:root{--bg-primary: #f5f7fa;--bg-secondary: #ffffff;--bg-tertiary: #f8f9fa;--text-primary: #333333;--text-secondary: #555555;--text-muted: #7f8c9a;--border-color: #e1e5eb;--border-light: #d1d8e4;--accent-primary: #3498db;--accent-secondary: #2980b9;--accent-dark: #1f6391;--accent-glow: rgba(52, 152, 219, .15);--accent-shadow: rgba(52, 152, 219, .4);--header-gradient-start: #2c3e50;--header-gradient-end: #34495e;--shadow-sm: 0 2px 10px rgba(0, 0, 0, .1);--shadow-md: 0 4px 20px rgba(0, 0, 0, .05);--shadow-lg: 0 8px 40px rgba(0, 0, 0, .1);--error-color: #e74c3c;--transition-smooth: .3s ease}[data-theme=dark]{--bg-primary: #1a1d23;--bg-secondary: #252a33;--bg-tertiary: #2d333d;--text-primary: #e8eaed;--text-secondary: #b8bcc2;--text-muted: #8b919a;--border-color: #3a4150;--border-light: #454d5a;--accent-primary: #5dade2;--accent-secondary: #3498db;--accent-dark: #2980b9;--accent-glow: rgba(93, 173, 226, .2);--accent-shadow: rgba(93, 173, 226, .4);--header-gradient-start: #1a1d23;--header-gradient-end: #2d333d;--shadow-sm: 0 2px 10px rgba(0, 0, 0, .3);--shadow-md: 0 4px 20px rgba(0, 0, 0, .25);--shadow-lg: 0 8px 40px rgba(0, 0, 0, .35);--error-color: #e57373}*{margin:0;padding:0;box-sizing:border-box}html,body{height:100%}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,sans-serif;background-color:var(--bg-primary);color:var(--text-primary);transition:background-color var(--transition-smooth),color var(--transition-smooth)}.header{position:fixed;top:0;left:0;width:100%;height:60px;background:linear-gradient(135deg,var(--header-gradient-start) 0%,var(--header-gradient-end) 100%);color:#fff;display:flex;align-items:center;padding:0 24px;z-index:100;box-shadow:var(--shadow-sm);transition:background var(--transition-smooth)}.menu-toggle{width:40px;height:40px;background:none;border:none;cursor:pointer;display:flex;align-items:center;justify-content:center;margin-right:16px;border-radius:6px;transition:background-color .2s}.menu-toggle:hover{background-color:#ffffff26}.hamburger{display:block;width:22px;height:2px;background-color:#fff;position:relative;transition:background-color .2s}.hamburger:before,.hamburger:after{content:"";position:absolute;width:22px;height:2px;background-color:#fff;left:0;transition:transform .3s ease}.hamburger:before{top:-7px}.hamburger:after{top:7px}.menu-toggle.active .hamburger{background-color:transparent}.menu-toggle.active .hamburger:before{transform:rotate(45deg);top:0}.menu-toggle.active .hamburger:after{transform:rotate(-45deg);top:0}.header-title{font-size:22px;font-weight:600;letter-spacing:-.5px;flex:1}.theme-toggle{width:44px;height:44px;background:#ffffff1a;border:none;border-radius:50%;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:background-color .2s,transform .2s}.theme-toggle:hover{background:#fff3;transform:scale(1.05)}.theme-icon{font-size:20px;position:absolute;transition:opacity .3s ease,transform .3s ease}.theme-icon.sun{opacity:1;transform:rotate(0) scale(1)}.theme-icon.moon{opacity:0;transform:rotate(-90deg) scale(.5)}[data-theme=dark] .theme-icon.sun{opacity:0;transform:rotate(90deg) scale(.5)}[data-theme=dark] .theme-icon.moon{opacity:1;transform:rotate(0) scale(1)}.page-container{display:flex;height:100vh;padding-top:60px}.sidebar{width:0;background-color:var(--bg-secondary);border-right:1px solid var(--border-color);min-height:calc(100vh - 60px);overflow:hidden;transition:width .35s cubic-bezier(.4,0,.2,1),box-shadow .3s ease,background-color var(--transition-smooth),border-color var(--transition-smooth);box-shadow:2px 0 8px #0000000d}.sidebar.expanded{width:280px;box-shadow:4px 0 20px #0000001a}.sidebar-content{width:280px;padding:24px;opacity:0;transition:opacity .25s ease .1s}.sidebar.expanded .sidebar-content{opacity:1}.main-content{flex:1;background-color:var(--bg-primary);min-height:calc(100vh - 60px);transition:padding .35s cubic-bezier(.4,0,.2,1),background-color var(--transition-smooth);padding:40px;overflow-y:auto}.input-area{display:flex;gap:16px;margin-bottom:32px;flex-wrap:wrap;align-items:stretch}.url-input{flex:1;min-width:250px;padding:14px 20px;font-size:16px;border:2px solid var(--border-color);border-radius:10px;outline:none;transition:border-color .2s,box-shadow .2s,background-color var(--transition-smooth),color var(--transition-smooth);background-color:var(--bg-secondary);color:var(--text-primary)}.url-input:focus{border-color:var(--accent-primary);box-shadow:0 0 0 3px var(--accent-glow)}.url-input::placeholder{color:var(--text-muted)}.generate-btn{padding:14px 32px;font-size:16px;font-weight:600;background:linear-gradient(135deg,var(--accent-primary) 0%,var(--accent-secondary) 100%);color:#fff;border:none;border-radius:10px;cursor:pointer;transition:transform .2s,box-shadow .2s,background .2s;white-space:nowrap}.generate-btn:hover{background:linear-gradient(135deg,var(--accent-secondary) 0%,var(--accent-dark) 100%);box-shadow:0 4px 15px var(--accent-shadow);transform:translateY(-1px)}.generate-btn:active{transform:translateY(0)}.qr-display{display:flex;justify-content:center;align-items:center;min-height:320px;background-color:var(--bg-secondary);border-radius:16px;border:2px dashed var(--border-light);box-shadow:var(--shadow-md);transition:box-shadow .3s ease,background-color var(--transition-smooth),border-color var(--transition-smooth)}.qr-display.has-qr{border:none;box-shadow:var(--shadow-lg);padding:40px}.qr-display .error{color:var(--error-color);font-size:16px;font-weight:500}.history-section{padding-top:8px;border-top:1px solid var(--border-color);margin-top:8px;transition:border-color var(--transition-smooth)}.history-title{font-size:14px;font-weight:700;color:var(--text-muted);text-transform:uppercase;letter-spacing:1px;margin-bottom:16px}.history-list{list-style:none;max-height:calc(100vh - 280px);overflow-y:auto}.history-item{padding:12px 14px;background-color:var(--bg-tertiary);border-radius:8px;margin-bottom:8px;cursor:pointer;transition:all .2s;word-break:break-all;font-size:14px;color:var(--text-secondary);border:1px solid transparent}.history-item:hover{background-color:var(--bg-secondary);border-color:var(--accent-primary);box-shadow:0 2px 8px var(--accent-glow);transform:translate(4px)}.history-item:active{transform:translate(2px)}.sidebar-overlay{display:none;position:fixed;inset:60px 0 0;background-color:#0006;z-index:40;opacity:0;transition:opacity .3s ease}.sidebar-overlay.visible{opacity:1}@media(max-width:768px){.page-container{flex-direction:column}.sidebar{position:fixed;top:60px;left:0;z-index:50;height:calc(100vh - 60px)}.sidebar.expanded{width:280px}.sidebar-overlay{display:block}.main-content{padding:24px 16px}.input-area{flex-direction:column;gap:12px}.url-input{min-width:100%;width:100%}.generate-btn{width:100%;padding:16px}.qr-display{min-height:280px;border-radius:12px}.qr-display.has-qr{padding:20px}.header-title{font-size:18px}}@media(max-width:480px){.main-content{padding:16px 12px}.header{padding:0 16px}.header-title{font-size:16px}.theme-toggle{width:38px;height:38px}}