:root {
    --bg: #f5f6fa;
    --card-bg: #ffffff;
    --text: #2d3436;
    --text-secondary: #636e72;
    --border: #e0e4e8;
    --accent: #4a90d9;
    --accent-hover: #357abd;
    --shadow: 0 2px 12px rgba(0,0,0,0.06);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.1);
    --radius: 12px;
    --radius-sm: 8px;
    --transition: 0.25s cubic-bezier(0.4,0,0.2,1);
    --header-height: 64px;
}
*{margin:0;padding:0;box-sizing:border-box;}
body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI','PingFang SC','Microsoft YaHei','Helvetica Neue',sans-serif;background:var(--bg);color:var(--text);line-height:1.6;min-height:100vh;display:flex;flex-direction:column;-webkit-font-smoothing:antialiased;}
.header{background:#fff;border-bottom:1px solid var(--border);position:sticky;top:0;z-index:100;box-shadow:0 1px 4px rgba(0,0,0,0.04);}
.header-inner{max-width:1400px;margin:0 auto;padding:0 24px;height:var(--header-height);display:flex;align-items:center;justify-content:space-between;}
.logo a{display:flex;align-items:center;gap:10px;text-decoration:none;color:#2d3436;font-weight:700;font-size:1.25rem;letter-spacing:-0.3px;transition:var(--transition);}
.logo a:hover{color:var(--accent);}
.logo-icon{width:38px;height:38px;border-radius:10px;background:linear-gradient(135deg,#4a90d9,#357abd);display:flex;align-items:center;justify-content:center;color:#fff;font-size:1rem;flex-shrink:0;}
.nav-desktop{display:flex;align-items:center;gap:6px;list-style:none;}
.nav-desktop li a{display:flex;align-items:center;gap:6px;padding:10px 16px;border-radius:8px;text-decoration:none;color:var(--text-secondary);font-size:0.9rem;font-weight:500;transition:var(--transition);white-space:nowrap;}
.nav-desktop li a:hover{background:#f0f4f8;color:var(--accent);}
.nav-desktop li a i{font-size:0.85rem;opacity:0.7;}
.hamburger{display:none;background:none;border:none;cursor:pointer;width:40px;height:40px;border-radius:8px;align-items:center;justify-content:center;font-size:1.4rem;color:var(--text);transition:var(--transition);z-index:110;}
.hamburger:hover{background:#f0f4f8;}
.overlay{position:fixed;inset:0;background:rgba(0,0,0,0.4);z-index:200;opacity:0;pointer-events:none;transition:opacity 0.3s ease;}
.overlay.active{opacity:1;pointer-events:auto;}
.sidebar{position:fixed;top:0;right:0;width:280px;height:100vh;background:#fff;z-index:210;box-shadow:-4px 0 20px rgba(0,0,0,0.12);transform:translateX(100%);transition:transform 0.3s cubic-bezier(0.4,0,0.2,1);display:flex;flex-direction:column;padding:24px 20px;gap:8px;}
.sidebar.active{transform:translateX(0);}
.sidebar-close{align-self:flex-end;background:none;border:none;font-size:1.5rem;cursor:pointer;color:var(--text-secondary);width:40px;height:40px;border-radius:50%;display:flex;align-items:center;justify-content:center;transition:var(--transition);margin-bottom:8px;}
.sidebar-close:hover{background:#f0f4f8;color:var(--text);}
.sidebar a{display:flex;align-items:center;gap:12px;padding:14px 16px;border-radius:10px;text-decoration:none;color:var(--text);font-size:1rem;font-weight:500;transition:var(--transition);}
.sidebar a:hover{background:#f0f4f8;color:var(--accent);}
.sidebar a i{width:22px;text-align:center;font-size:1rem;opacity:0.7;}
.main{flex:1;max-width:1400px;width:100%;margin:0 auto;padding:28px 24px 40px;}
.page-title{text-align:center;margin-bottom:6px;font-size:1.6rem;font-weight:700;letter-spacing:-0.4px;color:#1a1a2e;}
.page-subtitle{text-align:center;color:var(--text-secondary);font-size:0.9rem;margin-bottom:28px;}
.preview-section{background:#fff;border-radius:var(--radius);box-shadow:var(--shadow);padding:28px 24px;margin-bottom:24px;text-align:center;border:1px solid var(--border);}
.preview-label{font-size:0.8rem;text-transform:uppercase;letter-spacing:1px;color:var(--text-secondary);margin-bottom:16px;font-weight:600;}
.preview-img-wrap{display:inline-block;padding:20px;background:#f9fafb;border-radius:var(--radius-sm);border:1px dashed #dde1e6;min-width:160px;transition:var(--transition);}
.preview-img-wrap img{display:block;height:auto;image-rendering:auto;}
.preview-actions{margin-top:18px;display:flex;justify-content:center;}
.btn{display:inline-flex;align-items:center;gap:7px;padding:10px 18px;border-radius:8px;font-size:0.9rem;font-weight:600;cursor:pointer;border:none;transition:var(--transition);white-space:nowrap;text-decoration:none;letter-spacing:-0.2px;}
.btn-download{background:#27ae60;color:#fff;}
.btn-download:hover{background:#219a52;box-shadow:0 4px 14px rgba(39,174,96,0.35);transform:translateY(-1px);}
.btn-download:active{transform:scale(0.96);}
.config-section{background:#fff;border-radius:var(--radius);box-shadow:var(--shadow);padding:28px 24px;border:1px solid var(--border);}
.config-section h3{font-size:1.1rem;margin-bottom:20px;display:flex;align-items:center;gap:8px;color:#1a1a2e;}
.config-section h3 i{color:var(--accent);font-size:0.95rem;}
.config-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px 24px;}
.config-group{display:flex;flex-direction:column;gap:6px;}
.config-group label{font-size:0.82rem;font-weight:600;color:var(--text-secondary);letter-spacing:-0.1px;display:flex;align-items:center;gap:4px;}
.config-group label .unit{font-weight:400;color:#999;font-size:0.75rem;}
.config-group input[type="text"],.config-group input[type="number"],.config-group select{padding:10px 14px;border:1px solid var(--border);border-radius:8px;font-size:0.9rem;font-family:inherit;transition:var(--transition);background:#fafbfc;color:var(--text);}
.config-group input:focus,.config-group select:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px rgba(74,144,217,0.08);background:#fff;}
.config-group input[type="color"]{width:100%;height:42px;padding:4px 8px;cursor:pointer;border-radius:8px;border:1px solid var(--border);background:#fff;}
.color-row{display:flex;gap:8px;align-items:center;}
.color-row input[type="color"]{flex:0 0 48px;width:48px;height:40px;padding:3px;}
.color-row input[type="text"]{flex:1;font-family:'SF Mono','Fira Code','Consolas',monospace;font-size:0.85rem;text-transform:uppercase;}
.config-group-full{grid-column:1 / -1;}
.presets{display:flex;flex-wrap:wrap;gap:10px;margin-bottom:22px;}
.preset-btn{padding:9px 16px;border-radius:20px;border:1.5px solid var(--border);background:#fff;cursor:pointer;font-size:0.84rem;font-weight:500;transition:var(--transition);color:var(--text-secondary);white-space:nowrap;}
.preset-btn:hover{border-color:var(--accent);color:var(--accent);background:#f8fafe;}
.preset-btn.active{background:var(--accent);color:#fff;border-color:var(--accent);box-shadow:0 2px 8px rgba(74,144,217,0.3);}
.preset-btn i{margin-right:4px;}
.toast{position:fixed;bottom:30px;left:50%;transform:translateX(-50%) translateY(80px);background:#2d3436;color:#fff;padding:12px 24px;border-radius:25px;font-size:0.9rem;font-weight:500;z-index:999;opacity:0;pointer-events:none;transition:all 0.3s ease;box-shadow:0 8px 24px rgba(0,0,0,0.2);letter-spacing:-0.1px;}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0);}
.footer{text-align:center;padding:24px 20px;font-size:0.85rem;color:#999;letter-spacing:-0.1px;}
.footer a{color:var(--accent);text-decoration:none;font-weight:500;}
.footer a:hover{text-decoration:underline;}
@media (max-width:900px){.nav-desktop{display:none;}.hamburger{display:flex;}.page-title{font-size:1.35rem;}.config-grid{grid-template-columns:1fr;}}
@media (min-width:901px){.sidebar,.overlay{display:none;}}