:root {
	--grey: rgb(90, 90, 90);
	/* Steel Blue + Coral color scheme */
	--primary: #2d3748;      /* Headers, strong text */
	--secondary: #4a5568;    /* Subheadings */
	--accent: #FF7F50;       /* Important buttons, highlights */
	--link: #3182ce;         /* Links, interactive elements */
	--text: #1a202c;         /* Body text */
	--muted: #718096;        /* Meta info, timestamps */
	--background: #ffffff;   /* Main background */
	--surface: #edf2f7;      /* Cards, hover states */
	
	/* Legacy variables for compatibility */
	--blue1: #2d3748;
	--pink1: #FF7F50;
 }

html, p{
    margin: 0;
    padding: 0;
    border: 0;
    font-size: 100%;
    font: inherit;
    vertical-align: baseline;
    font-family: 'Source Sans Pro', sans-serif;
    font-weight: 300;
    letter-spacing: 0.5px;
    color: var(--grey);
}
p{
    margin: 0.2em;
}

ol, ul {
    list-style: none;
}

ul {
    list-style-position: inside;
    list-style-type: none;
}

a {
    text-decoration: none;
    color: var(--link);
    transition: color 0.3s ease;
}

a:hover {
    color: var(--accent);
}

i {
    font-style: italic;
}

h1 {
    font-weight: 500;
    color: var(--primary);
}

b {
    font-weight: 500;
}

strong {
    color: #FF7F50;
    font-weight: 700;
}

/**************************************************/

#header {
    height: 2em;
    line-height: 2em;
    padding-top: 10px;
    padding-bottom: 10px;
    border-bottom: 1px solid #ddd;
    position: fixed;
    top: 0;
    left: 50% - 500px;
    z-index: 9999;
    width: 1000px;
    background-color: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(8px);
}

#header a {
    text-decoration: none;
    color: var(--grey);
    transition: color 0.3s ease;
}

#header a:hover {
    color: var(--pink1);
}

/**************************************************/

#profile {
    padding: 90px 30px 10px 30px;
    border-bottom: 1px solid #ddd;
}

#profile-pic {
    float: left;
    margin-right: 40px;
    text-align: center;
}

#profile img {
    width: 300px;
    margin-bottom: 10px;
    border-radius: 50%;
}

#profile-name {
    font-size: 2.5em;
    line-height: 1.2em;
    font-weight: 400;
    margin-bottom: 10px;
    color: var(--primary);
    text-align: center;
}

.name-english {
    font-size: 1em;
    font-weight: 400;
}

.name-chinese {
    font-size: 0.4em;
    font-weight: 300;
    color: var(--secondary);
    margin-top: 5px;
}


#profile-email {
    margin-bottom: 20px;
    color: var(--blue1);
    text-align: center;
}

#profile p {
    margin-bottom: 20px;
}


.divider {
    width: 100%;
    border-bottom: 1px solid #ddd;
}

#research > div {
    margin-bottom: 1em;
}

.research-thumb {
    width: 20em;
    float: left;
    margin-top: 7px;
    padding-right: 30px;
    margin-bottom: 0;
}

.research-thumb img {
    width: 100%;
    height: auto;
    display: block;
}

.research-proj-title {
    color: var(--blue1);
    font-weight: 400;
}

/* Responsive Design for Mobile and Tablet */
@media screen and (max-width: 1024px) {
    #header {
        width: 100%;
        left: 0;
        padding-left: 20px;
        padding-right: 20px;
        box-sizing: border-box;
    }
    
    body > div {
        width: 100% !important;
        padding: 0 20px;
        box-sizing: border-box;
    }
}

@media screen and (max-width: 768px) {
    /* Stack profile layout on tablets */
    #profile-pic {
        float: none;
        margin: 0 auto 20px auto;
    }
    
    #profile img {
        width: 200px;
    }
    
    #profile-intro {
        text-align: center;
    }
    
    #profile-name {
        font-size: 2em;
    }
    
    /* Stack research thumbnails on tablets */
    .research-thumb {
        float: none;
        width: 100%;
        max-width: 400px;
        height: auto;
        margin: 0 auto 20px auto;
        padding-right: 0;
        display: block;
    }
    
    .research-thumb img,
    .research-thumb video {
        width: 100%;
        height: auto;
    }
}

@media screen and (max-width: 480px) {
    /* Mobile optimizations */
    #header {
        font-size: 0.9em;
        height: auto;
        line-height: 1.5em;
        flex-wrap: wrap;
    }
    
    #profile {
        padding: 70px 10px 10px 10px;
    }
    
    #profile img {
        width: 150px;
    }
    
    #profile-name {
        font-size: 1.5em;
    }
    
    #profile-email {
        font-size: 0.9em;
    }
    
    h1 {
        font-size: 1.5em;
    }
    
    p {
        font-size: 0.95em;
    }
}