/* ==========================================================================
   DESIGN SYSTEM & VARIABLES
   ========================================================================== */
:root {
    /* Color Palette */
    --color-bg-dark: #070707;
    --color-bg-card: #121212;
    --color-bg-accent: #171717;
    --color-primary: #C5A880; /* Champagne Gold */
    --color-primary-hover: #E2C9A1;
    --color-primary-alpha: rgba(197, 168, 128, 0.1);
    --color-text-main: #E2E2E2; /* Premium soft silver-white */
    --color-text-muted: #888888;
    --color-text-dark: #0A0A0A;
    --color-border: rgba(255, 255, 255, 0.06);
    --color-border-accent: rgba(197, 168, 128, 0.2);

    /* Fonts */
    --font-primary: 'Jost', sans-serif;
    --font-accent: 'Playfair Display', serif;

    /* Transitions */
    --transition-fast: 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    --transition-medium: 0.5s cubic-bezier(0.25, 0.8, 0.25, 1);
    --transition-slow: 0.7s cubic-bezier(0.16, 1, 0.3, 1);

    /* Layout values */
    --header-height: 80px;
    --container-width: 1200px;
    --border-radius: 4px;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
    background-color: var(--color-bg-dark);
}

body {
    font-family: var(--font-primary);
    background-color: var(--color-bg-dark);
    color: var(--color-text-main);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 6px;
}
::-webkit-scrollbar-track {
    background: var(--color-bg-dark);
}
::-webkit-scrollbar-thumb {
    background: #252525;
    border-radius: var(--border-radius);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--color-primary);
}

/* Typography Utilities */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-primary);
    font-weight: 300;
    letter-spacing: 0.05em;
    line-height: 1.2;
}

p {
    font-size: 0.95rem;
    color: var(--color-text-muted);
    font-weight: 300;
    letter-spacing: 0.02em;
}

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

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

.text-serif {
    font-family: var(--font-accent);
    font-style: italic;
}

.text-accent {
    color: var(--color-primary);
}

/* Common Layout Components */
.section-container {
    width: 90%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 100px 0;
}

.section-tag {
    display: block;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.3em;
    color: var(--color-primary);
    text-transform: uppercase;
    margin-bottom: 15px;
}

.section-title {
    font-family: var(--font-accent);
    font-size: 2.8rem;
    font-weight: 400;
    line-height: 1.15;
    margin-bottom: 40px;
    letter-spacing: -0.01em;
}

@media (max-width: 768px) {
    .section-title {
        font-size: 2.2rem;
    }
}

/* ==========================================================================
   BUTTONS
   ========================================================================== */
.btn {
    display: inline-block;
    padding: 12px 30px;
    font-size: 0.8rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.2em;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition-medium);
    position: relative;
    overflow: hidden;
    text-align: center;
}

.btn-primary {
    background-color: var(--color-primary);
    color: var(--color-text-dark);
    border: 1px solid var(--color-primary);
}

.btn-primary:hover {
    background-color: transparent;
    color: var(--color-primary);
    box-shadow: 0 0 15px rgba(197, 168, 128, 0.3);
}

.btn-secondary {
    background-color: transparent;
    color: var(--color-text-main);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.btn-nav {
    padding: 8px 18px;
    font-size: 0.75rem;
    border: 1px solid var(--color-primary);
    color: var(--color-primary);
    background-color: transparent;
}

.btn-nav:hover {
    background-color: var(--color-primary);
    color: var(--color-text-dark);
}

/* ==========================================================================
   PRELOADER
   ========================================================================== */
.preloader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background-color: var(--color-bg-dark);
    z-index: 9999;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: opacity 0.8s ease, visibility 0.8s ease;
}

.preloader.fade-out {
    opacity: 0;
    visibility: hidden;
}

.preloader-content {
    text-align: center;
}

.preloader-logo {
    font-family: var(--font-primary);
    font-size: 3rem;
    font-weight: 300;
    letter-spacing: 0.4em;
    color: var(--color-text-main);
    margin-bottom: 20px;
    animation: pulseLogo 2s infinite ease-in-out;
}

.preloader-bar {
    width: 200px;
    height: 1px;
    background-color: rgba(255, 255, 255, 0.1);
    margin: 0 auto;
    position: relative;
    overflow: hidden;
}

.preloader-progress {
    width: 0%;
    height: 100%;
    background-color: var(--color-primary);
    position: absolute;
    top: 0;
    left: 0;
    animation: fillProgress 1.8s forwards cubic-bezier(0.1, 0.8, 0.25, 1);
}

@keyframes pulseLogo {
    0%, 100% { opacity: 0.6; }
    50% { opacity: 1; }
}

@keyframes fillProgress {
    0% { width: 0%; }
    100% { width: 100%; }
}

/* ==========================================================================
   HEADER
   ========================================================================== */
.main-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    z-index: 100;
    transition: var(--transition-medium);
    border-bottom: 1px solid transparent;
}

.main-header.scrolled {
    height: 70px;
    background-color: rgba(7, 7, 7, 0.85);
    backdrop-filter: blur(15px);
    border-bottom: 1px solid var(--color-border);
}

.header-container {
    width: 90%;
    max-width: var(--container-width);
    height: 100%;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 400;
    letter-spacing: 0.2em;
    color: var(--color-text-main);
}

.nav-menu ul {
    display: flex;
    list-style: none;
    gap: 40px;
}

.nav-link {
    font-size: 0.8rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--color-text-muted);
    padding: 8px 0;
    position: relative;
}

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

.nav-link:hover, 
.nav-link.active {
    color: var(--color-text-main);
}

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

.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    flex-direction: column;
    gap: 6px;
}

.menu-toggle .bar {
    width: 25px;
    height: 1px;
    background-color: var(--color-text-main);
    transition: var(--transition-fast);
}

/* Mobile Nav Toggle states */
@media (max-width: 991px) {
    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 100%;
        max-width: 320px;
        height: 100vh;
        background-color: var(--color-bg-accent);
        z-index: 99;
        display: flex;
        align-items: center;
        padding-left: 50px;
        border-left: 1px solid var(--color-border);
        transition: var(--transition-medium);
    }
    
    .nav-menu.active {
        right: 0;
    }

    .nav-menu ul {
        flex-direction: column;
        gap: 30px;
    }
    
    .nav-link {
        font-size: 1.1rem;
    }
    
    .menu-toggle {
        display: flex;
        z-index: 101;
    }
    
    .menu-toggle.active .bar:nth-child(1) {
        transform: translateY(7px) rotate(45deg);
    }
    
    .menu-toggle.active .bar:nth-child(2) {
        opacity: 0;
    }
    
    .menu-toggle.active .bar:nth-child(3) {
        transform: translateY(-7px) rotate(-45deg);
    }

    .header-cta {
        display: none;
    }
}

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

.hero-container {
    width: 90%;
    max-width: var(--container-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1.15fr 0.85fr;
    gap: 50px;
    align-items: center;
    padding: 50px 0;
}

.hero-content {
    max-width: 650px;
    z-index: 2;
}

.hero-subtitle {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.25em;
    color: var(--color-primary);
    margin-bottom: 20px;
}

.hero-title {
    font-family: var(--font-primary);
    font-size: 4rem;
    font-weight: 300;
    line-height: 1.1;
    margin-bottom: 30px;
    letter-spacing: -0.02em;
}

.hero-description {
    font-size: 1.05rem;
    line-height: 1.75;
    margin-bottom: 40px;
    font-weight: 300;
}

.hero-description strong {
    font-weight: 500;
    color: #ffffff;
}

.hero-actions {
    display: flex;
    gap: 20px;
}

.hero-image-wrapper {
    position: relative;
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-image-frame {
    position: relative;
    width: 85%;
    max-width: 380px;
    aspect-ratio: 4 / 5;
    z-index: 1;
    transition: var(--transition-slow);
}

.hero-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: grayscale(10%);
    transition: var(--transition-slow);
}

.frame-border {
    position: absolute;
    top: 20px;
    left: 20px;
    width: 100%;
    height: 100%;
    border: 1px solid var(--color-primary);
    z-index: -1;
    transition: var(--transition-slow);
}

.frame-badge {
    position: absolute;
    bottom: -20px;
    left: -20px;
    background-color: var(--color-bg-dark);
    border: 1px solid var(--color-primary);
    color: var(--color-primary);
    padding: 10px 20px;
    font-size: 0.75rem;
    letter-spacing: 0.25em;
    font-weight: 600;
}

/* Hero Hover Interactivity */
.hero-image-frame:hover {
    transform: translate(-5px, -5px);
}

.hero-image-frame:hover .hero-image {
    filter: grayscale(0%);
}

.hero-image-frame:hover .frame-border {
    transform: translate(10px, 10px);
    border-color: #ffffff;
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 5%;
    display: flex;
    align-items: center;
    gap: 15px;
    transform: rotate(-90deg) translateX(50%);
    transform-origin: left bottom;
    opacity: 0.6;
}

.scroll-text {
    font-size: 0.65rem;
    letter-spacing: 0.3em;
    font-weight: 500;
    white-space: nowrap;
}

.scroll-line {
    width: 50px;
    height: 1px;
    background-color: var(--color-text-main);
    position: relative;
    overflow: hidden;
}

.scroll-line::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background-color: var(--color-primary);
    animation: scrollLineAnim 2s infinite cubic-bezier(0.1, 0.8, 0.25, 1);
}

@keyframes scrollLineAnim {
    0% { left: -100%; }
    50%, 100% { left: 100%; }
}

@media (max-width: 991px) {
    .hero-container {
        grid-template-columns: 1fr;
        gap: 60px;
        text-align: center;
        padding-top: 40px;
    }
    
    .hero-content {
        margin: 0 auto;
    }
    
    .hero-title {
        font-size: 3.2rem;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .hero-image-wrapper {
        order: -1;
    }
    
    .hero-image-frame {
        width: 65%;
    }
    
    .scroll-indicator {
        display: none;
    }
}

/* ==========================================================================
   ABOUT SECTION
   ========================================================================== */
.about-section {
    background-color: var(--color-bg-accent);
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}

.about-grid {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 80px;
    align-items: start;
}

.about-lead {
    font-family: var(--font-accent);
    font-size: 1.6rem;
    color: var(--color-text-main);
    line-height: 1.4;
    margin-bottom: 35px;
    font-weight: 300;
}

.about-text {
    font-size: 0.98rem;
    line-height: 1.8;
    margin-bottom: 35px;
}

.philosophy-quote-block {
    border-left: 2px solid var(--color-primary);
    padding: 10px 0 10px 30px;
    margin-top: 40px;
    position: relative;
}

.quote-icon-gold {
    font-size: 1.8rem;
    color: rgba(197, 168, 128, 0.15);
    position: absolute;
    top: 5px;
    left: 20px;
    z-index: 0;
}

.philosophy-quote-text {
    font-family: var(--font-accent);
    font-size: 1.15rem;
    font-style: italic;
    color: #ffffff;
    line-height: 1.6;
    position: relative;
    z-index: 1;
}

/* Objective Timeline */
.objective-card {
    background-color: var(--color-bg-dark);
    padding: 40px;
    border: 1px solid var(--color-border);
    margin-bottom: 40px;
}

.objective-tag {
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.2em;
    color: var(--color-primary);
}

.objective-title {
    font-size: 1.5rem;
    margin: 10px 0 30px;
    font-weight: 300;
}

.objective-timeline {
    display: flex;
    flex-direction: column;
    gap: 25px;
    position: relative;
    padding-left: 20px;
    border-left: 1px solid var(--color-border);
}

.timeline-item {
    position: relative;
}

.timeline-marker {
    position: absolute;
    top: 6px;
    left: -25px;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background-color: var(--color-primary);
    box-shadow: 0 0 8px var(--color-primary);
}

.timeline-content h4 {
    font-size: 1rem;
    color: #ffffff;
    margin-bottom: 6px;
    font-weight: 400;
}

.timeline-content p {
    font-size: 0.88rem;
    line-height: 1.6;
}

/* Research Interests list style */
.interests-container {
    background-color: var(--color-bg-dark);
    border: 1px solid var(--color-border);
    padding: 40px;
}

.interests-title {
    font-size: 1.25rem;
    margin-bottom: 25px;
    font-weight: 300;
    color: #ffffff;
}

.interests-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.interest-tag {
    display: inline-block;
    padding: 8px 16px;
    background-color: var(--color-bg-accent);
    border: 1px solid var(--color-border);
    border-radius: 2px;
    font-size: 0.8rem;
    letter-spacing: 0.05em;
    transition: var(--transition-fast);
    cursor: default;
}

.interest-tag:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
}

@media (max-width: 991px) {
    .about-grid {
        grid-template-columns: 1fr;
        gap: 60px;
    }
}

/* ==========================================================================
   MATHEMATICAL RIGOR SHOWCASE
   ========================================================================== */
.math-showcase-section {
    border-bottom: 1px solid var(--color-border);
}

.math-grid {
    display: grid;
    grid-template-columns: 0.9fr 1.1fr;
    gap: 80px;
    align-items: center;
}

.math-desc p {
    font-size: 1.05rem;
    line-height: 1.75;
    margin-top: 15px;
}

.math-equations-box {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.equation-card {
    background-color: var(--color-bg-accent);
    border: 1px solid var(--color-border);
    border-left: 2px solid var(--color-primary);
    padding: 30px 40px;
    transition: var(--transition-medium);
}

.equation-card:hover {
    transform: translateX(5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.eq-name {
    display: block;
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.15em;
    color: var(--color-primary);
    text-transform: uppercase;
    margin-bottom: 15px;
}

.eq-latex {
    font-size: 1.4rem;
    margin: 15px 0;
    color: #ffffff;
    overflow-x: auto;
}

.eq-explanation {
    font-size: 0.85rem;
    line-height: 1.5;
}

@media (max-width: 991px) {
    .math-grid {
        grid-template-columns: 1fr;
        gap: 50px;
    }
}

/* ==========================================================================
   SOFT SKILLS & PERSONAL STRENGTHS
   ========================================================================== */
.soft-skills-section {
    border-bottom: 1px solid var(--color-border);
}

.soft-skills-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
    margin-top: 50px;
}

.soft-skill-card {
    background-color: var(--color-bg-card);
    border: 1px solid var(--color-border);
    padding: 40px 30px;
    text-align: center;
    transition: var(--transition-medium);
    position: relative;
    overflow: hidden;
}

.soft-skill-card::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-primary);
    transition: var(--transition-medium);
}

.soft-skill-card:hover {
    transform: translateY(-6px);
    border-color: var(--color-border-accent);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
}

.soft-skill-card:hover::before {
    width: 100%;
}

.soft-skill-icon {
    font-size: 2rem;
    color: var(--color-primary);
    margin-bottom: 20px;
    opacity: 0.8;
}

.soft-skill-card:hover .soft-skill-icon {
    opacity: 1;
}

.soft-skill-card h3 {
    font-size: 1.1rem;
    font-weight: 400;
    margin-bottom: 15px;
    color: #ffffff;
}

.soft-skill-card p {
    font-size: 0.88rem;
    line-height: 1.6;
}

@media (max-width: 991px) {
    .soft-skills-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    .soft-skills-grid {
        grid-template-columns: 1fr;
    }
}

/* ==========================================================================
   TECHNICAL SKILLS DASHBOARD
   ========================================================================== */
.skills-section {
    background-color: var(--color-bg-accent);
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}

.skills-dashboard {
    margin-top: 50px;
    display: flex;
    flex-direction: column;
    gap: 40px;
}

.skills-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    border-bottom: 1px solid var(--color-border);
    padding-bottom: 10px;
}

.skill-tab-btn {
    background: none;
    border: none;
    color: var(--color-text-muted);
    font-family: var(--font-primary);
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    padding: 12px 20px;
    cursor: pointer;
    transition: var(--transition-fast);
    position: relative;
}

.skill-tab-btn:hover,
.skill-tab-btn.active {
    color: var(--color-primary);
}

.skill-tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: -11px;
    left: 0;
    width: 100%;
    height: 1px;
    background-color: var(--color-primary);
}

.skills-panels {
    min-height: 300px;
}

.skill-panel {
    display: none;
    opacity: 0;
    transform: translateY(15px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.skill-panel.active {
    display: block;
    opacity: 1;
    transform: translateY(0);
}

.panel-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 50px;
}

.skill-category h3 {
    font-size: 1.25rem;
    font-weight: 400;
    margin-bottom: 25px;
    color: #ffffff;
    border-bottom: 1px solid var(--color-border);
    padding-bottom: 10px;
}

.skill-list-lux {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.skill-list-lux li {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.95rem;
    color: var(--color-text-main);
    border-bottom: 1px solid rgba(255, 255, 255, 0.02);
    padding-bottom: 8px;
}

.badge-gold {
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-primary);
    border: 1px solid var(--color-primary);
    padding: 3px 8px;
    border-radius: 2px;
}

.badge-silver {
    font-size: 0.7rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-text-muted);
    border: 1px solid var(--color-border);
    padding: 3px 8px;
    border-radius: 2px;
}

@media (max-width: 768px) {
    .panel-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

/* ==========================================================================
   PORTFOLIO SECTION
   ========================================================================== */
.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    margin-top: 50px;
}

.project-card {
    background-color: var(--color-bg-card);
    border: 1px solid var(--color-border);
    overflow: hidden;
    height: 100%;
    display: flex;
    flex-direction: column;
    transition: var(--transition-medium);
}

.project-image-box {
    position: relative;
    width: 100%;
    aspect-ratio: 4 / 3;
    overflow: hidden;
    background-color: var(--color-bg-dark);
}

.project-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.8s cubic-bezier(0.25, 1, 0.5, 1);
}

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(11, 11, 11, 0.75);
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0;
    transition: var(--transition-medium);
}

.view-details-text {
    font-size: 0.8rem;
    font-weight: 500;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--color-primary);
    border-bottom: 1px solid var(--color-primary);
    padding-bottom: 4px;
    transform: translateY(10px);
    transition: var(--transition-medium);
}

.project-info {
    padding: 30px;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.project-category {
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.15em;
    color: var(--color-primary);
    margin-bottom: 12px;
    text-transform: uppercase;
}

.project-title {
    font-size: 1.3rem;
    font-weight: 400;
    margin-bottom: 15px;
    color: #ffffff;
}

.project-desc {
    font-size: 0.9rem;
    line-height: 1.65;
    margin-bottom: 25px;
    flex-grow: 1;
}

.btn-project-detail {
    width: 100%;
}

/* Portfolio Card Hover */
.project-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-primary-alpha);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.project-card:hover .project-image {
    transform: scale(1.06);
}

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

.project-card:hover .view-details-text {
    transform: translateY(0);
}

@media (max-width: 991px) {
    .portfolio-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    .portfolio-grid {
        grid-template-columns: 1fr;
    }
}

/* ==========================================================================
   SLIDE-OVER PROJECT DRAWER
   ========================================================================== */
.project-drawer {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1000;
    visibility: hidden;
    pointer-events: none;
    transition: visibility var(--transition-medium);
}

.project-drawer.active {
    visibility: visible;
    pointer-events: auto;
}

.drawer-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(7, 7, 7, 0.65);
    backdrop-filter: blur(12px);
    opacity: 0;
    transition: opacity var(--transition-medium);
}

.project-drawer.active .drawer-overlay {
    opacity: 1;
}

.drawer-content {
    position: absolute;
    top: 0;
    right: -100%;
    width: 100%;
    max-width: 700px;
    height: 100vh;
    background-color: var(--color-bg-card);
    border-left: 1px solid var(--color-primary);
    box-shadow: -10px 0 40px rgba(0, 0, 0, 0.5);
    display: flex;
    flex-direction: column;
    transition: right var(--transition-slow);
}

.project-drawer.active .drawer-content {
    right: 0;
}

.drawer-close {
    position: absolute;
    top: 25px;
    right: 30px;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--color-text-muted);
    cursor: pointer;
    z-index: 10;
    transition: var(--transition-fast);
}

.drawer-close:hover {
    color: var(--color-primary);
    transform: rotate(90deg);
}

.drawer-body-container {
    height: 100%;
    overflow-y: auto;
    padding: 60px 40px;
}

/* Modal Inner Tabs */
.drawer-header {
    margin-bottom: 35px;
    padding-right: 30px;
}

.drawer-category {
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.25em;
    color: var(--color-primary);
    text-transform: uppercase;
}

.drawer-title {
    font-family: var(--font-accent);
    font-size: 2.2rem;
    margin: 10px 0 20px;
    color: #ffffff;
}

.drawer-nav-tabs {
    display: flex;
    border-bottom: 1px solid var(--color-border);
    gap: 20px;
    overflow-x: auto;
    padding-bottom: 8px;
    margin-bottom: 30px;
}

.drawer-tab-btn {
    background: none;
    border: none;
    color: var(--color-text-muted);
    font-family: var(--font-primary);
    font-size: 0.8rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    padding: 8px 0;
    cursor: pointer;
    white-space: nowrap;
    position: relative;
    transition: var(--transition-fast);
}

.drawer-tab-btn:hover,
.drawer-tab-btn.active {
    color: var(--color-primary);
}

.drawer-tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: -9px;
    left: 0;
    width: 100%;
    height: 1px;
    background-color: var(--color-primary);
}

/* Modal Tab Panels */
.drawer-panel {
    display: none;
    animation: fadeInPanel 0.4s forwards ease;
}

.drawer-panel.active {
    display: block;
}

@keyframes fadeInPanel {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.panel-section {
    margin-bottom: 30px;
}

.panel-section h4 {
    font-size: 0.95rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    color: var(--color-primary);
    text-transform: uppercase;
    margin-bottom: 15px;
    border-left: 2px solid var(--color-primary);
    padding-left: 12px;
}

.panel-section p {
    font-size: 0.92rem;
    line-height: 1.7;
    margin-bottom: 12px;
}

.panel-section ul {
    list-style: none;
    padding-left: 15px;
    margin-bottom: 15px;
}

.panel-section ul li {
    font-size: 0.92rem;
    color: var(--color-text-muted);
    position: relative;
    padding-left: 15px;
    margin-bottom: 8px;
}

.panel-section ul li::before {
    content: '—';
    position: absolute;
    left: 0;
    color: var(--color-primary);
}

/* Metrics Dashboard Grid (Results Tab) */
.metrics-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
    margin-bottom: 35px;
}

.metric-card {
    background-color: var(--color-bg-dark);
    border: 1px solid var(--color-border);
    padding: 15px 10px;
    text-align: center;
    border-radius: 2px;
}

.metric-val {
    display: block;
    font-family: var(--font-accent);
    font-size: 1.6rem;
    color: var(--color-primary);
    font-weight: bold;
}

.metric-lbl {
    font-size: 0.7rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-top: 4px;
}

/* Elegant Table Styling */
.results-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0 35px;
    font-size: 0.9rem;
}

.results-table th {
    font-family: var(--font-primary);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-primary);
    border-bottom: 1px solid var(--color-border);
    padding: 12px 10px;
    text-align: left;
    font-size: 0.8rem;
}

.results-table td {
    padding: 12px 10px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.03);
    color: var(--color-text-main);
}

.results-table tr:hover td {
    background-color: rgba(255, 255, 255, 0.01);
}

/* Chart Container & Vector Plots */
.chart-container {
    background-color: var(--color-bg-dark);
    border: 1px solid var(--color-border);
    padding: 25px;
    border-radius: 2px;
    margin-bottom: 30px;
}

.chart-title {
    font-size: 0.8rem;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: #ffffff;
    margin-bottom: 20px;
    text-align: center;
}

.chart-svg {
    width: 100%;
    height: auto;
    overflow: visible;
}

/* Links & CTAs in Drawer */
.drawer-links-box {
    display: flex;
    gap: 20px;
    margin-top: 20px;
}

.drawer-links-box .btn {
    flex: 1;
}

@media (max-width: 576px) {
    .drawer-body-container {
        padding: 50px 20px;
    }
    
    .metrics-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* ==========================================================================
   CONTACT SECTION
   ========================================================================== */
.contact-grid {
    display: grid;
    grid-template-columns: 0.9fr 1.1fr;
    gap: 80px;
    align-items: center;
}

.contact-lead {
    font-size: 1.1rem;
    line-height: 1.8;
    font-weight: 400;
    color: var(--color-text-main);
    margin-bottom: 45px;
}

.contact-details {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 20px;
}

.contact-icon-box {
    width: 50px;
    height: 50px;
    border: 1px solid var(--color-border);
    color: var(--color-primary);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.1rem;
    transition: var(--transition-fast);
}

.contact-text-box span {
    display: block;
    font-size: 0.75rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 4px;
}

.contact-text-box a, 
.contact-text-box p {
    font-size: 1.1rem;
    color: var(--color-text-main);
    font-weight: 400;
}

.contact-text-box a:hover {
    color: var(--color-primary);
}

.contact-item:hover .contact-icon-box {
    border-color: var(--color-primary);
    background-color: var(--color-primary);
    color: var(--color-text-dark);
}

/* Contact Form */
.contact-form-box {
    background-color: var(--color-bg-card);
    padding: 50px;
    border: 1px solid var(--color-border);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 25px;
}

.form-group {
    position: relative;
    width: 100%;
}

.form-group input,
.form-group textarea {
    width: 100%;
    background-color: transparent;
    border: none;
    border-bottom: 1px solid var(--color-border);
    padding: 12px 0;
    color: var(--color-text-main);
    font-family: var(--font-primary);
    font-size: 0.95rem;
    outline: none;
    transition: var(--transition-fast);
}

.form-group label {
    position: absolute;
    top: 12px;
    left: 0;
    color: var(--color-text-muted);
    font-size: 0.95rem;
    font-weight: 300;
    pointer-events: none;
    transition: var(--transition-fast);
}

.input-focus-line {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background-color: var(--color-primary);
    transition: var(--transition-medium);
}

/* Floating Label Animation */
.form-group input:focus ~ label,
.form-group input:not(:placeholder-shown) ~ label,
.form-group textarea:focus ~ label,
.form-group textarea:not(:placeholder-shown) ~ label {
    top: -12px;
    font-size: 0.75rem;
    color: var(--color-primary);
    letter-spacing: 0.1em;
}

.form-group input:focus ~ .input-focus-line,
.form-group textarea:focus ~ .input-focus-line {
    width: 100%;
}

.btn-submit {
    align-self: flex-start;
    border: 1px solid var(--color-primary);
    background: transparent;
    color: var(--color-primary);
    display: flex;
    align-items: center;
    gap: 12px;
}

.btn-submit:hover {
    background-color: var(--color-primary);
    color: var(--color-text-dark);
}

.submit-icon {
    font-size: 0.85rem;
    transition: var(--transition-fast);
}

.btn-submit:hover .submit-icon {
    transform: translateX(4px) translateY(-2px);
}

.form-status {
    font-size: 0.85rem;
    letter-spacing: 0.05em;
    margin-top: 10px;
    line-height: 1.5;
}

.form-status.success {
    color: #a3e635; /* light green */
}

.form-status.error {
    color: #f87171; /* light red */
}

@media (max-width: 991px) {
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 60px;
    }
}

@media (max-width: 768px) {
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .contact-form-box {
        padding: 35px 25px;
    }
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.main-footer {
    border-top: 1px solid var(--color-border);
    padding: 80px 0 30px;
    background-color: #050505;
}

.footer-container {
    width: 90%;
    max-width: var(--container-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: 50px;
    margin-bottom: 60px;
}

.footer-logo {
    font-size: 1.6rem;
    font-weight: 400;
    letter-spacing: 0.25em;
    color: var(--color-text-main);
    display: block;
    margin-bottom: 20px;
}

.footer-tagline {
    font-size: 0.9rem;
    color: var(--color-text-muted);
}

.footer-container h4 {
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--color-primary);
    margin-bottom: 25px;
}

.footer-links ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links a {
    font-size: 0.9rem;
    color: var(--color-text-muted);
}

.footer-links a:hover {
    color: var(--color-primary);
    padding-left: 4px;
}

.social-icons {
    display: flex;
    gap: 15px;
}

.social-icons a {
    width: 40px;
    height: 40px;
    border: 1px solid var(--color-border);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 0.95rem;
    color: var(--color-text-muted);
    border-radius: var(--border-radius);
}

.social-icons a:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    transform: translateY(-3px);
}

.footer-bottom {
    width: 90%;
    max-width: var(--container-width);
    margin: 0 auto;
    border-top: 1px solid var(--color-border);
    padding-top: 30px;
    text-align: center;
}

.footer-bottom p {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    letter-spacing: 0.05em;
}

@media (max-width: 768px) {
    .footer-container {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

/* ==========================================================================
   INTERACTIVITY AND EXTRA CLASSES
   ========================================================================== */
/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 45px;
    height: 45px;
    background-color: var(--color-primary);
    color: var(--color-text-dark);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 0.95rem;
    border-radius: var(--border-radius);
    z-index: 90;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-medium);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

.back-to-top.active {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background-color: #ffffff;
    transform: translateY(-3px);
}

/* Scroll Animation classes */
.scroll-reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

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

.scroll-reveal-left {
    opacity: 0;
    transform: translateX(-40px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.scroll-reveal-left.reveal-active {
    opacity: 1;
    transform: translateX(0);
}

.scroll-reveal-right {
    opacity: 0;
    transform: translateX(40px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.scroll-reveal-right.reveal-active {
    opacity: 1;
    transform: translateX(0);
}

/* ==========================================================================
   LANGUAGE SWITCHER & VISIBILITY RULES
   ========================================================================== */
.header-actions-box {
    display: flex;
    align-items: center;
    gap: 25px;
}

.lang-switch {
    display: flex;
    align-items: center;
    user-select: none;
}

.lang-indicator {
    font-size: 0.75rem;
    font-weight: 400;
    letter-spacing: 0.08em;
    color: var(--color-text-muted);
    cursor: pointer;
    transition: var(--transition-fast);
}

.lang-indicator.active {
    color: var(--color-primary);
    font-weight: 600;
}

.lang-indicator:hover {
    color: #ffffff;
}

.lang-switch .divider {
    font-size: 0.75rem;
    color: rgba(255, 255, 255, 0.15);
    padding: 0 6px;
}

/* Language Visibility Rules */
body.lang-en-active .lang-vi {
    display: none !important;
}
body:not(.lang-en-active) .lang-en {
    display: none !important;
}

@media (max-width: 991px) {
    .header-actions-box {
        margin-right: 40px;
    }
}