:root{font-family:Inter,system-ui,-apple-system,sans-serif;line-height:1.5;font-weight:400;color-scheme:light dark}body{margin:0;min-width:320px;min-height:100vh}*{box-sizing:border-box;margin:0;padding:0}:root{--primary-color: #0d9488;--secondary-color: #10b981;--bg-gradient: linear-gradient(135deg, #f0fdfa 0%, #ccfbf1 100%);--card-bg: rgba(240, 253, 244, .95);--text-primary: #111827;--text-secondary: #4b5563;--shadow: 0 10px 30px rgba(13, 148, 136, .15);--white: #f9fafb;--nav-bg: #f9fafb;--footer-bg: #f9fafb;--item-bg: #ffffff;--border-color: #d1fae5}.dark-theme{--primary-color: #6366f1;--secondary-color: #a855f7;--bg-gradient: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);--card-bg: rgba(30, 41, 59, .8);--text-primary: #f1f5f9;--text-secondary: #94a3b8;--shadow: 0 10px 25px rgba(0, 0, 0, .3);--white: #1e293b;--nav-bg: #1e293b;--footer-bg: #0f172a;--item-bg: #334155;--border-color: #334155}body{margin:0;font-family:Inter,system-ui,-apple-system,sans-serif;background:var(--bg-gradient);min-height:100vh;color:var(--text-primary);transition:background .3s,color .3s}.app-wrapper{display:flex;flex-direction:column;min-height:100vh}.navbar{background:var(--nav-bg);padding:1rem 1.5rem;box-shadow:0 2px 10px #0000000d;position:sticky;top:0;z-index:100;transition:background .3s}.nav-content{max-width:1200px;margin:0 auto;display:flex;justify-content:space-between;align-items:center;width:100%}.logo{font-weight:800;font-size:1.5rem;background:linear-gradient(to right,var(--primary-color),var(--secondary-color));background-clip:text;-webkit-background-clip:text;-webkit-text-fill-color:transparent}.theme-toggle{background:none;border:1px solid var(--border-color);border-radius:50%;width:38px;height:38px;display:flex;align-items:center;justify-content:center;cursor:pointer;font-size:1.1rem;transition:all .3s}.theme-toggle:hover{background:var(--border-color);transform:rotate(15deg)}.main-header{text-align:center;padding:5rem 1rem 2rem}.main-header h1{font-size:clamp(2rem,8vw,3.5rem);font-weight:900;margin-bottom:.5rem;letter-spacing:-1px}.main-header p{color:var(--text-secondary);font-size:clamp(1rem,3vw,1.2rem);max-width:600px;margin:0 auto}.todo-container{max-width:550px;width:calc(100% - 2rem);margin:2rem auto;background:var(--card-bg);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);padding:clamp(1.5rem,5vw,2.5rem);border-radius:16px;box-shadow:var(--shadow);flex-grow:1;transition:all .3s}.input-group{display:flex;gap:10px;margin-bottom:2rem}input[type=text]{flex:1;padding:12px 14px;border:2px solid var(--border-color);border-radius:12px;outline:none;font-size:1rem;transition:all .3s;background:var(--white);color:var(--text-primary);min-width:0}input[type=text]:focus{border-color:var(--primary-color);box-shadow:0 0 0 4px #6366f11a}.add-btn{padding:12px 20px;background:var(--primary-color);color:#fff;border:none;border-radius:12px;font-weight:600;cursor:pointer;transition:all .2s;white-space:nowrap}.add-btn:hover{transform:translateY(-2px);box-shadow:0 4px 12px #6366f14d}.todo-list{list-style:none;padding:8px;max-height:290px;overflow-y:auto;scrollbar-gutter:stable}.todo-list::-webkit-scrollbar{width:6px}.todo-list::-webkit-scrollbar-track{background:transparent}.todo-list::-webkit-scrollbar-thumb{background:#e2e8f0;border-radius:10px}.dark-theme .todo-list::-webkit-scrollbar-thumb{background:#334155}.todo-list::-webkit-scrollbar-thumb:hover{background:var(--primary-color)}.todo-item{background:var(--item-bg);padding:.8rem 1rem;border-radius:16px;margin-bottom:12px;display:flex;align-items:center;justify-content:space-between;box-shadow:0 2px 8px #0000000a;transition:transform .2s,background .3s;border:1px solid transparent;gap:10px}.dark-theme .todo-item{box-shadow:0 4px 12px #0003}.todo-item:hover{transform:scale(1.01);border-color:var(--primary-color)}.todo-content{display:flex;align-items:center;gap:12px;cursor:pointer;flex:1;min-width:0}.checkbox{width:20px;height:20px;border:2px solid var(--border-color);border-radius:50%;display:flex;align-items:center;justify-content:center;transition:all .2s;background:var(--white);flex-shrink:0}.completed .checkbox{background:#22c55e;border-color:#22c55e}.completed .checkbox:after{content:"✓";color:#fff;font-size:12px}.todo-text{font-weight:500;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.completed .todo-text{text-decoration:line-through;color:var(--text-secondary)}.item-actions{display:flex;gap:10px;flex-shrink:0}.edit-btn,.delete-btn,.save-btn,.cancel-btn{background:none;border:none;padding:4px;font-size:1.1rem;cursor:pointer;transition:transform .2s;display:flex;align-items:center;justify-content:center}.edit-btn:hover,.delete-btn:hover{transform:scale(1.2)}.save-btn{background:#dcfce7;color:#15803d;padding:6px 12px;font-weight:600;font-size:.85rem;border-radius:8px}.cancel-btn{background:#f3f4f6;color:#4b5563;padding:6px 12px;font-weight:600;font-size:.85rem;border-radius:8px}.edit-mode{display:flex;flex-direction:column;gap:10px;width:100%}.edit-actions{display:flex;gap:8px;justify-content:flex-end}.footer{padding:2rem 1.5rem;margin-top:auto;border-top:1px solid var(--border-color);transition:background .3s}.footer-bottom{max-width:550px;margin:0 auto;display:flex;justify-content:center;align-items:center;flex-wrap:wrap;gap:1rem;width:100%}.footer-bottom p{color:var(--text-secondary);font-size:.9rem;margin:0}.footer-bottom p a{color:var(--primary-color);text-decoration:none;font-weight:700;transition:all .2s;padding:2px 4px;border-radius:4px}.footer-bottom p a:hover{background:var(--primary-color);color:#fff}@media(max-width:480px){.main-header{padding:3rem 1rem 1rem}.todo-container{padding:1.5rem 1rem;margin:1rem auto;border-radius:20px}.input-group{flex-direction:column;gap:8px}.add-btn{width:100%}.footer-bottom{flex-direction:column;text-align:center}}@media(max-width:350px){.logo{font-size:1.25rem}.todo-item{padding:.75rem}.item-actions{gap:5px}}.empty-msg{text-align:center;color:var(--text-secondary);padding:2rem 0}