:root {
    --bg-color: #fbfaf8;
    --text-color: #2c2c2c;
    --accent-color: #8b0000;
    --border-color: #d1cdc7;
    --font-serif: "Noto Serif SC", serif;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-serif);
    line-height: 1.8;
    overflow-x: hidden;
    overflow-y: hidden; /* 初始禁止滚动 */
}

/* =========================================
   1. 开场动画 (Apple 风格)
   ========================================= */
#intro-screen {
    position: fixed; top: 0; left: 0; width: 100vw; height: 100vh;
    background-color: var(--bg-color);
    display: flex; justify-content: center; align-items: center;
    z-index: 9999; transition: opacity 1.5s ease;
}

.intro-content { display: flex; flex-direction: column; align-items: center; width: 100%; }

.hat-container { width: 180px; height: 180px; margin-bottom: 20px; }

.hat-path {
    fill: transparent; stroke-dasharray: 100; stroke-dashoffset: 100;
    animation: draw 3s ease forwards, fillHat 1.5s ease 2.5s forwards;
}

@keyframes draw { 100% { stroke-dashoffset: 0; } }
@keyframes fillHat { 100% { fill: var(--target-fill); stroke: transparent; } }

.text-svg-container { width: 90vw; max-width: 600px; }

.draw-text {
    font-size: 65px; font-weight: 700; fill: transparent;
    stroke: var(--text-color); stroke-width: 1.2px;
    stroke-dasharray: 1200; stroke-dashoffset: 1200;
    animation: draw 3s ease 1s forwards, fillText 1s ease 3.5s forwards;
}

@keyframes fillText { 100% { fill: var(--text-color); stroke: transparent; } }

.intro-text { font-size: 0.8rem; letter-spacing: 0.3em; color: #999; opacity: 0; animation: fadeIn 1s ease 4s forwards; }
@keyframes fadeIn { to { opacity: 1; } }

/* =========================================
   2. 主页面 (JSTOR 学术风格)
   ========================================= */
#main-content {
    max-width: 1000px; margin: 0 auto; padding: 80px 40px;
    opacity: 0; transition: opacity 1.5s ease;
}

.journal-header { border-bottom: 3px solid var(--text-color); padding-bottom: 30px; margin-bottom: 60px; }
.header-top { display: flex; justify-content: space-between; font-size: 0.85rem; border-bottom: 1px solid var(--border-color); padding-bottom: 10px; margin-bottom: 30px; text-transform: uppercase; }
.site-title { font-size: 3.8rem; font-weight: 700; text-align: center; margin-bottom: 30px; letter-spacing: -1px; }

.journal-nav { display: flex; justify-content: center; gap: 40px; border-top: 1px solid var(--border-color); padding-top: 20px; }
.journal-nav a { color: var(--text-color); text-decoration: none; font-weight: 700; transition: 0.3s; }
.journal-nav a:hover { color: var(--accent-color); }

.abstract { background-color: #fff; padding: 40px; border: 1px solid var(--border-color); margin-bottom: 80px; }
.section-title { font-size: 1.5rem; font-weight: 700; margin-bottom: 25px; }
.section-title.border-top { border-top: 2px solid var(--text-color); padding-top: 20px; }

/* =========================================
   3. 科目大按钮 (一笔画图标)
   ========================================= */
.exam-grid {
    display: grid; grid-template-columns: repeat(5, 1fr); gap: 20px;
}

.exam-card {
    background: #fff; border: 1px solid var(--border-color);
    padding: 30px 10px; cursor: pointer;
    display: flex; flex-direction: column; align-items: center;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.icon-svg {
    width: 45px; height: 45px; fill: none;
    stroke: #ccc; stroke-width: 2.5px; stroke-linecap: round; stroke-linejoin: round;
    stroke-dasharray: 400; stroke-dashoffset: 400;
    transition: stroke 0.4s, stroke-dashoffset 1s ease;
}

.exam-card span { margin-top: 15px; font-weight: 700; font-size: 1.1rem; color: var(--text-color); }

/* 交互：悬停画线 */
.exam-card:hover { border-color: var(--accent-color); transform: translateY(-5px); box-shadow: 0 10px 20px rgba(0,0,0,0.05); }
.exam-card:hover .icon-svg { stroke: var(--accent-color); stroke-dashoffset: 0; }

/* 渐显动画类 */
.fade-up { opacity: 0; transform: translateY(30px); transition: 1s ease-out; }
.fade-up.visible { opacity: 1; transform: translateY(0); }

/* =========================================
   4. 响应式适配 (手机端)
   ========================================= */
@media (max-width: 768px) {
    #main-content { padding: 40px 20px; }
    
    .site-title { font-size: 2.2rem; }
    .header-top { flex-direction: column; align-items: center; gap: 5px; }
    .journal-nav { gap: 20px; font-size: 0.9rem; }

    .exam-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
    .exam-card { padding: 25px 10px; }

    /* 手机端图标默认直接画好，颜色变深，方便识别 */
    .icon-svg { stroke-dashoffset: 0; stroke: #555; stroke-width: 2.2px; }
    .exam-card:active { background: #f0f0f0; }
}

@media (max-width: 380px) {
    .site-title { font-size: 1.8rem; }
}

/* 贪吃蛇本体 */
#ink-snake {
    position: fixed;
    width: 20px;
    height: 20px;
    background: var(--text-color);
    border-radius: 50%; /* 看起来像一团墨水 */
    z-index: 10000;
    pointer-events: none; /* 不干扰点击 */
    display: none;
    box-shadow: 0 0 15px var(--text-color);
    transition: transform 0.1s linear;
}

/* 被“吃掉”时的消失动画 */
.eaten {
    opacity: 0 !important;
    transform: scale(0.5) rotate(5deg) !important;
    transition: all 0.5s cubic-bezier(0.6, -0.28, 0.735, 0.045) !important;
    pointer-events: none;
}

/* 最后的空白页提示 */
#archive-cleared {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-family: var(--font-serif);
    font-size: 1.2rem;
    color: #ccc;
    opacity: 0;
    transition: opacity 2s;
    pointer-events: none;
    text-align: center;
}