:root{
    --color-main-top: #18233c;
    --color-main-bot: #020617;
    --color-header: rgba(15, 23, 42, 0.95);
    --color-logo: #f1f5f9;
    --color-logo-hover: #38bdf8;
    --color-nav-links: #f8fafc;
    --color-nav-links-hover: #38bdf8;
    --color-h1: #f8fafc;
    --color-p: #94a3b8;
    --color-btnb: #38bdf8;
    --color-btnp: #0f172a;
    --color-btnb-hover: #7dd3fc;
    --color-cir: rgba(56, 189, 248, 0.15);
    --color-card: rgba(69, 82, 104, 0.5);
    --color-card-desc: rgba(82, 95, 119, 0.8);
    --color-card-hover: rgba(69, 82, 104, 0.8);
    --color-card-text: #f8fafc;
    --color-nav-bot: rgba(255, 255, 255, 0.1);
    --color-cursor: rgba(56, 189, 248, 0.1);
    /* ------------------------------ */
    --color-fitler: rgba(42, 56, 78, 0.7);
    --color-fitler-text: #cbd5f5;
    --color-fitler-hover: #334155;
    --color-fitler-active: #38bdf8;
    --color-fitler-active-text: #0f172a;
    --color-fitler-active-hover: #7dd3fc;
    --color-procard: rgba(42, 56, 78, 0.6);
    --color-procard-hover: rgba(51, 65, 85, 0.85);
    --color-protitle: #e2e8f0;
    --color-protitle-hover: #38bdf8;
    --color-prodesc: #94a3b8;
    --color-serchbox: rgba(42, 56, 78, 0.6);
    --color-serchbox-text: #e2e8f0;
    --color-serchbox-placeholder: #94a3b8;
    /* TAG */
    --color-tag-bg: rgba(56, 189, 248, 0.15);
    --color-tag-text: #38bdf8;
    --color-tag-border: rgba(56, 189, 248, 0.35);

    --color-tag-hover-bg: rgba(56, 189, 248, 0.25);
    --color-tag-hover-text: #7dd3fc;

    --color-tag-active-bg: #38bdf8;
    --color-tag-active-text: #0f172a;
    /* project */
    --color-project-card: rgba(33, 44, 71, 0.65);
    --color-project-card-border: rgba(56, 189, 248, 0.15);
    --color-project-card-shadow: rgba(0, 0, 0, 0.35);

    --color-project-title-left: #ffffff;
    --color-project-title-right: #38bdf8;

    --color-backbtn-hover: #38a8f8;

    --color-project-tags: rgba(56, 189, 248, 0.12);
    --color-project-tags-text: #38bdf8;
    --color-project-tags-border: rgba(56, 189, 248, 0.35);
    --color-project-text: #94a3b8;

    --color-project-run: linear-gradient(135deg, #38d2f8, #386ef8);
    --color-project-run-shadow: rgba(56, 149, 248, 0.25);
    --color-project-run-text: #0f172a;
    --color-project-run-shadow-hover: rgba(56, 155, 248, 0.4);
    --color-project-card-img-shadow: rgba(160, 203, 226, 0.15);
}

[data-theme='light'] {
    --color-main-top: #f3f7fb;
    --color-main-bot: #e4ecf3;
    --color-header: rgba(255, 255, 255, 0.95);
    --color-logo: #1e293b;
    --color-logo-hover: #38bdf8;
    --color-nav-links: #1e293b;
    --color-nav-links-hover: #38bdf8;
    --color-h1: #0f172a;
    --color-p: #64748b;
    --color-btnb: #38bdf8;
    --color-btnp: #ffffff;
    --color-btnb-hover: #0ea5e9;
    --color-cir: rgba(14, 165, 233, 0.15);
    --color-card: #ffffff;
    --color-card-desc: rgba(85, 104, 136, 0.15);
    --color-card-hover: #f8fbfd;
    --color-card-text: 1e293b;
    --color-nav-bot: rgba(0, 0, 0, 0.1);
    --color-cursor: rgba(14, 165, 233, 0.05);
    /* ------------------------------ */
    --color-procard: #ffffff;
    --color-procard-hover: rgb(247, 250, 252);
    --color-protitle: #0f172a;
    --color-protitle-hover: #0ea5e9;
    --color-prodesc: #64748b;
    --color-fitler: #d8e0eb;
    --color-fitler-text: #334155;
    --color-fitler-hover: #cbddf5;
    --color-fitler-active: #0ea5e9;
    --color-fitler-active-text: white;
    --color-fitler-active-hover: #0284c7;
    --color-serchbox: #d8e0eb;
    --color-serchbox-text: #0f172a;
    --color-serchbox-placeholder: #64748b;
    /* TAG (light) */
    --color-tag-bg: rgba(14, 165, 233, 0.12);
    --color-tag-text: #0ea5e9;
    --color-tag-border: rgba(14, 165, 233, 0.3);

    --color-tag-hover-bg: rgba(14, 165, 233, 0.2);
    --color-tag-hover-text: #0284c7;

    --color-tag-active-bg: #0ea5e9;
    --color-tag-active-text: white;
    /* project */
    --color-project-card: white;
    --color-project-card-border: rgba(109, 85, 247, 0.2);
    --color-project-card-shadow: rgba(0, 0, 0, 0.1);

    --color-project-title-left: #122e55;
    --color-project-title-right: #256084;

    --color-backbtn-hover: #5aacdc;

    --color-project-tags: rgba(54, 122, 217, 0.45);
    --color-project-tags-text: #ffffff;
    --color-project-tags-border: rgba(85, 128, 247, 0.4);
    --color-project-text: #455975;

    --color-project-run: linear-gradient(135deg, #8bcafa, #486eec);
    --color-project-run-shadow: rgba(85, 101, 247, 0.25);
    --color-project-run-text: #ffffff;
    --color-project-run-shadow-hover: rgba(72, 127, 236, 0.35);
    --color-project-card-img-shadow: rgba(0, 0, 0, 0.15);
}

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

html, body {
    height: 100%;
    margin: 0;
}

body {
    font-family: 'Inter', Arial, sans-serif;
    background-color: var(--color-main-top); 
    background-image: linear-gradient(
        to bottom, 
        transparent, 
        var(--color-main-bot)
    );
    
    background-attachment: fixed;
    color: var(--color-h1);
    transition: background-color 0.5s ease, color 0.5s ease; 
}

/* NAVBAR */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 40px;
    position: fixed;
    width: 100%;
    top: 0;
    background: var(--color-header);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid var(--color-nav-bot);
    transition: 0.2s;
}

.navbar h1 {
    font-size: 25px;
    color: var(--color-logo);
    transition: color 0.2s;
}

.nav-links {
    display: flex;       /* 变成弹性盒子 */
    align-items: center; /* 垂直方向居中对齐 */
}

.nav-links a {
    font-size: 17px;
    margin-left: 20px;
    text-decoration: none;
    color: var(--color-nav-links);
    transition: 0.2s;
}

.nav-links a:hover {
    color: var(--color-nav-links-hover);
}

/* HERO */
.hero {
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero h1 {
    font-size: 48px;
    animation: fadeInUp 1s ease forwards;
    z-index: 2;
    color: var(--color-h1);
}

.hero p {
    margin-top: 10px;
    font-size: 20px;
    color: var(--color-p);
    animation: fadeInUp 1.5s ease forwards;
    z-index: 2;
}

.buttons {
    margin-top: 20px;
    animation: fadeInUp 2s ease forwards;
    z-index: 3;
}

.btn {
    padding: 15px 25px;
    margin: 10px;
    border: none;
    border-radius: 20px;
    background: var(--color-btnb);
    color: var(--color-btnp);
    cursor: pointer;
    transition: 0.3s ease;
    z-index: 3;
    font-size: 20px;
}

.btn:hover {
    transform: scale(1.1);
    background: var(--color-btnb-hover)
}

/* FLOATING BACKGROUND */
.circle {
    position: absolute;
    border-radius: 50%;
    background: var(--color-cir);
    animation: float 10s infinite ease-in-out;
    z-index: 0;
}

.circle:nth-child(1) {
    width: 200px;
    height: 200px;
    top: 10%;
    left: 20%;
}

.circle:nth-child(2) {
    width: 150px;
    height: 150px;
    top: 70%;
    left: 60%;
    animation-duration: 12s;
}

.circle:nth-child(3) {
    width: 100px;
    height: 100px;
    top: 40%;
    left: 80%;
    animation-duration: 8s;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-40px); }
}

@keyframes fadeInUp {
    from {
    opacity: 0;
    transform: translateY(20px);
    }
    to {
    opacity: 1;
    transform: translateY(0);
    }
}

/* SECTION */
.section {
    padding: 60px 40px;
    text-align: center;
}

.cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.card-wrapper {
    position: relative;
    display: inline-block;
}

.card {
    background: var(--color-card);
    padding: 25px;
    border-radius: 30px;
    transition: 0.3s ease;
    cursor: pointer;
    font-size: 18px;
    font-weight: bold;
    color: var(--color-card-text)
}

.card:hover {
    transform: translateY(-10px);
    background: var(--color-card-hover);
}

.card-desc {
    position: absolute;
    top: 110%;   /* 在 card 下方 */
    left: 50%;
    transform: translateX(-50%);

    background: var(--color-card-desc);
    color: var(--color-card-text);
    padding: 8px 12px;
    border-radius: 10px;

    font-size: 13px;
    white-space: nowrap;

    opacity: 0;
    visibility: hidden;
    transition: 0.2s;
    pointer-events: none;
    
    z-index: 3;
}

/* hover 时显示 */
.card-wrapper:hover .card-desc {
    opacity: 1;
    visibility: visible;
}

hr {
    color: var(--color-p); 
    margin-top: auto;
}

footer {
    text-align: center;
    padding: 20px;
    color: var(--color-p);
    z-index: 1000;
}

.cursor-glow {
    position: fixed;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, var(--color-cursor), transparent 60%);
    pointer-events: none;
    transform: translate(-50%, -50%);
    z-index: 0;
}

canvas {
    position: absolute; 
    top: 0; 
    left: 0; 
    width: 100%;
    height: 100%;
    z-index: 1;
    pointer-events: none;
}

a {
    text-decoration: none;
    color: inherit;
}

#logo {
    height: 24px;
    cursor: pointer;
    color: var(--color-logo);
    transition: color 0.3s ease;
}

#logo path {
    fill: currentColor;
    transition: fill 0.3s ease;
}

.logo-group:hover h1, .logo-group:hover #logo {
    color: var(--color-logo-hover);
}

.navbar, .nav-links a, .hero h1 {
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme='light'] .card {
    box-shadow: 0 6px 10px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

[data-theme='light'] .card:hover {
    box-shadow: 0 12px 15px -3px rgba(0, 0, 0, 0.1);
}
/* -------------------------------------------------- */

.projects-header {
    padding: 120px 40px 15px;
    text-align: center;
    
    display: flex;
    flex-direction: column;
    align-items: center;
}

.projects-header h2 {
    font-size: 40px;
}

.projects-header p {
    margin-top: 10px;
    color: var(--color-p);
}

.category-buttons {
    margin-top: 15px;
}

.category-buttons button {
    margin: 5px;
    padding: 8px 14px;
    border-radius: 20px;
    border: none;
    cursor: pointer;
    background: var(--color-fitler);
    color: var(--color-fitler-text);
    transition: 0.3s;
    font-size: 11px;
}

.category-buttons button:hover {
    background: var(--color-fitler-hover);
}

.category-buttons .active {
    background: var(--color-fitler-active);
    color: var(--color-fitler-active-text);
}

.category-buttons .active:hover {
    background: var(--color-fitler-active-hover);
}

.project-list {
    padding: 40px;
    padding-top: 10px;
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.project-card {
    display: flex;
    background: var(--color-procard);
    border-radius: 20px;
    overflow: hidden;
    transition: 0.3s;
}

.project-card:hover {
    transform: translateY(-5px);
    background: var(--color-procard-hover);
}

.project-card img{
    width: 180px;
    height: 120px;
    object-fit: cover;
    cursor: pointer;
    padding: 6px;
    display: block;
    border-radius: 20px;
}

.project-info {
    padding: 15px;
    display: flex;
    flex-direction: column;
}

.title {
    font-size: 20px;
    color: var(--color-protitle);
    text-decoration: none;
    font-weight: bold;
}

.project-desc {
    color: var(--color-prodesc);
    font-size: 14px;
}

.search-wrapper {
    position: relative;
    width: 100%;
    max-width: 400px;
    margin-top: 15px;
    padding-right: 2px;
}

#searchBox {
    width: 100%;
    padding: 10px 38px 10px 14px;
    border-radius: 100px;
    border: 1px solid rgba(148, 163, 184, 0.25);
    background: rgba(148, 163, 184, 0.12);
    color: var(--color-serchbox-text);
    outline: none;
    transition: all 0.2s ease;
}

#searchBox:focus {
    border-color: var(--color-btnb);
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.2);
}

#searchBox::placeholder {
    color: var(--color-serchbox-placeholder);
}

#clearBtn {
    position: absolute;
    right: 6px;
    top: 50%;
    transform: translateY(-50%);

    width: 28px;
    height: 28px;

    display: flex;
    align-items: center;
    justify-content: center;

    border-radius: 100px;

    cursor: pointer;
    user-select: none;

    font-size: 14px;
    line-height: 1;

    color: var(--color-serchbox-placeholder);
    background: transparent;

    transition: 0.2s ease;
}

#clearBtn:hover {
    background: rgba(148, 163, 184, 0.15);
    color: var(--color-serchbox-text);
}

#clearBtn:active {
    transform: translateY(-50%) scale(0.95);
}

#resultInfo {
    margin-top: 15px;
    font-size: 14px;
    color: var(--color-p);
    min-height: 18px;
    font-weight: bold;
    cursor: default;
}

/* ---------- */

/* 外层容器 */
.img-wrapper {
    position: relative;
    display: block;
    overflow: hidden;
    border-radius: 12px;
    flex-shrink: 0;
}

/* 图片 */
.img-wrapper img {
    display: block;
    width: 180px;
    height: 120px;
    object-fit: cover;
    transition: 0.3s;
}

/* 覆盖层 */
.overlay {
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,0.4);

    display: flex;
    align-items: center;
    justify-content: center;

    opacity: 0;
    transition: 0.3s;
}

/* 文字 */
.overlay span {
    color: white;
    font-size: 16px;
    font-weight: bold;
}

/* hover 效果 */
.img-wrapper:hover .overlay {
    opacity: 1;
}

.img-wrapper:hover img {
    filter: brightness(0.6);
    transform: scale(1.05);
}

.img-wrapper { cursor: pointer; }
.tag { cursor: pointer; }
.project-card { cursor: pointer; }
.tag {
    pointer-events: auto;
}
.project-info {
    pointer-events: auto;
}

.tags {
    margin: 6px 0 6px;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tag {
    font-size: 12px;
    font-weight: bold;
    padding: 3px 8px;
    border-radius: 999px;

    background: var(--color-tag-bg);
    color: var(--color-tag-text);
    border: 1px solid var(--color-tag-border);

    transition: all 0.25s ease;
    cursor: pointer;

    /* 防止选中蓝色高亮 */
    user-select: none;
}

.tag:hover {
    background: var(--color-tag-hover-bg);
    color: var(--color-tag-hover-text);
    transform: translateY(-1px);
}

.tag:active {
    transform: scale(0.95);
}

.theme-toggle {
    /* 1. 核心：强制宽高相等并居中 */
    display: flex;
    align-items: center;
    justify-content: center;

    /* 2. 移除按钮默认样式 */
    background: transparent; /* 或者 var(--secondary-bg) */
    border: none;
    border-radius: 50%;
    cursor: pointer;
    color: var(--color-nav-links);
    padding: 0;           /* 必须设为0，防止内边距导致的偏移 */
    outline: none;
    margin-right: 5px;
    
    /* 3. 动画：显式定义缩放中心 */
    transform-origin: center; 
    transition: transform 0.2s ease, color 0.2s ease;
    will-change: transform;
}

.theme-toggle:hover {
    transform: scale(1.2); /* 稍微加大一点效果更明显 */
    color: var(--color-nav-links-hover);
}

/* 确保内部 SVG 不会干扰布局 */
.icon {
    width: 24px;
    height: 24px;
    fill: currentColor;
    display: block; /* 消除 baseline 间隙 */
}

.project-wrapper {
    transition: 0.25s ease;
}

.category-buttons button:active {
    transform: scale(0.95);
}

.project-wrapper:active:active, .theme-toggle:active, .btn:active, .card:active {
    transform: scale(0.99);
}

/* ----------------------------- */

.app {
    min-height: 100vh; 
    display: flex; 
    flex-direction: column;
}

.footer {
    margin-top: auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 25px 40px;
    font-size: 14px;
    color: var(--color-p);
    border-top: 2px solid var(--color-nav-bot);
    flex-wrap: wrap;
    gap: 10px;
}

.footer-left,
.footer-center,
.footer-right {
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer a {
    text-decoration: none;
    color: var(--color-p);
    transition: 0.2s;
}

.footer a:hover {
    color: var(--color-nav-links-hover);
}

.footer span {
    opacity: 1;
}

@media (max-width: 600px) {
    .footer {
        flex-direction: column;
        text-align: center;
    }
}

.footer-link {
    display: flex;
    align-items: center;
    gap: 6px;
    text-decoration: none;
    color: var(--color-p);
    transition: 0.2s;
}

.footer-link:hover {
    color: var(--color-nav-links-hover);
}

.footer-icon {
    width: 16px;
    height: 16px;
    fill: currentColor;
    display: block;
}

/* -------------------------------------------------- */

.container {
    max-width: 1000px;
    width: 100%;
    margin: 100px auto 60px;
    padding: 0 50px;
    flex: 1;
}

.projectpage-card {  
    background: var(--color-project-card);
    border-radius: 30px;
    padding: 35px 40px;
    border: 1px solid var(--color-project-card-border);
    box-shadow: 0 20px 50px var(--color-project-card-shadow);
}

.back-btn {
    display: inline-flex;
    align-items: center;
    color: var(--color-p);
    text-decoration: none;
    font-size: 1rem;
    font-weight: bold;
    margin-bottom: 20px;
    transition: 0.2s;
}

.back-btn:hover {
    transform: scale(1.05);
    color: var(--color-backbtn-hover)
}

.project-title {
    font-size: 2.5rem;
    margin-bottom: 15px;
    background: linear-gradient(to right, var(--color-project-title-left), var(--color-project-title-right));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.project-tags {
    display: flex;
    gap: 15px;
    margin-bottom: 25px;
    flex-wrap: wrap;
}

.project-tag {
    padding: 8px 15px;
    background: var(--color-project-tags);
    color: var(--color-project-tags-text);
    border-radius: 100px;
    font-size: 1rem;
    font-weight: bold;
    border: 1px solid var(--color-project-tags-border);
    transition: all 0.3s;
    cursor: default;
}

.project-img {
    max-width: 100%;
    max-height: 500px;
    margin-bottom: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 20px;
    position: relative;
}

.project-img img {
    max-width: 100%;
    max-height: 500px;
    width: auto;
    height: auto;
    display: block;
    border-radius: 20px;
    object-fit: contain;
    box-shadow: 0 0 40px var(--color-project-card-img-shadow);
}

.project-intro {
    color: var(--color-project-text);
    font-size: 1.1rem;
    margin-bottom: 40px;
    max-width: 800px;
}

.run-btn {
    display: flex;
    gap: 20px;
}

.run-btn button {
    max-width: 150px;
    display: inline-flex;
    align-items: center;
    padding: 14px 32px;
    background: var(--color-project-run);
    color: var(--color-project-run-text);
    border-radius: 20px;
    text-decoration: none;
    font-size: 15px;
    font-weight: 600;
    transition: all 0.3s;
    box-shadow: 0 10px 20px var(--color-project-run-shadow);
    border: none;
    cursor: pointer;
}
.run-btn button:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 25px var(--color-project-run-shadow-hover);
    filter: brightness(1.1);
}

.run-btn button:active, .back-btn:active {
    transform: scale(0.99);
}

.project-tag:hover {
    transform: scale(1.05);
}

/* 响应式调整 */
@media (max-width: 768px) {
    .project-title { font-size: 1.8rem; }
    .project-intro { font-size: 0.9rem; }
    .project-tags { margin-bottom: 15px; }
    .project-tag { font-size: 0.8rem; }
    .project-intro { margin-bottom: 20px; }
    .container { margin-top: 80px; padding: 0 35px; }
    .projectpage-card { padding: 25px; }
    .project-img { margin-bottom: 20px; }
}

@media (max-width: 400px) {
    .project-card { flex-direction: column; }
}

.project-date {
    font-size: 15px;
    color: var(--color-p)
}

.sort-select {
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;

    margin: 5px;
    padding: 8px 25px 8px 14px;
    border-radius: 20px;
    border: none;

    background: var(--color-fitler);
    color: var(--color-fitler-text);

    font-size: 11px;
    cursor: pointer;
    transition: 0.3s;

    position: relative;
}

.sort-select:hover {
    background-color: var(--color-fitler-hover);
}

.sort-select:focus {
    outline: none;
}

.select-wrapper {
    position: relative;
    display: inline-block;
}

.select-wrapper::after {
    content: "▼";
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY();
    transform: translate(-3px, -48%);
    
    font-size: 10px;
    pointer-events: none;

    color: var(--color-fitler-text);
}