:root {
    /* Material Design 3 Light Palette (浅蓝色主题) */
    --md-sys-color-primary: #0066cc;
    --md-sys-color-on-primary: #ffffff;
    --md-sys-color-primary-container: #d4e7ff;
    --md-sys-color-on-primary-container: #001d3a;
    --md-sys-color-secondary: #4e5c6e;
    --md-sys-color-on-secondary: #ffffff;
    --md-sys-color-secondary-container: #d7e3f8;
    --md-sys-color-on-secondary-container: #0a1929;
    --md-sys-color-surface: #f8fafd;
    --md-sys-color-on-surface: #1a1c1e;
    --md-sys-color-surface-variant: #dfe2eb;
    --md-sys-color-on-surface-variant: #43474e;
    --md-sys-color-outline: #73777f;
    --md-sys-color-background: #f8fafd;
    --md-sys-color-on-background: #1a1c1e;
    
    --header-bg: rgba(248, 250, 253, 0.8);
    --transition-speed: 0.3s;
    --font-main: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', sans-serif;
    --font-mono: 'Roboto Mono', 'Fira Code', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', monospace;
    
    --grid-color: rgba(0, 102, 204, 0.05);
}

[data-theme="dark"] {
    --md-sys-color-primary: #a8c8ff;
    --md-sys-color-on-primary: #002f65;
    --md-sys-color-primary-container: #004591;
    --md-sys-color-on-primary-container: #d4e7ff;
    --md-sys-color-secondary: #bbc7db;
    --md-sys-color-on-secondary: #253140;
    --md-sys-color-secondary-container: #3b4858;
    --md-sys-color-on-secondary-container: #d7e3f8;
    --md-sys-color-surface: #121418;
    --md-sys-color-on-surface: #e2e2e6;
    --md-sys-color-surface-variant: #43474e;
    --md-sys-color-on-surface-variant: #c3c6cf;
    --md-sys-color-outline: #8d9199;
    --md-sys-color-background: #121418;
    --md-sys-color-on-background: #e2e2e6;

    --header-bg: rgba(18, 20, 24, 0.8);
    --grid-color: rgba(168, 200, 255, 0.05);
}

/* Reset & Base */
* { 
    box-sizing: border-box; 
    margin: 0; 
    padding: 0; 
    -webkit-tap-highlight-color: transparent;
}

/* Ensure anchor links don't get hidden behind the sticky header */
[id] {
    scroll-margin-top: 5rem;
}

body {
    font-family: var(--font-main);
    background-color: var(--md-sys-color-background);
    color: var(--md-sys-color-on-background);
    line-height: 1.6;
    transition: background-color var(--transition-speed), color var(--transition-speed);
    overflow-x: hidden;
    background-image: 
        linear-gradient(var(--grid-color) 1px, transparent 1px),
        linear-gradient(90deg, var(--grid-color) 1px, transparent 1px);
    background-size: 20px 20px;
}

a {
    color: var(--md-sys-color-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-speed);
}

/* Layout */
.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem;
}

/* Header & Nav */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 100;
    background-color: var(--header-bg);
    border-bottom: 1px solid var(--md-sys-color-surface-variant);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
}

.logo {
    font-family: var(--font-mono);
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--md-sys-color-primary);
    text-decoration: none;
    display: flex;
    align-items: center;
    /* gap: 0.5rem; Removed gap to handle animation smoothly */
    overflow: hidden; /* Ensure text slides out cleanly */
}

.logo span:first-child {
    margin-right: 0.5rem;
    z-index: 2; /* Keep icon above text if they overlap */
    position: relative;
    background-color: transparent; /* Ensure transparency */
}

.logo span:last-child {
    display: inline-block;
    opacity: 0;
    transform: translateY(150%); /* Start from below */
    /* max-width: 0; Removed to prevent sliding effect */
    /* overflow: hidden; */
    white-space: nowrap;
    transition: 
        opacity 0.4s ease,
        transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275); /* Bouncy effect */
}

header.show-logo-text .logo span:last-child {
    opacity: 1;
    transform: translateY(0);
    /* max-width: 300px; */
}

.controls {
    display: flex;
    gap: 0.5rem;
}

.btn-icon {
    background: none;
    border: none;
    color: var(--md-sys-color-on-surface);
    cursor: pointer;
    padding: 12px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s, transform 0.2s;
    position: relative;
    overflow: hidden;
}

.btn-icon:hover {
    background-color: var(--md-sys-color-surface-variant);
    transform: scale(1.1);
}

.btn-icon:active {
    transform: scale(0.95);
}

/* Hero Section */
.hero {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 4rem;
    padding: 4rem 0 4rem;
    animation: slideUp 0.8s cubic-bezier(0.2, 0.8, 0.2, 1);
    
    /* Dynamic Scroll Effect Variables */
    --header-height: 0px;
    --hero-progress: 1; /* Default to 1 (collapsed) if JS fails or mobile */
}

@media (min-width: 769px) {
    .hero {
        /* 
           Initial state (progress=0): 
             min-height = 100vh - headerHeight
             padding-bottom = 4rem + headerHeight
           Final state (progress=1):
             min-height = 0
             padding-bottom = 4rem
        */
        min-height: calc((100vh - var(--header-height)) * (1 - var(--hero-progress)));
        padding-bottom: calc(4rem + var(--header-height) * (1 - var(--hero-progress)));
        
        /* Ensure smooth transition if JS updates are throttled, but not too slow to lag behind scroll */
        /* transition: min-height 0.1s linear, padding-bottom 0.1s linear; */
        /* Actually, no transition is better for scroll-linked effects to avoid "rubber banding" */
    }
}

.hero-avatar {
    position: relative;
    width: 280px;
    height: 280px;
    flex-shrink: 0;
    transition: transform 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.avatar-inner {
    position: relative;
    width: 100%;
    height: 100%;
    border-radius: 140px; /* circle */
    border: 4px solid var(--md-sys-color-primary-container);
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    overflow: hidden;
    background-color: var(--md-sys-color-surface-variant);
    transition: all 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.hero-avatar:hover {
    transform: scale(1.05) rotate(3deg);
}

.hero-avatar:hover .avatar-inner {
    border-radius: 40px;
    border-color: var(--md-sys-color-primary);
}

.hero-avatar img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: opacity 0.5s ease;
}

.avatar-hover {
    opacity: 0;
}

.hero-avatar:hover .avatar-hover {
    opacity: 1;
}

.hero-content {
    flex: 1;
    text-align: left;
}

.hero h1 {
    font-size: 4rem;
    margin-bottom: 1rem;
    font-weight: 700;
    letter-spacing: -1px;
    color: var(--md-sys-color-on-background);
}

.typing-container {
    margin: 1.5rem 0;
    min-height: 60px;
    display: flex;
    justify-content: flex-start;
    align-items: center;
}

/* Cards & Grid */
.section-title {
    font-size: 1.75rem;
    margin: 4rem 0 2rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--md-sys-color-primary);
    font-weight: 500;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.card {
    background-color: var(--md-sys-color-surface-variant);
    border-radius: 24px;
    padding: 2rem;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    text-decoration: none;
    color: inherit;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    border: 1px solid transparent;
    position: relative;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 12px 24px rgba(0,0,0,0.15);
    border-color: var(--md-sys-color-primary);
    background-color: var(--md-sys-color-surface);
}

.card h3 {
    font-size: 1.4rem;
    color: var(--md-sys-color-primary);
    font-weight: 600;
}

.card p {
    font-size: 1rem;
    color: var(--md-sys-color-on-surface-variant);
}

.card .icon {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    color: var(--md-sys-color-secondary);
}

/* Terminal Style Section */
.terminal {
    background-color: #121212;
    color: #e0e0e0;
    font-family: var(--font-mono);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.4);
    margin: 3rem 0;
    position: relative;
    border: 1px solid #333;
}

.terminal-header {
    display: flex;
    gap: 8px;
    margin-bottom: 1.5rem;
}

.dot { width: 12px; height: 12px; border-radius: 50%; }
.dot.red { background: #ff5f56; }
.dot.yellow { background: #ffbd2e; }
.dot.green { background: #27c93f; }

.terminal-line {
    margin-bottom: 0.75rem;
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
}


.terminal-prompt {
    color: #4edada;
    font-weight: bold;
}

.terminal-project {
    color: #98c379;
    text-decoration: none;
    margin-right: 1.5rem;
    display: inline-block;
}

.terminal-project:hover {
    text-decoration: underline;
}

.terminal-cursor {
    display: inline-block;
    width: 8px;
    height: 18px;
    background: #4edada;
    /* Neutralize the parent .terminal-line gap (8px) so the cursor sits flush */
    margin-left: -2px;
    animation: blink 1s step-end infinite;
    vertical-align: bottom;
}

@keyframes blink {
    from, to { opacity: 1; }
    50% { opacity: 0; }
}

#terminal-history {
    max-height: 400px;
    overflow-y: auto;
    margin-bottom: 0.5rem;
}

#terminal-history::-webkit-scrollbar {
    width: 4px;
}

#terminal-history::-webkit-scrollbar-thumb {
    background: #333;
    border-radius: 2px;
}

/* Social Links */
.social-links {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: flex-start;
    margin-top: 2rem;
}

.badge-link {
    transition: transform 0.2s;
}

.badge-link:hover {
    transform: translateY(-3px);
}

/* Footer */
.github-stats {
    text-align: center;
    margin-top: 4rem;
}

footer {
    text-align: center;
    padding: 2rem;
    font-size: 0.9rem;
    color: var(--md-sys-color-on-surface-variant);
    border-top: 1px solid var(--md-sys-color-surface-variant);
    margin-top: 4rem;
}

/* Animations */
@keyframes slideUp {
    from { opacity: 0; transform: translateY(40px); }
    to { opacity: 1; transform: translateY(0); }
}

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

/* Ripple Effect */
.ripple {
    position: absolute;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: scale(0);
    animation: ripple-animation 0.6s linear;
    pointer-events: none;
}

@keyframes ripple-animation {
    to { transform: scale(4); opacity: 0; }
}

/* Responsive */
@media (max-width: 768px) {
    header { padding: 0.75rem 1rem; }
    .logo { font-size: 1.2rem; }
    .hero { 
        flex-direction: column; 
        text-align: center; 
        gap: 2rem;
        padding: 3rem 0 2rem;
    }
    .hero-content { text-align: center; }
    .hero-avatar {
        width: 180px;
        height: 180px;
        border-radius: 40px;
    }
    .typing-container, .social-links {
        justify-content: center;
    }
    .hero h1 { font-size: 2.2rem; }
    .container { padding: 1rem; }
    .grid { grid-template-columns: 1fr; }
    .terminal { padding: 1rem; }
    .github-stats img, .typing-container img {
        max-width: 100%;
        height: auto;
    }
    .hero { padding: 3rem 0 2rem; }
    .section-title { font-size: 1.5rem; margin: 3rem 0 1.5rem; }
    .project-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
        padding: 1rem;
    }
    .project-info {
        width: 100%;
        text-align: left;
    }
    .project-stats {
        width: 100%;
        justify-content: flex-start;
    }
    .terminal-project {
        margin-right: 0.75rem;
    }
}

/* Legacy Browser Support */
@supports not (display: grid) {
    .grid { display: block; }
    .card { margin-bottom: 1rem; }
}

/* Project List (Compact) */
.github-project-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.project-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    background-color: var(--md-sys-color-surface-variant);
    border-radius: 12px;
    text-decoration: none;
    color: inherit;
    transition: all 0.2s;
}

.project-item:hover {
    background-color: var(--md-sys-color-secondary-container);
    transform: translateX(8px);
}

.project-info h4 {
    color: var(--md-sys-color-primary);
    margin-bottom: 0.25rem;
}

.project-stats {
    display: flex;
    gap: 1rem;
    font-size: 0.85rem;
    color: var(--md-sys-color-on-surface-variant);
}

.loading {
    text-align: center;
    padding: 2rem;
    grid-column: 1 / -1;
}

/* MD3 Outlined Button */
.btn-outlined {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 20px;
    border: 1px solid var(--md-sys-color-outline);
    border-radius: 100px;
    color: var(--md-sys-color-primary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.85rem;
    transition: all 0.2s;
    background: transparent;
    width: fit-content;
    margin-top: 0.5rem;
}

.btn-outlined:hover {
    background-color: var(--md-sys-color-primary-container);
    border-color: var(--md-sys-color-primary);
    color: var(--md-sys-color-on-primary-container);
}

.btn-outlined .material-symbols-outlined {
    font-size: 18px;
}

/* FAB */
.fab {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 56px;
    height: 56px;
    border-radius: 16px;
    background-color: var(--md-sys-color-primary-container);
    color: var(--md-sys-color-on-primary-container);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0.0, 0.2, 1);
    border: none;
    z-index: 1000;
    opacity: 0;
    transform: scale(0);
    visibility: hidden;
}

.fab.visible {
    opacity: 1;
    transform: scale(1);
    visibility: visible;
}

.fab:hover {
    box-shadow: 0 6px 12px rgba(0,0,0,0.3);
    transform: scale(1.05);
    background-color: var(--md-sys-color-primary);
    color: var(--md-sys-color-on-primary);
}

/* NoScript Fallback */
noscript {
    display: block;
    padding: 1rem;
    background: #fffbe6;
    border: 1px solid #ffe58f;
    color: #856404;
    text-align: center;
    margin-bottom: 1rem;
}