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

body {
    height: 100vh;
    width: 100vw;
    overflow: hidden;
    font-family: 'Inter', 'Noto Serif SC', system-ui, -apple-system, 'Segoe UI', serif;
    background: radial-gradient(circle at 20% 30%, rgba(245, 240, 235, 0.9), rgba(225, 220, 210, 0.95));
    background-blend-mode: overlay;
    backdrop-filter: blur(0px);
}

/* 液态玻璃全局氛围 */
.glass-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -2;
    background:
        linear-gradient(125deg, #f7f3ee 0%, #eae3da 100%);
}

/* 动态颗粒感 + 柔光 */
.glass-bg::before {
    content: "";
    position: absolute;
    width: 200%;
    height: 200%;
    top: -50%;
    left: -50%;
    background: radial-gradient(circle at 40% 60%, rgba(255, 245, 235, 0.4) 0%, rgba(210, 195, 180, 0.1) 80%);
    animation: slowDrift 32s infinite alternate ease-in-out;
    pointer-events: none;
}

@keyframes slowDrift {
    0% {
        transform: translate(0, 0) rotate(0deg);
        opacity: 0.5;
    }

    100% {
        transform: translate(3%, 2%) rotate(2deg);
        opacity: 0.9;
    }
}

/* 主布局：左侧导航 + 右侧全屏内容区 */
.app {
    display: flex;
    height: 100vh;
    width: 100vw;
    position: relative;
    backdrop-filter: blur(2px);
}

/* 左侧简约线条导航栏 (液态玻璃效果) */
.nav-sidebar {
    width: 280px;
    background: rgba(245, 240, 235, 0.35);
    backdrop-filter: blur(16px);
    border-right: 1px solid rgba(255, 255, 245, 0.6);
    box-shadow: 4px 0 20px rgba(0, 0, 0, 0.02);
    display: flex;
    flex-direction: column;
    padding: 2rem 0 2rem 0;
    z-index: 10;
    transition: all 0.2s ease;
    overflow-y: auto;
    scrollbar-width: thin;
}

.nav-header {
    padding: 0 1.5rem 1.8rem 1.8rem;
    border-bottom: 1px solid rgba(100, 70, 50, 0.15);
    margin-bottom: 1.2rem;
}

.nav-header h2 {
    font-weight: 500;
    font-size: 1.7rem;
    letter-spacing: 2px;
    color: #3a2c28;
    font-family: 'Noto Serif SC', serif;
    background: linear-gradient(135deg, #5e4b3c, #2f241f);
    background-clip: text;
    -webkit-background-clip: text;
    color: transparent;
}

.nav-header p {
    font-size: 0.75rem;
    color: #6b5a4e;
    margin-top: 8px;
    font-weight: 300;
    letter-spacing: 1px;
}

/* 简约线条风格列表 */
.nav-list {
    list-style: none;
    flex: 1;
    padding: 0 1rem 1rem 0.5rem;
}

.nav-item {
    margin: 0.4rem 0;
    position: relative;
}

.nav-btn {
    width: 100%;
    text-align: left;
    background: transparent;
    border: none;
    padding: 0.7rem 1.2rem 0.7rem 2rem;
    font-size: 1rem;
    font-weight: 450;
    font-family: 'Inter', sans-serif;
    color: #2c241f;
    cursor: pointer;
    border-radius: 40px 12px 12px 40px;
    transition: all 0.25s cubic-bezier(0.2, 0.9, 0.4, 1.1);
    position: relative;
    letter-spacing: 0.3px;
    backdrop-filter: blur(4px);
}

.nav-btn span {
    display: inline-block;
    transition: transform 0.2s;
}

.nav-btn:hover {
    background: rgba(230, 215, 195, 0.5);
    transform: translateX(5px);
    color: #1f1612;
    font-weight: 500;
}

.nav-btn.active {
    background: rgba(245, 235, 220, 0.7);
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05), inset 0 1px 0 rgba(255, 255, 240, 0.8);
    font-weight: 600;
    border-left: 3px solid #c07a5b;
    color: #4e2e21;
}

.nav-btn.active span {
    transform: translateX(3px);
}

/* 线条细节：简约下划线点缀 */
.nav-item:not(:last-child)::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 20px;
    width: calc(100% - 40px);
    height: 0.5px;
    background: rgba(100, 70, 50, 0.1);
}

/* 右侧主内容区：全屏显示诗词/hero */
.main-content {
    flex: 1;
    position: relative;
    overflow-y: auto;
    scroll-behavior: smooth;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    background: radial-gradient(ellipse at 70% 30%, rgba(250, 245, 240, 0.2), transparent);
}

/* 液态玻璃卡片容器 */
.poem-card {
    max-width: 880px;
    width: 100%;
    margin: 2rem auto;
    background: rgba(255, 248, 240, 0.55);
    backdrop-filter: blur(18px);
    border-radius: 56px;
    box-shadow: 0 20px 40px -12px rgba(0, 0, 0, 0.15), 0 1px 2px rgba(255, 255, 235, 0.6) inset, 0 -1px 1px rgba(0, 0, 0, 0.02) inset;
    border: 1px solid rgba(255, 250, 240, 0.7);
    transition: all 0.3s ease;
    animation: fadeSlideUp 0.45s ease-out;
}

@keyframes fadeSlideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.card-inner {
    padding: 2.5rem 2.8rem;
}

/* 排版精致 */
.poem-title {
    font-size: 2.2rem;
    font-weight: 600;
    font-family: 'Noto Serif SC', serif;
    color: #4b2e22;
    letter-spacing: 2px;
    border-left: 4px solid #d9996c;
    padding-left: 1.2rem;
    margin-bottom: 0.5rem;
}

.poem-sub {
    font-size: 0.9rem;
    color: #8b6f5c;
    margin-top: 6px;
    margin-bottom: 1.8rem;
    font-weight: 400;
    display: flex;
    gap: 12px;
    align-items: baseline;
    flex-wrap: wrap;
    border-bottom: 1px dashed rgba(120, 80, 55, 0.2);
    padding-bottom: 0.8rem;
}

.teacher-tag {
    background: rgba(210, 170, 130, 0.2);
    border-radius: 40px;
    padding: 0.2rem 0.9rem;
    font-size: 0.75rem;
    font-weight: 500;
    color: #946b4e;
}

.poem-body {
    font-family: 'Noto Serif SC', serif;
    font-size: 1.18rem;
    line-height: 1.85;
    color: #2c241f;
    white-space: pre-line;
    word-break: break-word;
    margin: 1.5rem 0 1.2rem 0;
    font-weight: 450;
}

.poem-body p {
    margin-bottom: 0.6rem;
}

.stanza {
    margin-bottom: 1rem;
}

.annotation {
    margin-top: 1.8rem;
    padding-top: 1rem;
    font-size: 0.8rem;
    color: #aa8870;
    border-top: 1px solid rgba(150, 110, 80, 0.2);
    font-style: normal;
    letter-spacing: 0.3px;
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.annotation i {
    font-style: normal;
    background: rgba(0, 0, 0, 0.03);
    padding: 0.15rem 0.4rem;
    border-radius: 20px;
}

.hero-quote {
    text-align: center;
}

.hero-quote h1 {
    font-size: 3.2rem;
    font-weight: 500;
    font-family: 'Noto Serif SC', serif;
    background: linear-gradient(125deg, #583c2c, #927256);
    background-clip: text;
    -webkit-background-clip: text;
    color: transparent;
    margin-bottom: 1rem;
}

.hero-quote .hero-sub {
    font-size: 1.2rem;
    color: #5f4233;
    margin: 1rem 0;
}

.hero-quote p {
    font-size: 1rem;
    max-width: 550px;
    margin: 0.6rem auto;
    color: #7e5f4b;
}

.hero-sign {
    margin-top: 2rem;
    font-style: italic;
    font-size: 0.9rem;
    color: #b48a6b;
}

/* 响应式 */
@media (max-width: 780px) {
    .nav-sidebar {
        width: 220px;
    }

    .card-inner {
        padding: 1.5rem;
    }

    .poem-title {
        font-size: 1.6rem;
    }

    .poem-body {
        font-size: 1rem;
    }

    .hero-quote h1 {
        font-size: 2.4rem;
    }
}

@media (max-width: 600px) {
    .nav-sidebar {
        width: 100px;
        padding: 1rem 0;
    }

    .nav-header h2 {
        font-size: 1rem;
        writing-mode: vertical-rl;
        text-orientation: mixed;
        margin: 0 auto;
    }

    .nav-header p {
        display: none;
    }

    .nav-btn {
        padding: 0.5rem 0.3rem;
        text-align: center;
        font-size: 0.75rem;
        border-radius: 20px;
    }

    .nav-btn span {
        display: block;
        word-break: keep-all;
    }

    .poem-title {
        font-size: 1.4rem;
    }

    .main-content {
        padding: 1rem;
    }
}

/* 滚动条美观 */
.main-content::-webkit-scrollbar {
    width: 5px;
}

.main-content::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.05);
    border-radius: 8px;
}

.main-content::-webkit-scrollbar-thumb {
    background: rgba(150, 110, 80, 0.4);
    border-radius: 8px;
}

.nav-sidebar::-webkit-scrollbar {
    width: 3px;
}