/* ============================================================
   PROFESSOR PORTFOLIO - MAIN STYLESHEET
   CSS Custom Properties (CSS Variables) for easy global 
   color modifications
   Designed and Maintained by Vikram I Mirji (www.vikrammirji.in)
============================================================ */

/* ---- Google Fonts ---- */
@import url('https://fonts.googleapis.com/css2?family=Anek+Kannada:wght@100..800&family=Baloo+Tamma+2:wght@400..800&display=swap');

/* ============================================================
   :ROOT - CENTRAL COLOR VARIABLES
   Change these to restyle the entire website globally
============================================================ */
:root {
    /* Layout Colors */
    --header-bg: #F3F4F4;
    --header-shadow: 0 2px 12px rgba(44, 44, 44, 0.12);
    --top-bar-bg: #612D53;
    --top-bar-text: #F3F4F4;
    --top-bar-link: #F3F4F4;
    --brand-bar-bg: #2C2C2C;
    --brand-bar-text: #F3F4F4;

    --menu-bg: #612D53;
    --menu-text: #F3F4F4;
    --menu-link-hover-bg: #853953;
    --menu-link-active: #F3F4F4;
    --menu-border: rgba(243, 244, 244, 0.1);

    --home-content-bg: #F3F4F4;
    --hero-bg: #2C2C2C;
    --hero-overlay: rgba(44, 44, 44, 0.75);

    --footer-bg: #2C2C2C;
    --footer-text: #F3F4F4;
    --footer-heading: #F3F4F4;
    --footer-link: #F3F4F4;
    --footer-link-hover: #853953;
    --footer-border: rgba(243, 244, 244, 0.1);
    --footer-bottom-bg: rgba(44, 44, 44, 0.25);

    /* Heading Colors (H1–H6) */
    --h1-color: #2C2C2C;
    --h2-color: #612D53;
    --h3-color: #612D53;
    --h4-color: #853953;
    --h5-color: #853953;
    --h6-color: #853953;

    /* Paragraph & Body */
    --p-color: #2C2C2C;
    --p-muted: #612D53;

    /* Accent */
    --accent: #853953;
    --accent-hover: #612D53;
    --accent-light: #F3F4F4;
    --accent-border: #853953;

    /* Card & Section */
    --card-bg: #F3F4F4;
    --card-border: #612D53;
    --card-shadow: 0 4px 24px rgba(44, 44, 44, 0.08);
    --card-shadow-hover: 0 12px 36px rgba(44, 44, 44, 0.18);
    --section-alt-bg: #F3F4F4;

    /* Badges & Tags */
    --badge-bg: #F3F4F4;
    --badge-text: #612D53;

    /* Typography */
    --font-heading: 'Anek Kannada', sans-serif;
    --font-body: 'Baloo Tamma 2', cursive;

    /* Transitions */
    --transition: 0.25s ease;
    --radius: 10px;
    --radius-lg: 18px;
}

/* ============================================================
   BASE STYLES
============================================================ */
*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    font-size: 1rem;
    background-color: var(--home-content-bg);
    color: var(--p-color);
    line-height: 1.75;
    transition: background-color var(--transition), color var(--transition);
}

/* Heading Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.3;
}

h1 {
    color: var(--h1-color);
    font-size: clamp(1.8rem, 4vw, 2.6rem);
}

h2 {
    color: var(--h2-color);
    font-size: clamp(1.5rem, 3vw, 2rem);
}

h3 {
    color: var(--h3-color);
    font-size: clamp(1.2rem, 2.5vw, 1.6rem);
}

h4 {
    color: var(--h4-color);
    font-size: 1.25rem;
}

h5 {
    color: var(--h5-color);
    font-size: 1.1rem;
}

h6 {
    color: var(--h6-color);
    font-size: 1rem;
}

p {
    color: var(--p-color);
    margin-bottom: 1rem;
}

a {
    color: #853953;
    text-decoration: none;
    transition: color var(--transition);
}

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

/* Accessibility Focus */
:focus-visible {
    outline: 3px solid var(--accent);
    outline-offset: 3px;
    border-radius: 4px;
}

/* Screen reader only helper */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Skip Navigation */
.skip-nav {
    position: absolute;
    top: -100px;
    left: 0;
    z-index: 9999;
    background: var(--accent);
    color: #F3F4F4;
    padding: 10px 20px;
    border-radius: 0 0 8px 0;
    font-weight: 700;
    transition: top 0.2s;
}

.skip-nav:focus {
    top: 0;
    color: #F3F4F4;
}

/* ============================================================
   HEADER
============================================================ */
#site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: var(--header-bg);
    box-shadow: var(--header-shadow);
    transition: background-color var(--transition);
}

/* Top Bar */
.top-bar {
    background-color: var(--top-bar-bg);
    padding: 6px 0;
    font-size: 0.82rem;
}

.top-bar-links a {
    color: var(--top-bar-link);
    display: inline-flex;
    align-items: center;
    gap: 5px;
    transition: color var(--transition);
}

.top-bar-links a:hover {
    color: #F3F4F4;
    text-decoration: none;
}

/* Brand Bar */
.brand-bar {
    background: linear-gradient(135deg, var(--brand-bar-bg) 0%, #612D53 100%);
    border-bottom: 3px solid var(--accent);
}

.brand-icon {
    width: 52px;
    height: 52px;
    background: rgba(243, 244, 244, 0.12);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.6rem;
    color: #F3F4F4;
    flex-shrink: 0;
}

.brand-name {
    font-family: var(--font-heading);
    color: #F3F4F4;
    font-size: clamp(1rem, 2.5vw, 1.35rem);
    font-weight: 800;
    letter-spacing: 0.3px;
}

.brand-title {
    font-family: var(--font-body);
    color: rgba(243, 244, 244, 0.75);
    font-size: 0.78rem;
    line-height: 1.4;
}

/* Main Nav */
#site-nav {
    background-color: var(--menu-bg);
    padding: 0;
}

#site-nav .navbar-nav .nav-link {
    color: var(--menu-text);
    font-family: var(--font-heading);
    font-size: 0.95rem;
    font-weight: 600;
    padding: 12px 16px;
    border-radius: 4px;
    position: relative;
    transition: background-color var(--transition), color var(--transition);
}

#site-nav .navbar-nav .nav-link:hover {
    background-color: var(--menu-link-hover-bg);
    color: #F3F4F4;
    text-decoration: none;
}

#site-nav .navbar-nav .nav-link.active {
    background-color: rgba(243, 244, 244, 0.15);
    color: var(--menu-link-active);
    border-bottom: 3px solid var(--menu-link-active);
}

#site-nav .navbar-toggler {
    color: #F3F4F4;
    border-color: rgba(243, 244, 244, 0.4);
    font-size: 1.3rem;
    padding: 4px 10px;
}

.lang-btn {
    font-size: 0.78rem;
    font-weight: 700;
}

/* ============================================================
   PAGE CONTENT AREA
============================================================ */
#main-content {
    min-height: 60vh;
}

/* ============================================================
   HERO SECTION
============================================================ */
.hero-section {
    background: linear-gradient(135deg, var(--hero-bg) 0%, #612D53 60%, #853953 100%);
    position: relative;
    overflow: hidden;
    padding: 80px 0 100px;
    color: #F3F4F4;
}

.hero-section::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23F3F4F4' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-badge {
    display: inline-block;
    background: rgba(243, 244, 244, 0.15);
    border: 1px solid rgba(243, 244, 244, 0.3);
    color: #F3F4F4;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 2px;
    text-transform: uppercase;
    padding: 4px 16px;
    border-radius: 100px;
    margin-bottom: 1rem;
}

.hero-title {
    font-family: var(--font-heading);
    font-size: clamp(1.8rem, 5vw, 3rem);
    color: #F3F4F4;
    font-weight: 800;
    line-height: 1.2;
    text-shadow: 0 2px 10px rgba(44, 44, 44, 0.3);
}

.hero-subtitle {
    font-size: 1.05rem;
    color: rgba(243, 244, 244, 0.8);
    max-width: 640px;
    margin: 0 auto 1.5rem;
}

.hero-btn-primary {
    background: #F3F4F4;
    color: var(--accent);
    padding: 12px 32px;
    border-radius: 100px;
    font-weight: 700;
    font-size: 1rem;
    transition: all var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.hero-btn-primary:hover {
    background: var(--accent);
    color: #F3F4F4;
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(133, 57, 83, 0.4);
}

.hero-btn-outline {
    background: rgba(243, 244, 244, 0.1);
    border: 2px solid rgba(243, 244, 244, 0.5);
    color: #F3F4F4;
    padding: 12px 32px;
    border-radius: 100px;
    font-weight: 700;
    font-size: 1rem;
    transition: all var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 8px;
    backdrop-filter: blur(4px);
}

.hero-btn-outline:hover {
    background: rgba(243, 244, 244, 0.25);
    border-color: #F3F4F4;
    color: #F3F4F4;
    transform: translateY(-2px);
}

/* ============================================================
   STATS CARDS
============================================================ */
.stats-row {
    margin-top: -56px;
    position: relative;
    z-index: 20;
}

.stat-card {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 24px 16px;
    text-align: center;
    box-shadow: var(--card-shadow);
    border: 1px solid var(--card-border);
    transition: transform var(--transition), box-shadow var(--transition);
}

.stat-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--card-shadow-hover);
}

.stat-icon {
    width: 52px;
    height: 52px;
    background: var(--accent-light);
    color: var(--accent);
    border-radius: 14px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    margin-bottom: 12px;
}

.stat-number {
    font-family: var(--font-heading);
    font-size: 2rem;
    font-weight: 800;
    color: var(--h1-color);
    line-height: 1;
}

.stat-label {
    font-size: 0.78rem;
    color: var(--p-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
    margin-top: 4px;
}

/* ============================================================
   SECTION STYLES
============================================================ */
.section-pad {
    padding: 60px 0;
}

.section-alt {
    background-color: var(--section-alt-bg);
}

.section-title {
    font-family: var(--font-heading);
    position: relative;
    padding-bottom: 12px;
    margin-bottom: 2rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 56px;
    height: 4px;
    background: var(--accent);
    border-radius: 2px;
}

.section-title.text-center::after {
    left: 50%;
    transform: translateX(-50%);
}

/* ============================================================
   CARDS
============================================================ */
.info-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: 28px;
    box-shadow: var(--card-shadow);
    transition: transform var(--transition), box-shadow var(--transition);
}

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

.info-card .card-icon {
    width: 48px;
    height: 48px;
    background: var(--accent-light);
    color: var(--accent);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    margin-bottom: 14px;
}

/* News Card */
.news-card {
    background: linear-gradient(135deg, #2C2C2C, #612D53);
    color: #F3F4F4;
    border-radius: var(--radius-lg);
    padding: 28px;
}

.news-item {
    border-bottom: 1px solid rgba(243, 244, 244, 0.1);
    padding: 12px 0;
}

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

.news-date {
    font-size: 0.72rem;
    color: #853953;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1.5px;
}

.news-title {
    font-size: 0.9rem;
    color: #F3F4F4;
    font-weight: 600;
    margin-top: 2px;
}

/* ============================================================
   PUBLICATIONS LIST
============================================================ */
.pub-item {
    background: var(--card-bg);
    border-left: 4px solid var(--accent);
    border-radius: 0 var(--radius) var(--radius) 0;
    padding: 18px 20px;
    margin-bottom: 14px;
    box-shadow: var(--card-shadow);
    transition: border-color var(--transition), transform var(--transition);
}

.pub-item:hover {
    border-color: var(--h4-color);
    transform: translateX(4px);
}

.pub-year {
    display: inline-block;
    background: var(--accent-light);
    color: var(--accent);
    font-size: 0.72rem;
    font-weight: 700;
    padding: 2px 10px;
    border-radius: 100px;
    margin-bottom: 6px;
    letter-spacing: 1px;
}

.pub-title {
    font-size: 0.92rem;
    font-weight: 600;
    color: var(--h3-color);
    margin-bottom: 4px;
}

.pub-authors {
    font-size: 0.82rem;
    color: var(--p-muted);
}

.pub-journal {
    font-size: 0.82rem;
    color: var(--accent);
    font-style: italic;
}

/* ============================================================
   ABOUT PAGE
============================================================ */
.timeline-item {
    display: flex;
    gap: 16px;
    margin-bottom: 24px;
}

.timeline-dot {
    width: 14px;
    height: 14px;
    background: var(--accent);
    border-radius: 50%;
    flex-shrink: 0;
    margin-top: 6px;
    position: relative;
}

.timeline-dot::after {
    content: '';
    position: absolute;
    top: 14px;
    left: 50%;
    transform: translateX(-50%);
    width: 2px;
    height: calc(100% + 16px);
    background: var(--accent-border);
    opacity: 0.3;
}

.timeline-item:last-child .timeline-dot::after {
    display: none;
}

.timeline-content h5 {
    color: var(--h4-color);
    margin-bottom: 2px;
}

.timeline-content p {
    font-size: 0.87rem;
    color: var(--p-muted);
    margin: 0;
}

/* Table Styles */
.prof-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.88rem;
}

.prof-table th {
    background: var(--menu-bg);
    color: #F3F4F4;
    padding: 10px 14px;
    text-align: left;
    font-family: var(--font-heading);
}

.prof-table td {
    padding: 10px 14px;
    border-bottom: 1px solid var(--card-border);
}

.prof-table tr:nth-child(even) td {
    background: var(--accent-light);
}

.prof-table tr:hover td {
    background: var(--section-alt-bg);
}

/* ============================================================
   CONTACT PAGE
============================================================ */
.contact-icon-box {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 20px;
}

.contact-icon {
    width: 48px;
    height: 48px;
    background: var(--accent-light);
    color: var(--accent);
    border-radius: 12px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
}

.contact-label {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--p-muted);
}

.contact-value {
    font-size: 0.95rem;
    color: var(--h3-color);
    font-weight: 600;
}

/* Contact Form */
.contact-form {
    background: linear-gradient(135deg, #2C2C2C, #612D53);
    border-radius: var(--radius-lg);
    padding: 36px;
}

.contact-form label {
    color: rgba(243, 244, 244, 0.8);
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 6px;
    display: block;
}

.contact-form .form-control {
    background: rgba(243, 244, 244, 0.1);
    border: 1px solid rgba(243, 244, 244, 0.2);
    color: #F3F4F4;
    border-radius: 8px;
    padding: 12px 16px;
    transition: border-color var(--transition), background var(--transition);
}

.contact-form .form-control:focus {
    background: rgba(243, 244, 244, 0.15);
    border-color: #853953;
    outline: none;
    box-shadow: 0 0 0 3px rgba(133, 57, 83, 0.3);
    color: #F3F4F4;
}

.contact-form .form-control::placeholder {
    color: rgba(243, 244, 244, 0.4);
}

/* ============================================================
   RESEARCH PAGE
============================================================ */
.research-card {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--card-shadow);
    border: 1px solid var(--card-border);
    transition: transform var(--transition), box-shadow var(--transition);
}

.research-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--card-shadow-hover);
}

.research-card-header {
    background: var(--menu-bg);
    padding: 20px;
    color: #F3F4F4;
}

.research-card-body {
    padding: 20px;
}

/* ============================================================
   ACCORDION
============================================================ */
.custom-accordion .accordion-button {
    font-family: var(--font-heading);
    font-weight: 700;
    color: var(--h3-color);
    background: var(--card-bg);
}

.custom-accordion .accordion-button:not(.collapsed) {
    background: var(--accent-light);
    color: var(--accent);
}

.custom-accordion .accordion-button:focus {
    box-shadow: 0 0 0 3px rgba(133, 57, 83, 0.25);
}

/* ============================================================
   FOOTER
============================================================ */
#site-footer {
    background-color: var(--footer-bg);
    color: var(--footer-text);
}

#site-footer p {
    color: var(--footer-text);
}

.footer-heading {
    font-family: var(--font-heading);
    color: var(--footer-heading);
    font-size: 1.1rem;
    font-weight: 700;
    padding-bottom: 10px;
    margin-bottom: 16px;
    border-bottom: 2px solid rgba(243, 244, 244, 0.15);
}

.footer-text {
    color: var(--footer-text);
    font-size: 0.88rem;
}

.footer-text a {
    color: var(--footer-link);
    transition: color var(--transition);
}

.footer-text a:hover {
    color: var(--footer-link-hover);
}

.footer-links li {
    margin-bottom: 8px;
}

.footer-links a {
    color: var(--footer-link);
    font-size: 0.88rem;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: color var(--transition), padding-left var(--transition);
}

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

.footer-icon-link {
    width: 36px;
    height: 36px;
    background: rgba(243, 244, 244, 0.1);
    color: var(--footer-link);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    transition: background var(--transition), color var(--transition);
}

.footer-icon-link:hover {
    background: var(--accent);
    color: #F3F4F4;
    text-decoration: none;
}

.footer-bottom {
    background: var(--footer-bottom-bg);
    border-top: 1px solid var(--footer-border);
    padding: 16px 0;
    font-size: 0.82rem;
    color: var(--footer-text);
}

.footer-bottom a {
    color: var(--footer-link);
}

.footer-bottom a:hover {
    color: var(--footer-link-hover);
}

/* ============================================================
   BACK TO TOP
============================================================ */
.back-to-top {
    position: fixed;
    bottom: 28px;
    right: 28px;
    z-index: 999;
    width: 48px;
    height: 48px;
    background: var(--accent);
    color: #F3F4F4;
    border: none;
    border-radius: 50%;
    font-size: 1.2rem;
    box-shadow: 0 4px 16px rgba(133, 57, 83, 0.4);
    cursor: pointer;
    transition: opacity var(--transition), background var(--transition), transform var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-to-top:hover {
    background: var(--accent-hover);
    transform: translateY(-3px);
}

.back-to-top.show {
    opacity: 1;
}

/* ============================================================
   PAGE LOADER
============================================================ */
#page-loader {
    min-height: 200px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

/* ============================================================
   BADGES & TAGS
============================================================ */
.badge-tag {
    display: inline-block;
    background: var(--badge-bg);
    color: var(--badge-text);
    font-size: 0.72rem;
    font-weight: 700;
    padding: 3px 12px;
    border-radius: 100px;
    margin: 3px;
    letter-spacing: 0.5px;
}

/* ============================================================
   BOOTSTRAP OVERRIDES (Buttons & Tabs)
============================================================ */
.btn-primary {
    background-color: var(--accent);
    border-color: var(--accent);
    color: #F3F4F4;
}

.btn-primary:hover,
.btn-primary:focus,
.btn-primary:active {
    background-color: var(--accent-hover);
    border-color: var(--accent-hover);
    color: #F3F4F4 !important;
}

.nav-tabs .nav-link.active,
.nav-pills .nav-link.active {
    background-color: var(--accent) !important;
    color: #F3F4F4 !important;
    border-color: var(--accent) !important;
}

.nav-tabs .nav-link,
.nav-pills .nav-link {
    color: var(--accent);
    font-weight: 600;
}

.nav-tabs .nav-link:hover,
.nav-pills .nav-link:hover {
    color: var(--accent-hover);
    border-color: transparent transparent var(--accent-hover);
}

/* ============================================================
   UTILITY
============================================================ */
.border-accent {
    border-left: 4px solid var(--accent) !important;
}

.bg-accent-light {
    background-color: var(--accent-light);
}

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

.rounded-xl {
    border-radius: var(--radius-lg);
}

.shadow-soft {
    box-shadow: var(--card-shadow);
}

/* ============================================================
   RESPONSIVE
============================================================ */
@media (max-width: 767px) {
    .stats-row {
        margin-top: 16px;
    }

    .stat-card {
        padding: 16px 10px;
    }

    .hero-section {
        padding: 48px 0 64px;
    }

    .contact-form {
        padding: 20px;
    }

    #site-nav .navbar-collapse {
        background: var(--menu-bg);
        border-top: 1px solid var(--menu-border);
        padding: 8px 0;
    }
}

@media (max-width: 576px) {
    .brand-name {
        font-size: 1rem;
    }

    .brand-title {
        font-size: 0.7rem;
    }

    .top-bar {
        display: none;
    }
}