/* ===== Design Tokens ===== */
:root {
    /* Light theme (default) */
    --bg: #ffffff;
    --bg-secondary: #f9fafb;
    --foreground: #2d2d2d;
    --foreground-muted: #666666;
    --foreground-subtle: #6b7280;
    --foreground-strong: #1a1a1a;
    --foreground-inverse: #111827;
    --primary: #00bcd4;
    --accent: #ff4081;
    --card-bg: #ffffff;
    --card-bg-hover: #fff;
    --border: #e5e7eb;
    --border-light: #d1d5db;
    --tag-bg: #f3f4f6;
    --tag-color: #4b5563;
    --skill-bg: #f3f4f6;
    --skill-border: #e5e7eb;
    --skill-color: #374151;
    --skill-hover-bg: #fff;
    --navbar-bg: rgba(255, 255, 255, 0.8);
    --social-border: #d1d5db;
    --social-color: #4b5563;
    --social-hover-color: #000;
    --social-hover-border: #38bdf8;
    --social-hover-bg: rgba(56, 189, 248, 0.05);
    --link-hover-bg: #f9fafb;
    --link-hover-color: #111827;
    --shadow-card: rgba(0, 0, 0, 0.05);
    --shadow-skill: rgba(0, 0, 0, 0.1);
    --footer-color: #888888;
    --title-line: #e5e7eb;
}

body:has(.theme-toggle-input:checked) {
    --bg: #0f0f11;
    --bg-secondary: #18181b;
    --foreground: #e4e4e7;
    --foreground-muted: #a1a1aa;
    --foreground-subtle: #a1a1aa;
    --foreground-strong: #fafafa;
    --foreground-inverse: #fafafa;
    --primary: #22d3ee;
    --accent: #f472b6;
    --card-bg: #18181b;
    --card-bg-hover: #1e1e22;
    --border: #27272a;
    --border-light: #3f3f46;
    --tag-bg: #27272a;
    --tag-color: #a1a1aa;
    --skill-bg: #1c1c20;
    --skill-border: #27272a;
    --skill-color: #d4d4d8;
    --skill-hover-bg: #27272a;
    --navbar-bg: rgba(15, 15, 17, 0.85);
    --social-border: #3f3f46;
    --social-color: #71717a;
    --social-hover-color: #ffffff;
    --social-hover-border: #22d3ee;
    --social-hover-bg: rgba(34, 211, 238, 0.08);
    --link-hover-bg: #27272a;
    --link-hover-color: #fafafa;
    --shadow-card: rgba(0, 0, 0, 0.3);
    --shadow-skill: rgba(0, 0, 0, 0.4);
    --footer-color: #71717a;
    --title-line: #27272a;
}

/* ===== Reset ===== */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg);
    color: var(--foreground);
    line-height: 1.6;
    transition: background-color 0.4s ease, color 0.4s ease;
}

/* ===== Layout ===== */
.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ===== Profile Pic ===== */
.profile-pic {
    border-radius: 50%;
    height: auto;
    width: clamp(150px, 50vw, 250px);
}

/* ===== Social Links ===== */
.social-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-top: 2rem;
}

.social-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 1px solid var(--social-border);
    color: var(--social-color);
    background-color: transparent;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-decoration: none;
}

.social-icon:hover {
    color: var(--social-hover-color);
    border-color: var(--social-hover-border);
    background-color: var(--social-hover-bg);
    transform: translateY(-4px);
    box-shadow: 0 4px 12px var(--shadow-card);
}

.social-icon svg {
    width: 20px;
    height: 20px;
}

/* ===== Navbar ===== */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: var(--navbar-bg);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: background 0.4s ease, border-color 0.4s ease;
}

.nav-container {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    justify-content: right;
    padding: 1rem 2rem;
    align-items: center;
}

.nav-links a {
    text-decoration: none;
    color: var(--foreground);
    margin-left: 1.5rem;
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--primary);
}

/* ===== Theme Toggle ===== */
.theme-toggle-input {
    position: fixed;
    width: 1px;
    height: 1px;
    opacity: 0;
    pointer-events: none;
}

.theme-toggle {
    margin-left: auto;
    padding: 0;
    background: none;
    border: 1px solid var(--border);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--foreground-muted);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    flex-shrink: 0;
}

.theme-toggle-input:focus-visible ~ .navbar .theme-toggle {
    outline: 3px solid var(--primary);
    outline-offset: 3px;
}

.theme-toggle:hover {
    color: var(--primary);
    border-color: var(--primary);
    background-color: var(--social-hover-bg);
    transform: rotate(15deg);
}

.theme-toggle svg {
    width: 18px;
    height: 18px;
    transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.3s ease;
    position: absolute;
    top: 50%;
    left: 50%;
}

.theme-toggle .icon-sun {
    opacity: 0;
    transform: translate(-50%, -50%) rotate(-90deg) scale(0.5);
}

.theme-toggle .icon-moon {
    opacity: 1;
    transform: translate(-50%, -50%) rotate(0deg) scale(1);
}

body:has(.theme-toggle-input:checked) .theme-toggle .icon-sun {
    opacity: 1;
    transform: translate(-50%, -50%) rotate(0deg) scale(1);
}

body:has(.theme-toggle-input:checked) .theme-toggle .icon-moon {
    opacity: 0;
    transform: translate(-50%, -50%) rotate(90deg) scale(0.5);
}

/* ===== Hero ===== */
.hero {
    padding: 10rem 0 5rem;
    text-align: center;
}

.hero-title {
    font-family: 'Montserrat', sans-serif;
    font-size: 4rem;
    font-weight: 900;
    margin-bottom: 1rem;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--foreground-muted);
    margin-bottom: 2rem;
}

/* ===== Sections ===== */
.section {
    padding: 6rem 0;
}

.section-text {
    color: var(--foreground-subtle);
}

.title-line {
    flex-grow: 1;
    height: 1px;
    background-color: var(--title-line);
    transition: background-color 0.4s ease;
}

.section-title {
    font-family: 'Montserrat', sans-serif;
    font-size: 2rem;
    margin-bottom: 2rem;
    text-align: center;
}

.skills-header {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 2rem;
}

.skills-header .section-title {
    margin-bottom: 0;
    padding: 0 1.5rem;
}

/* ===== Skills ===== */
.skills-grid-5 {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    margin-top: 2rem;
}

.skill-category {
    margin-bottom: 1rem;
}

.category-title {
    font-family: 'Montserrat', sans-serif;
    font-size: 0.9rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 1rem;
    color: var(--foreground-strong);
}

.skill-items {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    list-style: none;
    padding: 0;
    margin-bottom: 1rem;
}

.skill-items li {
    display: flex;
    align-items: center;
    padding: 6px 14px;
    background-color: var(--skill-bg);
    border: 1px solid var(--skill-border);
    border-radius: 6px;
    font-family: 'Inter', sans-serif;
    font-size: 0.9rem;
    color: var(--skill-color);
    transition: all 0.3s ease;
    cursor: default;
}

.skill-items li:hover {
    background-color: var(--skill-hover-bg);
    border-color: var(--primary);
    color: var(--primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 6px -1px var(--shadow-skill);
}

@media (max-width: 768px) {
    .skill-items {
        gap: 8px;
    }
    .skill-items li {
        font-size: 0.85rem;
        padding: 5px 10px;
    }
}

/* ===== Projects Grid ===== */
#projects .grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
    margin-top: 2rem;
}

@media (max-width: 992px) {
    #projects .grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

/* ===== Project Card ===== */
.project-card {
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease, background 0.4s ease, border-color 0.4s ease;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px var(--shadow-card);
    border-color: var(--primary);
}

.project-content {
    flex-grow: 1;
}

.project-card h3 {
    font-family: 'Inter', sans-serif;
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--foreground-strong);
    text-transform: lowercase;
}

.project-card p {
    font-size: 0.95rem;
    color: var(--foreground-subtle);
    line-height: 1.5;
    margin-bottom: 1.25rem;
}

.tech-stack-label {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--foreground-strong);
    margin-bottom: 0.5rem;
}

/* ===== Tags ===== */
.tags {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 1.5rem;
}

.tag {
    background-color: var(--tag-bg);
    color: var(--tag-color);
    font-size: 0.75rem;
    font-weight: 500;
    padding: 4px 12px;
    border-radius: 9999px;
    text-transform: none;
    letter-spacing: normal;
    transition: background-color 0.4s ease, color 0.4s ease;
}

/* ===== Project Footer / Links ===== */
.project-footer {
    display: flex;
    justify-content: flex-start;
    gap: 0.75rem;
}

.project-link {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.85rem;
    font-weight: 500;
    text-decoration: none;
    color: var(--tag-color);
    border: 1px solid var(--border);
    padding: 6px 12px;
    border-radius: 6px;
    transition: all 0.2s ease;
}

.project-link:hover {
    background-color: var(--link-hover-bg);
    color: var(--link-hover-color);
    border-color: var(--border-light);
}

.project-link svg {
    width: 16px;
    height: 16px;
    stroke: currentColor;
}

/* ===== Buttons ===== */
.btn {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    background: var(--primary);
    color: white;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    margin: 0.5rem;
    transition: opacity 0.3s;
}

.btn:hover {
    opacity: 0.8;
}

/* ===== Animations ===== */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.animate-fade-in {
    animation: fadeInUp 0.8s ease-out forwards;
}

/* ===== Footer ===== */
.footer {
    text-align: center;
    padding: 4rem 0;
    border-top: 1px solid var(--border);
    font-size: 0.9rem;
    color: var(--footer-color);
    transition: border-color 0.4s ease, color 0.4s ease;
}

@media (max-width: 768px) {
    .hero-title { font-size: 2.5rem; }
}

/* ===== Achievements / Timeline ===== */
.timeline {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
}

@media (max-width: 992px) {
    .timeline {
        grid-template-columns: 1fr;
    }
}

.timeline .card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease, background 0.4s ease, border-color 0.4s ease;
    display: flex;
    flex-direction: column;
}

.timeline .card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px var(--shadow-card);
    border-color: var(--primary);
}

.timeline .card h3 {
    font-family: 'Inter', sans-serif;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--foreground-strong);
    margin-bottom: 0.25rem;
}

.timeline .card .card-meta {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 1rem;
}

.timeline .card p:not(.card-meta) {
    font-size: 0.95rem;
    color: var(--foreground-subtle);
    line-height: 1.5;
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

.achievement-footer {
    display: flex;
    justify-content: flex-start;
}