/* =====================================================
   SANTOSH BARAL — PORTFOLIO STYLESHEET
   Microsoft Dynamics 365 Business Central Developer
   =====================================================

   TABLE OF CONTENTS
   ─────────────────────────────────────────────────
   1.  CSS Custom Properties (Variables)
   2.  Reset & Base Styles
   3.  Typography
   4.  Layout Utilities
   5.  Button Components
   6.  Navbar
   7.  Hero Section
   8.  About Section
   9.  Skills Section
   10. Projects Section
   11. Experience Timeline
   12. Education & Certifications
   13. Technical Insights
   14. Technical Articles
   15. Contact Section
   16. Footer
   17. Theme Toggle Button
   18. Light Mode Overrides
   19. Responsive — Tablet (≤1024px)
   20. Responsive — Mobile  (≤768px)
   21. Responsive — Small   (≤480px)
   ===================================================== */


/* ─────────────────────────────────────────────────────
   1. CSS CUSTOM PROPERTIES
───────────────────────────────────────────────────── */
:root {
    /* Backgrounds */
    --bg-primary:        #0f172a;
    --bg-section:        #1e293b;
    --bg-card:           #162032;
    --bg-input:          #0f172a;

    /* Accent Colors */
    --accent-blue:       #3b82f6;
    --accent-cyan:       #22d3ee;
    --accent-blue-dark:  #2563eb;

    /* Text Colors */
    --text-primary:      #f1f5f9;
    --text-sub:          #94a3b8;
    --text-muted:        #64748b;

    /* Borders */
    --border:            rgba(59, 130, 246, 0.14);
    --border-hover:      rgba(59, 130, 246, 0.42);
    --border-subtle:     rgba(255, 255, 255, 0.07);

    /* Shadows */
    --shadow-card:       0 4px 24px rgba(0, 0, 0, 0.35);
    --shadow-hover:      0 8px 40px rgba(59, 130, 246, 0.18);
    --shadow-btn:        0 8px 24px rgba(59, 130, 246, 0.38);

    /* Layout */
    --max-width:         1100px;
    --section-pad:       88px;
    --nav-height:        72px;

    /* Radii */
    --radius:            12px;
    --radius-sm:         8px;
    --radius-pill:       50px;

    /* Transitions */
    --transition:        0.25s ease;
    --transition-fast:   0.15s ease;
}


/* ─────────────────────────────────────────────────────
   2. RESET & BASE STYLES
───────────────────────────────────────────────────── */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: 'Inter', sans-serif;
    font-weight: 400;
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

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

button {
    font-family: inherit;
}


/* ─────────────────────────────────────────────────────
   3. TYPOGRAPHY
───────────────────────────────────────────────────── */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Poppins', sans-serif;
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
}


/* ─────────────────────────────────────────────────────
   4. LAYOUT UTILITIES
───────────────────────────────────────────────────── */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 28px;
}

.section {
    padding: var(--section-pad) 0;
}

/* Section Header */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-label {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--accent-blue);
    margin-bottom: 14px;
    position: relative;
    padding: 0 20px;
}

.section-label::before,
.section-label::after {
    content: '';
    position: absolute;
    top: 50%;
    width: 28px;
    height: 1px;
    background: var(--accent-blue);
    opacity: 0.45;
    transform: translateY(-50%);
}

.section-label::before { right: 100%; margin-right: -18px; }
.section-label::after  { left:  100%; margin-left:  -18px; }

.section-title {
    font-size: clamp(1.75rem, 3.5vw, 2.3rem);
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.25;
}

.section-subtitle {
    max-width: 600px;
    margin: 14px auto 0;
    color: var(--text-sub);
    font-size: 0.98rem;
    line-height: 1.75;
}

/* Gradient Text */
.gradient-text {
    background: linear-gradient(135deg, var(--accent-blue) 0%, var(--accent-cyan) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}


/* ─────────────────────────────────────────────────────
   5. BUTTON COMPONENTS
───────────────────────────────────────────────────── */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 9px;
    padding: 13px 28px;
    border-radius: var(--radius-sm);
    font-family: 'Inter', sans-serif;
    font-size: 0.93rem;
    font-weight: 500;
    cursor: pointer;
    border: 2px solid transparent;
    transition: background var(--transition),
                border-color var(--transition),
                transform var(--transition),
                box-shadow var(--transition);
    text-decoration: none;
    white-space: nowrap;
    line-height: 1;
}

.btn-primary {
    background: var(--accent-blue);
    color: #ffffff;
    border-color: var(--accent-blue);
}

.btn-primary:hover {
    background: var(--accent-blue-dark);
    border-color: var(--accent-blue-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-btn);
}

.btn-secondary {
    background: rgba(59, 130, 246, 0.11);
    color: var(--accent-blue);
    border-color: rgba(59, 130, 246, 0.28);
}

.btn-secondary:hover {
    background: rgba(59, 130, 246, 0.2);
    border-color: var(--accent-blue);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border-color: rgba(241, 245, 249, 0.18);
}

.btn-outline:hover {
    background: rgba(241, 245, 249, 0.06);
    border-color: rgba(241, 245, 249, 0.38);
    transform: translateY(-2px);
}

.btn-full {
    width: 100%;
}


/* ─────────────────────────────────────────────────────
   6. NAVBAR
───────────────────────────────────────────────────── */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    height: var(--nav-height);
    background: rgba(15, 23, 42, 0.88);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
    border-bottom: 1px solid var(--border);
    transition: background var(--transition);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 28px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-brand {
    font-family: 'Poppins', sans-serif;
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: -0.01em;
}

.brand-dot {
    color: var(--accent-blue);
    font-weight: 800;
}

.brand-dev {
    color: var(--accent-cyan);
    font-weight: 500;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2px;
}

.nav-link {
    padding: 7px 15px;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-sub);
    transition: color var(--transition-fast), background var(--transition-fast);
}

.nav-link:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.nav-cta {
    padding: 8px 20px;
    background: var(--accent-blue);
    color: #ffffff;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    margin-left: 8px;
    transition: background var(--transition), transform var(--transition);
}

.nav-cta:hover {
    background: var(--accent-blue-dark);
    transform: translateY(-1px);
}


/* ─────────────────────────────────────────────────────
   7. HERO SECTION
───────────────────────────────────────────────────── */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding-top: var(--nav-height);
}

/* Subtle tech grid background */
.hero-grid-pattern {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(59, 130, 246, 0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(59, 130, 246, 0.04) 1px, transparent 1px);
    background-size: 64px 64px;
    z-index: 0;
}

/* Decorative glow orbs */
.hero-glow {
    position: absolute;
    border-radius: 50%;
    filter: blur(110px);
    z-index: 0;
    pointer-events: none;
}

.hero-glow-1 {
    width: 520px;
    height: 520px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.14) 0%, transparent 70%);
    top: -80px;
    right: -60px;
}

.hero-glow-2 {
    width: 420px;
    height: 420px;
    background: radial-gradient(circle, rgba(34, 211, 238, 0.09) 0%, transparent 70%);
    bottom: 40px;
    left: -40px;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 840px;
    text-align: center;
    padding: 48px 28px;
}

/* Available badge */
.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 18px;
    border: 1px solid rgba(34, 211, 238, 0.28);
    border-radius: var(--radius-pill);
    font-size: 0.78rem;
    font-weight: 500;
    color: var(--accent-cyan);
    margin-bottom: 28px;
    background: rgba(34, 211, 238, 0.05);
    letter-spacing: 0.02em;
}

.badge-dot {
    width: 7px;
    height: 7px;
    background: var(--accent-cyan);
    border-radius: 50%;
    flex-shrink: 0;
    animation: pulse-badge 2.2s ease-in-out infinite;
}

@keyframes pulse-badge {
    0%, 100% { opacity: 1;   transform: scale(1);   }
    50%       { opacity: 0.4; transform: scale(0.75); }
}

/* Name */
.hero-name {
    font-size: clamp(3.2rem, 8.5vw, 5.8rem);
    font-weight: 800;
    line-height: 1;
    letter-spacing: -0.025em;
    margin-bottom: 18px;
    color: var(--text-primary);
}

/* Title */
.hero-title {
    font-family: 'Inter', sans-serif;
    font-size: clamp(1.05rem, 2.4vw, 1.35rem);
    font-weight: 500;
    color: var(--text-sub);
    margin-bottom: 12px;
    letter-spacing: 0.01em;
}

/* Experience tag */
.hero-exp-tag {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-bottom: 22px;
}

.exp-highlight {
    color: var(--accent-blue);
    font-weight: 600;
}

/* Summary paragraph */
.hero-summary {
    max-width: 680px;
    margin: 0 auto 26px;
    font-size: 1rem;
    color: var(--text-sub);
    line-height: 1.82;
}

/* Branding quote */
.hero-branding {
    border-left: 3px solid var(--accent-blue);
    padding: 11px 22px;
    margin: 0 auto 36px;
    max-width: 540px;
    font-style: italic;
    font-size: 1.04rem;
    color: var(--text-primary);
    background: rgba(59, 130, 246, 0.06);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    text-align: left;
    font-family: 'Poppins', sans-serif;
}

/* CTA Buttons row */
.hero-buttons {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 36px;
}

/* Meta info row */
.hero-meta-info {
    display: flex;
    align-items: center;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.meta-item {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.845rem;
    color: var(--text-muted);
}

.meta-item svg {
    flex-shrink: 0;
    color: var(--accent-blue);
}

.meta-divider {
    color: var(--text-muted);
    opacity: 0.4;
    font-size: 0.8rem;
}

/* Scroll hint */
.hero-scroll-hint {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    opacity: 0.35;
}

.hero-scroll-hint span {
    font-size: 0.65rem;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--text-sub);
}

.scroll-line {
    width: 1px;
    height: 44px;
    background: linear-gradient(to bottom, var(--accent-blue), transparent);
    animation: scroll-fade 2.4s ease-in-out infinite;
}

@keyframes scroll-fade {
    0%   { transform: scaleY(0); transform-origin: top; opacity: 1; }
    50%  { transform: scaleY(1); transform-origin: top; opacity: 1; }
    51%  { transform: scaleY(1); transform-origin: bottom; }
    100% { transform: scaleY(0); transform-origin: bottom; opacity: 0; }
}


/* ─────────────────────────────────────────────────────
   8. ABOUT SECTION
───────────────────────────────────────────────────── */
.about {
    background: var(--bg-section);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: 60px;
    align-items: start;
}

.about-para {
    color: var(--text-sub);
    font-size: 0.98rem;
    line-height: 1.82;
    margin-bottom: 18px;
}

.about-para:last-of-type {
    margin-bottom: 24px;
}

/* Expertise Tags */
.expertise-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.expertise-tag {
    padding: 5px 14px;
    background: rgba(59, 130, 246, 0.09);
    border: 1px solid rgba(59, 130, 246, 0.2);
    border-radius: var(--radius-pill);
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--accent-blue);
    transition: background var(--transition), border-color var(--transition);
}

.expertise-tag:hover {
    background: rgba(59, 130, 246, 0.18);
    border-color: rgba(59, 130, 246, 0.48);
}

/* Stat Cards */
.about-stats-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
}

.stat-card {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 22px 16px;
    text-align: center;
    transition: border-color var(--transition),
                box-shadow var(--transition),
                transform var(--transition);
}

.stat-card:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-hover);
    transform: translateY(-4px);
}

.stat-card-accent {
    background: linear-gradient(
        135deg,
        rgba(59, 130, 246, 0.11) 0%,
        rgba(34, 211, 238, 0.07) 100%
    );
    border-color: rgba(59, 130, 246, 0.28);
}

.stat-number {
    font-family: 'Poppins', sans-serif;
    font-size: 1.95rem;
    font-weight: 800;
    color: var(--accent-blue);
    line-height: 1;
    margin-bottom: 7px;
}

.stat-plus {
    font-size: 1.3rem;
    color: var(--accent-cyan);
}

.stat-label {
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
    line-height: 1.3;
}

.stat-sub {
    font-size: 0.7rem;
    color: var(--text-muted);
    line-height: 1.3;
}


/* ─────────────────────────────────────────────────────
   9. SKILLS SECTION
───────────────────────────────────────────────────── */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.skill-category {
    background: var(--bg-section);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px 24px;
    transition: border-color var(--transition),
                box-shadow var(--transition),
                transform var(--transition);
}

.skill-category:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-hover);
    transform: translateY(-4px);
}

.skill-category-header {
    display: flex;
    align-items: center;
    gap: 13px;
    margin-bottom: 22px;
    padding-bottom: 18px;
    border-bottom: 1px solid var(--border);
}

.skill-category-icon {
    width: 44px;
    height: 44px;
    background: rgba(59, 130, 246, 0.11);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: var(--accent-blue);
    transition: background var(--transition);
}

.skill-category:hover .skill-category-icon {
    background: rgba(59, 130, 246, 0.2);
}

.skill-category-title {
    font-size: 0.97rem;
    font-weight: 600;
    color: var(--text-primary);
}

.skill-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.skill-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.875rem;
    color: var(--text-sub);
    padding: 3px 0;
    transition: color var(--transition-fast);
}

.skill-item:hover {
    color: var(--text-primary);
}

.skill-dot {
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--accent-blue);
    flex-shrink: 0;
    transition: background var(--transition-fast);
}

.skill-item:hover .skill-dot {
    background: var(--accent-cyan);
}


/* ─────────────────────────────────────────────────────
   10. PROJECTS SECTION
───────────────────────────────────────────────────── */
.projects {
    background: var(--bg-section);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.project-card {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    transition: border-color var(--transition),
                box-shadow var(--transition),
                transform var(--transition);
}

.project-card:hover {
    border-color: rgba(59, 130, 246, 0.42);
    box-shadow: 0 10px 44px rgba(59, 130, 246, 0.14);
    transform: translateY(-5px);
}

.project-card-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.project-number {
    font-family: 'Poppins', sans-serif;
    font-size: 2.1rem;
    font-weight: 800;
    color: rgba(59, 130, 246, 0.16);
    line-height: 1;
    user-select: none;
}

.project-tags {
    display: flex;
    gap: 6px;
}

.project-tag {
    padding: 3px 10px;
    background: rgba(34, 211, 238, 0.08);
    border: 1px solid rgba(34, 211, 238, 0.2);
    border-radius: var(--radius-pill);
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--accent-cyan);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.project-title {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.3;
}

.project-client {
    font-size: 0.82rem;
    color: var(--text-muted);
    margin-top: -8px;
}

.project-section {
    /* spacing handled by parent gap */
}

.project-section-label {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--accent-blue);
    margin-bottom: 6px;
}

.project-section-text {
    font-size: 0.875rem;
    color: var(--text-sub);
    line-height: 1.72;
}

.project-impact {
    margin-top: auto;
}

.impact-badge {
    display: inline-block;
    padding: 5px 13px;
    background: rgba(59, 130, 246, 0.08);
    border: 1px solid rgba(59, 130, 246, 0.2);
    border-radius: var(--radius-sm);
    font-size: 0.78rem;
    color: var(--accent-blue);
    font-weight: 500;
    line-height: 1.4;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    border-top: 1px solid var(--border);
    padding-top: 16px;
}

.tech-tag {
    padding: 4px 10px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    font-size: 0.73rem;
    color: var(--text-sub);
    font-family: 'Inter', monospace;
    letter-spacing: 0.01em;
    transition: border-color var(--transition-fast), color var(--transition-fast);
}

.tech-tag:hover {
    border-color: rgba(59, 130, 246, 0.25);
    color: var(--text-primary);
}


/* ─────────────────────────────────────────────────────
   11. EXPERIENCE TIMELINE
───────────────────────────────────────────────────── */
.timeline {
    max-width: 820px;
    margin: 0 auto;
}

.timeline-item {
    display: grid;
    grid-template-columns: 28px 1fr;
    gap: 24px;
}

.timeline-marker {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding-top: 6px;
}

.timeline-dot {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--accent-blue);
    border: 3px solid var(--bg-primary);
    box-shadow: 0 0 0 2px var(--accent-blue);
    flex-shrink: 0;
    z-index: 1;
}

.timeline-line {
    width: 2px;
    flex: 1;
    background: linear-gradient(
        to bottom,
        rgba(59, 130, 246, 0.55) 0%,
        rgba(59, 130, 246, 0.08) 100%
    );
    margin-top: 8px;
    margin-bottom: -4px;
}

.timeline-content {
    background: var(--bg-section);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    margin-bottom: 24px;
    transition: border-color var(--transition), box-shadow var(--transition);
}

.timeline-content:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-hover);
}

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 18px;
    flex-wrap: wrap;
}

.timeline-role {
    font-size: 1.08rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.timeline-company {
    font-size: 0.875rem;
    color: var(--accent-blue);
    font-weight: 500;
}

.timeline-meta {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 6px;
    flex-shrink: 0;
}

.timeline-date {
    font-size: 0.8rem;
    color: var(--text-muted);
    white-space: nowrap;
}

.timeline-badge {
    padding: 2px 10px;
    border-radius: var(--radius-pill);
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.timeline-badge.current {
    background: rgba(34, 211, 238, 0.1);
    color: var(--accent-cyan);
    border: 1px solid rgba(34, 211, 238, 0.28);
}

.timeline-badge.volunteer {
    background: rgba(168, 85, 247, 0.1);
    color: #c084fc;
    border: 1px solid rgba(168, 85, 247, 0.28);
}

.timeline-dot-volunteer {
    background: #a855f7;
    box-shadow: 0 0 0 2px #a855f7;
}

.timeline-role-sub {
    font-weight: 400;
    font-size: 0.88rem;
    color: var(--text-muted);
    font-family: 'Inter', sans-serif;
}

.timeline-list {
    display: flex;
    flex-direction: column;
    gap: 9px;
}

.timeline-list li {
    padding-left: 18px;
    position: relative;
    font-size: 0.875rem;
    color: var(--text-sub);
    line-height: 1.65;
}

.timeline-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 8px;
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--accent-blue);
}


/* ─────────────────────────────────────────────────────
   12. EDUCATION & CERTIFICATIONS
───────────────────────────────────────────────────── */
.education {
    background: var(--bg-section);
}

.edu-certs-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 44px;
}

.edu-col-title {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 20px;
}

.edu-col-title svg {
    color: var(--accent-blue);
    flex-shrink: 0;
}

/* Education Card */
.edu-card {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    transition: border-color var(--transition), box-shadow var(--transition);
}

.edu-card:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-hover);
}

.edu-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 8px;
}

.edu-degree {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.3;
}

.edu-year {
    font-size: 0.78rem;
    color: var(--accent-blue);
    font-weight: 600;
    white-space: nowrap;
    padding: 2px 10px;
    background: rgba(59, 130, 246, 0.1);
    border-radius: var(--radius-pill);
    flex-shrink: 0;
}

.edu-institution {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 18px;
}

.edu-subjects {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.edu-subject-tag {
    padding: 4px 10px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    font-size: 0.73rem;
    color: var(--text-sub);
}

/* Certification Cards */
.cert-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.cert-card {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px 20px;
    transition: border-color var(--transition), transform var(--transition);
}

.cert-card:hover {
    border-color: var(--border-hover);
    transform: translateX(4px);
}

.cert-icon {
    width: 36px;
    height: 36px;
    background: rgba(59, 130, 246, 0.1);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: var(--accent-blue);
}

.cert-title {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
    line-height: 1.3;
}

.cert-detail {
    font-size: 0.78rem;
    color: var(--text-muted);
}


/* ─────────────────────────────────────────────────────
   13. TECHNICAL INSIGHTS
───────────────────────────────────────────────────── */
.insights-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.insight-card {
    background: var(--bg-section);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px 24px;
    transition: border-color var(--transition),
                box-shadow var(--transition),
                transform var(--transition);
}

.insight-card:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-hover);
    transform: translateY(-4px);
}

.insight-icon {
    width: 52px;
    height: 52px;
    background: rgba(59, 130, 246, 0.1);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-blue);
    margin-bottom: 18px;
    transition: background var(--transition);
}

.insight-card:hover .insight-icon {
    background: rgba(59, 130, 246, 0.2);
}

.insight-title {
    font-size: 0.97rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.insight-text {
    font-size: 0.855rem;
    color: var(--text-sub);
    line-height: 1.74;
}


/* ─────────────────────────────────────────────────────
   14. TECHNICAL ARTICLES SECTION
───────────────────────────────────────────────────── */
.articles {
    background: var(--bg-primary);
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 48px;
}

/* Article Card */
.article-card {
    background: var(--bg-section);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 30px;
    display: flex;
    flex-direction: column;
    gap: 18px;
    position: relative;
    overflow: hidden;
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.25);
    transition: transform 0.3s ease,
                box-shadow 0.3s ease,
                border-color 0.3s ease;
}

/* Gradient top-border accent — visible on hover */
.article-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--accent-blue), var(--accent-cyan));
    opacity: 0;
    transition: opacity 0.3s ease;
}

/* Subtle inner glow — visible on hover */
.article-card::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 14px;
    background: radial-gradient(
        ellipse at 50% 0%,
        rgba(59, 130, 246, 0.07) 0%,
        transparent 65%
    );
    opacity: 0;
    transition: opacity 0.3s ease;
    pointer-events: none;
}

.article-card:hover {
    transform: translateY(-6px);
    border-color: rgba(59, 130, 246, 0.38);
    box-shadow: 0 24px 60px rgba(0, 0, 0, 0.38),
                0 0 32px rgba(59, 130, 246, 0.1);
}

.article-card:hover::before {
    opacity: 1;
}

.article-card:hover::after {
    opacity: 1;
}

/* Card Top Row */
.article-card-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

/* Category Tag */
.article-category {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 4px 12px;
    border-radius: var(--radius-pill);
    font-size: 0.72rem;
    font-weight: 600;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.article-cat-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    flex-shrink: 0;
}

/* Category colour variants */
.article-category.performance {
    background: rgba(251, 146, 60, 0.1);
    border: 1px solid rgba(251, 146, 60, 0.25);
    color: #fb923c;
}
.article-category.performance .article-cat-dot {
    background: #fb923c;
}

.article-category.al-dev {
    background: rgba(59, 130, 246, 0.1);
    border: 1px solid rgba(59, 130, 246, 0.25);
    color: var(--accent-blue);
}
.article-category.al-dev .article-cat-dot {
    background: var(--accent-blue);
}

.article-category.control-addin {
    background: rgba(34, 211, 238, 0.08);
    border: 1px solid rgba(34, 211, 238, 0.22);
    color: var(--accent-cyan);
}
.article-category.control-addin .article-cat-dot {
    background: var(--accent-cyan);
}

/* Platform badge (LinkedIn) */
.article-platform {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    font-size: 0.7rem;
    font-weight: 500;
    color: var(--text-muted);
    padding: 3px 9px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-pill);
    white-space: nowrap;
    flex-shrink: 0;
}

/* Article Title */
.article-title {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.35;
    transition: color 0.25s ease;
}

.article-card:hover .article-title {
    color: #ffffff;
}

/* Article Description */
.article-description {
    font-size: 0.875rem;
    color: var(--text-sub);
    line-height: 1.75;
    flex: 1;
}

/* Divider */
.article-divider {
    height: 1px;
    background: linear-gradient(
        90deg,
        var(--border) 0%,
        transparent 100%
    );
    flex-shrink: 0;
    transition: background 0.3s ease;
}

.article-card:hover .article-divider {
    background: linear-gradient(
        90deg,
        rgba(59, 130, 246, 0.35) 0%,
        transparent 100%
    );
}

/* Read Link */
.article-link {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--accent-blue);
    text-decoration: none;
    transition: gap 0.25s ease, color 0.25s ease;
    align-self: flex-start;
}

.article-link:hover {
    gap: 11px;
    color: var(--accent-cyan);
}

.article-link svg {
    transition: transform 0.25s ease;
    flex-shrink: 0;
}

.article-link:hover svg {
    transform: translateX(3px);
}

/* Footer CTA row */
.articles-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    padding: 24px 28px;
    background: var(--bg-section);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    flex-wrap: wrap;
}

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


/* ─────────────────────────────────────────────────────
   15. CONTACT SECTION
───────────────────────────────────────────────────── */
.contact {
    background: var(--bg-section);
}

.contact-grid {
    display: grid;
    grid-template-columns: 380px 1fr;
    gap: 52px;
    align-items: start;
}

.contact-info-title {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 22px;
}

.contact-details {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.contact-detail-item {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    padding: 14px 16px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    text-decoration: none;
    color: inherit;
    transition: border-color var(--transition), transform var(--transition);
}

.contact-detail-item:not(.no-hover):hover {
    border-color: var(--border-hover);
    transform: translateX(4px);
}

.contact-detail-icon {
    width: 36px;
    height: 36px;
    background: rgba(59, 130, 246, 0.1);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: var(--accent-blue);
    margin-top: 2px;
}

.contact-detail-label {
    display: block;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
    margin-bottom: 3px;
}

.contact-detail-value {
    display: block;
    font-size: 0.855rem;
    color: var(--text-primary);
    font-weight: 500;
    word-break: break-all;
}

/* Contact Form */
.contact-form {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 18px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 7px;
}

.form-label {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-sub);
    letter-spacing: 0.01em;
}

.form-input,
.form-textarea {
    padding: 12px 16px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-family: 'Inter', sans-serif;
    font-size: 0.9rem;
    outline: none;
    transition: border-color var(--transition), box-shadow var(--transition);
    width: 100%;
    appearance: none;
    -webkit-appearance: none;
}

.form-input::placeholder,
.form-textarea::placeholder {
    color: var(--text-muted);
}

.form-input:focus,
.form-textarea:focus {
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.11);
}

.form-textarea {
    resize: vertical;
    min-height: 130px;
    line-height: 1.65;
}


/* ─────────────────────────────────────────────────────
   15. FOOTER
───────────────────────────────────────────────────── */
.footer {
    border-top: 1px solid var(--border);
    padding: 44px 0 24px;
}

.footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    margin-bottom: 28px;
    flex-wrap: wrap;
}

.footer-logo {
    font-family: 'Poppins', sans-serif;
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-primary);
    display: block;
    margin-bottom: 7px;
    letter-spacing: -0.01em;
}

.footer-tagline {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-style: italic;
    max-width: 340px;
    line-height: 1.5;
}

.footer-links {
    display: flex;
    gap: 4px;
    flex-wrap: wrap;
}

.footer-link {
    padding: 7px 14px;
    border-radius: var(--radius-sm);
    font-size: 0.845rem;
    color: var(--text-sub);
    transition: color var(--transition-fast), background var(--transition-fast);
}

.footer-link:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.footer-bottom {
    border-top: 1px solid var(--border);
    padding-top: 20px;
    text-align: center;
}

.footer-copy {
    font-size: 0.8rem;
    color: var(--text-muted);
}


/* ─────────────────────────────────────────────────────
   16. THEME TOGGLE BUTTON
───────────────────────────────────────────────────── */
.theme-toggle {
    width: 38px;
    height: 38px;
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid var(--border);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-sub);
    margin-left: 10px;
    flex-shrink: 0;
    transition: background var(--transition),
                border-color var(--transition),
                color var(--transition),
                transform 0.3s ease;
    outline: none;
}

.theme-toggle:hover {
    background: rgba(255, 255, 255, 0.12);
    border-color: var(--border-hover);
    color: var(--text-primary);
    transform: rotate(18deg) scale(1.08);
}

.theme-toggle:focus-visible {
    outline: 2px solid var(--accent-blue);
    outline-offset: 2px;
}

/* Sun = visible in dark mode  →  click to go light */
.icon-sun  { display: block; }
/* Moon = hidden in dark mode →  click to go dark  */
.icon-moon { display: none;  }

/* In light mode: flip visibility */
html.light-mode .icon-sun  { display: none;  }
html.light-mode .icon-moon { display: block; }

html.light-mode .theme-toggle {
    background: rgba(15, 23, 42, 0.05);
    color: var(--text-sub);
}

html.light-mode .theme-toggle:hover {
    background: rgba(15, 23, 42, 0.1);
    color: var(--text-primary);
}


/* ─────────────────────────────────────────────────────
   17. LIGHT MODE — CSS VARIABLE OVERRIDES
   Clean corporate palette: slate-white / pure-white
   Accent blue unchanged · cyan deepened for contrast
───────────────────────────────────────────────────── */
html.light-mode {
    /* Backgrounds */
    --bg-primary:        #f1f5f9;
    --bg-section:        #ffffff;
    --bg-card:           #ffffff;
    --bg-input:          #ffffff;

    /* Accent — cyan deepened for light bg readability */
    --accent-cyan:       #0891b2;

    /* Text */
    --text-primary:      #0f172a;
    --text-sub:          #475569;
    --text-muted:        #94a3b8;

    /* Borders */
    --border:            rgba(15, 23, 42, 0.1);
    --border-hover:      rgba(59, 130, 246, 0.45);
    --border-subtle:     rgba(15, 23, 42, 0.07);

    /* Shadows — softer on light */
    --shadow-card:       0 4px 24px rgba(15, 23, 42, 0.08);
    --shadow-hover:      0 8px 40px rgba(59, 130, 246, 0.16);
    --shadow-btn:        0 8px 24px rgba(59, 130, 246, 0.32);
}

/* ── Navbar ───────────────────────────────────────── */
html.light-mode .navbar {
    background: rgba(241, 245, 249, 0.94);
    border-bottom-color: rgba(15, 23, 42, 0.1);
}

html.light-mode .nav-link:hover {
    background: rgba(15, 23, 42, 0.05);
    color: var(--text-primary);
}

/* ── Buttons ─────────────────────────────────────── */
html.light-mode .btn-secondary {
    background: rgba(59, 130, 246, 0.08);
    border-color: rgba(59, 130, 246, 0.25);
}

html.light-mode .btn-secondary:hover {
    background: rgba(59, 130, 246, 0.16);
}

html.light-mode .btn-outline {
    border-color: rgba(15, 23, 42, 0.2);
    color: var(--text-primary);
}

html.light-mode .btn-outline:hover {
    background: rgba(15, 23, 42, 0.05);
    border-color: rgba(15, 23, 42, 0.35);
}

/* ── Hero Section ────────────────────────────────── */
html.light-mode .hero-grid-pattern {
    background-image:
        linear-gradient(rgba(15, 23, 42, 0.045) 1px, transparent 1px),
        linear-gradient(90deg, rgba(15, 23, 42, 0.045) 1px, transparent 1px);
}

html.light-mode .hero-glow-1 {
    background: radial-gradient(circle, rgba(59, 130, 246, 0.16) 0%, transparent 70%);
}

html.light-mode .hero-glow-2 {
    background: radial-gradient(circle, rgba(8, 145, 178, 0.12) 0%, transparent 70%);
}

html.light-mode .hero-badge {
    background: rgba(8, 145, 178, 0.07);
    border-color: rgba(8, 145, 178, 0.3);
    color: #0891b2;
}

html.light-mode .badge-dot {
    background: #0891b2;
}

html.light-mode .hero-branding {
    background: rgba(59, 130, 246, 0.05);
    color: #0f172a;
}

html.light-mode .scroll-line {
    background: linear-gradient(to bottom, var(--accent-blue), transparent);
}

/* ── About — Stat Cards ───────────────────────────── */
html.light-mode .stat-card-accent {
    background: linear-gradient(
        135deg,
        rgba(59, 130, 246, 0.08) 0%,
        rgba(8, 145, 178, 0.05) 100%
    );
}

/* ── Skills ──────────────────────────────────────── */
html.light-mode .skill-category-header {
    border-bottom-color: rgba(15, 23, 42, 0.08);
}

html.light-mode .skill-category-icon {
    background: rgba(59, 130, 246, 0.09);
}

html.light-mode .skill-category:hover .skill-category-icon {
    background: rgba(59, 130, 246, 0.16);
}

/* ── Tech/Subject Tags (white-based in dark → invert) */
html.light-mode .tech-tag,
html.light-mode .edu-subject-tag {
    background: rgba(15, 23, 42, 0.04);
    border-color: rgba(15, 23, 42, 0.1);
    color: var(--text-sub);
}

html.light-mode .tech-tag:hover {
    border-color: rgba(59, 130, 246, 0.3);
    color: var(--text-primary);
}

/* ── Projects ────────────────────────────────────── */
html.light-mode .project-number {
    color: rgba(59, 130, 246, 0.2);
}

/* ── Timeline ────────────────────────────────────── */
html.light-mode .timeline-dot {
    border-color: var(--bg-primary);
}

/* ── Insights ────────────────────────────────────── */
html.light-mode .insight-icon {
    background: rgba(59, 130, 246, 0.09);
}

html.light-mode .insight-card:hover .insight-icon {
    background: rgba(59, 130, 246, 0.16);
}

/* ── Articles ────────────────────────────────────── */
html.light-mode .article-platform {
    background: rgba(15, 23, 42, 0.04);
    border-color: rgba(15, 23, 42, 0.09);
    color: var(--text-muted);
}

html.light-mode .article-card:hover .article-title {
    color: #0f172a;
}

html.light-mode .article-card::after {
    background: radial-gradient(
        ellipse at 50% 0%,
        rgba(59, 130, 246, 0.06) 0%,
        transparent 65%
    );
}

html.light-mode .articles-footer {
    background: #f8fbff;
    border-color: rgba(15, 23, 42, 0.1);
}

/* ── Contact Form ─────────────────────────────────── */
html.light-mode .form-input,
html.light-mode .form-textarea {
    border-color: rgba(15, 23, 42, 0.14);
    color: var(--text-primary);
}

html.light-mode .form-input:focus,
html.light-mode .form-textarea:focus {
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

/* ── Footer ──────────────────────────────────────── */
html.light-mode .footer {
    border-top-color: rgba(15, 23, 42, 0.1);
}

html.light-mode .footer-bottom {
    border-top-color: rgba(15, 23, 42, 0.08);
}

html.light-mode .footer-link:hover {
    background: rgba(15, 23, 42, 0.05);
    color: var(--text-primary);
}


/* ─────────────────────────────────────────────────────
   18. RESPONSIVE — TABLET (≤1024px)
───────────────────────────────────────────────────── */
@media (max-width: 1024px) {

    .about-grid {
        grid-template-columns: 1fr;
        gap: 44px;
    }

    .about-stats-col {
        grid-template-columns: repeat(4, 1fr);
    }

    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .insights-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .articles-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .contact-grid {
        grid-template-columns: 1fr 1fr;
        gap: 36px;
    }
}


/* ─────────────────────────────────────────────────────
   20. RESPONSIVE — MOBILE (≤768px)
───────────────────────────────────────────────────── */
@media (max-width: 768px) {

    :root {
        --section-pad: 64px;
        --nav-height:  64px;
    }

    .container {
        padding: 0 20px;
    }

    /* Nav — hide links on mobile (no JS hamburger) */
    .nav-links {
        display: none;
    }

    /* Hero */
    .hero-name {
        font-size: clamp(2.8rem, 11vw, 3.8rem);
    }

    .hero-branding {
        font-size: 0.93rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
        max-width: 340px;
        margin-left: auto;
        margin-right: auto;
    }

    .hero-meta-info {
        flex-direction: column;
        gap: 10px;
    }

    .meta-divider {
        display: none;
    }

    /* About */
    .about-stats-col {
        grid-template-columns: repeat(2, 1fr);
    }

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

    /* Projects */
    .projects-grid {
        grid-template-columns: 1fr;
    }

    /* Timeline */
    .timeline-item {
        grid-template-columns: 22px 1fr;
        gap: 16px;
    }

    .timeline-header {
        flex-direction: column;
        gap: 10px;
    }

    .timeline-meta {
        align-items: flex-start;
        flex-direction: row;
        align-items: center;
        gap: 10px;
    }

    /* Education */
    .edu-certs-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    /* Insights */
    .insights-grid {
        grid-template-columns: 1fr;
    }

    /* Articles */
    .articles-grid {
        grid-template-columns: 1fr;
    }

    .articles-footer {
        flex-direction: column;
        align-items: flex-start;
        gap: 16px;
    }

    /* Contact */
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    /* Footer */
    .footer-inner {
        flex-direction: column;
        align-items: flex-start;
    }
}


/* ─────────────────────────────────────────────────────
   21. RESPONSIVE — SMALL MOBILE (≤480px)
───────────────────────────────────────────────────── */
@media (max-width: 480px) {

    .section-header {
        margin-bottom: 40px;
    }

    .hero-badge {
        font-size: 0.72rem;
    }

    .hero-branding {
        padding: 10px 16px;
        font-size: 0.88rem;
    }

    .hero-content {
        padding: 36px 0;
    }

    /* About stats — 2 columns */
    .about-stats-col {
        grid-template-columns: 1fr 1fr;
    }

    .stat-card {
        padding: 16px 12px;
    }

    .stat-number {
        font-size: 1.65rem;
    }

    .project-card {
        padding: 20px 18px;
    }

    .timeline-content {
        padding: 18px 16px;
    }

    .skill-category {
        padding: 22px 18px;
    }

    .insight-card {
        padding: 22px 18px;
    }

    .contact-detail-item {
        padding: 12px 14px;
    }

    .footer-links {
        gap: 2px;
    }
}