:root{--bg:#12141a;--surface:#1a1d2666;--surface-hover:#20242f73;--text:#e8eaed;--text-secondary:#9aa3af;--accent:#8b7cff;--accent-hover:#a294ff;--border:#2a2e3a;--danger:#f56565;--radius:12px;--shadow:0 8px 24px #00000073;--shadow-hover:0 12px 32px #0000008c}*{box-sizing:border-box}body{color:var(--text);background:linear-gradient(#00000073,#00000073),radial-gradient(at 50% 30%,#1f2333 0%,#161924 55%,#0d0f16 100%);flex-direction:column;min-height:100vh;margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Hiragino Sans GB,Microsoft YaHei,sans-serif;line-height:1.6;display:flex}main{flex:1}body>header,body>main,body>footer{width:100%}a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline}.container{max-width:960px;margin:0 auto;padding:0 20px}.nav{justify-content:space-between;align-items:center;padding:16px 0;display:flex}.nav-brand{color:var(--text);font-size:1.2rem;font-weight:700}.nav-right{align-items:center;gap:8px;display:flex}.nav-lang{border:1px solid var(--border);background:var(--surface);color:var(--text-secondary);cursor:pointer;box-sizing:border-box;border-radius:8px;align-items:center;gap:6px;height:30px;min-height:0;padding:6px 12px;font-family:inherit;font-size:.85rem;transition:border-color .15s,color .15s,background .15s;display:inline-flex;position:relative}.nav-lang:hover{color:var(--accent);border-color:var(--accent);background:var(--surface-hover);text-decoration:none}.nav-lang-icon{flex-shrink:0;width:15px;height:15px}.nav-lang-current{font:inherit;color:inherit;cursor:pointer;background:0 0;border:none;align-items:center;gap:6px;padding:0;display:inline-flex}.nav-lang-chevron{flex-shrink:0;width:12px;height:12px;transition:transform .15s}.nav-lang-current[aria-expanded=true] .nav-lang-chevron{transform:rotate(180deg)}.lang-list{z-index:50;background:var(--surface);border:1px solid var(--border);border-radius:10px;grid-template-columns:minmax(0,1fr);gap:2px;min-width:150px;max-width:min(220px,100vw - 24px);max-height:320px;margin:0;padding:6px;list-style:none;display:grid;position:absolute;top:calc(100% + 6px);left:0;overflow-y:auto;box-shadow:0 6px 24px #00000040}.lang-list[hidden]{display:none}.lang-item{cursor:pointer;color:var(--text);white-space:nowrap;border-radius:8px;padding:6px 10px;font-size:.78rem;transition:background .12s}.lang-item:hover{background:color-mix(in srgb, var(--accent) 12%, transparent)}.lang-item[aria-selected=true]{color:var(--accent);font-weight:600}.btn{background:var(--accent);color:#fff;cursor:pointer;border:none;border-radius:8px;padding:10px 20px;font-size:1rem;display:inline-block}.btn:hover{background:var(--accent-hover);text-decoration:none}.btn:disabled{opacity:.6;cursor:not-allowed}.btn[hidden]{display:none}.btn-secondary{background:var(--surface);color:var(--text);border:1px solid var(--border)}.btn-secondary:hover{background:var(--bg)}.hero{text-align:center;padding-top:72px;padding-bottom:40px}.hero h1{background:linear-gradient(90deg, var(--accent) 0%, #b8adff 60%, var(--accent) 100%);color:#0000;-webkit-background-clip:text;background-clip:text;margin:0 0 12px;font-size:2.6rem}.hero p{color:var(--text-secondary);max-width:560px;margin:0 auto;font-size:1.15rem}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:24px}.card:hover{box-shadow:var(--shadow-hover)}.workspace{grid-template-columns:4fr 6fr;align-items:start;gap:24px;padding-bottom:48px;display:grid}@media (width<=768px){.workspace{grid-template-columns:1fr}}.stem-item{border:1px solid var(--border);background:var(--bg);border-radius:10px;align-items:center;gap:10px;margin:8px 0;padding:8px 12px;display:flex}.stem-icon{text-align:center;flex-shrink:0;width:24px;font-size:1.15rem}.stem-name{flex-shrink:0;min-width:40px;font-weight:600}.stem-wave{cursor:pointer;border-radius:6px;flex:1 1 0;min-width:0;height:40px}.stem-wave.selected{outline:2px solid var(--accent);outline-offset:1px}.stem-play{border:1px solid var(--border);background:var(--surface);width:32px;height:32px;color:var(--accent);cursor:pointer;border-radius:8px;flex-shrink:0;justify-content:center;align-items:center;padding:0;display:inline-flex}.stem-play:hover{background:var(--bg)}.stem-play svg{width:16px;height:16px}.stem-dl{flex-shrink:0;padding:6px 12px;font-size:.88rem}@media (width<=640px){.stem-item{flex-wrap:wrap}.stem-wave{flex:100%;order:10;width:100%;height:44px}.cookie-inner{flex-wrap:wrap}}footer{color:var(--text-secondary);font-size:.9rem}.footer-nav{justify-content:space-between;align-items:center;padding:24px 0 16px;display:flex}.footer-brand{color:var(--text);font-size:1.1rem;font-weight:700}.footer-brand:hover{color:var(--accent);text-decoration:none}.footer-links{gap:8px;display:flex}.footer-links a{color:var(--text-secondary);margin:0}.footer-links a:hover{color:var(--accent)}.cookie-banner{z-index:100;background:var(--surface);border-top:1px solid var(--border);padding:12px 0;position:fixed;bottom:0;left:0;right:0;box-shadow:0 -4px 16px #1a202c14}.cookie-banner .cookie-inner{color:var(--text-secondary);align-items:center;gap:16px;font-size:.9rem;display:flex}.cookie-banner a{flex-shrink:0}.cookie-banner .btn{flex-shrink:0;padding:6px 18px;font-size:.9rem}