* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #4A90D9;
    --primary-light: #6BA3E0;
    --primary-dark: #3A7BC8;
    --bg: #F5F7FA;
    --card: #FFFFFF;
    --text: #2C3E50;
    --text-light: #7F8C8D;
    --border: #E8ECF0;
    --success: #27AE60;
    --warning: #F39C12;
    --danger: #E74C3C;
    --shadow: 0 2px 12px rgba(0,0,0,0.08);
    --radius: 12px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    overflow: hidden;
}

#app {
    max-width: 480px;
    margin: 0 auto;
    height: 100vh;
    display: flex;
    flex-direction: column;
    background: var(--bg);
}

.login-page {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 20px;
}

.login-container {
    background: var(--card);
    border-radius: 20px;
    padding: 32px 24px;
    width: 100%;
    max-width: 340px;
    text-align: center;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
}

.login-avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    overflow: hidden;
    margin: 0 auto 16px;
    border: 3px solid var(--primary);
}

.login-avatar img { width: 100%; height: 100%; object-fit: cover; }

.login-container h1 { font-size: 22px; margin-bottom: 4px; }
.login-container > p { font-size: 13px; color: var(--text-light); margin-bottom: 24px; }

.login-form { display: flex; flex-direction: column; gap: 12px; }
.login-form input { padding: 12px 16px; border: 1px solid var(--border); border-radius: 10px; font-size: 14px; outline: none; transition: border-color 0.2s; }
.login-form input:focus { border-color: var(--primary); }

.btn-primary { padding: 12px; border: none; border-radius: 10px; background: var(--primary); color: white; font-size: 15px; font-weight: 500; cursor: pointer; transition: background 0.2s; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-secondary { padding: 10px; border: none; border-radius: 10px; background: var(--bg); color: var(--text-light); font-size: 13px; cursor: pointer; }
.btn-danger { padding: 12px; border: none; border-radius: 10px; background: var(--danger); color: white; font-size: 14px; cursor: pointer; width: 100%; }
.btn-small { padding: 6px 12px; border: 1px solid var(--border); border-radius: 6px; background: var(--card); font-size: 12px; cursor: pointer; }

.login-tip { margin-top: 12px; font-size: 12px; color: var(--danger); min-height: 18px; }

.main-app { height: 100vh; display: flex; flex-direction: column; }

.tab-bar { display: flex; background: var(--card); border-top: 1px solid var(--border); padding: 6px 0; order: 1; position: fixed; bottom: 0; left: 0; right: 0; max-width: 480px; margin: 0 auto; z-index: 100; }
.tab-item { flex: 1; display: flex; flex-direction: column; align-items: center; gap: 3px; border: none; background: none; color: var(--text-light); font-size: 10px; padding: 4px; cursor: pointer; transition: color 0.2s; }
.tab-item.active { color: var(--primary); }
.tab-item svg { width: 22px; height: 22px; }

.page { display: none; flex: 1; flex-direction: column; overflow: hidden; padding-bottom: 65px; }
.page.active { display: flex; }

.chat-header { background: var(--card); padding: 16px 20px; display: flex; align-items: center; gap: 12px; border-bottom: 1px solid var(--border); }
.chat-header-avatar { width: 44px; height: 44px; border-radius: 50%; overflow: hidden; border: 2px solid var(--primary); flex-shrink: 0; }
.chat-header-avatar img { width: 100%; height: 100%; object-fit: cover; }
.chat-header h1 { font-size: 17px; font-weight: 600; }
.chat-header p { font-size: 11px; color: var(--text-light); margin-top: 2px; }

.chat-messages { flex: 1; overflow-y: auto; padding: 16px; display: flex; flex-direction: column; gap: 16px; }
.message { display: flex; gap: 10px; max-width: 85%; animation: fadeIn 0.3s ease; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }
.message.bot { align-self: flex-start; }
.message.user { align-self: flex-end; flex-direction: row-reverse; }

.avatar { width: 36px; height: 36px; border-radius: 50%; overflow: hidden; display: flex; align-items: center; justify-content: center; font-size: 18px; flex-shrink: 0; background: var(--card); box-shadow: var(--shadow); }
.avatar img { width: 100%; height: 100%; object-fit: cover; }

.bubble { padding: 12px 16px; border-radius: 16px; font-size: 14px; line-height: 1.6; word-break: break-word; }
.message.bot .bubble { background: var(--card); box-shadow: var(--shadow); border-top-left-radius: 4px; }
.message.user .bubble { background: var(--primary); color: white; border-top-right-radius: 4px; }

.chat-input-area { display: flex; gap: 8px; padding: 12px 16px; background: var(--card); border-top: 1px solid var(--border); }
.chat-input-area input { flex: 1; padding: 10px 16px; border: 1px solid var(--border); border-radius: 20px; font-size: 14px; outline: none; transition: border-color 0.2s; }
.chat-input-area input:focus { border-color: var(--primary); }
#sendBtn { width: 40px; height: 40px; border-radius: 50%; border: none; background: var(--primary); color: white; display: flex; align-items: center; justify-content: center; cursor: pointer; }
#sendBtn:hover { background: var(--primary-dark); }

.page-header { background: var(--card); padding: 20px; border-bottom: 1px solid var(--border); }
.page-header h1 { font-size: 18px; font-weight: 600; }
.page-header p { font-size: 12px; color: var(--text-light); margin-top: 4px; }

.todo-input-area { display: flex; gap: 8px; padding: 12px 16px; background: var(--card); border-bottom: 1px solid var(--border); }
.todo-input-area input { flex: 1; padding: 10px 12px; border: 1px solid var(--border); border-radius: 8px; font-size: 14px; outline: none; }
.todo-input-area input:focus { border-color: var(--primary); }
.todo-input-area select { padding: 8px; border: 1px solid var(--border); border-radius: 8px; font-size: 12px; outline: none; background: var(--card); }
.todo-input-area button, .habit-add-area button { padding: 8px 16px; border: none; border-radius: 8px; background: var(--primary); color: white; font-size: 14px; cursor: pointer; }

.todo-filters { display: flex; gap: 8px; padding: 12px 16px; }
.filter-btn { padding: 6px 14px; border: 1px solid var(--border); border-radius: 16px; background: var(--card); font-size: 12px; cursor: pointer; transition: all 0.2s; }
.filter-btn.active { background: var(--primary); color: white; border-color: var(--primary); }

.todo-list { flex: 1; overflow-y: auto; padding: 0 16px; }
.todo-item { display: flex; align-items: center; gap: 12px; padding: 14px 16px; background: var(--card); border-radius: var(--radius); margin-bottom: 8px; box-shadow: var(--shadow); animation: fadeIn 0.3s ease; }
.todo-item.completed .todo-text { text-decoration: line-through; color: var(--text-light); }
.todo-checkbox { width: 22px; height: 22px; border: 2px solid var(--border); border-radius: 50%; cursor: pointer; display: flex; align-items: center; justify-content: center; transition: all 0.2s; flex-shrink: 0; }
.todo-item.completed .todo-checkbox { background: var(--success); border-color: var(--success); }
.todo-item.completed .todo-checkbox::after { content: "\2713"; color: white; font-size: 12px; }
.todo-text { flex: 1; font-size: 14px; }
.todo-priority { font-size: 10px; padding: 2px 8px; border-radius: 10px; font-weight: 500; }
.todo-priority.important { background: #FEF3E2; color: var(--warning); }
.todo-priority.urgent { background: #FDEDEC; color: var(--danger); }
.todo-delete { width: 24px; height: 24px; border: none; background: none; color: var(--text-light); cursor: pointer; font-size: 16px; display: flex; align-items: center; justify-content: center; border-radius: 50%; }
.todo-delete:hover { background: #FDEDEC; color: var(--danger); }
.todo-stats { padding: 12px 16px; text-align: center; font-size: 12px; color: var(--text-light); }

.habit-add-area { display: flex; gap: 8px; padding: 12px 16px; background: var(--card); border-bottom: 1px solid var(--border); }
.habit-add-area input:first-child { flex: 1; }
.habit-add-area input { padding: 10px 12px; border: 1px solid var(--border); border-radius: 8px; font-size: 14px; outline: none; }
.habit-add-area input:focus { border-color: var(--primary); }
#habitIcon { width: 50px; text-align: center; }

.habit-list { flex: 1; overflow-y: auto; padding: 16px; }
.habit-item { display: flex; align-items: center; gap: 12px; padding: 16px; background: var(--card); border-radius: var(--radius); margin-bottom: 10px; box-shadow: var(--shadow); animation: fadeIn 0.3s ease; }
.habit-icon { font-size: 24px; width: 40px; height: 40px; display: flex; align-items: center; justify-content: center; background: var(--bg); border-radius: 10px; }
.habit-info { flex: 1; }
.habit-name { font-size: 14px; font-weight: 500; }
.habit-streak { font-size: 11px; color: var(--text-light); margin-top: 2px; }
.habit-check { width: 36px; height: 36px; border-radius: 50%; border: 2px solid var(--border); display: flex; align-items: center; justify-content: center; cursor: pointer; transition: all 0.3s; font-size: 16px; }
.habit-check.checked { background: var(--success); border-color: var(--success); color: white; transform: scale(1.1); }
.habit-delete { width: 24px; height: 24px; border: none; background: none; color: var(--text-light); cursor: pointer; font-size: 14px; border-radius: 50%; display: flex; align-items: center; justify-content: center; }
.habit-delete:hover { background: #FDEDEC; color: var(--danger); }
.habit-stats { padding: 16px; text-align: center; font-size: 13px; color: var(--text-light); }

.settings-list { flex: 1; overflow-y: auto; padding: 16px; }
.settings-section { background: var(--card); border-radius: var(--radius); padding: 16px; margin-bottom: 16px; box-shadow: var(--shadow); }
.settings-section h3 { font-size: 14px; font-weight: 600; margin-bottom: 12px; color: var(--text); }
.settings-item { display: flex; flex-direction: column; gap: 10px; }
.settings-item label { font-size: 13px; color: var(--text-light); }
.settings-item input { padding: 10px 12px; border: 1px solid var(--border); border-radius: 8px; font-size: 14px; outline: none; }
.settings-item input:focus { border-color: var(--primary); }
.settings-input-group { display: flex; gap: 8px; }
.settings-input-group input { flex: 1; }
.settings-hint { font-size: 11px; color: var(--text-light); }

.typing-indicator { display: flex; gap: 4px; padding: 8px 0; }
.typing-indicator span { width: 8px; height: 8px; background: var(--text-light); border-radius: 50%; animation: typing 1.4s infinite; }
.typing-indicator span:nth-child(2) { animation-delay: 0.2s; }
.typing-indicator span:nth-child(3) { animation-delay: 0.4s; }
@keyframes typing { 0%, 60%, 100% { transform: translateY(0); opacity: 0.4; } 30% { transform: translateY(-6px); opacity: 1; } }

::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }

@media (max-width: 480px) { #app { max-width: 100%; } .tab-bar { max-width: 100%; } }