:root{--bg:#000;--surface:#121212;--surface-2:#1a1a1a;--border:#2a2a2a;--ink:#f2f0ea;--ink-dim:#9a9891;--brass:#b08d57;--brass-dim:#7d6640;--danger:#a85c4a}*{box-sizing:border-box}body,html{margin:0;padding:0}body{background:var(--bg);color:var(--ink);font-family:Noto Sans TC,sans-serif;min-height:100vh;-webkit-font-smoothing:antialiased}.wrap{max-width:640px;margin:0 auto;padding:56px 24px 120px}.masthead{display:flex;align-items:baseline;justify-content:space-between;border-bottom:1px solid var(--border);padding-bottom:20px;margin-bottom:36px;flex-wrap:wrap;gap:10px}.masthead h1{font-weight:700;font-size:28px;letter-spacing:.02em;margin:0}.masthead .tagline,.masthead h1{font-family:"Noto Serif TC",serif}.masthead .tagline{font-size:13px;color:var(--ink-dim);font-style:italic}.seal{width:34px;height:34px;border-radius:50%;border:1.5px solid var(--brass);justify-content:center;color:var(--brass);font-family:"Noto Serif TC",serif;font-size:15px;flex-shrink:0}.masthead-left,.seal{display:flex;align-items:center}.masthead-left{gap:12px}.hero{margin-bottom:40px}.hero-title{font-family:"Noto Serif TC",serif;font-size:26px;line-height:1.5;font-weight:600;margin:0 0 14px;max-width:34ch}.hero-sub{font-size:15px;line-height:1.8;color:var(--ink-dim);max-width:56ch;margin:0}.howitworks{display:grid;grid-template-columns:repeat(3,1fr);grid-gap:20px;gap:20px;margin:40px 0 8px;padding:24px 0;border-top:1px solid var(--border);border-bottom:1px solid var(--border)}.how-mark{font-family:"Noto Serif TC",serif;color:var(--brass);font-size:15px;font-weight:600;margin-bottom:8px}.how-item p{font-size:13.5px;line-height:1.7;color:var(--ink-dim);margin:0}.address-card{background:var(--surface);border:1px solid var(--border);border-radius:4px;padding:24px;margin-bottom:16px}.address-label{font-size:13px;color:var(--ink-dim);margin-bottom:10px}.address-row{display:flex;align-items:center;gap:12px;flex-wrap:wrap}.address-value{font-family:Roboto Mono,monospace;font-size:19px;color:var(--ink);letter-spacing:.01em;word-break:break-all;flex:1 1;min-width:200px}.btn{font-family:Noto Sans TC,sans-serif;font-size:14px;padding:9px 16px;border-radius:3px;border:1px solid var(--border);background:transparent;color:var(--ink);cursor:pointer;transition:border-color .15s ease,color .15s ease;white-space:nowrap}.btn:hover{border-color:var(--brass);color:var(--brass)}.btn-brass{border-color:var(--brass-dim);color:var(--brass)}.btn-brass:hover{border-color:var(--brass);background:rgba(176,141,87,.08)}.btn-ghost{border:none;color:var(--ink-dim);padding:9px 4px}.btn-ghost:hover{color:var(--brass);border:none}.btn-small{padding:5px 10px;font-size:12.5px}.address-actions{gap:8px;margin-top:16px}.address-actions,.pin-row{display:flex;flex-wrap:wrap}.pin-row{align-items:center;gap:10px;margin-top:14px;padding-top:14px;border-top:1px dashed var(--border)}.pin-label{font-size:13px;color:var(--ink-dim)}.pin-value{font-family:Roboto Mono,monospace;font-size:16px;color:var(--brass);letter-spacing:.1em}.pin-hint{font-size:12px;color:var(--ink-dim);flex-basis:100%;margin-top:2px}@media (min-width:520px){.pin-hint{flex-basis:auto;margin-top:0;margin-left:auto}}.switch-panel{margin-top:14px;padding-top:14px;border-top:1px dashed var(--border);display:none}.switch-panel.open{display:block}.switch-panel input{width:100%;background:var(--surface-2);border:1px solid var(--border);color:var(--ink);font-family:Roboto Mono,monospace;font-size:14px;padding:10px 12px;border-radius:3px;margin-bottom:10px}.switch-panel input:focus{outline:none;border-color:var(--brass)}.switch-error{font-size:13px;color:var(--danger);min-height:18px;margin-top:2px}.inbox-header{display:flex;justify-content:space-between;align-items:baseline;margin:40px 0 12px}.inbox-header h2{font-family:"Noto Serif TC",serif;font-size:17px;font-weight:600;margin:0}.inbox-count{font-size:13px;color:var(--ink-dim)}.letter-list{border-top:1px solid var(--border)}.letter-row{display:flex;gap:16px;padding:18px 4px;border-bottom:1px solid var(--border);cursor:pointer;position:relative}.letter-row:hover{background:hsla(0,0%,100%,.02)}.letter-row .dot{width:6px;height:6px;border-radius:50%;background:var(--brass);margin-top:8px;flex-shrink:0}.letter-row.read .dot{background:transparent}.letter-main{flex:1 1;min-width:0}.letter-top{display:flex;justify-content:space-between;gap:12px}.letter-from{font-size:14px;color:var(--ink);font-weight:500}.letter-row.read .letter-from{color:var(--ink-dim);font-weight:400}.letter-time{font-size:12px;color:var(--ink-dim);flex-shrink:0;font-family:Roboto Mono,monospace}.letter-subject{font-size:14px;color:var(--ink-dim);margin-top:4px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.letter-row.read .letter-subject{color:#6d6b65}.letter-delete{background:none;border:none;color:var(--ink-dim);font-size:13px;cursor:pointer;padding:4px;opacity:0;transition:opacity .15s;align-self:flex-start}.letter-row:hover .letter-delete{opacity:1}.letter-delete:hover{color:var(--danger)}.empty-state{padding:60px 4px;text-align:center;color:var(--ink-dim);border-top:1px solid var(--border)}.empty-state p:first-child{font-family:"Noto Serif TC",serif;font-size:16px;color:var(--ink);margin-bottom:8px}.empty-state p{font-size:14px;margin:0}.overlay{position:fixed;inset:0;background:rgba(0,0,0,.7);display:none;align-items:flex-start;justify-content:center;padding:60px 20px;z-index:10;overflow-y:auto}.overlay.open{display:flex}.paper{background:var(--surface);border:1px solid var(--border);border-radius:4px;max-width:560px;width:100%;padding:32px;animation:unfold .28s cubic-bezier(.2,.8,.3,1)}@keyframes unfold{0%{opacity:0;transform:translateY(10px) scaleY(.98);transform-origin:top}to{opacity:1;transform:translateY(0) scaleY(1)}}.paper-header{border-bottom:1px solid var(--border);padding-bottom:16px;margin-bottom:20px}.paper-subject{font-family:"Noto Serif TC",serif;font-size:20px;font-weight:600;margin:0 0 12px}.paper-meta{font-size:13px;color:var(--ink-dim);display:flex;justify-content:space-between}.paper-body{font-size:15px;line-height:1.8;color:var(--ink);white-space:pre-wrap}.paper-close{display:block;margin-top:24px;background:none;border:1px solid var(--border);color:var(--ink-dim);padding:8px 18px;border-radius:3px;cursor:pointer;font-family:Noto Sans TC,sans-serif;font-size:13px}.paper-close:hover{border-color:var(--brass);color:var(--brass)}.code-chip{display:inline-flex;align-items:center;gap:8px;background:var(--surface-2);border:1px solid var(--brass-dim);padding:6px 12px;border-radius:3px;font-family:Roboto Mono,monospace;font-size:15px;color:var(--brass);margin-top:14px}.code-chip button{background:none;border:none;color:var(--brass);cursor:pointer;font-family:Noto Sans TC,sans-serif;font-size:12px;padding:0}.footnote{margin-top:56px;padding-top:20px;border-top:1px solid var(--border);font-size:12.5px;color:var(--ink-dim);line-height:1.7}@media (max-width:480px){.wrap{padding:36px 16px 100px}.masthead h1{font-size:24px}.address-value{font-size:15px}.howitworks{grid-template-columns:1fr;gap:18px}.hero-title{font-size:22px}}