/* ==========================================================================
   Portfolio Design System — Engineering Minimal
   Restrained palette: Deep Navy / Charcoal, Slate Grays, Crisp White, 
   Subtle Accent Blue (#1d4ed8)
   ========================================================================== */

:root {
    --slate-950: #020617;
    --slate-900: #0f172a;
    --slate-800: #1e293b;
    --slate-700: #334155;
    --slate-600: #475569;
    --slate-500: #64748b;
    --slate-400: #94a3b8;
    --slate-300: #cbd5e1;
    --slate-200: #e2e8f0;
    --slate-100: #f1f5f9;
    --slate-50:  #f8fafc;
    --white:     #ffffff;

    /* Semantic tokens */
    --color-bg: var(--slate-50);
    --color-surface: var(--white);
    --color-surface-subtle: var(--slate-100);
    --color-border: var(--slate-200);
    --color-border-hover: var(--slate-300);

    --color-text-main: var(--slate-900);
    --color-text-muted: var(--slate-600);
    --color-text-subtle: var(--slate-500);

    /* Subtle Accent */
    --color-accent: #1d4ed8;
    --color-accent-hover: #1e40af;
    --color-accent-subtle: #eff6ff;
    --color-accent-border: #bfdbfe;

    /* Status indicators */
    --color-success: #059669;
    --color-success-bg: #ecfdf5;
    --color-success-border: #a7f3d0;

    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;

    --shadow-subtle: 0 1px 3px rgba(15, 23, 42, 0.06), 0 1px 2px rgba(15, 23, 42, 0.04);
    --shadow-card: 0 4px 6px -1px rgba(15, 23, 42, 0.05), 0 2px 4px -2px rgba(15, 23, 42, 0.04);
    --shadow-card-hover: 0 10px 15px -3px rgba(15, 23, 42, 0.08), 0 4px 6px -4px rgba(15, 23, 42, 0.03);
}

/* Base resets and typography */
html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    background-color: var(--color-bg);
    color: var(--color-text-main);
    font-family: var(--font-sans);
    line-height: 1.65;
    font-size: 1rem;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--color-text-main);
    font-weight: 600;
    line-height: 1.3;
    letter-spacing: -0.02em;
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color 0.15s ease;
}

a:hover {
    color: var(--color-accent-hover);
}

/* ==========================================================================
   Navigation
   ========================================================================== */
.site-navbar {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--color-border);
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
    padding: 0.85rem 0;
}

.site-navbar.scrolled {
    box-shadow: var(--shadow-subtle);
}

.brand-wrap {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    color: var(--color-text-main);
    text-decoration: none;
}

.brand-name {
    font-weight: 700;
    font-size: 1.15rem;
    letter-spacing: -0.02em;
    color: var(--slate-900);
}

.brand-badge {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 600;
    background-color: var(--slate-100);
    color: var(--slate-700);
    border: 1px solid var(--slate-200);
    padding: 0.15rem 0.45rem;
    border-radius: var(--radius-sm);
    letter-spacing: 0.02em;
}

.nav-link {
    color: var(--color-text-muted) !important;
    font-weight: 500;
    font-size: 0.925rem;
    padding: 0.4rem 0.85rem !important;
    border-radius: var(--radius-sm);
    transition: color 0.15s ease, background-color 0.15s ease;
}

.nav-link:hover, .nav-link:focus {
    color: var(--color-text-main) !important;
    background-color: var(--slate-100);
}

.nav-cv-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--slate-900);
    background-color: var(--white);
    border: 1px solid var(--slate-300);
    padding: 0.4rem 0.9rem;
    border-radius: var(--radius-sm);
    transition: all 0.15s ease;
}

.nav-cv-btn:hover {
    color: var(--color-accent);
    border-color: var(--color-accent);
    background-color: var(--color-accent-subtle);
}

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn-engineering-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    background-color: var(--slate-900);
    color: var(--white);
    border: 1px solid var(--slate-900);
    padding: 0.65rem 1.35rem;
    font-size: 0.925rem;
    font-weight: 500;
    border-radius: var(--radius-sm);
    transition: all 0.15s ease;
}

.btn-engineering-primary:hover {
    background-color: var(--slate-800);
    color: var(--white);
    border-color: var(--slate-800);
    box-shadow: var(--shadow-subtle);
}

.btn-engineering-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    background-color: var(--white);
    color: var(--slate-800);
    border: 1px solid var(--slate-300);
    padding: 0.65rem 1.35rem;
    font-size: 0.925rem;
    font-weight: 500;
    border-radius: var(--radius-sm);
    transition: all 0.15s ease;
}

.btn-engineering-secondary:hover {
    background-color: var(--slate-50);
    color: var(--slate-900);
    border-color: var(--slate-400);
}

.btn-engineering-sm {
    padding: 0.35rem 0.75rem;
    font-size: 0.85rem;
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
    padding: 5rem 0 4rem 0;
    background-color: var(--white);
    border-bottom: 1px solid var(--color-border);
}

.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background-color: var(--color-success-bg);
    color: var(--color-success);
    border: 1px solid var(--color-success-border);
    padding: 0.3rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.825rem;
    font-weight: 500;
    margin-bottom: 1.25rem;
}

.status-indicator-dot {
    width: 7px;
    height: 7px;
    background-color: var(--color-success);
    border-radius: 50%;
}

.hero-title {
    font-size: 2.75rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    color: var(--slate-950);
    margin-bottom: 0.75rem;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-muted);
    font-weight: 500;
    margin-bottom: 1.25rem;
    line-height: 1.4;
}

.hero-bio {
    font-size: 1.05rem;
    color: var(--color-text-muted);
    line-height: 1.7;
    margin-bottom: 1.75rem;
    max-width: 620px;
}

.hero-meta-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 1.25rem;
    padding-top: 1.5rem;
    margin-top: 1.5rem;
    border-top: 1px solid var(--color-border);
}

.hero-meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

.hero-meta-item i {
    color: var(--slate-500);
}

.profile-card {
    background-color: var(--white);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 1.25rem;
    box-shadow: var(--shadow-card);
    text-align: center;
}

.profile-img-wrap {
    width: 240px;
    height: 240px;
    margin: 0 auto 1.25rem auto;
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--color-border);
    background-color: var(--slate-100);
}

.profile-img-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.profile-card-name {
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
}

.profile-card-role {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-bottom: 1rem;
}

.profile-social-links {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
}

.social-icon-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    background-color: var(--slate-100);
    color: var(--slate-700);
    border: 1px solid var(--slate-200);
    transition: all 0.15s ease;
}

.social-icon-btn:hover {
    color: var(--color-accent);
    background-color: var(--color-accent-subtle);
    border-color: var(--color-accent-border);
}

/* ==========================================================================
   Section Headers
   ========================================================================== */
.section-wrap {
    padding: 4.5rem 0;
}

.section-wrap-alt {
    background-color: var(--white);
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}

.section-header {
    margin-bottom: 2.75rem;
}

.section-eyebrow {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 0.4rem;
}

.section-title {
    font-size: 1.85rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 0.5rem;
}

.section-description {
    font-size: 1rem;
    color: var(--color-text-muted);
    max-width: 640px;
    margin: 0;
}

/* ==========================================================================
   Projects Cards
   ========================================================================== */
.project-card {
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.project-card:hover {
    border-color: var(--slate-400);
    box-shadow: var(--shadow-card-hover);
}

.project-card-header {
    padding: 1.25rem 1.5rem 0.5rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 0.75rem;
}

.project-category-badge {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--slate-700);
    background-color: var(--slate-100);
    border: 1px solid var(--slate-200);
    padding: 0.2rem 0.5rem;
    border-radius: var(--radius-sm);
}

.project-card-body {
    padding: 0.75rem 1.5rem 1.5rem 1.5rem;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.project-card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.project-card-title a {
    color: var(--slate-900);
}

.project-card-title a:hover {
    color: var(--color-accent);
}

.project-card-text {
    font-size: 0.925rem;
    color: var(--color-text-muted);
    line-height: 1.6;
    margin-bottom: 1.25rem;
    flex-grow: 1;
}

.project-tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
    margin-bottom: 1.5rem;
}

.tech-tag {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    background-color: var(--slate-100);
    color: var(--slate-700);
    padding: 0.2rem 0.55rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--slate-200);
}

.project-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding-top: 1rem;
    border-top: 1px solid var(--color-border);
}

/* ==========================================================================
   Technical Skills (Categorized, Professional Badges)
   ========================================================================== */
.skill-category-card {
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    height: 100%;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.skill-category-card:hover {
    border-color: var(--slate-400);
    box-shadow: var(--shadow-card);
}

.skill-category-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
    padding-bottom: 0.85rem;
    border-bottom: 1px solid var(--color-border);
}

.skill-icon-wrap {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--slate-100);
    color: var(--slate-800);
    border: 1px solid var(--slate-200);
    border-radius: var(--radius-sm);
    font-size: 1rem;
}

.skill-category-title {
    font-size: 1.05rem;
    font-weight: 600;
    margin: 0;
}

.skill-category-desc {
    font-size: 0.85rem;
    color: var(--color-text-subtle);
    margin-bottom: 1rem;
}

.skill-pill-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.45rem;
}

.skill-pill {
    display: inline-flex;
    align-items: center;
    font-size: 0.825rem;
    font-weight: 500;
    color: var(--slate-800);
    background-color: var(--slate-50);
    border: 1px solid var(--slate-200);
    padding: 0.25rem 0.6rem;
    border-radius: var(--radius-sm);
    transition: background-color 0.15s ease, border-color 0.15s ease;
}

.skill-pill:hover {
    background-color: var(--white);
    border-color: var(--slate-400);
}

/* ==========================================================================
   Education & Background
   ========================================================================== */
.timeline-item-card {
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    margin-bottom: 1.25rem;
    transition: border-color 0.2s ease;
}

.timeline-item-card:hover {
    border-color: var(--slate-300);
}

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.timeline-degree {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--slate-900);
    margin: 0;
}

.timeline-period {
    font-family: var(--font-mono);
    font-size: 0.825rem;
    color: var(--color-text-subtle);
    background-color: var(--slate-100);
    padding: 0.2rem 0.55rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--slate-200);
}

.timeline-institution {
    font-size: 0.95rem;
    color: var(--color-accent);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.timeline-meta {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    line-height: 1.55;
    margin: 0;
}

.coursework-box {
    margin-top: 1rem;
    padding-top: 0.85rem;
    border-top: 1px dashed var(--color-border);
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

/* ==========================================================================
   Contact Section & Form
   ========================================================================== */
.contact-card {
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 2rem;
    box-shadow: var(--shadow-card);
}

.contact-direct-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1rem 0;
    border-bottom: 1px solid var(--color-border);
}

.contact-direct-item:last-child {
    border-bottom: none;
}

.contact-icon-box {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--slate-100);
    color: var(--slate-800);
    border: 1px solid var(--slate-200);
    border-radius: var(--radius-sm);
    font-size: 1.05rem;
    flex-shrink: 0;
}

.contact-label {
    font-size: 0.8rem;
    text-transform: uppercase;
    font-family: var(--font-mono);
    color: var(--color-text-subtle);
    letter-spacing: 0.05em;
    margin-bottom: 0.2rem;
}

.contact-value {
    font-size: 0.95rem;
    color: var(--slate-900);
    font-weight: 500;
    margin: 0;
}

.contact-value a {
    color: var(--slate-900);
}

.contact-value a:hover {
    color: var(--color-accent);
}

.form-label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--slate-800);
    margin-bottom: 0.35rem;
}

.form-control {
    background-color: var(--white);
    border: 1px solid var(--slate-300);
    border-radius: var(--radius-sm);
    padding: 0.6rem 0.85rem;
    font-size: 0.925rem;
    color: var(--slate-900);
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.form-control:focus {
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(29, 78, 216, 0.15);
    outline: none;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
    background-color: var(--white);
    border-top: 1px solid var(--color-border);
    padding: 2.5rem 0 2rem 0;
    font-size: 0.875rem;
    color: var(--color-text-subtle);
}

.footer-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 1.25rem;
    justify-content: center;
    margin-bottom: 1.25rem;
}

.footer-nav a {
    color: var(--color-text-muted);
}

.footer-nav a:hover {
    color: var(--slate-900);
}

/* Productivity Widgets (API Lab) */
.productivity-widget {
    background-color: var(--white);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    box-shadow: var(--shadow-subtle);
    color: var(--slate-900);
}
.productivity-widget h5 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
}
.productivity-widget.weather-widget { border-top: 3px solid #0284c7; }
.productivity-widget.quote-widget { border-top: 3px solid #d97706; }
.productivity-widget.news-widget { border-top: 3px solid #059669; }
.productivity-widget.crypto-widget { border-top: 3px solid #7c3aed; }

/* Responsive adjustments */
@media (max-width: 991.98px) {
    .hero-title {
        font-size: 2.25rem;
    }
    .profile-card {
        margin-top: 2rem;
    }
}

@media (max-width: 767.98px) {
    .hero-section {
        padding: 3.5rem 0 2.5rem 0;
    }
    .hero-title {
        font-size: 1.85rem;
    }
    .hero-subtitle {
        font-size: 1.1rem;
    }
    .profile-img-wrap {
        width: 180px;
        height: 180px;
    }
    .section-wrap {
        padding: 3.25rem 0;
    }
    .timeline-header {
        flex-direction: column;
    }
}