/* CSS Reset and Theme Variables */
:root {
    /* Light theme (defaults) */
    --bg: #f0ebebdc;
    --surface: #ffffff00;
    --primary: #2c3e50;
    --secondary: #3498db;
    --accent: #e74c3c;
    --muted: #6b7280;
    --text: #202731;
    --inverse-text: #ffffff;
    --card-shadow: rgba(175, 175, 179, 0.849);
    --glass: rgba(63, 28, 28, 0.397);
    --transition: all 0.3s ease;
}

/* Dark theme overrides */
:root[data-theme='dark'],
[data-theme='dark'] {
    --bg: #0b1020;
    --surface: #0f172441;
    --primary: #e6eef8;       /* headings */
    --secondary: #60a5fa;     /* accent */
    --accent: #fb7185;
    --muted: #9aa6b2;
    --text: #e6eef8;
    --inverse-text: #0b1020;
    --card-shadow: rgba(2,6,23,0.6);
    --glass: rgba(12,18,28,0.6);
}

/* Global */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

html {
    scroll-behavior: smooth;
}

body {
    line-height: 1.6;
    color: var(--text);
    background-color: var(--bg);
    transition: background-color 0.35s ease, color 0.35s ease;
}

/* Container */
.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* Typography */
h1, h2, h3, h4 {
    margin-bottom: 15px;
    color: var(--primary);
}

h1 {
    font-size: 2.5rem;
}

h2 {
    font-size: 2rem;
    text-align: center;
    margin-bottom: 40px;
    position: relative;
}

h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background-color: var(--secondary);
}

p {
    margin-bottom: 15px;
    color: var(--muted);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 10px 25px;
    background-color: var(--secondary);
    color: var(--inverse-text);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    text-decoration: none;
    transition: var(--transition);
    font-weight: 600;
    box-shadow: 0 6px 18px var(--card-shadow);
}

.btn.ghost {
    background: transparent;
    color: var(--text);
    border: 1px solid rgba(0,0,0,0.06);
    box-shadow: none;
}

.btn.small {
    padding: 8px 12px;
    font-size: 0.9rem;
    border-radius: 6px;
}

.btn:hover {
    transform: translateY(-3px);
    filter: brightness(1.05);
}

/* Header and Navigation */
header {
    background-color: var(--surface);
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: background-color 0.25s ease, box-shadow 0.25s ease;
    backdrop-filter: blur(6px);
}

header.scrolled {
    box-shadow: 0 8px 30px rgba(2,6,23,0.12);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 0;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
}

.logo span {
    color: var(--secondary);
}

/* Theme toggle button */
.theme-toggle {
    background: transparent;
    border: none;
    color: var(--text);
    font-size: 1.125rem;
    cursor: pointer;
    margin-left: 12px;
    padding: 8px;
    border-radius: 8px;
    transition: var(--transition);
}
.theme-toggle:hover {
    background: var(--glass);
}

/* Desktop nav */
.menu-toggle {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
    margin-left: 12px;
    color: var(--text);
    background: transparent;
    border: none;
}

/* Nav links */
.nav-links {
    display: flex;
    list-style: none;
    align-items: center;
    gap: 12px;
}

.nav-links li {
    margin-left: 18px;
}

.nav-links a {
    text-decoration: none;
    color: var(--text);
    font-weight: 500;
    transition: var(--transition);
    padding: 8px 10px;
    border-radius: 6px;
}
.nav-links a:hover {
    color: var(--secondary);
    background: rgba(0,0,0,0.03);
}

/* Theme banner */
.theme-banner {
    position: fixed;
    right: 20px;
    bottom: 20px;
    background: linear-gradient(180deg, rgba(255,255,255,0.95), rgba(255,255,255,0.90));
    color: var(--text);
    border-radius: 12px;
    box-shadow: 0 12px 40px rgba(2,6,23,0.12);
    padding: 14px;
    min-width: 280px;
    z-index: 1500;
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.3s ease, transform 0.3s ease;
}
:root[data-theme='dark'] .theme-banner,
[data-theme='dark'] .theme-banner {
    background: linear-gradient(180deg, rgba(12,18,28,0.95), rgba(12,18,28,0.90));
    color: var(--text);
    box-shadow: 0 12px 40px rgba(2,6,23,0.5);
}
.theme-banner[hidden] { display: none; }
.theme-banner[style] { /* when script toggles inline opacity/hidden */ }
.theme-banner-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}
.banner-sub {
    font-size: 0.9rem;
    color: var(--muted);
    margin-top: 6px;
}

/* Sections */
section {
    padding: 100px 0;
}

/* Home Section */
#home {
    background: linear-gradient(145deg, var(--surface) 0%, var( --primary) 100%);
    color: var(--inverse-text);
    text-align: center;
    padding: 150px 0 100px;
    min-height: 100vh;
    display: flex;
    align-items: center;
}

#home h1 {
    color: var(--inverse-text);
    font-size: 5.0rem;
    margin-bottom: 20px;
}

#home p {
    font-size: 2.0rem;
    max-width: 700px;
    margin: 0 auto 30px;
    color: rgba(255,255,255,0.9);
}

/* About Section */
#about {
    background-color: var(--bg);
}

.about-content {
    display: flex;
    align-items: center;
    gap: 40px;
}

.about-img {
    flex: 1;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 10px 30px var(--card-shadow);
}

.about-img img {
    width: 100%;
    height: auto;
    display: block;
    filter: saturate(0.95);
}

.about-text {
    flex: 1;
     font-size: 1.1rem;
}
.about-text p {
    margin-bottom: 20px;
    color: var(--text-light);
    line-height: 1.7;
}

.about-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin: 30px 0;
}

.info-item {
    display: flex;
    align-items: center;
}

.info-label {
    font-weight: 600;
    margin-right: 10px;
    color: var(--dark-color);
    min-width: 80px;
}

.info-value {
    color: var(--text-light);
}


/* Skills Section */
#skills {
    background-color: var(--bg);
}

.skills-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.skill-category {
    background-color: var(--surface);
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 6px 20px var(--card-shadow);
}

.skill-category h3 {
    margin-bottom: 20px;
    color: var(--secondary);
}

.skill-item {
    margin-bottom: 15px;
}

.skill-name {
    display: flex;
    justify-content: space-between;
    margin-bottom: 5px;
    color: var(--muted);
    font-weight: 600;
}

.skill-bar {
    height: 10px;
    background-color: rgba(0,0,0,0.06);
    border-radius: 5px;
    overflow: hidden;
}

.skill-level {
    height: 100%;
    background-color: var(--secondary);
    border-radius: 5px;
    transition: width 0.6s ease;
}

/* Education Section */
#education {
    background-color: var(--bg);
}

/* Timeline (new) */
.timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
    padding: 10px 0 30px;
}

/* vertical line */
.timeline::before {
    content: '';
    position: absolute;
    left: 105px;               /* distance from left edge - controls line placement */
    top: 0;
    bottom: 0;
    width: 3px;
    background-color: rgba(96,165,250,0.18); /* soft blue line */
    border-radius: 2px;
}

/* single item */
.timeline-item {
    position: relative;
    padding: 25px 5px 25px 140px; /* space for the line + icon */
    box-sizing: border-box;
}

/* round icon on the line */
.timeline-icon {
    position: absolute;
    left: 90px; /* centers icon over the vertical line */
    top: 28px;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: rgba(96,165,250,0.14);
    border: 3px solid rgba(96,165,250,0.28);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--secondary);
    font-size: 14px;
    box-shadow: 0 6px 18px var(--card-shadow);
}

/* card with content */
.timeline-content {
    background: var(--surface);
    color: var(--text);
    padding: 18px;
    border-radius: 10px;
    box-shadow: 0 8px 28px var(--card-shadow);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}

/* headline and meta */
.timeline-content h3 {
    margin-bottom: 6px;
    font-size: 1.05rem;
    color: var(--primary);
}
.small-meta {
    color: var(--secondary);
    font-size: 1rem;
    margin-bottom: 8px;
    font-weight: bold; 
}



.timeline-institute::before {
    content: '\f19d';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    margin-right: 8px;
     color: var(--secondary);
    font-size: 1rem;
}



/* pill date on the right */
.date-badge {
    position: absolute;
    right: 10px;
    top: 28px;
    background: rgba(96,165,250,0.12); /* subtle blue background */
    color: var(--secondary);
    font-weight: 600;
    font-size: 0.85rem;
    padding: 3px 10px;
    border-radius: 999px;
    border: 1px solid rgba(96,165,250,0.22);
    white-space: nowrap;
}

/* hover effect */
.timeline-item:hover .timeline-content {
    transform: translateY(-6px);
    box-shadow: 0 18px 40px rgba(2,6,23,0.12);
}

/* alternate spacing tweak (optional if you want them closer) */
.timeline-item + .timeline-item { margin-top: 22px; }

/* responsive: stack items and move icon to left edge on small screens */
@media (max-width: 768px) {
    .timeline::before { left: 28px; }
    .timeline-item { padding: 18px 16px 18px 72px; }
    .timeline-icon { left: 20px; top: 20px; width: 30px; height: 30px; font-size: 12px; }
    .date-badge { position: static; display: inline-block; margin-top: 10px; float: right; }
    .timeline-content { margin-right: 0; }
}

.left {
    left: 0;
}

.right {
    left: 50%;
}

.left::after {
    right: -10px;
}

.right::after {
    left: -10px;
}


/* Projects Section */
#projects {
    background-color: var(--bg);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.project-card {
    
    background-color: var(--surface);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 6px 20px var(--card-shadow);
    transition: var(--transition);
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(2,6,23,0.12);
}

.project-img {
    height: 200px;
    overflow: hidden;
}

.project-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.project-card:hover .project-img img {
    transform: scale(1.05);
}

.project-info {
    padding: 20px;
}

.project-info h3 {
    margin-bottom: 10px;
    color: var(--text);
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 5px;
    margin-bottom: 15px;
}

.project-tags span {
    background-color: rgba(0,0,0,0.06);
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 0.8rem;
}

/* Contact Section */
#contact {
    background-color: var(--bg);
}

.contact-container {
    display: flex;
    gap: 40px;
    align-items: flex-start;
}

.contact-info {
    flex: 1;
}

.contact-item {
    display: flex;
    align-items: center;
    margin-bottom: 20px;
    color: var(--text);
}

.contact-icon {
    width: 50px;
    height: 50px;
    background-color: var(--secondary);
    color: var(--inverse-text);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 15px;
    font-size: 1.2rem;
}

.contact-form {
    flex: 1;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: 600;
    color: var(--text);
}

.form-control {
    width: 100%;
    padding: 10px 15px;
    border: 1px solid rgba(0,0,0,0.08);
    border-radius: 8px;
    font-size: 1rem;
    background: var(--surface);
    color: var(--text);
}

/* Footer */
footer {
    background-color: var(--surface);
    color: var(--inverse-text);
    text-align: center;
    padding: 30px 0;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 20px;
}

.social-links a {
    color: var( --text);
    font-size: 1.5rem;
    transition: var(--transition);
}

.social-links a:hover {
    color: var(--secondary);
}

/* Responsive Design */
@media (max-width: 768px) {
    .menu-toggle {
        display: block;
    }
    
    .nav-links {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        flex-direction: column;
        background-color: var(--surface);
        text-align: center;
        transition: var(--transition);
        box-shadow: 0 10px 10px rgba(0, 0, 0, 0.06);
    }
    
    .nav-links.active {
        left: 0;
    }
    
    .nav-links li {
        margin: 15px 0;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    #home h1 {
        font-size: 2.5rem;
    }
    
    .about-content {
        flex-direction: column;
    }
    
    .timeline::after {
        left: 31px;
    }
    
    .timeline-item {
        width: 100%;
        padding-left: 70px;
        padding-right: 25px;
    }
    
    .timeline-item::after {
        left: 21px;
    }
    
    .left, .right {
        left: 0;
    }
    
    .contact-container {
        flex-direction: column;
    }

    .theme-banner {
        left: 12px;
        right: 12px;
        bottom: 16px;
        min-width: auto;
    }
}

/* Small utility for animation */
[data-animate] {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}
[data-animate].visible {
    opacity: 1;
    transform: translateY(0);
}