File size: 38,041 Bytes
b5d4a34
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>AMC8 中文学习平台 - 历年真题与解析</title>
    <script src="https://cdn.tailwindcss.com"></script>
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/css/all.min.css">
    <style>
        /* 自定义CSS补充Tailwind */
        .problem-card {
            transition: all 0.3s ease;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        }
        .problem-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 15px rgba(0, 0, 0, 0.1);
        }
        .solution-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease;
        }
        .solution-content.expanded {
            max-height: 1000px;
        }
        /* 兼容性处理 */
        .grid-fallback {
            display: flex;
            flex-wrap: wrap;
        }
        @supports (display: grid) {
            .grid-fallback {
                display: grid;
            }
        }
        /* 打印样式 */
        @media print {
            .no-print {
                display: none !important;
            }
            body {
                padding: 0;
                margin: 0;
                font-size: 12pt;
            }
            .problem-card {
                page-break-inside: avoid;
                box-shadow: none;
                border: 1px solid #ddd;
            }
        }
    </style>
</head>
<body class="bg-gray-50 font-sans antialiased">
    <!-- 导航栏 -->
    <nav class="bg-blue-600 text-white shadow-lg no-print">
        <div class="container mx-auto px-4 py-3">
            <div class="flex justify-between items-center">
                <div class="flex items-center space-x-4">
                    <a href="#" class="flex items-center">
                        <i class="fas fa-square-root-alt text-2xl mr-2"></i>
                        <span class="font-bold text-xl">AMC8 学习平台</span>
                    </a>
                </div>
                <div class="hidden md:flex items-center space-x-6">
                    <a href="#problems" class="hover:text-blue-200 transition">历年真题</a>
                    <a href="#features" class="hover:text-blue-200 transition">学习资源</a>
                    <a href="#about" class="hover:text-blue-200 transition">关于AMC8</a>
                    <a href="#contact" class="hover:text-blue-200 transition">联系我们</a>
                </div>
                <div class="md:hidden">
                    <button id="mobile-menu-button" class="text-white focus:outline-none">
                        <i class="fas fa-bars text-2xl"></i>
                    </button>
                </div>
            </div>
            <!-- 移动端菜单 -->
            <div id="mobile-menu" class="hidden md:hidden mt-2 pb-2">
                <a href="#problems" class="block py-2 hover:bg-blue-500 px-2 rounded">历年真题</a>
                <a href="#features" class="block py-2 hover:bg-blue-500 px-2 rounded">学习资源</a>
                <a href="#about" class="block py-2 hover:bg-blue-500 px-2 rounded">关于AMC8</a>
                <a href="#contact" class="block py-2 hover:bg-blue-500 px-2 rounded">联系我们</a>
            </div>
        </div>
    </nav>

    <!-- 英雄区域 -->
    <header class="bg-gradient-to-r from-blue-700 to-blue-500 text-white py-16">
        <div class="container mx-auto px-4 text-center">
            <h1 class="text-4xl md:text-5xl font-bold mb-4">AMC8 中文学习平台</h1>
            <p class="text-xl md:text-2xl mb-8">提供2000-2023年完整真题与详细解析</p>
            <div class="flex flex-col md:flex-row justify-center gap-4">
                <a href="#problems" class="bg-white text-blue-600 font-bold py-3 px-6 rounded-lg hover:bg-blue-50 transition duration-300">
                    <i class="fas fa-book-open mr-2"></i>开始学习
                </a>
                <a href="#features" class="bg-transparent border-2 border-white text-white font-bold py-3 px-6 rounded-lg hover:bg-blue-600 transition duration-300">
                    <i class="fas fa-star mr-2"></i>特色功能
                </a>
            </div>
        </div>
    </header>

    <!-- 关于AMC8 -->
    <section id="about" class="py-12 bg-white">
        <div class="container mx-auto px-4">
            <h2 class="text-3xl font-bold text-center mb-12 text-gray-800">关于 AMC8 竞赛</h2>
            <div class="grid grid-cols-1 md:grid-cols-3 gap-8">
                <div class="bg-blue-50 p-6 rounded-lg shadow-md">
                    <div class="text-blue-600 mb-4">
                        <i class="fas fa-info-circle text-4xl"></i>
                    </div>
                    <h3 class="text-xl font-semibold mb-3 text-gray-800">竞赛简介</h3>
                    <p class="text-gray-600">AMC8是美国数学竞赛系列中的初中级别比赛,面向8年级及以下学生,旨在激发学生对数学的兴趣和才能。</p>
                </div>
                <div class="bg-blue-50 p-6 rounded-lg shadow-md">
                    <div class="text-blue-600 mb-4">
                        <i class="fas fa-calendar-alt text-4xl"></i>
                    </div>
                    <h3 class="text-xl font-semibold mb-3 text-gray-800">考试形式</h3>
                    <p class="text-gray-600">40分钟完成25道选择题,满分25分。题目涵盖算术、代数、几何、数论和概率等数学领域。</p>
                </div>
                <div class="bg-blue-50 p-6 rounded-lg shadow-md">
                    <div class="text-blue-600 mb-4">
                        <i class="fas fa-trophy text-4xl"></i>
                    </div>
                    <h3 class="text-xl font-semibold mb-3 text-gray-800">奖项设置</h3>
                    <p class="text-gray-600">荣誉证书(15分以上)、成就证书(18分以上)、卓越证书(21分以上)和满分奖(25分)。</p>
                </div>
            </div>
        </div>
    </section>

    <!-- 历年真题 -->
    <section id="problems" class="py-12 bg-gray-50">
        <div class="container mx-auto px-4">
            <h2 class="text-3xl font-bold text-center mb-8 text-gray-800">历年真题与解析</h2>
            
            <!-- 年份筛选 -->
            <div class="mb-8 bg-white p-4 rounded-lg shadow-md no-print">
                <h3 class="text-xl font-semibold mb-4 text-gray-700">筛选题目</h3>
                <div class="flex flex-col md:flex-row gap-4">
                    <div class="flex-1">
                        <label for="year-select" class="block text-sm font-medium text-gray-700 mb-1">选择年份</label>
                        <select id="year-select" class="w-full p-2 border border-gray-300 rounded-md focus:ring-blue-500 focus:border-blue-500">
                            <option value="all">全部年份</option>
                            <option value="2023">2023年</option>
                            <option value="2022">2022年</option>
                            <option value="2021">2021年</option>
                            <option value="2020">2020年</option>
                            <option value="2019">2019年</option>
                        </select>
                    </div>
                    <div class="flex-1">
                        <label for="difficulty-select" class="block text-sm font-medium text-gray-700 mb-1">难度级别</label>
                        <select id="difficulty-select" class="w-full p-2 border border-gray-300 rounded-md focus:ring-blue-500 focus:border-blue-500">
                            <option value="all">全部难度</option>
                            <option value="easy">简单</option>
                            <option value="medium">中等</option>
                            <option value="hard">困难</option>
                        </select>
                    </div>
                    <div class="flex-1">
                        <label for="topic-select" class="block text-sm font-medium text-gray-700 mb-1">题目类型</label>
                        <select id="topic-select" class="w-full p-2 border border-gray-300 rounded-md focus:ring-blue-500 focus:border-blue-500">
                            <option value="all">全部类型</option>
                            <option value="algebra">代数</option>
                            <option value="geometry">几何</option>
                            <option value="number-theory">数论</option>
                            <option value="combinatorics">组合数学</option>
                            <option value="probability">概率</option>
                        </select>
                    </div>
                </div>
            </div>
            
            <!-- 题目列表 -->
            <div class="grid-fallback grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
                <!-- 题目卡片1 -->
                <div class="problem-card bg-white rounded-lg overflow-hidden shadow-md" data-year="2023" data-difficulty="medium" data-topic="geometry">
                    <div class="p-6">
                        <div class="flex justify-between items-start mb-2">
                            <span class="bg-blue-100 text-blue-800 text-xs font-semibold px-2.5 py-0.5 rounded">2023年</span>
                            <span class="bg-green-100 text-green-800 text-xs font-semibold px-2.5 py-0.5 rounded">几何</span>
                        </div>
                        <h3 class="text-xl font-bold text-gray-800 mb-3">第15题</h3>
                        <p class="text-gray-600 mb-4">一个正方形的边长为4,四个角上各剪去一个边长为1的小正方形,然后将剩余部分折叠成一个无盖的盒子。这个盒子的体积是多少?</p>
                        <div class="flex flex-wrap gap-2 mb-4">
                            <span class="bg-gray-100 text-gray-800 text-xs font-medium px-2.5 py-0.5 rounded">中等难度</span>
                            <span class="bg-purple-100 text-purple-800 text-xs font-medium px-2.5 py-0.5 rounded">体积计算</span>
                        </div>
                        <button class="solution-toggle-btn w-full bg-blue-600 hover:bg-blue-700 text-white font-medium py-2 px-4 rounded transition duration-300 flex items-center justify-center">
                            <i class="fas fa-lightbulb mr-2"></i>查看解析
                        </button>
                    </div>
                    <div class="solution-content bg-gray-50 px-6 pt-0 pb-6">
                        <div class="border-t border-gray-200 pt-4">
                            <h4 class="font-semibold text-gray-800 mb-2">解析:</h4>
                            <p class="text-gray-700 mb-3">1. 原正方形边长为4,剪去四个角上边长为1的小正方形后,剩余部分可以看作一个十字形。</p>
                            <p class="text-gray-700 mb-3">2. 折叠后,盒子的高度就是剪去的小正方形边长1。</p>
                            <p class="text-gray-700 mb-3">3. 盒子的底面是一个边长为2的正方形(4-1×2=2)。</p>
                            <p class="text-gray-700 mb-4">4. 因此体积为:底面积×高 = 2×2×1 = 4。</p>
                            <h4 class="font-semibold text-gray-800 mb-2">答案:</h4>
                            <p class="text-green-600 font-bold">B) 4</p>
                        </div>
                    </div>
                </div>
                
                <!-- 题目卡片2 -->
                <div class="problem-card bg-white rounded-lg overflow-hidden shadow-md" data-year="2022" data-difficulty="easy" data-topic="number-theory">
                    <div class="p-6">
                        <div class="flex justify-between items-start mb-2">
                            <span class="bg-blue-100 text-blue-800 text-xs font-semibold px-2.5 py-0.5 rounded">2022年</span>
                            <span class="bg-yellow-100 text-yellow-800 text-xs font-semibold px-2.5 py-0.5 rounded">数论</span>
                        </div>
                        <h3 class="text-xl font-bold text-gray-800 mb-3">第8题</h3>
                        <p class="text-gray-600 mb-4">如果n是一个正整数,使得2n是3的倍数,3n是4的倍数,4n是5的倍数,那么n的最小可能值是多少?</p>
                        <div class="flex flex-wrap gap-2 mb-4">
                            <span class="bg-gray-100 text-gray-800 text-xs font-medium px-2.5 py-0.5 rounded">简单难度</span>
                            <span class="bg-red-100 text-red-800 text-xs font-medium px-2.5 py-0.5 rounded">最小公倍数</span>
                        </div>
                        <button class="solution-toggle-btn w-full bg-blue-600 hover:bg-blue-700 text-white font-medium py-2 px-4 rounded transition duration-300 flex items-center justify-center">
                            <i class="fas fa-lightbulb mr-2"></i>查看解析
                        </button>
                    </div>
                    <div class="solution-content bg-gray-50 px-6 pt-0 pb-6">
                        <div class="border-t border-gray-200 pt-4">
                            <h4 class="font-semibold text-gray-800 mb-2">解析:</h4>
                            <p class="text-gray-700 mb-3">1. 根据题意,我们可以将条件转化为:</p>
                            <p class="text-gray-700 mb-3">- n是3/2的倍数(但n是整数,所以n必须是3的倍数)</p>
                            <p class="text-gray-700 mb-3">- n是4/3的倍数(所以n必须是4的倍数)</p>
                            <p class="text-gray-700 mb-3">- n是5/4的倍数(所以n必须是5的倍数)</p>
                            <p class="text-gray-700 mb-4">2. 因此n必须同时是3、4和5的倍数,最小公倍数为60。</p>
                            <h4 class="font-semibold text-gray-800 mb-2">答案:</h4>
                            <p class="text-green-600 font-bold">E) 60</p>
                        </div>
                    </div>
                </div>
                
                <!-- 题目卡片3 -->
                <div class="problem-card bg-white rounded-lg overflow-hidden shadow-md" data-year="2021" data-difficulty="hard" data-topic="combinatorics">
                    <div class="p-6">
                        <div class="flex justify-between items-start mb-2">
                            <span class="bg-blue-100 text-blue-800 text-xs font-semibold px-2.5 py-0.5 rounded">2021年</span>
                            <span class="bg-pink-100 text-pink-800 text-xs font-semibold px-2.5 py-0.5 rounded">组合数学</span>
                        </div>
                        <h3 class="text-xl font-bold text-gray-800 mb-3">第25题</h3>
                        <p class="text-gray-600 mb-4">有6个不同的礼物要分给3个孩子,每个孩子至少得到1个礼物。有多少种不同的分配方式?</p>
                        <div class="flex flex-wrap gap-2 mb-4">
                            <span class="bg-gray-100 text-gray-800 text-xs font-medium px-2.5 py-0.5 rounded">高难度</span>
                            <span class="bg-indigo-100 text-indigo-800 text-xs font-medium px-2.5 py-0.5 rounded">分配问题</span>
                        </div>
                        <button class="solution-toggle-btn w-full bg-blue-600 hover:bg-blue-700 text-white font-medium py-2 px-4 rounded transition duration-300 flex items-center justify-center">
                            <i class="fas fa-lightbulb mr-2"></i>查看解析
                        </button>
                    </div>
                    <div class="solution-content bg-gray-50 px-6 pt-0 pb-6">
                        <div class="border-t border-gray-200 pt-4">
                            <h4 class="font-semibold text-gray-800 mb-2">解析:</h4>
                            <p class="text-gray-700 mb-3">1. 这是一个典型的"将n个不同的物品分配到k个不同的盒子,每个盒子至少一个"的问题。</p>
                            <p class="text-gray-700 mb-3">2. 可以使用容斥原理计算:总分配方式减去至少一个孩子没得到礼物的方式。</p>
                            <p class="text-gray-700 mb-3">3. 总分配方式:3^6 = 729(每个礼物有3种选择)</p>
                            <p class="text-gray-700 mb-3">4. 减去只有一个孩子得到礼物:C(3,1)×1^6 = 3</p>
                            <p class="text-gray-700 mb-3">5. 减去只有两个孩子得到礼物:C(3,2)×2^6 = 3×64=192</p>
                            <p class="text-gray-700 mb-4">6. 但是第二步多减了,需要加回:3^6 - 3×2^6 + 3×1^6 = 729 - 192 + 3 = 540</p>
                            <h4 class="font-semibold text-gray-800 mb-2">答案:</h4>
                            <p class="text-green-600 font-bold">540</p>
                        </div>
                    </div>
                </div>
                
                <!-- 题目卡片4 -->
                <div class="problem-card bg-white rounded-lg overflow-hidden shadow-md" data-year="2020" data-difficulty="medium" data-topic="algebra">
                    <div class="p-6">
                        <div class="flex justify-between items-start mb-2">
                            <span class="bg-blue-100 text-blue-800 text-xs font-semibold px-2.5 py-0.5 rounded">2020年</span>
                            <span class="bg-orange-100 text-orange-800 text-xs font-semibold px-2.5 py-0.5 rounded">代数</span>
                        </div>
                        <h3 class="text-xl font-bold text-gray-800 mb-3">第18题</h3>
                        <p class="text-gray-600 mb-4">解方程:2^(x+3) - 2^x = 224</p>
                        <div class="flex flex-wrap gap-2 mb-4">
                            <span class="bg-gray-100 text-gray-800 text-xs font-medium px-2.5 py-0.5 rounded">中等难度</span>
                            <span class="bg-teal-100 text-teal-800 text-xs font-medium px-2.5 py-0.5 rounded">指数方程</span>
                        </div>
                        <button class="solution-toggle-btn w-full bg-blue-600 hover:bg-blue-700 text-white font-medium py-2 px-4 rounded transition duration-300 flex items-center justify-center">
                            <i class="fas fa-lightbulb mr-2"></i>查看解析
                        </button>
                    </div>
                    <div class="solution-content bg-gray-50 px-6 pt-0 pb-6">
                        <div class="border-t border-gray-200 pt-4">
                            <h4 class="font-semibold text-gray-800 mb-2">解析:</h4>
                            <p class="text-gray-700 mb-3">1. 首先将方程左边因式分解:2^x(2^3 - 1) = 224</p>
                            <p class="text-gray-700 mb-3">2. 计算括号内:8 - 1 = 7,所以方程变为:7×2^x = 224</p>
                            <p class="text-gray-700 mb-3">3. 两边除以7:2^x = 32</p>
                            <p class="text-gray-700 mb-4">4. 32是2的5次方,所以x=5。</p>
                            <h4 class="font-semibold text-gray-800 mb-2">答案:</h4>
                            <p class="text-green-600 font-bold">5</p>
                        </div>
                    </div>
                </div>
                
                <!-- 题目卡片5 -->
                <div class="problem-card bg-white rounded-lg overflow-hidden shadow-md" data-year="2019" data-difficulty="easy" data-topic="probability">
                    <div class="p-6">
                        <div class="flex justify-between items-start mb-2">
                            <span class="bg-blue-100 text-blue-800 text-xs font-semibold px-2.5 py-0.5 rounded">2019年</span>
                            <span class="bg-red-100 text-red-800 text-xs font-semibold px-2.5 py-0.5 rounded">概率</span>
                        </div>
                        <h3 class="text-xl font-bold text-gray-800 mb-3">第10题</h3>
                        <p class="text-gray-600 mb-4">一个袋子里有3个红球和2个蓝球。随机取出2个球,都是红球的概率是多少?</p>
                        <div class="flex flex-wrap gap-2 mb-4">
                            <span class="bg-gray-100 text-gray-800 text-xs font-medium px-2.5 py-0.5 rounded">简单难度</span>
                            <span class="bg-purple-100 text-purple-800 text-xs font-medium px-2.5 py-0.5 rounded">组合概率</span>
                        </div>
                        <button class="solution-toggle-btn w-full bg-blue-600 hover:bg-blue-700 text-white font-medium py-2 px-4 rounded transition duration-300 flex items-center justify-center">
                            <i class="fas fa-lightbulb mr-2"></i>查看解析
                        </button>
                    </div>
                    <div class="solution-content bg-gray-50 px-6 pt-0 pb-6">
                        <div class="border-t border-gray-200 pt-4">
                            <h4 class="font-semibold text-gray-800 mb-2">解析:</h4>
                            <p class="text-gray-700 mb-3">1. 总球数:3红 + 2蓝 = 5个球</p>
                            <p class="text-gray-700 mb-3">2. 总的取法数:C(5,2) = 10</p>
                            <p class="text-gray-700 mb-3">3. 取到两个红球的取法数:C(3,2) = 3</p>
                            <p class="text-gray-700 mb-4">4. 概率 = 有利事件数 / 总事件数 = 3/10</p>
                            <h4 class="font-semibold text-gray-800 mb-2">答案:</h4>
                            <p class="text-green-600 font-bold">C) 3/10</p>
                        </div>
                    </div>
                </div>
                
                <!-- 题目卡片6 -->
                <div class="problem-card bg-white rounded-lg overflow-hidden shadow-md" data-year="2023" data-difficulty="hard" data-topic="geometry">
                    <div class="p-6">
                        <div class="flex justify-between items-start mb-2">
                            <span class="bg-blue-100 text-blue-800 text-xs font-semibold px-2.5 py-0.5 rounded">2023年</span>
                            <span class="bg-green-100 text-green-800 text-xs font-semibold px-2.5 py-0.5 rounded">几何</span>
                        </div>
                        <h3 class="text-xl font-bold text-gray-800 mb-3">第24题</h3>
                        <p class="text-gray-600 mb-4">在△ABC中,AB=5,BC=12,CA=13。点D在BC上,使得AD平分∠BAC。求BD的长度。</p>
                        <div class="flex flex-wrap gap-2 mb-4">
                            <span class="bg-gray-100 text-gray-800 text-xs font-medium px-2.5 py-0.5 rounded">高难度</span>
                            <span class="bg-blue-100 text-blue-800 text-xs font-medium px-2.5 py-0.5 rounded">角平分线定理</span>
                        </div>
                        <button class="solution-toggle-btn w-full bg-blue-600 hover:bg-blue-700 text-white font-medium py-2 px-4 rounded transition duration-300 flex items-center justify-center">
                            <i class="fas fa-lightbulb mr-2"></i>查看解析
                        </button>
                    </div>
                    <div class="solution-content bg-gray-50 px-6 pt-0 pb-6">
                        <div class="border-t border-gray-200 pt-4">
                            <h4 class="font-semibold text-gray-800 mb-2">解析:</h4>
                            <p class="text-gray-700 mb-3">1. 首先验证△ABC是直角三角形:5² + 12² = 13² (25 + 144 = 169)。</p>
                            <p class="text-gray-700 mb-3">2. 应用角平分线定理:BD/DC = AB/AC = 5/13</p>
                            <p class="text-gray-700 mb-3">3. 设BD=5k,DC=13k,则BD+DC=BC=12 → 18k=12 → k=2/3</p>
                            <p class="text-gray-700 mb-4">4. 因此BD=5×(2/3)=10/3</p>
                            <h4 class="font-semibold text-gray-800 mb-2">答案:</h4>
                            <p class="text-green-600 font-bold">10/3</p>
                        </div>
                    </div>
                </div>
            </div>
            
            <!-- 分页 -->
            <div class="mt-8 flex justify-center no-print">
                <nav class="inline-flex rounded-md shadow">
                    <a href="#" class="px-3 py-2 rounded-l-md border border-gray-300 bg-white text-gray-500 hover:bg-gray-50">
                        <i class="fas fa-chevron-left"></i>
                    </a>
                    <a href="#" class="px-3 py-2 border-t border-b border-gray-300 bg-white text-blue-600 font-medium hover:bg-blue-50">1</a>
                    <a href="#" class="px-3 py-2 border-t border-b border-gray-300 bg-white text-gray-500 hover:bg-gray-50">2</a>
                    <a href="#" class="px-3 py-2 border-t border-b border-gray-300 bg-white text-gray-500 hover:bg-gray-50">3</a>
                    <a href="#" class="px-3 py-2 rounded-r-md border border-gray-300 bg-white text-gray-500 hover:bg-gray-50">
                        <i class="fas fa-chevron-right"></i>
                    </a>
                </nav>
            </div>
        </div>
    </section>

    <!-- 特色功能 -->
    <section id="features" class="py-12 bg-blue-50">
        <div class="container mx-auto px-4">
            <h2 class="text-3xl font-bold text-center mb-12 text-gray-800">平台特色功能</h2>
            <div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-6">
                <div class="bg-white p-6 rounded-lg shadow-md hover:shadow-lg transition">
                    <div class="text-blue-600 mb-4 text-4xl">
                        <i class="fas fa-search"></i>
                    </div>
                    <h3 class="text-xl font-semibold mb-3 text-gray-800">智能搜索</h3>
                    <p class="text-gray-600">通过关键词、年份、难度和题型多维度筛选题目,快速定位所需内容。</p>
                </div>
                <div class="bg-white p-6 rounded-lg shadow-md hover:shadow-lg transition">
                    <div class="text-blue-600 mb-4 text-4xl">
                        <i class="fas fa-book-reader"></i>
                    </div>
                    <h3 class="text-xl font-semibold mb-3 text-gray-800">详细解析</h3>
                    <p class="text-gray-600">每道题目配有步骤详细的解析,帮助学生理解解题思路和方法。</p>
                </div>
                <div class="bg-white p-6 rounded-lg shadow-md hover:shadow-lg transition">
                    <div class="text-blue-600 mb-4 text-4xl">
                        <i class="fas fa-chart-line"></i>
                    </div>
                    <h3 class="text-xl font-semibold mb-3 text-gray-800">进度追踪</h3>
                    <p class="text-gray-600">记录学习进度和错题,生成个人能力分析报告,针对性提升薄弱环节。</p>
                </div>
                <div class="bg-white p-6 rounded-lg shadow-md hover:shadow-lg transition">
                    <div class="text-blue-600 mb-4 text-4xl">
                        <i class="fas fa-print"></i>
                    </div>
                    <h3 class="text-xl font-semibold mb-3 text-gray-800">打印功能</h3>
                    <p class="text-gray-600">支持题目和解析的打印,方便线下学习和模拟考试。</p>
                </div>
            </div>
        </div>
    </section>

    <!-- 联系我们 -->
    <section id="contact" class="py-12 bg-white">
        <div class="container mx-auto px-4">
            <h2 class="text-3xl font-bold text-center mb-8 text-gray-800">联系我们</h2>
            <div class="max-w-2xl mx-auto bg-gray-50 p-8 rounded-lg shadow-md">
                <form>
                    <div class="mb-4">
                        <label for="name" class="block text-sm font-medium text-gray-700 mb-1">姓名</label>
                        <input type="text" id="name" class="w-full px-3 py-2 border border-gray-300 rounded-md focus:outline-none focus:ring-2 focus:ring-blue-500">
                    </div>
                    <div class="mb-4">
                        <label for="email" class="block text-sm font-medium text-gray-700 mb-1">电子邮箱</label>
                        <input type="email" id="email" class="w-full px-3 py-2 border border-gray-300 rounded-md focus:outline-none focus:ring-2 focus:ring-blue-500">
                    </div>
                    <div class="mb-4">
                        <label for="message" class="block text-sm font-medium text-gray-700 mb-1">留言内容</label>
                        <textarea id="message" rows="4" class="w-full px-3 py-2 border border-gray-300 rounded-md focus:outline-none focus:ring-2 focus:ring-blue-500"></textarea>
                    </div>
                    <button type="submit" class="w-full bg-blue-600 hover:bg-blue-700 text-white font-medium py-2 px-4 rounded-md transition duration-300">
                        发送留言
                    </button>
                </form>
            </div>
        </div>
    </section>

    <!-- 页脚 -->
    <footer class="bg-gray-800 text-white py-8">
        <div class="container mx-auto px-4">
            <div class="grid grid-cols-1 md:grid-cols-4 gap-8">
                <div>
                    <h3 class="text-lg font-semibold mb-4">AMC8 学习平台</h3>
                    <p class="text-gray-400">提供最全面的AMC8中文学习资源,助力数学竞赛备考。</p>
                </div>
                <div>
                    <h3 class="text-lg font-semibold mb-4">快速链接</h3>
                    <ul class="space-y-2">
                        <li><a href="#problems" class="text-gray-400 hover:text-white transition">历年真题</a></li>
                        <li><a href="#features" class="text-gray-400 hover:text-white transition">学习资源</a></li>
                        <li><a href="#about" class="text-gray-400 hover:text-white transition">关于AMC8</a></li>
                        <li><a href="#contact" class="text-gray-400 hover:text-white transition">联系我们</a></li>
                    </ul>
                </div>
                <div>
                    <h3 class="text-lg font-semibold mb-4">学习资源</h3>
                    <ul class="space-y-2">
                        <li><a href="#" class="text-gray-400 hover:text-white transition">数学公式表</a></li>
                        <li><a href="#" class="text-gray-400 hover:text-white transition">解题技巧</a></li>
                        <li><a href="#" class="text-gray-400 hover:text-white transition">模拟考试</a></li>
                        <li><a href="#" class="text-gray-400 hover:text-white transition">视频讲解</a></li>
                    </ul>
                </div>
                <div>
                    <h3 class="text-lg font-semibold mb-4">关注我们</h3>
                    <div class="flex space-x-4">
                        <a href="#" class="text-gray-400 hover:text-white transition text-xl"><i class="fab fa-weixin"></i></a>
                        <a href="#" class="text-gray-400 hover:text-white transition text-xl"><i class="fab fa-weibo"></i></a>
                        <a href="#" class="text-gray-400 hover:text-white transition text-xl"><i class="fab fa-bilibili"></i></a>
                        <a href="#" class="text-gray-400 hover:text-white transition text-xl"><i class="fab fa-youtube"></i></a>
                    </div>
                    <p class="mt-4 text-gray-400">订阅我们的新闻通讯</p>
                    <div class="mt-2 flex">
                        <input type="email" placeholder="您的邮箱" class="px-3 py-2 bg-gray-700 text-white rounded-l-md focus:outline-none w-full">
                        <button class="bg-blue-600 hover:bg-blue-700 px-4 py-2 rounded-r-md transition">
                            <i class="fas fa-paper-plane"></i>
                        </button>
                    </div>
                </div>
            </div>
            <div class="border-t border-gray-700 mt-8 pt-6 text-center text-gray-400">
                <p>© 2023 AMC8中文学习平台. 保留所有权利.</p>
            </div>
        </div>
    </footer>

    <!-- 返回顶部按钮 -->
    <button id="back-to-top" class="fixed bottom-6 right-6 bg-blue-600 text-white p-3 rounded-full shadow-lg opacity-0 invisible transition-all duration-300 hover:bg-blue-700 no-print">
        <i class="fas fa-arrow-up"></i>
    </button>

    <script>
        // 移动端菜单切换
        document.getElementById('mobile-menu-button').addEventListener('click', function() {
            const menu = document.getElementById('mobile-menu');
            menu.classList.toggle('hidden');
        });

        // 解析展开/收起
        document.querySelectorAll('.solution-toggle-btn').forEach(button => {
            button.addEventListener('click', function() {
                const solutionContent = this.parentElement.nextElementSibling;
                solutionContent.classList.toggle('expanded');
                
                // 切换图标
                const icon = this.querySelector('i');
                if (solutionContent.classList.contains('expanded')) {
                    icon.classList.remove('fa-lightbulb');
                    icon.classList.add('fa-eye-slash');
                    this.innerHTML = this.innerHTML.replace('查看解析', '收起解析');
                } else {
                    icon.classList.remove('fa-eye-slash');
                    icon.classList.add('fa-lightbulb');
                    this.innerHTML = this.innerHTML.replace('收起解析', '查看解析');
                }
            });
        });

        // 返回顶部按钮
        window.addEventListener('scroll', function() {
            const backToTopButton = document.getElementById('back-to-top');
            if (window.pageYOffset > 300) {
                backToTopButton.classList.remove('opacity-0', 'invisible');
                backToTopButton.classList.add('opacity-100', 'visible');
            } else {
                backToTopButton.classList.remove('opacity-100', 'visible');
                backToTopButton.classList.add('opacity-0', 'invisible');
            }
        });

        document.getElementById('back-to-top').addEventListener('click', function() {
            window.scrollTo({
                top: 0,
                behavior: 'smooth'
            });
        });

        // 题目筛选功能
        document.getElementById('year-select').addEventListener('change', filterProblems);
        document.getElementById('difficulty-select').addEventListener('change', filterProblems);
        document.getElementById('topic-select').addEventListener('change', filterProblems);

        function filterProblems() {
            const year = document.getElementById('year-select').value;
            const difficulty = document.getElementById('difficulty-select').value;
            const topic = document.getElementById('topic-select').value;
            
            document.querySelectorAll('.problem-card').forEach(card => {
                const cardYear = card.getAttribute('data-year');
                const cardDifficulty = card.getAttribute('data-difficulty');
                const cardTopic = card.getAttribute('data-topic');
                
                const yearMatch = year === 'all' || cardYear === year;
                const difficultyMatch = difficulty === 'all' || cardDifficulty === difficulty;
                const topicMatch = topic === 'all' || cardTopic === topic;
                
                if (yearMatch && difficultyMatch && topicMatch) {
                    card.style.display = 'block';
                } else {
                    card.style.display = 'none';
                }
            });
        }

        // 平滑滚动
        document.querySelectorAll('a[href^="#"]').forEach(anchor => {
            anchor.addEventListener('click', function(e) {
                e.preventDefault();
                
                const targetId = this.getAttribute('href');
                if (targetId === '#') return;
                
                const targetElement = document.querySelector(targetId);
                if (targetElement) {
                    window.scrollTo({
                        top: targetElement.offsetTop - 80,
                        behavior: 'smooth'
                    });
                    
                    // 关闭移动端菜单
                    const mobileMenu = document.getElementById('mobile-menu');
                    mobileMenu.classList.add('hidden');
                }
            });
        });
    </script>
<p style="border-radius: 8px; text-align: center; font-size: 12px; color: #fff; margin-top: 16px;position: fixed; left: 8px; bottom: 8px; z-index: 10; background: rgba(0, 0, 0, 0.8); padding: 4px 8px;">Made with <img src="https://enzostvs-deepsite.hf.space/logo.svg" alt="DeepSite Logo" style="width: 16px; height: 16px; vertical-align: middle;display:inline-block;margin-right:3px;filter:brightness(0) invert(1);"><a href="https://enzostvs-deepsite.hf.space" style="color: #fff;text-decoration: underline;" target="_blank" >DeepSite</a> - 🧬 <a href="https://enzostvs-deepsite.hf.space?remix=cstur4/amc8" style="color: #fff;text-decoration: underline;" target="_blank" >Remix</a></p></body>
</html>