/* 
 * Deepanshu Kumar Portfolio - Stylesheet
 * 
 * Design Philosophy:
 * - Minimal: Only essential styles, no decoration for decoration's sake
 * - Calm: Generous whitespace, muted colors, no visual noise
 * - Professional: Clean typography, clear hierarchy, consistent spacing
 * - Timeless: No trendy effects, classic proportions, will age well
 *
 * Color Palette:
 * - Background: Pure black (#000) - elegant, modern, easy on eyes
 * - Text Primary: White (#fff) - maximum contrast for readability
 * - Text Secondary: Muted gray (#a0a0a0) - for supporting content
 * - Text Tertiary: Darker gray (#666) - for subtle labels
 * - Accent: Soft blue (#6b9ac4) - calm, professional, not aggressive
 * - Borders: Very subtle white (#ffffff0d) - structure without distraction
 *
 * Typography:
 * - System font stack - loads instantly, feels native, always readable
 * - Base size 18px - comfortable reading on all devices
 * - Scale: 1.25 ratio - clear hierarchy without drama
 */


/* ============================================
   CSS CUSTOM PROPERTIES
   ============================================ */

:root {
    /* Colors */
    --color-bg: #000000;
    --color-bg-subtle: #0a0a0a;
    --color-text: #ffffff;
    --color-text-secondary: #a0a0a0;
    --color-text-tertiary: #666666;
    --color-accent: #6b9ac4;
    --color-border: rgba(255, 255, 255, 0.08);

    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-size-base: 1.125rem;     /* 18px */
    --font-size-sm: 0.889rem;       /* 16px */
    --font-size-xs: 0.79rem;        /* 14px */
    --font-size-lg: 1.25rem;        /* 20px */
    --font-size-xl: 1.563rem;       /* 25px */
    --font-size-2xl: 1.953rem;      /* 31px */
    --font-size-3xl: 2.441rem;      /* 39px */
    --font-size-4xl: 3.052rem;      /* 49px */
    --line-height: 1.6;
    --line-height-tight: 1.2;

    /* Spacing - based on 8px unit */
    --space-xs: 0.5rem;     /* 8px */
    --space-sm: 1rem;       /* 16px */
    --space-md: 1.5rem;     /* 24px */
    --space-lg: 2rem;       /* 32px */
    --space-xl: 3rem;       /* 48px */
    --space-2xl: 4rem;      /* 64px */
    --space-3xl: 6rem;      /* 96px */
    --space-4xl: 8rem;      /* 128px */

    /* Layout */
    --max-width: 1100px;
    --max-width-narrow: 720px;
}


/* ============================================
   RESET & BASE
   ============================================ */

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: var(--line-height);
    color: var(--color-text);
    background-color: var(--color-bg);
}

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

a {
    color: var(--color-accent);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

ul, ol {
    list-style: none;
}

blockquote {
    font-style: italic;
    color: var(--color-text-secondary);
}

address {
    font-style: normal;
}

/* Focus styles for accessibility */
a:focus-visible,
button:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}


/* ============================================
   TYPOGRAPHY
   ============================================ */

h1, h2, h3, h4 {
    line-height: var(--line-height-tight);
    font-weight: 600;
    color: var(--color-text);
}

h1 {
    font-size: var(--font-size-3xl);
    font-weight: 700;
}

h2 {
    font-size: var(--font-size-2xl);
}

h3 {
    font-size: var(--font-size-xl);
}

h4 {
    font-size: var(--font-size-lg);
    font-weight: 500;
}

p {
    color: var(--color-text-secondary);
}

strong {
    color: var(--color-text);
    font-weight: 600;
}

.section-label {
    display: inline-block;
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    margin-bottom: var(--space-sm);
    letter-spacing: 0.02em;
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.section-header h2 {
    margin-top: var(--space-xs);
}


/* ============================================
   LAYOUT
   ============================================ */

main {
    /* Push content below fixed nav */
    padding-top: var(--space-2xl);
}

section {
    padding: var(--space-3xl) var(--space-md);
    max-width: var(--max-width);
    margin: 0 auto;
}

/* Divider between major sections */
#work,
#abilities,
#experience,
#skills,
#testimonials,
#contact {
    border-top: 1px solid var(--color-border);
}


/* ============================================
   NAVIGATION
   ============================================ */

/* 
 * Design choice: Minimal top bar with subtle border.
 * No background until scrolled would require JS, so we use
 * a very subtle dark background that's nearly invisible.
 */

header#top {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background-color: rgba(0, 0, 0, 0.9);
    border-bottom: 1px solid var(--color-border);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

header#top nav {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--space-sm) var(--space-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.nav-logo {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-text);
}

.nav-logo:hover {
    text-decoration: none;
    color: var(--color-accent);
}

header#top nav ul {
    display: flex;
    gap: var(--space-md);
    flex-wrap: wrap;
}

header#top nav ul li a {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

header#top nav ul li a:hover {
    color: var(--color-text);
    text-decoration: none;
}


/* ============================================
   HERO SECTION
   ============================================ */

/*
 * Design choice: Unified first-screen with headline, bio, and photo.
 * Two-column layout on desktop, stacked on mobile.
 * Photo provides immediate visual engagement.
 */

#hero {
    display: flex;
    flex-direction: column;
    padding-top: var(--space-2xl);
    padding-bottom: var(--space-2xl);
    border-top: none;
}

.hero-headline {
    font-size: var(--font-size-4xl);
    margin-bottom: var(--space-xl);
}

.hero-headline .highlight {
    color: var(--color-accent);
}

.hero-container {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: var(--space-2xl);
    align-items: center;
}

.hero-content {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.greeting {
    font-size: var(--font-size-xl);
    color: var(--color-text);
    margin-bottom: var(--space-xs);
}

.hero-bio {
    color: var(--color-text-secondary);
    line-height: var(--line-height);
}

.hero-journey {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
    line-height: var(--line-height);
    margin-top: var(--space-xs);
}

.hero-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    margin-top: var(--space-xs);
}

.hero-tags li {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    padding: var(--space-xs) var(--space-sm);
    border: 1px solid var(--color-border);
    border-radius: 4px;
}

.hero-image {
    display: flex;
    justify-content: center;
}

.hero-image img {
    width: 100%;
    max-width: 260px;
    aspect-ratio: 3 / 4;
    object-fit: cover;
    border-radius: 8px;
    border: 1px solid var(--color-border);
}

.cta-group {
    display: flex;
    gap: var(--space-md);
    flex-wrap: wrap;
    margin-top: var(--space-sm);
}

.cta-button {
    display: inline-block;
    padding: var(--space-sm) var(--space-lg);
    background-color: var(--color-text);
    color: var(--color-bg);
    font-weight: 500;
    font-size: var(--font-size-sm);
    border-radius: 4px;
    width: fit-content;
}

.cta-button:hover {
    text-decoration: none;
    background-color: var(--color-accent);
    color: var(--color-bg);
}

.cta-button-outline {
    background-color: transparent;
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

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


/* ============================================
   STATS SECTION
   ============================================ */

/*
 * Design choice: Simple 4-column grid with large numbers.
 * Numbers are the focus - labels are secondary.
 * Subtle background to separate from hero.
 */

#stats {
    background-color: var(--color-bg-subtle);
    padding: var(--space-2xl) var(--space-md);
    max-width: none;
    border-top: none;
}

.stats-grid {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-lg);
    text-align: center;
}

.stat-item {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.stat-value {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--color-text);
}

.stat-label {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}


/* ============================================
   ABOUT SECTION
   ============================================ */

/*
 * Design choice: Two-column layout - photo and text.
 * Photo has subtle border to define it against dark bg.
 * Text is conversational, not bullet points.
 */

.about-container {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: var(--space-2xl);
    align-items: start;
}

.about-image img {
    border-radius: 8px;
    border: 1px solid var(--color-border);
}

.about-content h2 {
    margin-bottom: var(--space-md);
}

.about-content p {
    margin-bottom: var(--space-md);
}

.about-content p:last-of-type {
    margin-bottom: var(--space-lg);
}

.about-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.about-tags li {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    padding: var(--space-xs) var(--space-sm);
    border: 1px solid var(--color-border);
    border-radius: 4px;
}


/* ============================================
   PROJECTS SECTION
   ============================================ */

/*
 * Design choice: Featured project gets more space (full width).
 * Other projects in 2-column grid below.
 * Each card has image, title, description, and link.
 * Simple hover state on links only.
 */

.projects-grid {
    display: grid;
    gap: var(--space-xl);
}

.project-card {
    display: grid;
    gap: var(--space-md);
}

.project-featured {
    grid-template-columns: 1.2fr 1fr;
    align-items: start;
}

.project-featured .project-image img {
    border-radius: 8px;
    border: 1px solid var(--color-border);
}

.project-card:not(.project-featured) {
    grid-template-columns: 1fr 1fr;
}

.project-card:not(.project-featured) .project-image img {
    border-radius: 8px;
    border: 1px solid var(--color-border);
    aspect-ratio: 16 / 10;
    object-fit: cover;
}

.project-content h3 {
    margin-bottom: var(--space-xs);
}

.project-subtitle {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    margin-bottom: var(--space-sm);
}

.project-description {
    margin-bottom: var(--space-md);
}

.project-link {
    font-size: var(--font-size-sm);
    font-weight: 500;
}

.project-links {
    display: flex;
    gap: var(--space-md);
}

.project-note {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}


/* ============================================
   ABILITIES SECTION
   ============================================ */

/*
 * Design choice: Three equal cards with icon, title, description.
 * Icons are small and muted - text carries the message.
 * Cards have subtle border, no background difference.
 */

.abilities-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.ability-card {
    padding: var(--space-lg);
    border: 1px solid var(--color-border);
    border-radius: 8px;
}

.ability-icon {
    margin-bottom: var(--space-md);
}

.ability-icon img {
    width: 48px;
    height: 48px;
    opacity: 0.8;
}

.ability-card h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--space-sm);
}

.ability-card p {
    font-size: var(--font-size-sm);
}


/* ============================================
   EXPERIENCE SECTION
   ============================================ */

/*
 * Design choice: Vertical timeline with cards.
 * Each card has sidebar (logo + image) and main content.
 * Quote from manager adds credibility.
 * Responsibilities as bullet list for easy scanning.
 */

.experience-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-2xl);
}

.experience-card {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: var(--space-xl);
}

.experience-sidebar {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.experience-logo img {
    width: 64px;
    height: 64px;
    object-fit: contain;
    opacity: 0.9;
}

.experience-image img {
    border-radius: 8px;
    border: 1px solid var(--color-border);
}

.experience-header h3 {
    margin-bottom: var(--space-xs);
}

.experience-company {
    font-size: var(--font-size-base);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-xs);
}

.experience-date {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    margin-bottom: var(--space-md);
}

.experience-quote {
    padding-left: var(--space-md);
    border-left: 2px solid var(--color-border);
    margin-bottom: var(--space-lg);
    font-size: var(--font-size-sm);
}

.experience-details h4 {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-sm);
}

.experience-details ul {
    list-style: disc;
    padding-left: var(--space-md);
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.experience-details li {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.experience-awards {
    margin-top: var(--space-md);
    display: flex;
    gap: var(--space-md);
}

.experience-awards a {
    font-size: var(--font-size-sm);
}


/* ============================================
   SKILLS SECTION
   ============================================ */

/*
 * Design choice: Simple grid of skill badges.
 * Logo + name, nothing fancy.
 * Skills speak for themselves.
 */

.skills-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: var(--space-lg);
}

.skill-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: var(--space-sm);
    padding: var(--space-lg);
    border: 1px solid var(--color-border);
    border-radius: 8px;
}

.skill-icon img {
    width: 48px;
    height: 48px;
    object-fit: contain;
}

.skill-icon-text {
    font-size: var(--font-size-3xl);
    line-height: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
}

.skill-card h3 {
    font-size: var(--font-size-sm);
    font-weight: 500;
}


/* ============================================
   TESTIMONIALS SECTION
   ============================================ */

/*
 * Design choice: Cards with quote and attribution.
 * Photos are circular and small - focus is on words.
 * Masonry-like layout via grid.
 */

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-lg);
    align-items: start;
}

.testimonial-card {
    padding: var(--space-lg);
    border: 1px solid var(--color-border);
    border-radius: 8px;
}

.testimonial-card blockquote {
    margin-bottom: var(--space-lg);
}

.testimonial-card blockquote p {
    font-size: var(--font-size-sm);
    margin-bottom: var(--space-sm);
}

.testimonial-card blockquote p:last-child {
    margin-bottom: 0;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.testimonial-photo img {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    object-fit: cover;
}

.testimonial-name {
    font-style: normal;
    font-weight: 600;
    font-size: var(--font-size-sm);
    color: var(--color-text);
}

.testimonial-title {
    font-size: var(--font-size-xs);
    color: var(--color-text-secondary);
    margin: 0;
}

.testimonial-company {
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
    margin: 0;
}


/* ============================================
   CONTACT SECTION
   ============================================ */

/*
 * Design choice: Centered, simple call to action.
 * Email is prominent.
 * Social links are secondary but accessible.
 */

#contact {
    text-align: center;
}

.contact-content {
    max-width: var(--max-width-narrow);
    margin: 0 auto;
}

.contact-intro {
    font-size: var(--font-size-lg);
    margin-bottom: var(--space-lg);
}

.contact-email-link {
    display: inline-block;
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--space-xl);
}

.contact-social {
    margin-bottom: var(--space-lg);
}

.contact-social > p {
    font-size: var(--font-size-sm);
    margin-bottom: var(--space-sm);
}

.social-links {
    display: flex;
    justify-content: center;
    gap: var(--space-lg);
}

.social-links li a {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

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

.social-links li a img {
    width: 20px;
    height: 20px;
    opacity: 0.7;
}


/* ============================================
   FOOTER
   ============================================ */

/*
 * Design choice: Three-column layout.
 * Brand on left, socials in center, info on right.
 * Subtle, doesn't compete with content above.
 */

#footer {
    background-color: var(--color-bg-subtle);
    padding: var(--space-2xl) var(--space-md);
    border-top: 1px solid var(--color-border);
}

.footer-content {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: var(--space-xl);
    align-items: start;
    margin-bottom: var(--space-xl);
}

.footer-brand {
    /* Align left */
}

.footer-name {
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--space-xs);
}

.footer-title {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

.footer-social {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
}

.footer-social a img {
    width: 24px;
    height: 24px;
    opacity: 0.6;
}

.footer-social a:hover img {
    opacity: 1;
}

.footer-info {
    text-align: right;
}

.footer-status {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-xs);
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: var(--space-xs);
}

.status-dot {
    width: 8px;
    height: 8px;
    background-color: #22c55e;
    border-radius: 50%;
}

.footer-info address {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

.footer-info address a {
    color: var(--color-text-tertiary);
}

.footer-info address a:hover {
    color: var(--color-accent);
}

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

.footer-bottom p {
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
}


/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

/*
 * Mobile-first adjustments.
 * Breakpoints: 768px (tablet), 1024px (desktop).
 * Key changes: stack layouts, reduce font sizes, adjust spacing.
 */

/* Tablet and below */
@media (max-width: 1024px) {
    :root {
        --font-size-4xl: 2.5rem;
        --font-size-3xl: 2rem;
    }

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

    .hero-container {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
        text-align: center;
    }

    .hero-content {
        align-items: center;
    }

    .hero-tags {
        justify-content: center;
    }

    .cta-group {
        justify-content: center;
    }

    .hero-image {
        order: -1;
    }

    .hero-image img {
        max-width: 200px;
    }

    .project-featured {
        grid-template-columns: 1fr;
    }

    .project-card:not(.project-featured) {
        grid-template-columns: 1fr;
    }

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

    .experience-card {
        grid-template-columns: 1fr;
    }

    .experience-sidebar {
        flex-direction: row;
        align-items: center;
    }

    .experience-image {
        display: none;
    }

    .skills-grid {
        grid-template-columns: repeat(3, 1fr);
    }

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

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: var(--space-lg);
    }

    .footer-info {
        text-align: center;
    }

    .footer-status {
        justify-content: center;
    }
}

/* Mobile */
@media (max-width: 768px) {
    :root {
        --font-size-4xl: 2rem;
        --font-size-3xl: 1.75rem;
        --font-size-2xl: 1.5rem;
        --space-3xl: 4rem;
        --space-4xl: 5rem;
    }

    section {
        padding: var(--space-2xl) var(--space-sm);
    }

    header#top nav {
        justify-content: center;
        text-align: center;
    }

    header#top nav ul {
        justify-content: center;
        gap: var(--space-sm);
    }

    header#top nav ul li a {
        font-size: var(--font-size-xs);
    }

    #hero {
        padding-top: var(--space-lg);
        padding-bottom: var(--space-xl);
    }

    .hero-headline {
        font-size: var(--font-size-3xl);
        text-align: center;
    }

    .hero-image img {
        max-width: 160px;
    }

    .hero-bio,
    .hero-journey {
        text-align: center;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--space-md);
    }

    .stat-value {
        font-size: var(--font-size-2xl);
    }

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

    .social-links {
        flex-wrap: wrap;
    }

    .footer-social {
        flex-wrap: wrap;
        justify-content: center;
    }
}

/* Very small screens */
@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr 1fr;
    }

    .skills-grid {
        grid-template-columns: 1fr 1fr;
        gap: var(--space-sm);
    }

    .skill-card {
        padding: var(--space-sm);
    }
}