/* ============================================
   ATRAJIT SARKAR - PROFESSIONAL ACADEMIC PORTFOLIO
   ============================================ */

/* Custom Font - Atrajit Handwriting */
@font-face {
    font-family: 'AtrajitHandwriting';
    src: url('Atrajithandwriting-Regular.ttf') format('truetype');
    font-weight: normal;
    font-style: normal;
}

/* ============================================
   CSS VARIABLES - COLOR THEMES
   ============================================ */

:root {
    /* Dark Theme (Default) */
    --bg-primary: #1a1f2e;
    --bg-secondary: #242938;
    --bg-tertiary: #2d3343;
    --text-primary: #f5f3ed;
    --text-secondary: #c9c4b8;
    --text-muted: #9a9584;
    --accent-primary: #d4a574;
    --accent-secondary: #8b7355;
    --border-color: rgba(212, 165, 116, 0.2);
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.35);

    /* Spacing & Typography */
    --font-family: 'AtrajitHandwriting', serif;
    --line-height-base: 1.7;
    --line-height-heading: 1.3;
    --max-width: 1200px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 5rem;
    --radius: 8px;
}

/* ============================================
   BASE STYLES
   ============================================ */

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

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: var(--line-height-base);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-family);
    line-height: var(--line-height-heading);
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
}

h1 {
    font-size: clamp(2rem, 5vw, 3rem);
    letter-spacing: -0.02em;
}

h2 {
    font-size: clamp(1.75rem, 4vw, 2.25rem);
    letter-spacing: -0.01em;
}

h3 {
    font-size: clamp(1.25rem, 3vw, 1.5rem);
}

p {
    font-family: var(--font-family);
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

a {
    font-family: var(--font-family);
    color: var(--accent-primary);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--accent-secondary);
    text-decoration: underline;
}

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

em {
    font-family: var(--font-family);
    font-style: italic;
}

ul,
ol {
    font-family: var(--font-family);
    margin-left: var(--spacing-md);
    color: var(--text-secondary);
}

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

.navbar {
    position: sticky;
    top: 0;
    z-index: 100;
    background-color: rgba(26, 31, 46, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-sm) var(--spacing-md);
    box-shadow: var(--shadow);
}

.navbar nav {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.logo {
    font-family: var(--font-family);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--accent-primary);
    letter-spacing: 0.02em;
}

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

.nav-links {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
    align-items: center;
    flex-wrap: wrap;
    margin: 0;
}

.nav-links a {
    font-family: var(--font-family);
    font-size: 0.95rem;
    color: var(--text-secondary);
    padding-bottom: 2px;
    border-bottom: 2px solid transparent;
    transition: all 0.2s ease;
}

.nav-links a:hover {
    color: var(--accent-primary);
    border-bottom-color: var(--accent-primary);
    text-decoration: none;
}

/* ============================================
   BUTTONS
   ============================================ */

.btn-primary,
.btn-secondary,
.btn-outline {
    font-family: var(--font-family);
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius);
    font-size: 0.95rem;
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    text-decoration: none;
}

.btn-primary {
    background-color: var(--accent-primary);
    color: var(--bg-primary);
    border-color: var(--accent-primary);
}

.btn-primary:hover {
    background-color: var(--accent-secondary);
    border-color: var(--accent-secondary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    text-decoration: none;
}

.btn-secondary {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    border-color: var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--bg-secondary);
    border-color: var(--accent-primary);
    text-decoration: none;
}

.btn-outline {
    background-color: transparent;
    color: var(--accent-primary);
    border-color: var(--accent-primary);
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
}

.btn-outline:hover {
    background-color: var(--accent-primary);
    color: var(--bg-primary);
    text-decoration: none;
}

/* ============================================
   LAYOUT & SECTIONS
   ============================================ */

main {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section {
    padding: var(--spacing-xl) var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
}

.section:last-child {
    border-bottom: none;
}

.section-alt {
    background-color: var(--bg-secondary);
    padding: var(--spacing-lg) var(--spacing-lg);
    border-radius: var(--radius);
    margin: var(--spacing-md) 0;
    border: 1px solid var(--border-color);
}

.section-title {
    font-family: var(--font-family);
    margin-bottom: var(--spacing-xs);
    color: var(--accent-primary);
}

.section-subtitle {
    font-family: var(--font-family);
    color: var(--text-muted);
    font-size: 1rem;
    margin-bottom: var(--spacing-lg);
    font-style: italic;
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-md);
}

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

.hero {
    padding: var(--spacing-xl) var(--spacing-md);
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
}

.eyebrow {
    font-family: var(--font-family);
    font-size: 0.9rem;
    color: var(--accent-primary);
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-xs);
    text-transform: uppercase;
}

.hero h1 span {
    color: var(--accent-primary);
}

.hero-subtitle {
    font-family: var(--font-family);
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.5;
}

.hero-description {
    font-family: var(--font-family);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    max-width: 700px;
}

.hero-actions {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
    margin-top: var(--spacing-md);
}

.hero-card {
    background-color: var(--bg-tertiary);
    padding: var(--spacing-lg);
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
}

.hero-badge {
    font-family: var(--font-family);
    display: inline-block;
    background-color: var(--bg-secondary);
    color: var(--accent-primary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius);
    font-size: 0.85rem;
    margin-bottom: var(--spacing-sm);
    border: 1px solid var(--border-color);
    font-weight: 500;
}

.hero-card-text {
    font-family: var(--font-family);
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ============================================
   CARDS
   ============================================ */

.cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.card {
    background-color: var(--bg-tertiary);
    padding: var(--spacing-lg);
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

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

.card h3 {
    font-family: var(--font-family);
    color: var(--accent-primary);
    margin-bottom: var(--spacing-sm);
    font-size: 1.25rem;
}

.card p {
    font-family: var(--font-family);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.card-list {
    font-family: var(--font-family);
    list-style: disc;
    margin-left: var(--spacing-md);
    color: var(--text-secondary);
}

.card-list li {
    font-family: var(--font-family);
    margin-bottom: var(--spacing-xs);
}

/* ============================================
   LISTS
   ============================================ */

.info-list {
    font-family: var(--font-family);
    list-style: none;
    margin: 0;
    padding: 0;
}

.info-list li {
    font-family: var(--font-family);
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
    padding-left: 0;
}

.info-list span {
    font-family: var(--font-family);
    display: inline-block;
    min-width: 120px;
    color: var(--accent-primary);
    font-weight: 500;
}

.tag-list {
    font-family: var(--font-family);
    list-style: none;
    margin: var(--spacing-sm) 0;
    padding: 0;
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.tag-list li {
    font-family: var(--font-family);
    background-color: var(--bg-tertiary);
    color: var(--accent-primary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius);
    font-size: 0.85rem;
    border: 1px solid var(--border-color);
}

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

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-md);
}

.contact-form {
    background-color: var(--bg-tertiary);
    padding: var(--spacing-lg);
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
}

.contact-form label {
    font-family: var(--font-family);
    display: block;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
}

.contact-form input,
.contact-form textarea {
    font-family: var(--font-family);
    width: 100%;
    padding: 0.75rem;
    margin-top: var(--spacing-xs);
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    color: var(--text-primary);
    font-size: 0.95rem;
    transition: border-color 0.2s ease;
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(212, 165, 116, 0.1);
}

.contact-form textarea {
    resize: vertical;
    min-height: 120px;
}

.form-note {
    font-family: var(--font-family);
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: var(--spacing-sm);
    font-style: italic;
}

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

.footer {
    background-color: var(--bg-secondary);
    padding: var(--spacing-lg) var(--spacing-md);
    text-align: center;
    border-top: 1px solid var(--border-color);
    margin-top: var(--spacing-xl);
}

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

/* ============================================
   LIGHT THEME
   ============================================ */

body.light-theme {
    --bg-primary: #f5f3ed;
    --bg-secondary: #eae7dd;
    --bg-tertiary: #ffffff;
    --text-primary: #2d2d2d;
    --text-secondary: #4a4a4a;
    --text-muted: #6b6b6b;
    --accent-primary: #8b6f47;
    --accent-secondary: #6b5435;
    --border-color: rgba(139, 111, 71, 0.2);
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
}

body.light-theme .navbar {
    background-color: rgba(245, 243, 237, 0.95);
}

/* ============================================
   RESPONSIVE DESIGN - MOBILE FIRST
   ============================================ */

/* Tablets and larger phones */
@media (min-width: 768px) {
    html {
        font-size: 17px;
    }

    .hero {
        grid-template-columns: 1.5fr 1fr;
    }

    .navbar nav {
        flex-wrap: nowrap;
    }

    main {
        padding: 0 var(--spacing-lg);
    }
}

/* Desktop */
@media (min-width: 1024px) {
    html {
        font-size: 18px;
    }

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

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

/* Small mobile devices */
@media (max-width: 480px) {
    html {
        font-size: 15px;
    }

    .navbar {
        padding: var(--spacing-sm);
    }

    .nav-links {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-xs);
        width: 100%;
    }

    .hero-actions {
        flex-direction: column;
    }

    .btn-primary,
    .btn-secondary {
        width: 100%;
    }

    .cards,
    .grid-2,
    .contact-grid {
        grid-template-columns: 1fr;
    }
}

/* Touch device improvements */
@media (hover: none) and (pointer: coarse) {

    .btn-primary,
    .btn-secondary,
    .btn-outline {
        padding: 1rem 1.75rem;
    }

    .nav-links a {
        padding: var(--spacing-xs) 0;
    }
}

.hero-image {
  width: 100%;
  max-width: 280px;
  height: auto;
  border-radius: 50%;
  border: 4px solid var(--accent-primary);
  box-shadow: var(--shadow-lg);
  object-fit: cover;
  aspect-ratio: 1;
  margin: 0 auto;
  display: block;
}


.hero-video {
  width: 100%;
  max-width: 280px;
  height: auto;
  border-radius: var(--radius);
  margin-top: var(--spacing-md);
  box-shadow: var(--shadow-lg);
  display: block;
  margin-left: auto;
  margin-right: auto;
  mix-blend-mode: screen;
}