@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;600;800&display=swap');

:root {
    --bg-color: #0d1117;
    --text-color: #c9d1d9;
    --card-bg: rgba(22, 27, 34, 0.7);
    --border-color: rgba(255, 255, 255, 0.1);
    --primary-color: #58a6ff;
    --accent-color: #79c0ff;
    --nav-bg: rgba(13, 17, 23, 0.85);
    --shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
    --glass-blur: blur(12px);
    --gradient: linear-gradient(135deg, #1f6feb 0%, #ff7b72 100%);
}

[data-theme="light"] {
    --bg-color: #f6f8fa;
    --text-color: #24292f;
    --card-bg: rgba(255, 255, 255, 0.7);
    --border-color: rgba(0, 0, 0, 0.1);
    --primary-color: #0969da;
    --accent-color: #0550ae;
    --nav-bg: rgba(246, 248, 250, 0.85);
    --shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.15);
    --gradient: linear-gradient(135deg, #0969da 0%, #cf222e 100%);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Glassmorphism Navigation */
nav {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--nav-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
    list-style: none;
}

.nav-links a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -4px;
    left: 0;
    background-color: var(--primary-color);
    transition: width 0.3s ease;
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

.controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.btn {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-color);
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    font-family: inherit;
    font-weight: 600;
    text-decoration: none;
    display: inline-block;
}

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

.btn-primary {
    background: var(--primary-color);
    color: #fff;
    border: none;
}
.btn-primary:hover {
    background: var(--accent-color);
}

/* Layout */
main {
    flex: 1;
    padding: 3rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

h1, h2, h3 {
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.gradient-text {
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

/* Glassmorphism Cards */
.card {
    background: var(--card-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px 0 rgba(0,0,0,0.4);
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

/* Profile Picture */
.profile-pic {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--primary-color);
    box-shadow: var(--shadow);
}

/* Publications */
.pub-meta {
    font-size: 0.85rem;
    color: var(--accent-color);
    margin-bottom: 1rem;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem;
    border-top: 1px solid var(--border-color);
    background: var(--nav-bg);
}

/* Language Switcher */
.lang-switcher form {
    display: inline;
}
.lang-switcher select {
    background: transparent;
    color: var(--text-color);
    border: 1px solid var(--border-color);
    padding: 0.3rem;
    border-radius: 4px;
    outline: none;
    font-family: inherit;
}
.lang-switcher select option {
    background: var(--bg-color);
}