/* Color variables for theme switching */
:root {
    /* Light theme - soft whites and grey palette */
    --color-background: #f8f9fa; /* Soft white */
    --color-surface: #e1e8f0;    /* Darker grey */
    --color-blue: #58a6ff;       /* Blue accent */
    
    /* Text colors */
    --text-primary: #333340;     /* Deep grey */
    --text-secondary: #666670;   /* Medium grey */
}

[data-theme="dark"] {
    /* Dark theme - deep greys palette */
    --color-background: #1a1d23; /* Deep grey */
    --color-surface: #2d3440;    /* Lighter grey */
    --color-blue: #58a6ff;       /* Blue accent */
    
    /* Text colors */
    --text-primary: #e2e8f0;     /* Soft off-white */
    --text-secondary: #a0aec0;   /* Medium light grey */
}

/* Base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    outline: none;
}

html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    overflow-x: hidden;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--color-background);
    transition: background-color 0.3s ease;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 100;
}

.logo-placeholder {
    /* Maintain space for layout balance */
    width: 2rem;
    height: 1.8rem;
}

.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: background-color 0.3s ease;
}

.theme-icon {
    color: var(--text-primary);
    font-size: 1.2rem;
    transition: color 0.3s ease;
}

.theme-toggle:hover {
    background-color: var(--color-surface);
}

.theme-toggle:hover .theme-icon {
    color: var(--color-blue);
}

/* Page structure */
.page {
    min-height: 100vh;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    position: relative;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

/* Landing page */
#landing {
    background-color: var(--color-background);
    text-align: center;
    position: relative;
}

.name {
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.title {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 1.2rem;
    font-weight: 400;
}

.tagline {
    font-size: 1.125rem;
    color: var(--text-primary);
    margin-bottom: 2.5rem;
    font-weight: normal;
}

.buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
}

.btn {
    padding: 0.8rem 1.5rem;
    background-color: transparent;
    color: var(--color-blue);
    border: 1px solid var(--color-blue);
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
    text-decoration: none;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn i {
    margin-right: 0.5rem;
}

.btn:hover {
    background-color: var(--color-blue);
    color: white;
}

.scroll-down {
    position: static;
    margin: 0 auto;
    cursor: pointer;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: background-color 0.3s ease;
    text-decoration: none;
}

.scroll-down:hover {
    background-color: var(--color-surface);
}

.scroll-down i {
    color: var(--color-blue);
    font-size: 1.5rem;
}

/* Content page */
#content {
    background-color: var(--color-background);
    padding-top: 4rem;
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    gap: 2rem;
    margin-bottom: 2rem;
}

.grid-section {
    margin-bottom: 0;
    display: flex;
    flex-direction: column;
}

.section-title {
    font-size: 2.2rem;
    color: var(--text-primary);
    margin-bottom: 2rem;
    text-align: center;
}

.projects-section {
    grid-column: 1 / span 12;
}

.skills-section {
    grid-column: 1 / span 5;
    display: flex;
    flex-direction: column;
}

.publication-section {
    grid-column: 6 / span 7;
}

.contact-section {
    grid-column: 1 / span 12;
    margin-top: 2rem;
}

.contact-container {
    display: flex;
    justify-content: center;
}

.contact-btn {
    padding: 1rem 2rem;
    font-size: 1.1rem;
}

/* Projects section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-bottom: 2rem;
}

.project-card {
    background-color: var(--color-surface);
    border-radius: 8px;
    overflow: hidden;
    border: none;
    outline: none;
    box-shadow: none;
    display: flex;
    flex-direction: column;
}

.project-img {
    width: 100%;
    height: 180px;
    background-color: var(--color-background);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
}

.project-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.project-info {
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.project-title {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.project-desc {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: auto;
}

.project-tag {
    padding: 0.3rem 0.8rem;
    background-color: var(--color-background);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.8rem;
    border: none;
    outline: none;
    box-shadow: none;
}

/* Link styling */
.content-link {
    display: flex;
    align-items: center;
    color: var(--color-blue);
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.content-link i {
    margin-right: 0.4rem;
}

.content-link:hover {
    text-decoration: underline;
}

/* Project links */
.project-links {
    display: flex;
    margin-top: 1rem;
    gap: 1rem;
}

/* Skills section */
.skills-card {
    background-color: var(--color-surface);
    border-radius: 8px;
    padding: 1.5rem;
    height: 100%;
    display: flex;
    flex-direction: column;
    border: none;
    outline: none;
    box-shadow: none;
}

.skills-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    padding: 0.5rem;
    align-content: flex-start;
}

.skill-tag {
    padding: 0.3rem 0.8rem;
    background-color: var(--color-background);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.8rem;
    border: none;
    outline: none;
    box-shadow: none;
}

/* Publication section */
.publication-card {
    background-color: var(--color-surface);
    border-radius: 8px;
    padding: 1.5rem;
    height: 100%;
    display: flex;
    flex-direction: column;
    border: none;
    outline: none;
    box-shadow: none;
}

.publication-title {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.publication-authors {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-style: italic;
}

.publication-journal {
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.publication-abstract {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 1rem;
}

/* Media dropdown styles */
.media-dropdown-container {
    position: relative;
    display: inline-block;
}

.media-dropdown {
    display: none;
    position: absolute;
    left: 0;
    top: 100%;
    min-width: 100%;
    width: 280px;
    background-color: var(--color-surface);
    border-radius: 8px;
    padding: 0.5rem;
    padding-top: 10px;
    z-index: 10;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    margin-top: 0;
}

.media-dropdown-container:hover .media-dropdown,
.media-dropdown:hover {
    display: block;
}

.media-dropdown-item {
    display: block;
    width: 100%;
    padding: 0.5rem;
    color: var(--text-primary);
    text-decoration: none;
    border-radius: 4px;
    transition: background-color 0.2s ease;
    font-size: 0.9rem;
}

.media-dropdown-item:hover {
    text-decoration: underline;
    color: var(--color-blue);
}

/* More container for buttons */
.more-container {
    display: flex;
    justify-content: center;
    margin-top: 2rem;
}

/* Footer */
.footer {
    padding: 2rem 0;
    text-align: center;
}

.footer-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Responsive adjustments */
@media (max-width: 1024px) {
    .projects-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .skills-section {
        grid-column: 1 / span 12;
        margin-bottom: 2rem;
    }
    
    .publication-section {
        grid-column: 1 / span 12;
    }
}

@media (max-width: 768px) {
    .name {
        font-size: 2rem;
    }

    .title { 
        font-size: 1.125rem; 
    }

    .tagline { 
        font-size: 1rem; 
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 80%;
    }
    
    .content-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .skills-section,
    .publication-section,
    .projects-section,
    .contact-section {
        grid-column: 1;
    }
}