/* Color variables */
:root {
    --color-bg-main: #f8f9fbdd;
    --color-bg-alt: #ebf4ffdd;
    --color-bg-even: #fffdf3dd;
    --color-bg-contact: #fef9e6dd;
    --color-bg-form: #fffbe8dd;
    --color-border-main: #e5e5e5dd;
    --color-border-btn: #333;
    --color-text-main: #23272f;
    --color-link: #23272f;
    --color-link-hover: #4361ee;
}
hmtl {
    scroll-behavior: smooth;
}
body {
    font-family: 'Inter', 'Segoe UI', Arial, sans-serif;
    margin: 0;
    background-color: var(--color-bg-main);
    color: var(--color-text-main);
    cursor: default;
    font-size: 1.08em;
    line-height: 1.7;
    letter-spacing: 0.01em;
    min-height: 100vh;
}
h1, h2, h3, h4, h5, h6, .logo, footer {
    font-family: 'Georgia', 'Times New Roman', serif;
    letter-spacing: 0.01em;
}


header {
    display: flex;
    justify-content: space-between;
    top: 0;
    position: relative;
    z-index: 1000;
    align-items: center;
    padding: 0.7em 1.5em;
    border-bottom: 1.5px solid var(--color-border-main);
    background: #ebf4ff;
    backdrop-filter: blur(2px);
}
.avatar {
    display: flex;
    align-items: center;
    margin-right: 0.7em;
    font-size: 1.15em;
    letter-spacing: 0.03em;

}
.logo img {
    height: 24px; 
    vertical-align: middle; 
    margin-right: 8px;
}
nav a {
    margin: 0 0.7em;
    text-decoration: none;

    padding: 0.5em 1.1em;
    border-radius: 6px;
    font-weight: 500;
}
nav a:hover, nav a.active {

}
/* Buttons */
.btn {
    margin-left: 0.7em;
    padding: 0.4em 0.9em;
    border: 1.5px solid var(--color-link-hover);
    text-decoration: none;
    border-radius: 6px;

    font-weight: 500;
    box-shadow: 0 2px 8px rgba(67,97,238,0.04);
}
ol {
    margin: 0;
    padding-left: 1.5em;
}
ol li {
    margin-bottom: 1em;
}
.btn:hover {

    
}
.btn-primary,
.btn-dark {

}
.btn-primary:hover,
.btn-dark:hover {

}
/* Headings */
h2 {
    font-size: 1.6em;
    margin: 0;
    font-weight: 700;
    text-align: center;
    letter-spacing: 0.01em;
}
h3 {
    margin: 0 auto;
    text-align: center;
}
h3.sub {
    margin: -0.5em auto 0;
    color: #666;
}

footer {
    text-align: center;
    padding: 1.2em 1em;
    font-size: 1em;
    letter-spacing: 0.01em;
}
.section-content {
    max-width: 900px;
    margin: auto;
    padding: 1.2em;
    border-radius: 18px;
    background-color: #ebf4ffdd;
}



/* Hero Section */
#hero > div {
    display: flex;
    position: relative;
    align-items: center;
    gap: 1.2em;
    flex-wrap: wrap;
}
#hero h1 {
    font-size: 2.1em;
    margin-bottom: 0.2em;
    font-weight: 800;

    letter-spacing: 0.01em;
}
#hero p {
    font-size: 1.05em;
    max-width: 480px;
}
#hero img {
    width: 256px; 
    border-radius: 18px;
}
#hero h2 {
    text-align: left;
}
section {
    padding: 1.5em 1em;
    margin: 0 auto;
}

input, textarea {
    width: 100%;
    padding: 0.5em;
    margin: 0.4em 0 0.7em 0;
    border: 1.5px solid #e5e5e5;
    border-radius: 6px;
    font-size: 1em;
    transition: border 0.18s, box-shadow 0.18s;
    box-sizing: border-box;
}
input:focus, textarea:focus {
    outline: none;
    box-shadow: 0 0 0 2px #e6f6d6;
}
form {
    background: #fffbe8;
    border-radius: 12px;
    box-shadow: 0 5px 12px rgba(67,97,238,0.06);
    padding: 1.1em 1em;
    margin: 1.2em auto;
    max-width: 500px;
    display: block;
}

.form-checkbox {
    display: flex;
    border-radius: 7px;
    border: 1.5px solid #e9ecef;
    padding: 0.4em 0.7em;
    cursor: pointer;
    transition: border 0.2s, box-shadow 0.2s;
    gap: 0.7em;
    margin: 0.3em 0;
    align-items: center;
}
.form-checkbox:hover{
    box-shadow: 0 0 3px 3px #6b8dff33;
}
.form-checkbox input[type="checkbox"] {
    display: none;
}
.form-checkbox:has(input[type="checkbox"]:checked) {
    background: #e6f6d6;
    border-color: #4361ee;
    box-shadow: 0 0 2px 2px #9aff35;
}
.option-title {
    font-weight: 600;
    font-size: 1.1em;
}
.option-desc {
    margin-left: auto;
    color: #6c757d;
}
.contact-textarea {
    display: block;
    border-radius: 6px;
    border: 1px solid #e9ecef;
    padding: 0.4em 0.7em;
    min-height: 150px;
    box-sizing: border-box;
}
.alert {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.7em 1em;
    margin: 0.7rem 0;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(67,97,238,0.04);
    border-left: 4px solid #4361ee;
    background: #f8f9fb;
}
.alert.success {
    background-color: #e6f6d6;
    border-left: 5px solid #6bc048;
    color: #2c5e1a;
}
.alert-content {
    flex: 1;
}
.alert-content h3 {
    margin-top: 0;
    margin-bottom: 0.5em;
}
.alert-content p {
    margin: 0;
}
.alert-close {
    background: none;
    border: none;
    color: #666;
    font-size: 1.5em;
    cursor: pointer;
    padding: 0 0.5em;
    transition: color 0.18s;
}
.alert-close:hover {
    color: #4361ee;
}

/* Responsive Design */
@media (max-width: 900px) {
    header {
        padding: 0.5em 0.7em;
    }
    .section-content {
        padding: 0.7em 0;
    }
    #hero > div {
        flex-direction: column;
        gap: 0.7em;
        align-items: flex-start;
    }
    #hero img {
        width: 110px;
    }
    section {
        padding: 0.7em 0.5em;
    }
}

.dropdown-menu {
    display: none;
    position: absolute;
    background: #fff;
    border: 1px solid #ccc;
    z-index: 1000;
    min-width: 240px;
}

.dropdown-menu a {
    display: block; 
    padding: 8px 16px;
}

.dropdown {
    display: inline-block; 
    position: relative;
}

.lang-option {
    width: 100%; 
    text-align: left;
}

a.active {
    font-weight: bold;
    background-color: var(--color-bg-alt)    ;
}

.card-list {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5em;
    margin-top: 1rem;
}
.card {
    position: relative;
    background: #fff;
    border: 1px solid #eee;
    border-radius: 8px;
    padding: 1.2em;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    flex: 1 1 calc(33.333% - 1.5em);
    box-sizing: border-box;
}
.card img {
    max-width: 61%;
    height: auto;
    object-fit: cover;
    border-radius: 20px;
}

.tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5em;
    list-style: none;
    padding: 0;
    margin: 0.5em 0 0 0;
    font-size: 0.9em;
    color: #666;
}
.tech-stack li {
    background: #f0f4fa;
    color: #4361ee;
    border-radius: 16px;
    padding: 0.25em 0.9em;
    margin: 0;
    font-weight: 500;
    border: 1px solid #e5e5e5;
    display: inline-block;
}

.wide {
    width: 100%;
    flex: unset;
}

.card p {
    text-align: justify;
}

.center {
    text-align: center;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hidden-link {
    color: inherit;
    text-decoration: none;
}

.hidden-link:hover {
    transition: color 0.5s;
    color: #4361ee;
}

.box {
    border: 1px solid #eee;
}

#mandelbrot {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -2;
    background: #000;
}

#background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    opacity: 0.7;
}

.profiles {
    list-style-type: none;
    padding-left: 0;
    margin: 0;
}

.profiles li {
    font-size: 20px;
    border: 1px solid #627fff;
    padding: 0.5rem;
    margin: 1rem;
    border-radius: 12px;
    text-align: left;
}

.profiles li:hover {
    background: #e6f6d6;
    box-shadow: 0 0 8px 2px #9aff35;
}


.twitter::before,
.github::before,
.linkedin::before,
.upwork::before,
.researchgate::before {
    display: inline-block;
    vertical-align: middle;
    
    margin-right: 8px;
    width: 40px;
    height: 40px;
}

.twitter::before {
    content: url('../img/x.svg');
}

.github::before {
    content: url('../img/github.svg');
}

.linkedin::before {
    content: url('../img/linkedin.svg');
}

.upwork::before {
    content: url('../img/upwork.svg');
}

.researchgate::before {
    content: url('../img/researchgate.svg');
}