:root {
    /* Light theme variables */
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #3b82f6;
    --background-color: #f8fafc;
    --card-background: #ffffff;
    --text-color: #1e293b;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --hover-color: #dbeafe;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --light-bg: #f9f9f9;
}

/* Dark theme */
@media (prefers-color-scheme: dark) {
    :root {
        --primary-color: #3b82f6;
        --secondary-color: #60a5fa;
        --accent-color: #2563eb;
        --background-color: #0f172a;
        --card-background: #1e293b;
        --text-color: #f1f5f9;
        --text-muted: #94a3b8;
        --border-color: #334155;
        --hover-color: #1e40af;
        --shadow-color: rgba(0, 0, 0, 0.3);
    }
}

/* Manual dark mode class for JavaScript toggle */
.dark-mode {
    --primary-color: #3b82f6;
    --secondary-color: #60a5fa;
    --accent-color: #2563eb;
    --background-color: #0f172a;
    --card-background: #1e293b;
    --text-color: #f1f5f9;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --hover-color: #1e40af;
    --shadow-color: rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.8;
    color: var(--text-color);
    background-color: var(--background-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

.content-wrapper {
    max-width: 800px;
    margin: 0 auto;
}

header {
    background-color: var(--card-background);
    border-bottom: 1px solid var(--border-color);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: 1rem 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
}

header.scrolled {
    padding: 0.5rem 0;
    background-color: var(--card-background);
    opacity: 0.98;
}

header.hidden {
    transform: translateY(-100%);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    color: var(--text-color);
    font-size: 1.5rem;
    font-weight: bold;
    transition: all 0.3s ease;
}

.menu-toggle {
    display: none;
    color: #ffffff;
    font-size: 1.5rem;
    cursor: pointer;
    z-index: 1001; 
    padding: 0.5rem;
    background-color: rgba(52, 152, 219, 0.8); /* Semi-transparent primary color */
    border-radius: 5px;
}

.nav-menu {
    list-style-type: none;
    display: flex;
}

.nav-menu li {
    margin-left: 1rem;
}

.nav-menu li a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: bold;
    transition: color 0.3s ease;
    position: relative;
}

.nav-menu li a::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 2px;
    bottom: -5px;
    left: 0;
    background-color: var(--accent-color);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.nav-menu li a:hover::after {
    transform: scaleX(1);
}

main {
    margin-top: 60px;
    flex: 1;
}

section {
    padding: 3rem 0;
}

.bg-light {
    background-color: var(--card-background);
}

h1, h2, h3 {
    font-family: 'Montserrat', sans-serif;
}

.hero {
    text-align: center;
    padding: 8rem 0 6rem;
    position: relative;
    overflow: hidden;
    color: #ffffff;
}

/* Light mode hero background */
.hero {
    background: linear-gradient(135deg, #2563eb, #1d4ed8);
}

/* Dark mode hero background */
.dark-mode .hero {
    background: linear-gradient(135deg, #1e40af, #1e3a8a);
}

/* Hero overlay for better text visibility */
.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(rgba(0, 0, 0, 0.1), rgba(0, 0, 0, 0.2));
    z-index: 1;
}

/* Ensure hero content is above the overlay */
.hero > * {
    position: relative;
    z-index: 2;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -50px;
    left: 0;
    right: 0;
    height: 100px;
    background-color: var(--background-color);
    transform: skewY(-3deg);
    z-index: 3;
}

.profile-photo {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    margin-bottom: 2rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    border: 5px solid rgba(255, 255, 255, 0.9);
    object-fit: cover;
    position: relative;
    z-index: 2;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.hero .lead {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    opacity: 0.95;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

#subtitle {
    max-width: 600px;
    margin: 0 auto;
    font-size: 1.1rem;
    opacity: 0.9;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.skill-item, .education-item, .achievement-item, .experience-item {
    background-color: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 4px 6px var(--shadow-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.skill-item:hover, .education-item:hover, .achievement-item:hover, .experience-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px var(--shadow-color);
    border-color: var(--accent-color);
}

#social-links {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
}

#social-links a {
    color: var(--text-color);
    font-size: 1.5rem;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
}

#social-links a:hover {
    color: var(--primary-color);
    transform: translateY(-3px);
}

footer {
    background-color: var(--card-background);
    border-top: 1px solid var(--border-color);
    color: var(--text-color);
    text-align: center;
    padding: 0.5rem 0; /* Minimal padding */
    margin-top: 1rem; /* Üstten biraz boşluk */
}

footer p {
    margin: 0;
    font-size: 0.9rem; /* Metin boyutunu biraz küçülttük */
}

.school-logo, .achievement-logo, .experience-logo {
    width: 100px;
    height: 100px;
    object-fit: contain;
    margin-bottom: 1rem;
}

.achievement-item a, .education-item a, .experience-item a {
    display: inline-block;
    margin-top: 1rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: bold;
}

.achievement-item a:hover, .education-item a:hover, .experience-item a:hover {
    text-decoration: underline;
}

.experience-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
}

.experience-logo {
    flex-shrink: 0;
}

.experience-content {
    flex: 1;
}

#skills-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
    margin-top: 1rem;
}

.skill-item {
    width: 40px;
    height: 40px;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    box-shadow: 0 2px 4px var(--shadow-color);
    transition: all 0.3s ease;
    position: relative;
    z-index: 1;
    color: var(--text-color);
}

.skill-item i {
    font-size: 1.2rem;
    color: var(--primary-color);
}

.skill-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 6px var(--shadow-color);
    border-color: var(--accent-color);
}

.skill-item::after {
    content: attr(data-skill);
    position: absolute;
    top: -30px;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--card-background);
    color: var(--text-color);
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 0.8rem;
    white-space: nowrap;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 2;
    border: 1px solid var(--border-color);
    box-shadow: 0 2px 4px var(--shadow-color);
}

.skill-item:hover::after {
    opacity: 1;
    visibility: visible;
    top: -35px;
}

.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in.appear {
    opacity: 1;
    transform: translateY(0);
}

.progress-container {
    position: fixed;
    top: 0;
    z-index: 1001;
    width: 100%;
    height: 4px;
    background: var(--border-color);
}

.progress-bar {
    height: 4px;
    background: var(--primary-color);
    width: 0%;
}

@media (max-width: 768px) {
    .menu-toggle {
        display: block;
    }

    .nav-menu {
        position: fixed;
        top: 60px;
        left: -100%;
        background-color: var(--card-background);
        width: 100%;
        height: calc(100vh - 60px); 
        flex-direction: column;
        align-items: center;
        transition: 0.3s;
        overflow-y: auto; 
        backdrop-filter: blur(5px); 
        box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1); 
        border: 1px solid var(--border-color);
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-menu li {
        margin: 1.5rem 0;
    }

    .nav-menu li a {
        font-size: 1.2rem; 
        padding: 0.5rem 1rem; 
        border-radius: 5px; 
        transition: background-color 0.3s ease;
    }

    .nav-menu li a:hover {
        background-color: var(--hover-color);
    }

    .grid {
        grid-template-columns: 1fr;
    }

    .experience-item {
        flex-direction: column;
        align-items: center;
    }

    .experience-logo {
        margin-bottom: 1rem;
    }

    .container, .content-wrapper {
        padding: 0 15px;
    }

    header {
        padding: 0.3rem 0;
    }

    .logo {
        font-size: 1.2rem;
    }

    .menu-toggle {
        font-size: 1.2rem;
    }

    .nav-menu {
        top: 50px; 
    }
}

.item-card {
    background-color: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: 0 4px 6px var(--shadow-color);
    padding: 2rem;
    display: flex;
    align-items: flex-start;
    margin-bottom: 2rem;
    transition: all 0.3s ease;
}

.item-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 12px var(--shadow-color);
    border-color: var(--accent-color);
}

.item-logo {
    width: 100px;
    height: 100px;
    object-fit: contain;
    margin-right: 2rem;
    border-radius: 5px;
}

#experience-content .item-logo {
    width: 150px;  
    height: 150px; 
}

.item-content h3 {
    color: var(--text-color);
    margin-bottom: 0.5rem;
    font-size: 1.5rem;
}

.item-subtitle {
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.item-duration {
    color: var(--text-muted);
    margin-bottom: 1rem;
}

.item-link {
    display: inline-block;
    margin-top: 1rem;
    color: var(--accent-color);
    text-decoration: none;
    font-weight: bold;
    transition: color 0.3s ease;
}

.item-link:hover {
    color: var(--primary-color);
}

@media (max-width: 768px) {
    .item-card {
        flex-direction: column;
        align-items: center;
        text-align: center;
        padding: 1rem;
    }

    .item-logo {
        margin-right: 0;
        margin-bottom: 1rem;
    }

    #achievements-content .item-card {
        max-width: 100%;
    }
}

.certificate-links {
    margin-top: 1rem;
}

.certificate-links .item-link {
    display: inline-block;
    margin-right: 1rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

section h2 {
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-color);
    font-size: 2.5rem;
    font-weight: bold;
    position: relative;
    padding-bottom: 1rem;
}

section h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 3px;
    background-color: var(--primary-color);
}

#about h2,
#skills h2,
#education h2,
#experience h2,
#achievements h2 {
    text-align: center;
    margin-bottom: 2rem;
    color: var(--text-color);
}

@media (max-width: 768px) {
    section h2 {
        font-size: 2rem;
    }
}

.experience-bullet {
    margin-top: 0.25rem;
    color: var(--text-color);
}

.project-card {
    background-color: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: 0 4px 6px var(--shadow-color);
    padding: 2rem;
    margin-bottom: 2rem;
    transition: all 0.3s ease;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 12px var(--shadow-color);
    border-color: var(--accent-color);
}

.project-title {
    color: var(--text-color);
    margin-bottom: 0.5rem;
    font-size: 1.5rem;
}

.project-description, .project-full-description {
    color: var(--text-color);
    margin-bottom: 1rem;
    display: inline; /* Yazı ve More butonu aynı satırda olsun */
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.tech-tag {
    background-color: var(--primary-color);
    color: #ffffff;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.8rem;
}

.project-links {
    display: flex;
    gap: 1rem;
}

.project-link {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: bold;
    transition: color 0.3s ease;
}

.project-link:hover {
    color: var(--primary-color);
}

.toggle-bullets {
    background-color: var(--primary-color);
    color: #ffffff;
    border: none;
    padding: 5px 10px;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 10px;
}

.toggle-bullets:hover {
    background-color: var(--accent-color);
}

.experience-bullets {
    margin-top: 10px;
}

.toggle-project-description {
    color: var(--primary-color);
    cursor: pointer;
    font-weight: bold;
    margin-left: 5px;
    transition: color 0.3s ease;
}

.toggle-project-description:hover {
    color: var(--accent-color);
}

.project-full-description {
    margin-top: 10px;
}

.theme-toggle {
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 0.5rem;
    margin-left: 1rem;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.theme-toggle:hover {
    background-color: var(--hover-color);
    transform: scale(1.1);
}

.theme-toggle:focus {
    outline: none;
    box-shadow: 0 0 0 2px var(--accent-color);
}

/* Update general text colors */
p, span, div {
    color: var(--text-color);
}

/* Update background colors */
body, main, section {
    background-color: var(--background-color);
}

/* Update link colors */
a {
    color: var(--primary-color);
}

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

/* Update mobile menu */
@media (max-width: 768px) {
    .menu-toggle {
        color: var(--text-color);
        background-color: var(--card-background);
    }
}

/* Update hero section text */
.hero h1, .hero p, .hero .lead, #subtitle {
    color: #ffffff;
}

/* Update section backgrounds */
section:nth-child(even) {
    background-color: var(--background-color);
}

section:nth-child(odd) {
    background-color: var(--card-background);
}

/* Update progress bar */
.progress-container {
    background-color: var(--card-background);
    border-bottom: 1px solid var(--border-color);
}

/* Update all text content to ensure visibility */
.item-content p, 
.project-description, 
.project-full-description,
.experience-bullet,
.education-bullet {
    color: var(--text-color);
}

/* Update theme toggle button */
.theme-toggle {
    background-color: var(--card-background);
    border: 1px solid var(--border-color);
}

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

/* Ensure all headings are visible */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-color);
}