:root {
    --bg-color: #f4f7f9;
    --text-color: #333;
    --primary-color: #007acc;
    --card-bg-color: #ffffff;
    --header-bg-color: rgba(255, 255, 255, 0.85);
    --border-color: #e0e0e0;
    --shadow-color: rgba(0, 0, 0, 0.08);
}

[data-theme="dark"] {
    --bg-color: #121212;
    --text-color: #e0e0e0;
    --primary-color: #38bdf8;
    --card-bg-color: #1e1e1e;
    --header-bg-color: rgba(30, 30, 30, 0.85);
    --border-color: #333;
    --shadow-color: rgba(0, 0, 0, 0.4);
}

[data-theme="blue-light"] {
    --bg-color: #fdf6e3;
    --text-color: #657b83;
    --primary-color: #268bd2;
    --card-bg-color: #f6efdf;
    --header-bg-color: rgba(246, 239, 223, 0.85);
    --border-color: #eee8d5;
    --shadow-color: rgba(0, 0, 0, 0.08);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Lato', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

main {
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    text-decoration: underline;
}

h1, h2, h3, h4 {
    font-family: 'Montserrat', sans-serif;
    color: var(--text-color);
    margin-bottom: 1rem;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; border-bottom: 2px solid var(--primary-color); padding-bottom: 0.5rem; margin-top: 0; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.2rem; color: var(--text-color); opacity: 0.8; }

ul {
    list-style-position: inside;
    padding-left: 1rem;
}

.main-header {
    background-color: var(--header-bg-color);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 1000;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.main-title {
    font-size: 1.5rem;
    margin: 0;
}

.main-nav a {
    margin: 0 1rem;
    font-weight: 600;
    font-family: 'Montserrat', sans-serif;
}

.theme-switcher {
    display: flex;
    gap: 0.5rem;
}

.theme-switcher button {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: 50%;
    width: 30px;
    height: 30px;
    cursor: pointer;
    font-size: 1rem;
    transition: transform 0.2s ease, background-color 0.2s ease;
}

.theme-switcher button:hover {
    transform: scale(1.1);
    background-color: var(--card-bg-color);
}

.card {
    background-color: var(--card-bg-color);
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 4px 15px var(--shadow-color);
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.card.visible {
    opacity: 1;
    transform: translateY(0);
}

#about .social-networks {
    margin-top: 1.5rem;
    display: flex;
    gap: 1.5rem;
    align-items: center;
    flex-wrap: wrap;
}

#about .social-networks img {
    height: 40px;
    width: auto;
    max-width: 60px;
    transition: transform 0.2s ease;
    border-radius: 4px;
}

#about .social-networks img:hover {
    transform: scale(1.15);
}

#skills .skill-category {
    margin-bottom: 2rem;
}

#skills .skills-icons {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    align-items: center;
}

#skills .skills-icons img {
    height: 40px;
    width: 40px;
    object-fit: contain;
    transition: transform 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

#skills .skills-icons img:hover {
    transform: scale(1.2) rotate(5deg);
}

.table-container {
    overflow-x: auto;
    width: 100%;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}

th, td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

thead th {
    background-color: var(--bg-color);
    color: var(--primary-color);
    font-weight: 700;
    font-family: 'Montserrat', sans-serif;
}

tbody tr {
    transition: background-color 0.2s ease;
}

tbody tr:hover {
    background-color: var(--shadow-color);
}

.main-footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-color);
    opacity: 0.7;
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .main-header {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }

    .main-nav {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        gap: 0.5rem 1rem;
    }
    
    .main-nav a {
        margin: 0;
    }

    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.3rem; }
}