* { margin: 0; padding: 0; box-sizing: border-box; }
:root { --bg: #f4f6f8; --card: #fff; --text: #1a1a2e; --text-secondary: #6b7280; --border: #e5e7eb; --primary: #4f46e5; --primary-hover: #4338ca; --danger: #ef4444; --success: #10b981; --input-bg: #fff; --hover: #f9fafb; --shadow: 0 1px 3px rgba(0,0,0,.08); }
body { font-family: -apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif; background: var(--bg); color: var(--text); padding: 16px; line-height: 1.5; min-height: 100vh; }
.app { max-width: 640px; margin: 0 auto; }
.auth-overlay { position: fixed; inset: 0; background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); display: flex; align-items: center; justify-content: center; z-index: 300; }
.auth-panel { background: var(--card); border-radius: 16px; padding: 40px; width: 90%; max-width: 420px; box-shadow: 0 20px 60px rgba(0,0,0,.3); text-align: center; }
.auth-panel h1 { font-size: 24px; margin-bottom: 8px; color: var(--text); }
.auth-subtitle { color: var(--text-secondary); margin-bottom: 24px; font-size: 14px; }
#loginForm, #registerForm { display: flex; flex-direction: column; gap: 12px; }
.auth-panel input { padding: 12px 16px; border: 1px solid var(--border); border-radius: 8px; font-size: 15px; background: var(--input-bg); color: var(--text); width: 100%; }
.auth-panel input:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(79,70,229,.15); }
.btn-full { width: 100%; margin-top: 4px; }
.auth-switch { margin-top: 16px; font-size: 14px; color: var(--text-secondary); }
.auth-switch a { color: var(--primary); text-decoration: none; font-weight: 600; }
.auth-switch a:hover { text-decoration: underline; }
.auth-error { background: #fef2f2; border: 1px solid #fecaca; color: #dc2626; padding: 10px 14px; border-radius: 8px; font-size: 13px; margin-top: 12px; }

.hidden { display: none !important; }
.header { display: flex; align-items: center; justify-content: space-between; padding: 12px 0; border-bottom: 2px solid var(--border); margin-bottom: 12px; }
.header h1 { font-size: 22px; font-weight: 700; }
.header-right { display: flex; align-items: center; gap: 8px; }
.user-badge { font-size: 12px; color: var(--text-secondary); background: var(--bg); padding: 4px 10px; border-radius: 6px; }
.project-tabs { display: flex; align-items: center; gap: 6px; overflow-x: auto; padding-bottom: 4px; margin-bottom: 12px; scrollbar-width: none; }
.project-tabs::-webkit-scrollbar { display: none; }
/* Project dropdown */
.project-dropdown { position: relative; flex-shrink: 0; }
.project-selector-btn { display: inline-flex; align-items: center; gap: 6px; padding: 5px 14px; border: 1px solid var(--border); border-radius: 20px; background: var(--card); color: var(--text-secondary); cursor: pointer; font-size: 13px; transition: all .15s; min-width: 96px; justify-content: center; }
.project-selector-btn:hover { border-color: var(--primary); color: var(--primary); }
.project-selector-btn .arrow { display: inline-block; width: 0; height: 0; border-left: 4px solid transparent; border-right: 4px solid transparent; border-top: 5px solid currentColor; transition: transform .15s; }
.project-selector-btn.open .arrow { transform: rotate(180deg); }
.project-dropdown-menu { position: absolute; top: calc(100% + 6px); left: 0; min-width: 180px; background: var(--card); border: 1px solid var(--border); border-radius: 12px; box-shadow: 0 12px 32px rgba(0,0,0,.12); z-index: 9999; overflow: hidden; list-style: none; padding: 4px; }
.project-dropdown-menu li { padding: 8px 14px; border-radius: 8px; cursor: pointer; font-size: 13px; color: var(--text); transition: background .1s; display: flex; align-items: center; gap: 6px; }
.project-dropdown-menu li:hover { background: var(--hover); }
.project-dropdown-menu li.selected { background: var(--primary); color: #fff; }
.project-dropdown-menu li .dot { width: 8px; height: 8px; border-radius: 50%; flex-shrink: 0; }
.tab-list { display: flex; gap: 4px; flex: 1; overflow-x: auto; }
.tab { padding: 6px 14px; border: 1px solid var(--border); border-radius: 20px; background: var(--card); color: var(--text-secondary); cursor: pointer; white-space: nowrap; font-size: 13px; transition: all .15s; }
.tab:hover { border-color: var(--primary); color: var(--primary); }
.tab.active { background: var(--primary); color: #fff; border-color: var(--primary); }
.tab-del { margin-left: 6px; padding: 0 4px; cursor: pointer; color: var(--text-secondary); opacity: 0; transition: opacity .15s, color .15s; font-size: 14px; line-height: 1; user-select: none; }
.tab:hover .tab-del { opacity: .6; }
.tab-del:hover { opacity: 1 !important; color: var(--danger) !important; }
.tab-add { flex-shrink: 0; width: 32px; height: 32px; font-size: 18px; display: flex; align-items: center; justify-content: center; background: var(--card); border: 1px dashed var(--border); border-radius: 50%; color: var(--text-secondary); cursor: pointer; transition: all .15s; }
.tab-add:hover { border-color: var(--primary); color: var(--primary); }
.progress-section { margin-bottom: 14px; display: flex; align-items: center; gap: 10px; }
.progress-bar { flex: 1; height: 8px; background: var(--border); border-radius: 99px; overflow: hidden; }
.progress-fill { height: 100%; background: linear-gradient(90deg, var(--success), #34d399); border-radius: 99px; transition: width .3s ease; }
.progress-text { font-size: 12px; color: var(--text-secondary); white-space: nowrap; }
.filters { display: flex; gap: 6px; margin-bottom: 14px; flex-wrap: wrap; align-items: center; }
.filter-btn { padding: 5px 12px; border: 1px solid var(--border); border-radius: 6px; background: var(--card); color: var(--text-secondary); cursor: pointer; font-size: 13px; transition: all .15s; }
.filter-btn:hover { border-color: var(--primary); }
.filter-btn.active { background: var(--primary); color: #fff; border-color: var(--primary); }
.filter-select { padding: 5px 8px; border: 1px solid var(--border); border-radius: 6px; background: var(--card); color: var(--text-secondary); font-size: 13px; cursor: pointer; margin-left: auto; }
.input-section { display: flex; gap: 8px; margin-bottom: 14px; }
#todoInput { flex: 1; padding: 10px 14px; border: 1px solid var(--border); border-radius: 8px; font-size: 15px; background: var(--input-bg); color: var(--text); transition: border-color .15s; }
#todoInput:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(79,70,229,.15); }
.btn-primary { padding: 10px 20px; background: var(--primary); color: #fff; border: none; border-radius: 8px; cursor: pointer; font-size: 15px; font-weight: 600; transition: background .15s; }
.btn-primary:hover { background: var(--primary-hover); }
.btn-secondary { padding: 8px 14px; background: var(--card); color: var(--text-secondary); border: 1px solid var(--border); border-radius: 6px; cursor: pointer; font-size: 13px; transition: all .15s; }
.btn-secondary:hover { border-color: var(--primary); color: var(--primary); }
.btn-danger-text { padding: 8px 14px; background: none; color: var(--danger); border: 1px solid transparent; border-radius: 6px; cursor: pointer; font-size: 13px; transition: all .15s; }
.btn-danger-text:hover { border-color: var(--danger); }
.icon-btn { background: none; border: 1px solid var(--border); border-radius: 8px; width: 36px; height: 36px; cursor: pointer; display: flex; align-items: center; justify-content: center; color: var(--text-secondary); transition: background .15s, color .15s; }
.icon-btn:hover { background: var(--hover); color: var(--text); }
#todoList { list-style: none; margin-bottom: 14px; }
#todoList li { display: flex; align-items: center; gap: 8px; padding: 10px 12px; background: var(--card); border: 1px solid var(--border); border-radius: 8px; margin-bottom: 6px; transition: all .15s; }
#todoList li:hover { border-color: #c7d2fe; box-shadow: var(--shadow); }
#todoList li.done { opacity: .55; }
#todoList li.done .todo-text { text-decoration: line-through; color: var(--text-secondary); }
#todoList li[data-priority="high"] { border-left: 3px solid #ef4444; }
#todoList li[data-priority="medium"] { border-left: 3px solid #f59e0b; }
#todoList li[data-priority="low"] { border-left: 3px solid #10b981; }
#todoList li.done-section { background: none; border: none; padding: 8px 12px; color: var(--text-secondary); font-size: 12px; }
#todoList li[data-priority="none"] { border-left: 3px solid transparent; }
#todoList input[type="checkbox"] { width: 18px; height: 18px; accent-color: var(--primary); cursor: pointer; flex-shrink: 0; }
.priority-dot { font-size: 14px; cursor: pointer; flex-shrink: 0; user-select: none; }
.todo-text { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: 14px; }
.arrow-btn { background: none; border: none; color: var(--text-secondary); cursor: pointer; font-size: 12px; padding: 2px; opacity: .5; transition: opacity .15s; flex-shrink: 0; }
.arrow-btn:hover { opacity: 1; }
.delete-btn { background: none; border: none; color: var(--danger); cursor: pointer; font-size: 18px; padding: 2px 6px; opacity: .5; transition: opacity .15s; flex-shrink: 0; }
.delete-btn:hover { opacity: 1; }
.empty-state { text-align: center; padding: 40px 20px; color: var(--text-secondary); font-size: 14px; }
.actions { display: flex; gap: 8px; flex-wrap: wrap; }
.toast { position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%) translateY(10px); background: var(--text); color: #fff; padding: 10px 18px; border-radius: 8px; font-size: 13px; opacity: 0; pointer-events: none; transition: all .2s ease; max-width: 90%; text-align: center; z-index: 100; }
.toast.visible { opacity: 1; transform: translateX(-50%) translateY(0); }
.modal-overlay { position: fixed; inset: 0; background: rgba(0,0,0,.4); display: flex; align-items: center; justify-content: center; z-index: 200; }
.modal { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 24px; min-width: 320px; max-width: 90vw; box-shadow: 0 8px 32px rgba(0,0,0,.2); }
.modal h2 { margin-bottom: 16px; font-size: 18px; color: var(--text); }
.template-item { padding: 12px; margin-bottom: 8px; border: 1px solid var(--border); border-radius: 8px; cursor: pointer; transition: all .15s; }
.template-item:hover { border-color: var(--primary); background: var(--hover); }
.template-item strong { color: var(--text); }
.template-item small { color: var(--text-secondary); }
.modal .btn-secondary { margin-top: 12px; }
.template-list { max-height: 45vh; overflow-y: auto; margin: 12px 0; }
.tmpl-divider { display: flex; align-items: center; gap: 8px; margin: 14px 0 8px; color: var(--text-secondary); font-size: 12px; text-transform: uppercase; letter-spacing: .04em; }
.tmpl-divider::before, .tmpl-divider::after { content: ""; height: 1px; background: var(--border); flex: 1; }
.template-empty { padding: 10px; color: var(--text-secondary); font-size: 13px; }
.tmpl-actions { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 12px; }
.manage-item { cursor: default; }
.manage-item .tmpl-title { display: flex; align-items: baseline; gap: 6px; }
.manage-item .tmpl-edit { margin-top: 8px; display: flex; gap: 8px; }
.manage-item .tmpl-edit button { font-size: 12px; padding: 4px 10px; border: 1px solid var(--border); background: var(--input-bg); color: var(--text); border-radius: 6px; cursor: pointer; }
.manage-item .tmpl-edit button:hover { border-color: var(--primary); }
.tmpl-form label { display: block; font-size: 12px; color: var(--text-secondary); margin: 10px 0 4px; }
.tmpl-form input, .tmpl-form textarea { width: 100%; box-sizing: border-box; padding: 8px 10px; border: 1px solid var(--border); border-radius: 8px; background: var(--input-bg); color: var(--text); font-family: inherit; font-size: 14px; }
.tmpl-form textarea { resize: vertical; min-height: 120px; }
body.dark-mode { --bg: #0f172a; --card: #1e293b; --border: #334155; --text: #e2e8f0; --text-secondary: #94a3b8; --input-bg: #1e293b; --hover: #334155; }
body.dark-mode .header { border-bottom-color: var(--border) !important; }
body.dark-mode .auth-panel { background: var(--card); }
body.dark-mode .modal { background: var(--card); border-color: var(--border); }
.loading-spinner { display: inline-block; width: 20px; height: 20px; border: 2px solid var(--border); border-top-color: var(--primary); border-radius: 50%; animation: spin .6s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
@media (max-width: 480px) { body { padding: 8px; } .project-tabs { gap: 4px; } .tab { padding: 5px 10px; font-size: 12px; } #todoList li { padding: 8px 10px; gap: 6px; } .auth-panel { padding: 24px; } .header h1 { font-size: 18px; } }

.project-selector { width: auto; min-width: 120px; max-width: 200px; padding: 6px 8px; border: 1px solid var(--border); border-radius: 8px; background: var(--bg); color: var(--text); font-size: 13px; cursor: pointer; flex-shrink: 0; }
.project-selector:focus { outline: none; border-color: var(--primary); }

.tab-del-always { visibility: visible; }
.project-dropdown-menu li .tab-del { opacity: .45; cursor: pointer; transition: opacity .15s, color .15s; font-size: 14px; margin-left: auto; padding: 0 2px; flex-shrink: 0; user-select: none; }
.project-dropdown-menu li .tab-del:hover { opacity: 1 !important; color: var(--danger) !important; }