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

body {
    min-height: 100vh;
    font-family: system-ui, -apple-system, 'PingFang TC', 'Microsoft JhengHei', 'Noto Sans TC', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

/* ===== Layout ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ===== Profile Photo ===== */
.profile-photo {
    width: 180px;
    height: 180px;
    object-fit: cover;
    border-radius: 50%;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
    margin: 1rem 1rem 0.5rem;
    display: block;
}

/* ===== Header ===== */
header {
    background:
        linear-gradient(135deg, rgba(20, 83, 45, 0.85) 0%, rgba(26, 119, 69, 0.85) 100%),
        url('https://images.unsplash.com/photo-1526374965328-7f61d4dc18c5?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80') center/cover no-repeat;
    color: white;
    padding: 2rem 0;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    position: relative;
}

header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
    background:
        radial-gradient(circle at 20% 30%, rgba(255,255,255,0.1) 1px, transparent 1px),
        radial-gradient(circle at 80% 70%, rgba(255,255,255,0.08) 2px, transparent 2px),
        radial-gradient(circle at 60% 20%, rgba(0,0,0,0.05) 1px, transparent 1px),
        radial-gradient(circle at 40% 80%, rgba(255,255,255,0.06) 1.5px, transparent 1.5px);
    background-size: 200px 200px, 150px 150px, 300px 300px, 250px 250px;
    opacity: 0.8;
}

.header-text h1 {
    font-size: 2.5rem;
    font-weight: 400;
    margin-bottom: 0.3rem;
}

.subheadline {
    font-size: 1.4rem;
    font-weight: 300;
    letter-spacing: -0.02em;
    color: hsl(210, 100%, 93%);
    text-shadow: 0 0 2px rgba(255, 255, 255, 0.15);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
    text-align: center;
}

/* ===== Navigation ===== */
nav {
    background: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    display: flex;
    justify-content: center;
    flex-wrap: nowrap;
    overflow-x: auto;
}

.nav-item {
    background: none;
    border: none;
    padding: 0.5rem 1rem;
    font-size: 1rem;
    color: #2c3e50;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
    white-space: nowrap;
    text-decoration: none;
}

.nav-item:hover {
    background: #27ae60;
    color: white;
    text-decoration: none;
}

.nav-toggle {
    display: none;
    font-size: 1.5rem;
    background: none;
    border: none;
    color: #4c1d95;
    cursor: pointer;
    padding: 1rem;
}

/* ===== Main Content ===== */
main {
    padding: 40px 0;
}

/* ===== Chapter ===== */
.chapter {
    background: white;
    margin: 40px 0;
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
    animation: fadeInUp 0.6s ease-out;
}

.chapter:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.15);
}

.chapter-title {
    font-size: 2.5em;
    color: #4c1d95;
    margin-bottom: 30px;
    text-align: center;
    position: relative;
    padding-bottom: 15px;
}

.chapter-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: linear-gradient(135deg, #4c1d95, #6b21a8);
    border-radius: 2px;
}

/* ===== Section ===== */
.section {
    margin: 30px 0;
    scroll-margin-top: 70px;
}

.section-title {
    font-size: 1.8em;
    color: #4c1d95;
    margin-bottom: 20px;
    padding-left: 20px;
    border-left: 4px solid #4c1d95;
    position: relative;
}

/* ===== Story Content ===== */
.story-content {
    font-size: 1.1em;
    line-height: 1.9;
    text-align: justify;
    margin-bottom: 25px;
    padding: 20px;
    background: #f8f9ff;
    border-radius: 10px;
    border-left: 4px solid #e3e8ff;
    transition: all 0.3s ease;
    text-indent: 2em;
}

.story-content:hover {
    background: #f0f4ff;
    border-left-color: #4c1d95;
}

.highlight {
    background: linear-gradient(120deg, #e9d5ff 0%, #f3e8ff 100%);
    padding: 2px 6px;
    border-radius: 4px;
    font-weight: 600;
}

/* ===== Poem ===== */
.poem {
    background: linear-gradient(135deg, #4c1d95, #6b21a8);
    color: white;
    padding: 30px;
    border-radius: 15px;
    margin: 30px 0;
    text-align: center;
    font-style: italic;
    line-height: 2;
    box-shadow: 0 10px 25px rgba(76, 29, 149, 0.3);
}

/* ===== Footer ===== */
footer {
    background: #2c3e50;
    color: white;
    text-align: center;
    padding: 40px 0;
    margin-top: 60px;
}

/* ===== Back to Top ===== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background: #4c1d95;
    color: white;
    border: none;
    border-radius: 50%;
    width: 60px;
    height: 60px;
    font-size: 20px;
    cursor: pointer;
    box-shadow: 0 5px 15px rgba(76, 29, 149, 0.4);
    transition: all 0.3s ease;
    opacity: 0;
    visibility: hidden;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: #6b21a8;
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(76, 29, 149, 0.6);
}

/* ===== Animation ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== Table of Contents ===== */
.table-of-contents {
    background: linear-gradient(135deg, #27ae60 0%, #219150 100%);
    color: white;
    padding: 30px;
    border-radius: 15px;
    margin: 30px 0;
    position: relative;
}

.toc-title {
    font-size: 1.7em;
    font-weight: 500;
    margin-bottom: 25px;
    text-align: center;
    border: none;
    border-bottom: 2px solid rgba(255,255,255,0.3);
    padding-bottom: 15px;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    background: none;
    color: inherit;
    width: 100%;
    display: block;
}

.toc-title:hover {
    color: #e9d5ff;
    transform: translateY(-2px);
}

.toc-arrow {
    display: inline-block;
    transition: transform 0.3s ease;
    margin-right: 10px;
    font-size: 0.8em;
    color: #e9d5ff;
}

.toc-arrow.expanded {
    transform: rotate(90deg);
}

.toc-hint {
    font-size: 0.5em;
    opacity: 0.7;
    margin-left: 10px;
    font-style: italic;
}

.toc-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s ease-out;
    pointer-events: none;
}

.toc-content.expanded {
    max-height: none;
    transition: none;
    pointer-events: auto;
}

.toc-chapter {
    margin-bottom: 25px;
}

.toc-chapter-title {
    font-size: 1.3em;
    font-weight: bold;
    margin-bottom: 15px;
    color: #e9d5ff;
    border-bottom: 1px solid rgba(255,255,255,0.2);
    padding-bottom: 8px;
}

.toc-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 10px;
}

.toc-item {
    margin: 5px 0;
    padding: 8px 12px;
    background: rgba(255,255,255,0.1);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.toc-item:hover {
    background: rgba(255,255,255,0.2);
    transform: translateX(5px);
}

.toc-link {
    color: white;
    text-decoration: none;
    display: block;
    transition: all 0.3s ease;
}

.toc-link:hover {
    color: #e9d5ff;
}

/* ===== Story Figure ===== */
.story-figure {
    text-align: center;
    margin: 30px 0;
}

.story-caption {
    margin-top: 8px;
    font-size: 0.95em;
    color: #555;
}

/* ===== Story Image ===== */
.story-image {
    width: 600px;
    max-width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

/* ===== Responsive: Mobile ===== */
@media (max-width: 768px) {
    .section {
        padding: 0 15px;
    }

    .header-text h1 {
        font-size: 1.7rem;
        line-height: 1.4;
        margin-bottom: 0.3rem;
    }

    .subheadline {
        font-size: 1.1rem;
        line-height: 1.4;
    }

    .profile-photo {
        width: 140px;
        height: 140px;
        margin: 0.5rem;
    }

    .chapter {
        padding: 25px;
        margin: 20px 0;
    }

    .chapter-title {
        font-size: 1.8em;
    }

    .nav-container {
        display: none;
        flex-direction: column;
        align-items: flex-start;
        background: white;
        box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        z-index: 999;
    }

    .nav-container.show {
        display: flex;
    }

    .nav-toggle {
        display: block;
    }

    .nav-item {
        padding: 8px 15px;
        font-size: 0.9em;
    }

    .toc-list {
        grid-template-columns: 1fr;
    }
}

/* ===== Responsive: Tablet ===== */
@media (max-width: 1024px) and (min-width: 769px) {
    .nav-item {
        padding: 0.5rem 0.6rem;
        font-size: 0.9rem;
    }
}