feat: 优化 landing page 字体样式和功能介绍

- 主标题使用更优雅的字体样式和柔和阴影
- 副标题添加半透明背景提升可读性
- 新增四个功能模块的详细介绍卡片（纪念日/提醒/AI/便签）
- 使用毛玻璃效果增强视觉层次
- 响应式布局适配不同屏幕

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/pages/LandingPage.tsx

@@ -1,5 +1,5 @@
 import { useEffect, useRef } from 'react';
-import { Button, Container, Title, Text, Group, Stack } from '@mantine/core';
+import { Button, Container, Title, Text, Group, Stack, Paper, ThemeIcon, SimpleGrid, Box } from '@mantine/core';
 import { useNavigate } from 'react-router-dom';
 import iconUrl from '../assets/icon.png';
 
@@ -48,7 +48,7 @@ function ZenBackground() {
     let strokes: InkStroke[] = [];
     let time = 0;
     let lastStrokeTime = 0;
-    const strokeInterval = 30; // 每隔一段时间生成新笔触
+    const strokeInterval = 30;
 
     // 生成随机笔触
     const createStroke = (): InkStroke | null => {
@@ -65,7 +65,7 @@ function ZenBackground() {
         speed: random(0.4, 1.0),
         inkAlpha: random(10, 30),
         baseWeight: random(0.3, 1.5),
-        maxLength: random(30, 90),  // 缩短笔触长度，加快消失
+        maxLength: random(30, 90),
         currentLength: 0,
         complete: false,
       };
@@ -77,7 +77,6 @@ function ZenBackground() {
       for (let i = 0; i < 8; i++) {
         const stroke = createStroke();
         if (stroke) {
-          // 随机偏移起始位置
           stroke.currentLength = random(0, stroke.maxLength * 0.5);
           strokes.push(stroke);
         }
@@ -93,7 +92,7 @@ function ZenBackground() {
     const animate = () => {
       time += 0.008;
 
-      // 快速淡出背景 - 让水墨痕迹更快消失
+      // 快速淡出背景
       if (Math.floor(time * 125) % 3 === 0) {
         ctx.fillStyle = 'rgba(250, 249, 247, 0.12)';
         ctx.fillRect(0, 0, canvas.width, canvas.height);
@@ -102,9 +101,7 @@ function ZenBackground() {
       // 定期生成新笔触
       if (time - lastStrokeTime > strokeInterval * 0.01) {
         lastStrokeTime = time;
-        // 移除已完成太久的笔触
         strokes = strokes.filter(s => !s.complete || s.currentLength < s.maxLength);
-        // 添加新笔触（随机数量）
         const newCount = Math.floor(random(0, 2));
         for (let i = 0; i < newCount; i++) {
           const stroke = createStroke();
@@ -116,18 +113,15 @@ function ZenBackground() {
       for (const stroke of strokes) {
         if (stroke.complete) continue;
 
-        // 噪声驱动
         const n = noise(stroke.x, stroke.y, time);
         stroke.angle += (n - 0.5) * 0.12;
 
-        // 呼吸感 - 更柔和
         const breath = Math.sin(time * 1.5 + stroke.x * 0.01) * 0.25;
         const currentSpeed = stroke.speed * (1 + breath * 0.2);
 
         stroke.x += Math.cos(stroke.angle) * currentSpeed;
         stroke.y += Math.sin(stroke.angle) * currentSpeed;
 
-        // 笔触粗细 - 模拟提按
         const progress = stroke.currentLength / stroke.maxLength;
         const weightVar = Math.sin(progress * Math.PI) * 1.0;
         const weight = Math.max(0.2, stroke.baseWeight + weightVar);
@@ -143,16 +137,13 @@ function ZenBackground() {
           stroke.complete = true;
         }
 
-        // 绘制 - 水墨晕染效果
         if (stroke.points.length > 1) {
           for (let i = 1; i < stroke.points.length; i++) {
             const p1 = stroke.points[i - 1];
             const p2 = stroke.points[i];
-            // 渐变透明度
             const alpha = stroke.inkAlpha * (1 - i / stroke.points.length * 0.4) / 100;
             const size = p2.weight * random(0.8, 1.2);
 
-            // 绘制柔和的笔触
             ctx.beginPath();
             ctx.moveTo(p1.x, p1.y);
             ctx.lineTo(p2.x, p2.y);
@@ -161,7 +152,6 @@ function ZenBackground() {
             ctx.lineCap = 'round';
             ctx.stroke();
 
-            // 添加淡淡的墨点晕染
             if (random(0, 1) < 0.3) {
               ctx.beginPath();
               ctx.arc(p2.x, p2.y, size * random(0.5, 1.5), 0, Math.PI * 2);
@@ -172,12 +162,12 @@ function ZenBackground() {
         }
       }
 
-      // 绘制圆相（Ensō）- 缓慢呼吸
+      // 绘制圆相（Ensō）
       const centerX = canvas.width / 2;
       const centerY = canvas.height / 2;
       const breathScale = 1 + Math.sin(time * 0.3) * 0.015;
       const radius = Math.min(canvas.width, canvas.height) * 0.18 * breathScale;
-      const gap = Math.PI * 0.18; // 开口
+      const gap = Math.PI * 0.18;
       const startAngle = -Math.PI / 2 + time * 0.05;
 
       ctx.beginPath();
@@ -224,6 +214,40 @@ function ZenBackground() {
   );
 }
 
+// 功能特性卡片
+function FeatureCard({
+  icon,
+  title,
+  description,
+}: {
+  icon: string;
+  title: string;
+  description: string;
+}) {
+  return (
+    <Paper
+      p="lg"
+      radius="sm"
+      style={{
+        background: 'rgba(255, 255, 255, 0.6)',
+        backdropFilter: 'blur(10px)',
+        border: '1px solid rgba(0, 0, 0, 0.05)',
+        height: '100%',
+      }}
+    >
+      <Stack gap="sm">
+        <Text size="xl" fw={300} style={{ letterSpacing: '0.1em' }}>{icon}</Text>
+        <Text size="md" fw={500} style={{ letterSpacing: '0.08em', color: '#1a1a1a' }}>
+          {title}
+        </Text>
+        <Text size="sm" c="#666" style={{ lineHeight: 1.8, fontWeight: 300 }}>
+          {description}
+        </Text>
+      </Stack>
+    </Paper>
+  );
+}
+
 export function LandingPage() {
   const navigate = useNavigate();
 
@@ -285,75 +309,95 @@ export function LandingPage() {
       </svg>
 
       <Container
-        size="sm"
+        size="lg"
         style={{
           position: 'relative',
           zIndex: 1,
           minHeight: '100vh',
           display: 'flex',
           flexDirection: 'column',
-          justifyContent: 'center',
-          alignItems: 'center',
-          textAlign: 'center',
-          padding: '2rem',
+          padding: '3rem 1rem',
+        }}
+      >
+        {/* Hero 区域 */}
+        <Box
+          style={{
+            display: 'flex',
+            flexDirection: 'column',
+            alignItems: 'center',
+            textAlign: 'center',
+            paddingTop: 'min(15vh, 120px)',
+            paddingBottom: 'min(10vh, 80px)',
           }}
         >
-        <Stack align="center" gap="lg">
           {/* 产品图标 */}
           <div
             style={{
-              width: 90,
-              height: 90,
+              width: 100,
+              height: 100,
               borderRadius: '50%',
-              background: 'rgba(26, 26, 26, 0.03)',
+              background: 'rgba(26, 26, 26, 0.04)',
               display: 'flex',
               alignItems: 'center',
               justifyContent: 'center',
-              marginBottom: '0.5rem',
+              marginBottom: '2rem',
             }}
           >
             <img
               src={iconUrl}
               alt="掐日子"
               style={{
-                width: 60,
-                height: 60,
+                width: 65,
+                height: 65,
                 borderRadius: '50%',
               }}
             />
           </div>
 
+          {/* 主标题 */}
           <Title
             order={1}
             style={{
-              fontWeight: 300,
-              fontSize: 'clamp(2.2rem, 7vw, 3.2rem)',
-              letterSpacing: '0.25em',
+              fontWeight: 200,
+              fontSize: 'clamp(2.5rem, 8vw, 4rem)',
+              letterSpacing: '0.2em',
               color: '#1a1a1a',
-              fontFamily: 'Noto Serif SC, serif',
+              fontFamily: 'Noto Serif SC, Georgia, serif',
+              marginBottom: '0.5rem',
+              textShadow: '0 2px 10px rgba(0,0,0,0.03)',
             }}
           >
             掐日子
           </Title>
 
+          {/* 副标题 - 增强可读性 */}
           <Text
-            size="sm"
+            size="lg"
             style={{
-              letterSpacing: '0.35em',
-              color: '#888',
-              fontWeight: 300,
+              fontWeight: 400,
+              fontSize: 'clamp(1rem, 2.5vw, 1.25rem)',
+              letterSpacing: '0.3em',
+              color: '#333',
+              fontFamily: 'Noto Serif SC, serif',
+              marginBottom: '1rem',
+              padding: '0.5rem 1.5rem',
+              background: 'rgba(255, 255, 255, 0.7)',
+              backdropFilter: 'blur(4px)',
+              borderRadius: '2px',
             }}
           >
             AI 纪念日 · 提醒
           </Text>
 
+          {/* 描述文案 */}
           <Text
-            size="xs"
+            size="sm"
             style={{
-              color: '#999',
-              maxWidth: 300,
-              lineHeight: 1.9,
+              color: '#666',
+              maxWidth: 360,
+              lineHeight: 2,
               fontWeight: 300,
+              fontSize: '0.9rem',
             }}
           >
             轻便、灵活的倒数日和提醒应用
@@ -361,57 +405,70 @@ export function LandingPage() {
             让每一个重要的日子都被铭记
           </Text>
 
-          <Group gap="md" mt="lg">
+          <Group gap="md" mt="xl">
             <Button
-              size="sm"
+              size="md"
               onClick={() => navigate('/login')}
               style={{
                 background: '#1a1a1a',
                 border: '1px solid #1a1a1a',
-                padding: '0 2rem',
+                padding: '0.75rem 2.5rem',
                 fontWeight: 400,
-                letterSpacing: '0.15em',
+                letterSpacing: '0.2em',
                 borderRadius: 2,
+                fontSize: '0.85rem',
               }}
             >
               登录
             </Button>
             <Button
-              size="sm"
+              size="md"
               variant="outline"
               onClick={() => navigate('/register')}
               style={{
-                borderColor: '#ccc',
+                borderColor: '#999',
                 color: '#1a1a1a',
-                padding: '0 2rem',
+                padding: '0.75rem 2.5rem',
                 fontWeight: 400,
-                letterSpacing: '0.15em',
+                letterSpacing: '0.2em',
                 borderRadius: 2,
+                fontSize: '0.85rem',
               }}
             >
               注册
             </Button>
           </Group>
+        </Box>
 
-          <Group gap={40} mt={50} style={{ opacity: 0.7 }}>
-            <Stack gap={3} align="center">
-              <Text size="xs" fw={300} c="#444">◯</Text>
-              <Text size="xs" c="#666" style={{ letterSpacing: '0.1em' }}>纪念日</Text>
-            </Stack>
-            <Stack gap={3} align="center">
-              <Text size="xs" fw={300} c="#444">◎</Text>
-              <Text size="xs" c="#666" style={{ letterSpacing: '0.1em' }}>提醒</Text>
-            </Stack>
-            <Stack gap={3} align="center">
-              <Text size="xs" fw={300} c="#444">◇</Text>
-              <Text size="xs" c="#666" style={{ letterSpacing: '0.1em' }}>AI</Text>
-            </Stack>
-            <Stack gap={3} align="center">
-              <Text size="xs" fw={300} c="#444">▫</Text>
-              <Text size="xs" c="#666" style={{ letterSpacing: '0.1em' }}>便签</Text>
-            </Stack>
-          </Group>
-        </Stack>
+        {/* 功能介绍区域 */}
+        <Box
+          style={{
+            paddingBottom: 'min(15vh, 120px)',
+          }}
+        >
+          <SimpleGrid cols={{ base: 1, sm: 2, md: 4 }} spacing="lg">
+            <FeatureCard
+              icon="◯"
+              title="纪念日"
+              description="记录生日、结婚纪念日等重要日子。支持农历日期，自动计算倒数日。轻松掌握还有多少天到来，让每个值得纪念的日子都不被遗忘。"
+            />
+            <FeatureCard
+              icon="◎"
+              title="提醒"
+              description="设置一次性或重复提醒事项。支持多种提前提醒时间：准时、提前5/15分钟、1小时、1天。重要事项准时送达，不错过任何关键节点。"
+            />
+            <FeatureCard
+              icon="◇"
+              title="AI 智能"
+              description="AI 智能解析自然语言，快速创建事件。只需输入「生日是3月15日」，AI 自动识别日期、类型和重复规则。创建提醒从未如此简单。"
+            />
+            <FeatureCard
+              icon="▫"
+              title="便签"
+              description="支持 Markdown 的个人笔记空间。随时记录想法、灵感或待办事项。与纪念日和提醒功能无缝配合，打造完整的个人时间管理工具。"
+            />
+          </SimpleGrid>
+        </Box>
       </Container>
     </div>
   );