/* ===================================
   CUSTOM FONTS
   =================================== */
@font-face {
    font-family: 'Sato';
    src: url('../fonts/Sato-Regular.woff') format('woff');
    font-weight: 400;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Sato';
    src: url('../fonts/Sato-RegularSlanted.woff') format('woff');
    font-weight: 400;
    font-style: italic;
    font-display: swap;
}

@font-face {
    font-family: 'Sato';
    src: url('../fonts/Sato-Medium.woff') format('woff');
    font-weight: 500;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Sato';
    src: url('../fonts/Sato-Bold.woff') format('woff');
    font-weight: 700;
    font-style: normal;
    font-display: swap;
}

/* ===================================
   CSS VARIABLES (Easy Customization)
   =================================== */
:root {
    /* Colors - Light Mode (Default) */
    --color-primary: #1a1a1a;        /* Dampened black */
    --color-secondary: #525252;      /* Refined gray */
    --color-accent: #1a1a1a;         /* Minimal accent */
    --color-bg: #fafafa;             /* Soft white */
    --color-bg-alt: #f5f5f5;         /* Subtle gray */
    --color-text: #1a1a1a;           /* Dark text */
    --color-text-light: #737373;     /* Medium gray text */
    --color-utility-gray: #666666;   /* For captions, metadata */
    --color-border: #e8e8e8;         /* Whisper borders */

    /* Typography - Scalable System */
    --font-primary: 'Sato', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-heading: 'Sato', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* Fluid Typography Scale */
    --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
    --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
    --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
    --text-lg: clamp(1.125rem, 1rem + 0.5vw, 1.375rem);
    --text-xl: clamp(1.5rem, 1.2rem + 1vw, 2rem);
    --text-2xl: clamp(2rem, 1.5rem + 2vw, 3.5rem);
    --text-3xl: clamp(2.5rem, 2rem + 2.5vw, 4.5rem);

    /* Spacing - Generous Whitespace */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    --spacing-2xl: 8rem;
    --spacing-3xl: 12rem;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-medium: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Mode */
[data-theme="dark"] {
    --color-primary: #fafafa;        /* Light text */
    --color-secondary: #b8b8b8;      /* Light gray */
    --color-accent: #fafafa;         /* Light accent */
    --color-bg: #1a1a1a;             /* Dampened black (updated from #0a0a0a) */
    --color-bg-alt: #2a2a2a;         /* Slightly lighter (updated) */
    --color-text: #fafafa;           /* Light text */
    --color-text-light: #a0a0a0;     /* Medium light gray */
    --color-utility-gray: #999999;   /* For captions, metadata in dark mode */
    --color-border: #333333;         /* Dark borders (updated from #2a2a2a) */
}

/* ===================================
   RESET & BASE STYLES
   =================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.65;
    font-size: var(--text-base);
    font-weight: 400;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background-color var(--transition-medium), color var(--transition-medium);
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition-fast);
}

ul {
    list-style: none;
}

/* ===================================
   CONTAINER
   =================================== */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-md);
    }
}

/* ===================================
   NAVIGATION
   =================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(250, 250, 250, 0.92);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
    padding: var(--spacing-md) 0;
}

.nav-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: var(--text-base);
    font-weight: 500;
    color: var(--color-primary);
    letter-spacing: -0.02em;
}

.nav-menu {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-link {
    color: var(--color-text-light);
    font-weight: 400;
    font-size: var(--text-sm);
    position: relative;
    transition: color var(--transition-medium);
    letter-spacing: 0.01em;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -6px;
    left: 0;
    width: 0;
    height: 1px;
    background-color: var(--color-primary);
    transition: width var(--transition-medium);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-link.active {
    color: var(--color-primary);
}

/* Hamburger Menu (Mobile) */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 2px;
    background-color: var(--color-primary);
    transition: var(--transition-medium);
}

/* ===================================
   HERO SECTION
   =================================== */
.hero {
    min-height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: var(--spacing-3xl) var(--spacing-lg);
    margin-top: 80px;
    background-color: var(--color-bg);
}

.hero-content {
    max-width: 800px;
}

.hero-title {
    font-family: var(--font-heading);
    font-size: var(--text-3xl);
    font-weight: 500;
    line-height: 1.15;
    color: var(--color-primary);
    margin-bottom: var(--spacing-lg);
    letter-spacing: -0.03em;
}

.hero-subtitle {
    font-size: var(--text-lg);
    color: var(--color-text-light);
    margin-bottom: var(--spacing-2xl);
    font-weight: 400;
    line-height: 1.6;
    letter-spacing: -0.01em;
}

.cta-button {
    display: inline-block;
    padding: 0.875rem 2rem;
    background-color: transparent;
    color: var(--color-primary);
    font-weight: 400;
    border: 1px solid var(--color-border);
    border-radius: 0;
    transition: all var(--transition-medium);
    font-size: var(--text-sm);
    letter-spacing: 0.02em;
}

.cta-button:hover {
    background-color: var(--color-primary);
    color: var(--color-bg);
    border-color: var(--color-primary);
}

/* ===================================
   FILTER SECTION
   =================================== */
.filter-section {
    padding: var(--spacing-2xl) 0 var(--spacing-xl) 0;
    background-color: var(--color-bg);
}

.section-title {
    font-family: var(--font-heading);
    font-size: var(--text-xl);
    font-weight: 500;
    margin-bottom: var(--spacing-lg);
    color: var(--color-primary);
    text-align: center;
    letter-spacing: -0.02em;
}

.filter-buttons {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.625rem 1.25rem;
    background-color: transparent;
    border: 1px solid var(--color-border);
    color: var(--color-text-light);
    font-weight: 400;
    cursor: pointer;
    transition: all var(--transition-medium);
    border-radius: 0;
    font-size: var(--text-sm);
    letter-spacing: 0.01em;
}

.filter-btn:hover,
.filter-btn.active {
    background-color: var(--color-primary);
    color: var(--color-bg);
    border-color: var(--color-primary);
}

/* ===================================
   PROJECTS GRID
   =================================== */
.projects-grid {
    padding: 0 0 var(--spacing-3xl) 0;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(380px, 1fr));
    gap: var(--spacing-2xl) var(--spacing-xl);
}

.project-card {
    background-color: var(--color-bg);
    transition: var(--transition-medium);
}

.project-card.hidden {
    display: none;
}

.project-link {
    display: block;
}

.project-image {
    position: relative;
    aspect-ratio: 3/2;
    overflow: hidden;
    background-color: var(--color-bg-alt);
    margin-bottom: var(--spacing-md);
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: grayscale(100%);
    transition: transform var(--transition-slow), opacity var(--transition-medium), filter var(--transition-slow);
}

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(26, 26, 26, 0.03);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition-medium);
}

.view-project {
    color: var(--color-primary);
    font-weight: 400;
    font-size: var(--text-sm);
    letter-spacing: 0.02em;
}

.project-card:hover .project-image img {
    transform: scale(1.02);
    opacity: 0.92;
    filter: grayscale(0%);
}

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

.project-info {
    padding: 0;
}

.project-title {
    font-size: var(--text-lg);
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
    color: var(--color-primary);
    letter-spacing: -0.02em;
    line-height: 1.4;
}

.project-category {
    font-size: var(--text-xs);
    color: var(--color-text-light);
    font-weight: 400;
    margin-bottom: var(--spacing-sm);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.project-description {
    font-size: var(--text-sm);
    color: var(--color-text-light);
    line-height: 1.65;
}

/* ===================================
   FOOTER
   =================================== */
.footer {
    background-color: var(--color-bg);
    border-top: 1px solid var(--color-border);
    color: var(--color-text-light);
    padding: var(--spacing-2xl) 0;
    text-align: center;
}

.footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer p {
    font-size: var(--text-xs);
    letter-spacing: 0.01em;
}

.social-links {
    display: flex;
    gap: var(--spacing-lg);
}

.social-links a {
    color: var(--color-text-light);
    font-weight: 400;
    font-size: var(--text-xs);
    transition: color var(--transition-medium);
    letter-spacing: 0.02em;
}

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

/* ===================================
   RESPONSIVE DESIGN
   =================================== */
@media (max-width: 768px) {
    .nav-container {
        padding: 0 var(--spacing-md);
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 80px;
        flex-direction: column;
        background-color: rgba(250, 250, 250, 0.98);
        backdrop-filter: blur(20px);
        width: 100%;
        text-align: center;
        transition: left var(--transition-medium);
        border-bottom: 1px solid var(--color-border);
        padding: var(--spacing-lg) 0;
        gap: var(--spacing-md);
    }

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

    .hamburger {
        display: flex;
    }

    .hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .hamburger.active span:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }

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

    .hero {
        min-height: 80vh;
        padding: var(--spacing-2xl) var(--spacing-md);
    }

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

@media (max-width: 480px) {
    .filter-buttons {
        gap: var(--spacing-sm);
    }

    .filter-btn {
        padding: 0.5rem 0.875rem;
        font-size: var(--text-xs);
    }

    .grid {
        gap: var(--spacing-lg);
    }

    .hero {
        padding: var(--spacing-xl) var(--spacing-md);
    }

    .theme-toggle {
        margin-left: var(--spacing-sm);
    }
}

/* ===================================
   THEME TOGGLE
   =================================== */
.theme-toggle {
    position: relative;
    background: transparent;
    border: 1px solid var(--color-border);
    padding: 0.5rem 0.75rem;
    cursor: pointer;
    color: var(--color-text-light);
    font-size: var(--text-xs);
    font-family: var(--font-primary);
    font-weight: 400;
    letter-spacing: 0.02em;
    transition: all var(--transition-medium);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-left: var(--spacing-md);
}

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

.theme-icon {
    font-size: 1rem;
}

/* ===================================
   ANIMATED ESA INITIALS
   =================================== */
.esa-animation {
    position: relative;
    display: inline-block;
    font-size: clamp(4rem, 10vw, 6rem);
    font-weight: 500;
    font-family: var(--font-heading);
    color: var(--color-primary);
    letter-spacing: -0.05em;
    margin-bottom: var(--spacing-xl);
    transition: opacity var(--transition-medium), transform var(--transition-medium);
}

.esa-text {
    position: relative;
    z-index: 1;
    display: block;
}

.esa-glow {
    position: absolute;
    width: 24px;
    height: 24px;
    background: radial-gradient(circle, rgba(255, 200, 100, 1) 0%, rgba(255, 220, 120, 0.7) 30%, transparent 70%);
    border-radius: 50%;
    filter: blur(6px);
    pointer-events: none;
    z-index: 2;
    animation: tracePath 20s infinite;
    offset-rotate: 0deg;
}

[data-theme="dark"] .esa-glow {
    background: radial-gradient(circle, rgba(255, 240, 200, 1) 0%, rgba(255, 230, 180, 0.8) 30%, rgba(255, 200, 100, 0.3) 60%, transparent 80%);
    filter: blur(8px);
}

@keyframes tracePath {
    0% {
        offset-distance: 0%;
        opacity: 0;
    }
    3% {
        opacity: 1;
    }
    97% {
        opacity: 1;
    }
    100% {
        offset-distance: 100%;
        opacity: 0;
    }
}

/* SVG Path Animation */
.esa-svg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    opacity: 0;
}

.esa-path {
    fill: none;
    stroke: red;        /* Changed from transparent */
    stroke-width: 20;    /* Changed from 1 */
    opacity: 1;         /* Add this to make it visible */
}

@media (max-width: 768px) {
    .esa-animation {
        font-size: clamp(3rem, 12vw, 4rem);
        margin-bottom: var(--spacing-lg);
    }

    .esa-glow {
        width: 18px;
        height: 18px;
    }
}

/* ===================================
   RESUME PAGE STYLES
   =================================== */
.resume-item {
    margin-bottom: var(--spacing-xl);
}

.resume-title {
    font-size: clamp(1.25rem, 2vw, 1.5rem);
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--color-primary);
}

.resume-meta {
    font-size: 0.875rem;
    color: var(--color-utility-gray);
    text-transform: uppercase;
    letter-spacing: 0.02em;
    margin-bottom: 0.75rem;
}

.resume-degree {
    font-style: italic;
    margin-bottom: 0.5rem;
    color: var(--color-primary);
}

.resume-detail {
    margin-bottom: 0.5rem;
    color: var(--color-primary);
    line-height: 1.6;
}

.resume-list {
    list-style: disc;
    padding-left: 1.5rem;
    margin-top: 0.75rem;
}

.resume-list li {
    margin-bottom: 0.5rem;
    line-height: 1.6;
    color: var(--color-primary);
}

.download-container {
    margin-top: var(--spacing-md);
}

.download-btn {
    display: inline-block;
    padding: 1rem 2rem;
    background: transparent;
    color: var(--color-primary);
    text-decoration: none;
    border: 1px solid var(--color-primary);
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.02em;
    font-size: 0.875rem;
    font-weight: 500;
}

.download-btn:hover {
    background: var(--color-primary);
    color: var(--color-bg);
}