body {
    margin: 0;
    padding: 0;
    background: #1a1a1a;
    overflow: hidden;
    font-family: 'Arial', sans-serif;
}

#fireworks {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

.content {
    position: relative;
    z-index: 2;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    color: #fff;
}

.message {
    text-align: center;
    padding: 2rem;
    background: rgba(255, 255, 255, 0.15);
    border-radius: 20px;
    backdrop-filter: blur(10px);
    box-shadow: 0 0 30px rgba(255, 105, 180, 0.3),
                inset 0 0 20px rgba(255, 105, 180, 0.2);
    transform-style: preserve-3d;
    perspective: 1000px;
    animation: float 3s ease-in-out infinite;
}

.message:hover {
    transform: translateY(-5px) rotateX(5deg);
    box-shadow: 0 0 40px rgba(255, 105, 180, 0.4),
                inset 0 0 25px rgba(255, 105, 180, 0.3);
}

h1 {
    color: #ff69b4;
    font-size: 2.5em;
    margin-bottom: 1rem;
    text-shadow: 0 0 10px rgba(255, 105, 180, 0.5);
    background: linear-gradient(45deg, #ff69b4, #ff1493, #ff69b4);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    animation: gradient 3s ease infinite;
}

.text-container {
    margin: 2rem 0;
}

.typing {
    font-size: 1.2em;
    color: #fff;
    margin: 0;
    white-space: nowrap;
    overflow: hidden;
    animation: typing 4s steps(40) infinite;
    background: linear-gradient(90deg, #fff, #ff69b4);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.heart {
    width: 40px;
    height: 40px;
    background: #ff69b4;
    position: relative;
    transform: rotate(45deg);
    animation: heartbeat 1.5s ease-in-out infinite;
    margin: 2rem auto;
    box-shadow: 0 0 15px #ff69b4;
}

.heart:before,
.heart:after {
    content: '';
    width: 40px;
    height: 40px;
    background: #ff69b4;
    border-radius: 50%;
    position: absolute;
}

.heart:before {
    left: -20px;
}

.heart:after {
    top: -20px;
}

@keyframes float {
    0%, 100% { 
        transform: translateY(0) rotate(0deg); 
    }
    50% { 
        transform: translateY(-20px) rotate(2deg); 
    }
}

@keyframes typing {
    from { width: 0; }
    to { width: 100%; }
}

@keyframes heartbeat {
    0% { transform: rotate(45deg) scale(1); }
    25% { transform: rotate(45deg) scale(1.1); }
    50% { transform: rotate(45deg) scale(1); }
    75% { transform: rotate(45deg) scale(1.2); }
    100% { transform: rotate(45deg) scale(1); }
}

/* 音乐按钮样式 */
.music-btn {
    position: relative;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 28px;
    color: #ff69b4;
    padding: 12px;
    border-radius: 50%;
    transition: all 0.3s ease;
    animation: pulse 2s infinite;
}

.music-btn:hover {
    transform: scale(1.1);
}

.music-icon {
    display: inline-block;
    animation: rotate 3s linear infinite;
}

/* 新增动画 */
@keyframes gradient {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(255, 105, 180, 0.4); }
    70% { box-shadow: 0 0 0 10px rgba(255, 105, 180, 0); }
    100% { box-shadow: 0 0 0 0 rgba(255, 105, 180, 0); }
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* 添加信封样式 */
.envelope-wrapper {
    position: fixed;
    top: 45%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 10;
    perspective: 1000px;
}

.envelope {
    position: relative;
    width: 450px;
    height: 280px;
    background: #f5f5f5;
    border-radius: 20px;
    box-shadow: 0 0 40px rgba(255, 105, 180, 0.3),
                inset 0 0 25px rgba(255, 105, 180, 0.2);
    cursor: pointer;
    transform-style: preserve-3d;
    transition: all 1s cubic-bezier(0.4, 0, 0.2, 1);
    overflow: visible;
}

.envelope:hover {
    transform: translateY(-5px);
    box-shadow: 0 0 40px rgba(255, 105, 180, 0.4),
                inset 0 0 25px rgba(255, 105, 180, 0.3);
}

.front {
    position: absolute;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #ff69b4, #ff1493, #ff69b4);
    border-radius: 15px;
    overflow: hidden;
}

.front.flap {
    height: 50%;
    transform-origin: top;
    transition: transform 1s;
    z-index: 3;
    background: linear-gradient(135deg, #ff69b4, #ff1493, #ff69b4);
}

.envelope.open .front.flap {
    transform: rotateX(180deg);
    z-index: 1;
}

.front.pocket {
    background: linear-gradient(45deg, #ff1493, #ff69b4);
    z-index: 1;
}

.letter {
    position: absolute;
    width: 90%;
    height: 260%;
    background: #fff;
    border-radius: 15px;
    padding: 30px;
    margin: 5%;
    text-align: center;
    transition: all 1s cubic-bezier(0.4, 0, 0.2, 1);
    transform-style: preserve-3d;
    transform-origin: top center;
    box-shadow: 0 0 25px rgba(0, 0, 0, 0.1);
    z-index: 2;
    opacity: 0;
    top: 0;
}

.envelope.open .letter {
    transform: translateY(-35%) rotateX(0deg);
    opacity: 1;
    box-shadow: 0 5px 30px rgba(255, 105, 180, 0.3);
}

.letter-content {
    transform: rotateX(0deg);
    padding: 20px;
    height: 100%;
    opacity: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    position: relative;
}

.letter-header {
    position: sticky;
    top: 0;
    background: white;
    padding: 5px 0;
    z-index: 2;
    margin: 0;
}

.letter-content h2 {
    position: sticky;
    top: 30px;
    background: white;
    padding: 5px 0;
    z-index: 2;
    margin: 0;
}

.letter-text {
    margin: 0;
    position: relative;
    z-index: 1;
    line-height: 1.8;
}

.letter-header {
    font-size: 1.4em;
    color: #ff1493;
    margin-bottom: 30px;
    text-shadow: 0 0 5px rgba(255, 105, 180, 0.3);
    letter-spacing: 2px;
}

.letter-content h2 {
    font-size: 2.2em;
    margin: 20px 0;
    background: linear-gradient(45deg, #ff69b4, #ff1493);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    text-shadow: 0 0 5px rgba(255, 105, 180, 0.3);
}

.letter-text {
    font-size: 18px;
    line-height: 2.4;
    color: #444;
    text-shadow: 0 0 1px rgba(0, 0, 0, 0.1);
    margin: 35px 0;
}

.signature {
    font-size: 1.3em;
    margin-top: 40px;
    font-style: italic;
    color: #ff1493;
}

.open-envelope {
    text-align: center;
    color: #fff;
    margin-top: 20px;
    font-size: 20px;
    text-shadow: 0 0 10px rgba(255, 105, 180, 0.5);
    animation: pulse 2s infinite;
    letter-spacing: 2px;
}

/* 优化过渡效果 */
.content.hidden {
    display: none;
    opacity: 0;
    transform: scale(0.9);
    transition: all 1s cubic-bezier(0.4, 0, 0.2, 1);
}

.content.visible {
    display: flex;
    opacity: 1;
    transform: scale(1);
}

/* 添加闪光效果 */
.sparkles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    background: 
        radial-gradient(circle at 20% 20%, rgba(255, 255, 255, 0.1) 0%, transparent 8%),
        radial-gradient(circle at 80% 30%, rgba(255, 255, 255, 0.1) 0%, transparent 8%),
        radial-gradient(circle at 40% 70%, rgba(255, 255, 255, 0.1) 0%, transparent 8%),
        radial-gradient(circle at 70% 80%, rgba(255, 255, 255, 0.1) 0%, transparent 8%);
    animation: sparkle 4s linear infinite;
}

@keyframes sparkle {
    0%, 100% { opacity: 0.5; }
    50% { opacity: 1; }
}

/* 自定义滚动条样式 */
.letter-content::-webkit-scrollbar {
    width: 6px;
}

.letter-content::-webkit-scrollbar-track {
    background: rgba(255, 105, 180, 0.1);
    border-radius: 3px;
}

.letter-content::-webkit-scrollbar-thumb {
    background: rgba(255, 105, 180, 0.3);
    border-radius: 3px;
}

/* 更新信封打开动画 */
@keyframes openEnvelope {
    0% {
        transform: rotateX(0);
    }
    100% {
        transform: rotateX(180deg);
    }
}

@keyframes showLetter {
    0% {
        opacity: 0;
        transform: translateY(0);
    }
    100% {
        opacity: 1;
        transform: translateY(-100px);
    }
}

/* 更新心形样式 */
.heart-container {
    margin: 30px 0;
}

/* 添加信纸展开动画 */
@keyframes unfoldLetter {
    0% {
        transform: translateY(0) rotateX(180deg);
        opacity: 0;
    }
    50% {
        transform: translateY(-17.5%) rotateX(90deg);
        opacity: 0.5;
    }
    100% {
        transform: translateY(-35%) rotateX(0deg);
        opacity: 1;
    }
}

.envelope.open .letter {
    animation: unfoldLetter 1s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

/* 修改爱心装饰样式 */
.envelope-heart {
    position: absolute;
    width: 30px;
    height: 30px;
    background: #ff0000;  /* 改为纯红色 */
    transform: rotate(45deg);
    top: 45%;
    left: 50%;
    margin-left: -15px;
    z-index: 4;
    box-shadow: 0 0 10px rgba(255, 0, 0, 0.5);  /* 改为纯红色阴影 */
    animation: heartbeat 1.5s ease-in-out infinite;
}

.envelope-heart:before,
.envelope-heart:after {
    content: '';
    width: 30px;
    height: 30px;
    background: #ff0000;  /* 改为纯红色 */
    border-radius: 50%;
    position: absolute;
    box-shadow: 0 0 10px rgba(255, 0, 0, 0.5);  /* 改为纯红色阴影 */
}

.envelope-heart:before {
    left: -15px;
}

.envelope-heart:after {
    top: -15px;
}

/* 当信封打开时隐藏爱心 */
.envelope.open .envelope-heart {
    opacity: 0;
    transition: opacity 0.5s ease-in-out;
}

/* 爱心跳动动画 */
@keyframes heartbeat {
    0% { transform: rotate(45deg) scale(1); }
    25% { transform: rotate(45deg) scale(1.1); }
    50% { transform: rotate(45deg) scale(1); }
    75% { transform: rotate(45deg) scale(1.2); }
    100% { transform: rotate(45deg) scale(1); }
}

/* 添加打字机效果的样式 */
.typing-text {
    opacity: 0;
}

.typing-text.visible {
    opacity: 1;
    transition: opacity 0.1s;
}

/* 移动端适配 */
@media screen and (max-width: 768px) {
    .envelope {
        width: 90vw;
        height: 56vw;
        max-width: 450px;
        max-height: 280px;
    }

    .letter {
        width: 85%;
        height: 240%;
        padding: 15px;
        font-size: 0.9em;
    }

    .letter-content h2 {
        font-size: 1.5em;
        margin: 10px 0;
    }

    .letter-header {
        font-size: 1.2em;
        margin-bottom: 10px;
    }

    .letter-text {
        font-size: 0.9em;
        line-height: 1.6;
    }

    .envelope-wrapper {
        top: 50%;
    }

    .music-btn {
        font-size: 24px;
        padding: 8px;
    }

    .open-envelope {
        font-size: 0.9em;
        margin-top: 10px;
    }

    .envelope.open .letter {
        transform: translateY(-30%) rotateX(0deg);
    }
}

@media screen and (max-width: 480px) {
    .letter {
        font-size: 0.85em;
    }

    .letter-content h2 {
        font-size: 1.3em;
    }

    .letter-header {
        font-size: 1.1em;
    }

    .letter-text {
        font-size: 0.85em;
    }

    .music-btn {
        font-size: 20px;
        padding: 6px;
    }
}