/* --- Google Font Import --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;700&display=swap');
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+TC:wght@400;500;700&display=swap');
@import url('https://fonts.googleapis.com/css2?family=Fira+Code:wght@400;500&display=swap');

/* --- Dark Tech Theme & Global Styles --- */
:root {
    --background-color: #121212;
    --surface-color: #1E1E1E;
    --text-color: #E0E0E0;
    --subtle-text-color: #A0A0A0;
    --accent-color: #007AFF;
    --hover-accent-color: #409CFF;
    --border-color: #333333;
    --container-width: 800px;
}

body {
    font-family: 'Inter', 'Noto Sans TC', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--background-color);
    background-image: url('tech-background.svg');
    background-size: cover;
    color: var(--text-color);
    line-height: 1.7;
    margin: 0;
    padding: 2rem;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* --- Layout --- */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 2rem 0;
}

header {
    text-align: center;
    margin-bottom: 4rem;
}

main {
    width: 100%;
}

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

/* --- Header Elements --- */
.profile-picture {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    margin-bottom: 1.5rem;
    border: 3px solid var(--accent-color);
    box-shadow: 0 0 15px rgba(0, 122, 255, 0.3);
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin: 0;
    color: #FFFFFF;
}

header .subtitle {
    font-size: 1.1rem;
    color: var(--subtle-text-color);
    margin-top: 0.5rem;
    margin-bottom: 1.5rem;
}

.social-links a {
    color: var(--accent-color);
    text-decoration: none;
    font-size: 1.8rem; /* Larger icon size */
    margin: 0 1rem;
    transition: color 0.2s ease-in-out, text-shadow 0.2s ease-in-out;
}

.social-links a:hover {
    color: var(--hover-accent-color);
    text-shadow: 0 0 8px rgba(64, 156, 255, 0.7);
}

/* --- Typography & Content --- */
h2 {
    font-size: 1.8rem;
    font-weight: 500;
    margin-top: 3rem;
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.75rem;
    color: #FFFFFF;
}

h3 {
    font-size: 1.2rem;
    font-weight: 500;
    margin-bottom: 1rem;
    color: #FFFFFF;
}

p {
    margin-bottom: 1rem;
}

section {
    background-color: rgba(30, 30, 30, 0.85); /* Slightly transparent surface */
    backdrop-filter: blur(10px); /* Frosted glass effect */
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 3rem;
    border: 1px solid var(--border-color);
}

/* --- Skills Section --- */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 2rem;
}

.skill-category h3 {
    margin-top: 0;
}

.skills-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.skills-tags span {
    font-family: 'Fira Code', monospace;
    display: inline-flex;
    align-items: center;
    background-color: rgba(0, 122, 255, 0.1);
    color: var(--accent-color);
    padding: 0.6rem 1rem;
    border-radius: 6px;
    font-size: 1rem;
    border: 1px solid rgba(0, 122, 255, 0.3);
    transition: background-color 0.2s ease, color 0.2s ease, transform 0.2s ease;
}

.skills-tags span:hover {
    background-color: var(--accent-color);
    color: #FFFFFF;
    transform: translateY(-2px);
}

.skills-tags span i {
    font-size: 1.2rem;
    margin-right: 0.75rem;
}

/* --- Experience Section --- */
.timeline {
    position: relative;
    padding-left: 2rem;
    border-left: 2px solid var(--border-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 2rem;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -2.5rem;
    top: 0.3rem;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background-color: var(--surface-color);
    border: 3px solid var(--accent-color);
    transition: box-shadow 0.2s ease;
}

.timeline-item:hover::before {
    box-shadow: 0 0 10px rgba(0, 122, 255, 0.5);
}

.timeline-content h3 {
    margin: 0 0 0.25rem 0;
    font-size: 1.1rem;
}

.timeline-content p {
    margin: 0;
    color: var(--subtle-text-color);
    font-size: 0.95rem;
}