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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #e8eef5 0%, #f5f7fa 100%);
    min-height: 100vh;
    color: #1a1a2e;
}

/* NAVBAR */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 30px 80px;
    background: transparent;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    background: linear-gradient(90deg, 
        rgb(255, 0, 0) 0%, 
        rgb(0, 255, 0) 50%, 
        rgb(0, 0, 255) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: rgbShift 3s linear infinite;
    background-size: 200% 100%;
}

@keyframes rgbShift {
    0% {
        background-position: 0% 50%;
    }
    100% {
        background-position: 200% 50%;
    }
}

nav {
    display: flex;
    gap: 40px;
}

nav a {
    text-decoration: none;
    color: #1a1a2e;
    font-size: 16px;
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
}

nav a.active {
    color: #4169ff;
}

nav a:hover {
    color: #4169ff;
}

/* TOGGLE SWITCH */
.switch {
    font-size: 17px;
    position: relative;
    display: inline-block;
    width: 3.5em;
    height: 2em;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    --background: #28096b;
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--background);
    transition: .5s;
    border-radius: 30px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 1.4em;
    width: 1.4em;
    border-radius: 50%;
    left: 10%;
    bottom: 15%;
    box-shadow: inset 8px -4px 0px 0px #fff000;
    background: var(--background);
    transition: .5s;
}

input:checked + .slider {
    background-color: #522ba7;
}

input:checked + .slider:before {
    transform: translateX(100%);
    box-shadow: inset 15px -4px 0px 15px #fff000;
}

/* SKILLS SECTION */
.skills-section {
    padding: 60px 80px;
    max-width: 1400px;
    margin: 0 auto;
}

.skills-header {
    text-align: center;
    margin-bottom: 60px;
}

.skills-header h1 {
    font-size: 48px;
    margin-bottom: 15px;
    background: linear-gradient(90deg, #4169ff, #22d3ee);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.skills-header p {
    font-size: 18px;
    color: #4a5568;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

.skill-category {
    background: white;
    padding: 35px;
    border-radius: 20px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
}

.skill-category::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, #4169ff, #22d3ee);
}

.skill-category:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 50px rgba(65, 105, 255, 0.3);
}

.category-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, #4169ff, #22d3ee);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.category-icon i {
    font-size: 32px;
    color: white;
}

.skill-category h2 {
    font-size: 24px;
    color: #1a1a2e;
    margin-bottom: 25px;
}

.skill-items {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
}

.skill-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 15px;
    background: #f8fafc;
    border-radius: 10px;
    transition: all 0.3s;
    border: 2px solid transparent;
}

.skill-item:hover {
    background: #e8eef5;
    border-color: #4169ff;
    transform: translateX(5px);
}

.skill-item i {
    font-size: 24px;
    color: #4169ff;
}

.skill-item span {
    font-size: 15px;
    font-weight: 500;
    color: #1a1a2e;
}

/* RESPONSIVE */
@media (max-width: 1024px) {
    .navbar,
    .skills-section {
        padding: 30px 40px;
    }

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

    .skills-header h1 {
        font-size: 36px;
    }
}

@media (max-width: 768px) {
    .navbar {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 20px;
    }

    nav {
        gap: 20px;
        flex-wrap: wrap;
        justify-content: center;
        order: 3;
        width: 100%;
    }

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

    .skills-header h1 {
        font-size: 32px;
    }

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

/* DARK MODE */
body.dark-mode {
    background: linear-gradient(135deg, #0d0d1a 0%, #1a1a2e 100%);
    color: #e2e8f0;
}

body.dark-mode .logo,
body.dark-mode nav a,
body.dark-mode .skill-category h2,
body.dark-mode .skill-item span {
    color: #e2e8f0;
}

body.dark-mode nav a.active {
    color: #4169ff;
}

body.dark-mode .skills-header p {
    color: #94a3b8;
}

body.dark-mode .skill-category {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

body.dark-mode .skill-item {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.1);
}

body.dark-mode .skill-item:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: #4169ff;
}

/* ── FOOTER ── */
.footer {
    text-align: center;
    padding: 40px 6%;
    margin-top: 60px;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    color: #4a5568;
    font-size: 0.9rem;
}

.footer span {
    background: linear-gradient(135deg, #a78bfa, #22d3ee);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 600;
}

body.dark-mode .footer {
    color: #94a3b8;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
}

body.dark-mode .footer span {
    background: linear-gradient(135deg, #a78bfa, #22d3ee);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}