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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    line-height: 1.6;
    color: #1a1a1a;
    background-color: #fafafa;
    transition: background-color 0.3s, color 0.3s;
}

.container {
    max-width: 720px;
    margin: 0 auto;
    padding: 80px 24px 120px;
}

/* Hero Section */
.hero {
    margin-bottom: 64px;
}

.hero-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
}

.hero-text {
    flex: 1;
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 8px;
    letter-spacing: -0.02em;
}

.hero-image {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid #000000;
    transition: border-color 0.3s;
    flex-shrink: 0;
}

.subtitle {
    font-size: 1.125rem;
    color: #666;
    margin-bottom: 24px;
}

.links {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
}

.link-item {
    display: flex;
    align-items: center;
    gap: 8px;
    color: #666;
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.2s;
}

.link-item:hover {
    color: #0066cc;
}

.link-item i {
    font-size: 1.1rem;
}

/* Sections */
section {
    margin-bottom: 64px;
}

section h2 {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: 24px;
    letter-spacing: -0.01em;
}

/* About Section */
.about p {
    color: #444;
    margin-bottom: 16px;
    line-height: 1.7;
}

/* Education Section */
.education p {
    color: #444;
    margin-bottom: 8px;
}

/* Experience Items */
.experience-item {
    margin-bottom: 40px;
}

.experience-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 12px;
    gap: 24px;
}

.experience-item h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.company {
    color: #666;
    font-size: 0.95rem;
    margin: 0;
}

.date {
    font-size: 0.875rem;
    color: #999;
    white-space: nowrap;
    flex-shrink: 0;
}

.experience-item ul {
    list-style: none;
    margin-left: 0;
}

.experience-item li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 8px;
    color: #444;
    line-height: 1.6;
}

.experience-item li::before {
    content: "•";
    position: absolute;
    left: 4px;
    color: #999;
}

/* Projects Section */
.project-item {
    margin-bottom: 32px;
}

.project-item h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.project-subtitle {
    color: #666;
    font-size: 0.95rem;
    margin-bottom: 12px;
}

.project-item ul {
    list-style: none;
    margin-left: 0;
}

.project-item li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 8px;
    color: #444;
    line-height: 1.6;
}

.project-item li::before {
    content: "•";
    position: absolute;
    left: 4px;
    color: #999;
}

/* Skills Section */
.skills-list {
    list-style: none;
    margin-left: 0;
}

.skills-list li {
    margin-bottom: 12px;
    color: #444;
    line-height: 1.6;
}

.skills-list strong {
    font-weight: 600;
    color: #1a1a1a;
}

/* Theme Toggle Button */
#theme-toggle {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 1px solid #e0e0e0;
    background-color: #fff;
    color: #666;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    transition: all 0.2s;
    z-index: 1000;
    font-size: 1.1rem;
}

#theme-toggle:hover {
    background-color: #f5f5f5;
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
}

#theme-toggle:active {
    transform: scale(0.95);
}

/* Dark Mode */
body.dark-mode {
    background-color: #0a0a0a;
    color: #e0e0e0;
}

body.dark-mode .hero h1 {
    color: #ffffff;
}

body.dark-mode .hero-image {
    border-color: #ffffff;
}

body.dark-mode .subtitle,
body.dark-mode .company,
body.dark-mode .date,
body.dark-mode .link-item,
body.dark-mode .project-subtitle {
    color: #999;
}

body.dark-mode .about p,
body.dark-mode .education p,
body.dark-mode .experience-item li,
body.dark-mode .project-item li,
body.dark-mode .skills-list li {
    color: #b0b0b0;
}

body.dark-mode .link-item:hover {
    color: #4d9fff;
}

body.dark-mode section h2,
body.dark-mode .experience-item h3,
body.dark-mode .project-item h3 {
    color: #ffffff;
}

body.dark-mode .skills-list strong {
    color: #ffffff;
}

body.dark-mode #theme-toggle {
    background-color: #1a1a1a;
    border-color: #333;
    color: #e0e0e0;
}

body.dark-mode #theme-toggle:hover {
    background-color: #2a2a2a;
}

body.dark-mode .experience-item li::before,
body.dark-mode .project-item li::before {
    color: #555;
}

/* Responsive Design */
@media (max-width: 640px) {
    .container {
        padding: 60px 20px 100px;
    }

    .hero {
        margin-bottom: 48px;
    }

    .hero-content {
        flex-direction: column;
        align-items: center;
        text-align: center;
        gap: 24px;
    }

    .hero-image {
        order: -1;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .links {
        gap: 16px;
        justify-content: center;
    }

    section {
        margin-bottom: 48px;
    }

    section h2 {
        font-size: 1.5rem;
    }

    .experience-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
    }

    .date {
        font-size: 0.8rem;
    }

    #theme-toggle {
        bottom: 24px;
        right: 24px;
        width: 44px;
        height: 44px;
    }

    .resume iframe {
        box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    }

    body.dark-mode .resume iframe {
        filter: invert(0.93) hue-rotate(180deg);
        box-shadow: 0 2px 12px rgba(255,255,255,0.08);
    }
}