/* ===== CSS VARIABLES ===== */
:root {
    /* Colors - ML/AI Inspired Theme (Dark) */
    --clr-bg-primary: #0a0f0f;
    --clr-bg-secondary: #0f1a1a;
    --clr-bg-card: #142424;
    --clr-text-primary: #ffffff;
    --clr-text-secondary: #94a3b8;
    --clr-accent-primary: #14b8a6;
    --clr-accent-secondary: #2dd4bf;
    --clr-accent-warm: #f59e0b;
    --clr-accent-gradient: linear-gradient(135deg, #14b8a6 0%, #06b6d4 50%, #0ea5e9 100%);
    --clr-accent-gradient-warm: linear-gradient(135deg, #f59e0b 0%, #f97316 100%);
    --clr-border: rgba(20, 184, 166, 0.15);
    --clr-header-bg: rgba(10, 15, 15, 0.9);

    /* Typography */
    --ff-primary: 'Inter', sans-serif;
    --fs-xs: 0.75rem;
    --fs-sm: 0.875rem;
    --fs-base: 1rem;
    --fs-lg: 1.125rem;
    --fs-xl: 1.25rem;
    --fs-2xl: 1.5rem;
    --fs-3xl: 2rem;
    --fs-4xl: 2.5rem;
    --fs-5xl: 3.5rem;
    --fw-regular: 400;
    --fw-medium: 500;
    --fw-semibold: 600;
    --fw-bold: 700;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    --spacing-4xl: 6rem;

    /* Effects */
    --border-radius-sm: 0.375rem;
    --border-radius-md: 0.5rem;
    --border-radius-lg: 1rem;
    --border-radius-xl: 1.5rem;
    --border-radius-full: 9999px;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 30px rgba(20, 184, 166, 0.3);
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;

    /* Layout */
    --header-height: 4rem;
    --container-max-width: 1200px;
}

/* Light Theme */
[data-theme="light"] {
    --clr-bg-primary: #f8fafc;
    --clr-bg-secondary: #e2e8f0;
    --clr-bg-card: #ffffff;
    --clr-text-primary: #0f172a;
    --clr-text-secondary: #475569;
    --clr-accent-primary: #0d9488;
    --clr-accent-secondary: #14b8a6;
    --clr-border: rgba(13, 148, 136, 0.2);
    --clr-header-bg: rgba(248, 250, 252, 0.9);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.15);
    --shadow-glow: 0 0 30px rgba(13, 148, 136, 0.2);
}

/* ===== CSS RESET ===== */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--header-height);
}

body {
    font-family: var(--ff-primary);
    font-size: var(--fs-base);
    line-height: 1.6;
    color: var(--clr-text-primary);
    background-color: var(--clr-bg-primary);
    overflow-x: hidden;
}

ul {
    list-style: none;
}

a {
    text-decoration: none;
    color: inherit;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

button {
    font-family: inherit;
    font-size: inherit;
    background: none;
    border: none;
    cursor: pointer;
    color: inherit;
}

/* ===== UTILITY CLASSES ===== */
.container {
    width: 100%;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.section {
    padding: var(--spacing-4xl) 0;
}

.section__title {
    font-size: var(--fs-3xl);
    font-weight: var(--fw-bold);
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.text-gradient {
    background: var(--clr-accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--fs-base);
    font-weight: var(--fw-medium);
    border-radius: var(--border-radius-full);
    transition: all var(--transition-base);
    cursor: pointer;
}

.btn--primary {
    background: var(--clr-accent-gradient);
    color: var(--clr-text-primary);
    box-shadow: var(--shadow-glow);
}

.btn--primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 0 40px rgba(20, 184, 166, 0.5);
}

.btn--outline {
    border: 2px solid var(--clr-accent-primary);
    color: var(--clr-accent-primary);
    background: transparent;
}

.btn--outline:hover {
    background: var(--clr-accent-primary);
    color: var(--clr-text-primary);
}

.btn--large {
    padding: var(--spacing-lg) var(--spacing-2xl);
    font-size: var(--fs-lg);
}

/* ===== HEADER & NAVIGATION ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background: var(--clr-header-bg);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid var(--clr-border);
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.nav__logo {
    font-size: var(--fs-xl);
    font-weight: var(--fw-bold);
    color: var(--clr-text-primary);
}

.nav__logo span {
    color: var(--clr-accent-primary);
}

.nav__list {
    display: flex;
    gap: var(--spacing-xl);
}

.nav__link {
    font-size: var(--fs-sm);
    font-weight: var(--fw-medium);
    color: var(--clr-text-secondary);
    transition: color var(--transition-fast);
    position: relative;
}

.nav__link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--clr-accent-gradient);
    transition: width var(--transition-base);
}

.nav__link:hover,
.nav__link.active {
    color: var(--clr-text-primary);
}

.nav__link:hover::after,
.nav__link.active::after {
    width: 100%;
}

.nav__toggle,
.nav__close {
    display: none;
}

.nav__actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

/* Theme Toggle */
.theme-toggle {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--clr-bg-card);
    border: 1px solid var(--clr-border);
    border-radius: var(--border-radius-full);
    color: var(--clr-text-secondary);
    cursor: pointer;
    transition: all var(--transition-base);
}

.theme-toggle:hover {
    background: var(--clr-accent-primary);
    border-color: var(--clr-accent-primary);
    color: var(--clr-text-primary);
}

.theme-toggle__icon--moon {
    display: none;
}

[data-theme="light"] .theme-toggle__icon--sun {
    display: none;
}

[data-theme="light"] .theme-toggle__icon--moon {
    display: block;
}

/* ===== HERO SECTION ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    padding-top: var(--header-height);
}

.hero__container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.hero__subtitle {
    display: block;
    font-size: var(--fs-lg);
    color: var(--clr-accent-primary);
    margin-bottom: var(--spacing-sm);
}

.hero__title {
    font-size: var(--fs-5xl);
    font-weight: var(--fw-bold);
    line-height: 1.1;
    margin-bottom: var(--spacing-lg);
}

.hero__description {
    font-size: var(--fs-lg);
    color: var(--clr-text-secondary);
    margin-bottom: var(--spacing-xl);
    max-width: 500px;
}

.hero__buttons {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.hero__image {
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

.hero__photo-wrapper {
    position: relative;
    z-index: 2;
}

.hero__photo {
    width: 300px;
    height: 300px;
    object-fit: cover;
    border-radius: 50%;
    border: 4px solid var(--clr-accent-primary);
    box-shadow: var(--shadow-glow);
}

.hero__blob {
    position: absolute;
    width: 350px;
    height: 350px;
    background: var(--clr-accent-gradient);
    border-radius: 60% 40% 30% 70% / 60% 30% 70% 40%;
    animation: blob-morph 8s ease-in-out infinite;
    opacity: 0.6;
    filter: blur(40px);
}

@keyframes blob-morph {

    0%,
    100% {
        border-radius: 60% 40% 30% 70% / 60% 30% 70% 40%;
    }

    50% {
        border-radius: 30% 60% 70% 40% / 50% 60% 30% 60%;
    }
}

.scroll-down {
    position: absolute;
    bottom: var(--spacing-xl);
    left: 50%;
    transform: translateX(-50%);
}

.scroll-down__icon {
    display: block;
    width: 24px;
    height: 40px;
    border: 2px solid var(--clr-text-secondary);
    border-radius: var(--border-radius-full);
    position: relative;
}

.scroll-down__icon::before {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: var(--clr-accent-primary);
    border-radius: var(--border-radius-full);
    animation: scroll-indicator 2s infinite;
}

@keyframes scroll-indicator {
    0% {
        opacity: 1;
        top: 8px;
    }

    100% {
        opacity: 0;
        top: 20px;
    }
}

/* ===== ABOUT SECTION ===== */
.about__content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.about__image-wrapper {
    position: relative;
}

.about__photo {
    width: 100%;
    aspect-ratio: 1;
    object-fit: cover;
    border-radius: var(--border-radius-xl);
    border: 3px solid var(--clr-accent-primary);
}

.about__image-wrapper::before {
    content: '';
    position: absolute;
    top: var(--spacing-lg);
    left: var(--spacing-lg);
    width: 100%;
    height: 100%;
    border: 3px solid var(--clr-accent-primary);
    border-radius: var(--border-radius-xl);
    z-index: -1;
}

.about__text {
    font-size: var(--fs-lg);
    color: var(--clr-text-secondary);
    margin-bottom: var(--spacing-lg);
}

.about__stats {
    display: flex;
    gap: var(--spacing-2xl);
    margin-top: var(--spacing-xl);
}

.about__stat {
    text-align: center;
}

.about__stat-number {
    display: block;
    font-size: var(--fs-3xl);
    font-weight: var(--fw-bold);
    background: var(--clr-accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.about__stat-label {
    font-size: var(--fs-sm);
    color: var(--clr-text-secondary);
}

/* ===== SKILLS SECTION ===== */
.skills__content {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
}

.skills__group {
    background: var(--clr-bg-card);
    padding: var(--spacing-xl);
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--clr-border);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.skills__group:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-glow);
}

.skills__group-title {
    font-size: var(--fs-xl);
    font-weight: var(--fw-semibold);
    margin-bottom: var(--spacing-lg);
    color: var(--clr-accent-primary);
}

.skills__tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.skill-tag {
    background: var(--clr-bg-secondary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--border-radius-full);
    font-size: var(--fs-sm);
    color: var(--clr-text-secondary);
    border: 1px solid var(--clr-border);
    transition: all var(--transition-fast);
}

.skill-tag:hover {
    border-color: var(--clr-accent-primary);
    color: var(--clr-text-primary);
}

/* ===== PROJECTS SECTION ===== */
.projects__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-xl);
}

.project-card {
    background: var(--clr-bg-card);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    border: 1px solid var(--clr-border);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-glow);
}

.project-card__image {
    position: relative;
    aspect-ratio: 16/10;
    overflow: hidden;
}

.project-card__placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--clr-bg-secondary), var(--clr-bg-card));
}

.project-card__img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.project-card__overlay {
    position: absolute;
    inset: 0;
    background: rgba(20, 184, 166, 0.9);
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-md);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.project-card:hover .project-card__overlay {
    opacity: 1;
}

.project-card__link {
    width: 50px;
    height: 50px;
    background: var(--clr-text-primary);
    border-radius: var(--border-radius-full);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: var(--fs-xl);
    transition: transform var(--transition-fast);
}

.project-card__link:hover {
    transform: scale(1.1);
}

.project-card__content {
    padding: var(--spacing-lg);
}

.project-card__title {
    font-size: var(--fs-xl);
    font-weight: var(--fw-semibold);
    margin-bottom: var(--spacing-sm);
}

.project-card__description {
    font-size: var(--fs-sm);
    color: var(--clr-text-secondary);
    margin-bottom: var(--spacing-md);
}

.project-card__tags {
    display: flex;
    gap: var(--spacing-sm);
}

.project-card__tags span {
    font-size: var(--fs-xs);
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--clr-bg-secondary);
    border-radius: var(--border-radius-sm);
    color: var(--clr-accent-secondary);
}

/* ===== CONTACT SECTION ===== */
.contact__content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.contact__text {
    font-size: var(--fs-lg);
    color: var(--clr-text-secondary);
    margin-bottom: var(--spacing-xl);
}

.contact__info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.contact__info-item {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    color: var(--clr-text-secondary);
}

.contact__info-item a {
    color: var(--clr-accent-secondary);
    transition: color var(--transition-fast);
}

.contact__info-item a:hover {
    color: var(--clr-accent-primary);
}

.contact__info-icon {
    font-size: var(--fs-lg);
}

.contact__socials {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.contact__social-link {
    width: 48px;
    height: 48px;
    display: flex;
    justify-content: center;
    align-items: center;
    background: var(--clr-bg-card);
    border: 1px solid var(--clr-border);
    border-radius: var(--border-radius-full);
    color: var(--clr-text-secondary);
    transition: all var(--transition-base);
}

.contact__social-link:hover {
    background: var(--clr-accent-primary);
    border-color: var(--clr-accent-primary);
    color: var(--clr-text-primary);
    transform: translateY(-3px);
}

/* ===== CERTIFICATES SECTION ===== */
.certificates__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-xl);
}

.certificate-card {
    background: var(--clr-bg-card);
    padding: var(--spacing-xl);
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--clr-border);
    text-align: center;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.certificate-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-glow);
}

.certificate-card__icon {
    font-size: var(--fs-4xl);
    margin-bottom: var(--spacing-md);
}

.certificate-card__title {
    font-size: var(--fs-lg);
    font-weight: var(--fw-semibold);
    margin-bottom: var(--spacing-xs);
}

.certificate-card__issuer {
    font-size: var(--fs-sm);
    color: var(--clr-accent-primary);
    margin-bottom: var(--spacing-sm);
}

.certificate-card__description {
    font-size: var(--fs-sm);
    color: var(--clr-text-secondary);
}

/* ===== PROJECT CARD PLACEHOLDERS ===== */
.project-card__placeholder--ml {
    background: linear-gradient(135deg, #14b8a6 0%, #06b6d4 100%);
}

.project-card__placeholder--data {
    background: linear-gradient(135deg, #f59e0b 0%, #f97316 100%);
}

.project-card__placeholder--forest {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
}

.project-card__placeholder--finance {
    background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
}

/* ===== FOOTER ===== */
.footer {
    padding: var(--spacing-xl) 0;
    border-top: 1px solid var(--clr-border);
    text-align: center;
}

.footer__text {
    font-size: var(--fs-sm);
    color: var(--clr-text-secondary);
}

/* ===== ANIMATIONS ===== */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* ===== RESPONSIVE DESIGN ===== */
@media screen and (max-width: 992px) {
    .hero__container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero__description {
        margin: 0 auto var(--spacing-xl);
    }

    .hero__buttons {
        justify-content: center;
    }

    .hero__image {
        order: -1;
    }

    .hero__blob {
        width: 250px;
        height: 250px;
    }

    .about__content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .about__image {
        max-width: 300px;
        margin: 0 auto;
    }

    .about__stats {
        justify-content: center;
    }

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

@media screen and (max-width: 768px) {
    :root {
        --fs-5xl: 2.5rem;
        --fs-3xl: 1.75rem;
    }

    .nav__menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 70%;
        height: 100vh;
        background: var(--clr-bg-secondary);
        padding: var(--spacing-4xl) var(--spacing-xl);
        transition: right var(--transition-base);
        z-index: 1001;
    }

    .nav__menu.show-menu {
        right: 0;
    }

    .nav__list {
        flex-direction: column;
        gap: var(--spacing-xl);
    }

    .nav__link {
        font-size: var(--fs-lg);
    }

    .nav__close {
        display: block;
        position: absolute;
        top: var(--spacing-lg);
        right: var(--spacing-lg);
        font-size: var(--fs-2xl);
        color: var(--clr-text-primary);
    }

    .nav__toggle {
        display: flex;
        flex-direction: column;
        gap: 5px;
    }

    .nav__toggle span {
        display: block;
        width: 25px;
        height: 2px;
        background: var(--clr-text-primary);
        transition: all var(--transition-fast);
    }

    .scroll-down {
        display: none;
    }
}

@media screen and (max-width: 480px) {
    .hero__buttons {
        flex-direction: column;
        width: 100%;
    }

    .btn {
        width: 100%;
    }

    .about__stats {
        flex-direction: column;
        gap: var(--spacing-lg);
    }
}