0 16px 16px;padding:14px 16px;border:1px solid #b9e8d8;background:#f0fbf7;border-radius:12px;align-items:center;justify-content:space-between;gap:14px;color:#176c53;font-size:14px}
.result-card.visible{display:flex}.result-card a{color:#fff;background:#0c8b64;border-radius:8px;padding:8px 12px;font-weight:800}
.hidden-file{position:absolute;width:1px;height:1px;opacity:0;pointer-events:none}
.modal{position:fixed;inset:0;z-index:1000;display:none;align-items:center;justify-content:center;padding:20px}
.modal.visible{display:flex}.modal-backdrop{position:absolute;inset:0;background:rgba(11,18,44,.55);backdrop-filter:blur(4px)}
.modal-card{position:relative;width:min(420px,100%);background:#fff;border-radius:20px;box-shadow:0 30px 90px rgba(9,16,46,.34);overflow:hidden}
.modal-header{padding:18px 21px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between}
.modal-header h2{font-size:19px;margin:0}.modal-close{border:0;background:#f1f3f8;color:#647087;width:32px;height:32px;border-radius:50%;font-size:21px;cursor:pointer;line-height:1}
.modal-body{padding:24px;text-align:center}.qr-frame{width:226px;height:226px;margin:0 auto 15px;border:1px solid var(--line);border-radius:15px;background:#f7f8fc;display:grid;place-items:center;overflow:hidden}.qr-frame img{width:100%;height:100%;object-fit:contain}.qr-frame img.loading{width:42px;height:42px;opacity:.55}
.modal-body h3{margin:0 0 6px;font-size:18px}.modal-body p{color:var(--muted);font-size:14px;margin:5px 0}.modal-message{min-height:24px;color:#6c7890;font-size:13px;margin-top:10px}.modal-message.error{color:#c0394b}.modal-message.success{color:#087c5a}
.payment-button{width:100%;border:0;cursor:pointer;font:inherit;margin-top:13px}.payment-button:disabled{opacity:.65;cursor:wait}
.support-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}.support-item{border:1px solid var(--line);border-radius:16px;padding:20px;background:#fff}.support-item b{display:block;margin-bottom:5px}.support-item span{font-size:14px;color:var(--muted)}
@media(max-width:900px){.editor-grid{grid-template-columns:1fr;height:auto}.editor-pane:first-child{border-right:0;border-bottom:1px solid var(--line)}#markdownInput,#latexInput,.preview{height:330px;min-height:330px;max-height:330px;flex-basis:330px}.converter-toolbar{align-items:flex-start}.account-area{justify-content:flex-end}.support-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:600px){.tool-hero{padding:38px 0 24px}.tool-intro h1{font-size:36px}.tool-intro p{font-size:16px}.converter-shell{border-radius:17px}.converter-toolbar{display:block}.tool-actions{margin-top:9px}.account-area{margin-top:9px;justify-content:flex-start}.editor-grid{height:auto}#markdownInput,#latexInput,.preview{height:300px;min-height:300px;max-height:300px;flex-basis:300px;padding:16px}.latex-shortcuts{padding:8px 12px}.converter-bottom{display:block}.convert-button{width:100%;margin-top:10px}.result-card.visible{display:block}.result-card a{display:inline-flex;margin-top:9px}.support-grid{grid-template-columns:1fr}.trust-row{gap:8px 14px}}