/* =========================================================
   VEDANADHI
   Main stylesheet
   ========================================================= */


/* =========================================================
   DESIGN TOKENS
   ========================================================= */

:root {
  --color-primary: #4a274f;
  --color-primary-dark: #352039;
  --color-primary-light: #6a456f;

  --color-accent: #ff9933;
  --color-accent-dark: #d97819;

  --color-text: #252525;
  --color-text-muted: #555;
  --color-text-light: #777;

  --color-white: #fff;
  --color-border: #e5e5e5;
  --color-background: #fff;
  --color-background-soft: #faf8fa;
  --color-footer: #252525;

  --font-body: "Source Sans 3", sans-serif;
  --font-heading: "Merriweather", serif;

  --container-width: 1170px;

  --section-padding: 90px;
  --content-width: 900px;

  --radius: 6px;

  --transition: 180ms ease;
}


/* =========================================================
   RESET
   ========================================================= */

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;

  background: var(--color-background);
  color: var(--color-text);

  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
}

img,
svg {
  display: block;
}

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

button,
input,
textarea,
select {
  font: inherit;
}

button {
  cursor: pointer;
}

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

a:focus-visible,
button:focus-visible {
  outline: 3px solid rgba(255, 153, 51, 0.55);
  outline-offset: 3px;
}


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

h1,
h2,
h3,
h4,
h5,
h6 {
  margin-top: 0;
  font-family: var(--font-heading);
  color: var(--color-primary);
  line-height: 1.25;
}

p {
  margin-top: 0;
}

strong {
  font-weight: 700;
}


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

.container {
  width: min(100% - 40px, var(--container-width));
  margin-inline: auto;
}

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

.content-box {
  width: min(100%, var(--content-width));
  margin-inline: auto;
}


/* =========================================================
   HEADER
   ========================================================= */

.site-header {
  position: relative;
  z-index: 100;
  background: var(--color-white);
}


/* ---------- Top contact bar ---------- */

.header-top {
  padding: 14px 0;
  background: var(--color-white);
  border-bottom: 1px solid var(--color-border);
}

.contact-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 28px;
}

.contact-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;

  color: var(--color-text-muted);
  font-size: 0.95rem;
}

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

a.contact-link:hover {
  color: var(--color-primary);
}

.icon {
  width: 18px;
  height: 18px;
  flex: 0 0 auto;

  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}


/* ---------- Main header ---------- */

.header-main {
  background: var(--color-primary);
}

.site-nav {
  min-height: 78px;

  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 25px;
}


/* ---------- Brand ---------- */

.site-brand {
  display: inline-flex;
  align-items: center;

  padding: 13px 28px;

  background: var(--color-white);
}

.brand-tamil {
  font-family: var(--font-heading);
  font-size: 1.7rem;
  line-height: 1;
  white-space: nowrap;
}

.brand-vedha {
  color: var(--color-primary);
}

.brand-nadhi {
  color: var(--color-accent);
}


/* ---------- Navigation ---------- */

.nav-menu {
  display: flex;
  align-items: center;
  gap: 5px;
}

.nav-link {
  position: relative;

  display: inline-flex;
  align-items: center;

  padding: 10px 15px;

  color: var(--color-white);

  font-size: 0.95rem;
  font-weight: 600;
  text-transform: uppercase;

  transition:
    color var(--transition),
    background-color var(--transition);
}

.nav-link:hover,
.nav-link:focus-visible,
.nav-link.active {
  color: var(--color-accent);
}


/* ---------- Mobile navigation button ---------- */

.nav-toggle {
  display: none;

  width: 42px;
  height: 42px;
  padding: 7px;

  border: 0;
  background: transparent;
}

.nav-toggle span {
  display: block;

  width: 100%;
  height: 3px;

  margin: 5px 0;

  border-radius: 3px;
  background: var(--color-white);

  transition: transform var(--transition), opacity var(--transition);
}

.site-nav.nav-open .nav-toggle span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.site-nav.nav-open .nav-toggle span:nth-child(2) {
  opacity: 0;
}

.site-nav.nav-open .nav-toggle span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}


/* =========================================================
   ACADEMIC SECTIONS
   ========================================================= */

.research-section,
.trainee-section {
  background: var(--color-white);
}

.about-section,
.education-section {
  background: var(--color-background-soft);
}


/* =========================================================
   SECTION ICON
   ========================================================= */

.section-icon {
  position: relative;

  width: 64px;
  height: 64px;

  display: flex;
  align-items: center;
  justify-content: center;

  margin-bottom: 30px;

  border-radius: 50%;
  background: var(--color-primary);

  color: var(--color-white);
}

.section-icon::after {
  content: "";

  position: absolute;
  inset: -7px;

  border: 2px solid rgba(74, 39, 79, 0.15);
  border-radius: 50%;
}

.section-icon svg {
  width: 29px;
  height: 29px;

  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}


/* =========================================================
   BRAND NAME
   ========================================================= */

.brand-name {
  margin-bottom: 18px;

  font-family: var(--font-heading);
  font-size: 1.25rem;
}


/* =========================================================
   SECTION HEADINGS
   ========================================================= */

.section-title {
  margin-bottom: 25px;

  color: var(--color-primary);

  font-size: clamp(2.4rem, 5vw, 3.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.section-title span {
  color: var(--color-accent);
}

.section-title small {
  font-size: 0.65em;
  color: var(--color-primary);
}

.section-title-small {
  font-size: clamp(2rem, 4vw, 2.8rem);
}


/* =========================================================
   CONTENT
   ========================================================= */

.section-text {
  margin-bottom: 20px;

  color: var(--color-text-muted);
  font-size: 1.05rem;
}

.content-list {
  margin: 0 0 25px;
  padding-left: 25px;

  color: var(--color-text-muted);
}

.content-list li {
  margin-bottom: 12px;
  padding-left: 5px;
}

.mission-list {
  color: var(--color-text);
}

.subheading {
  margin-top: 35px;
  margin-bottom: 15px;

  color: var(--color-primary);
  font-size: 1.35rem;
}


/* =========================================================
   SECTION LABEL
   ========================================================= */

.section-label {
  display: inline-block;

  margin: 25px 0 12px;

  color: var(--color-primary);

  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 700;
}


/* =========================================================
   PUBLICATION CARD
   ========================================================= */

.publication-card {
  margin: 0 0 25px;
  padding: 25px;

  border-left: 4px solid var(--color-accent);
  background: var(--color-background-soft);
}

.publication-title {
  margin-bottom: 20px;

  color: var(--color-primary);

  font-family: var(--font-heading);
  font-size: 1.2rem;
  line-height: 1.5;
}

.publication-author {
  color: var(--color-text-muted);
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
}

.publication-summary {
  margin-bottom: 15px;

  color: var(--color-text-muted);
}

.publication-marker {
  color: var(--color-accent);
  margin-right: 7px;
}

.publication-details {
  margin-top: 20px;
  margin-bottom: 0;

  color: var(--color-text-light);
  font-size: 0.95rem;
}

.publication-details a {
  color: #0645ad;
  word-break: break-word;
}

.publication-details a:hover {
  color: var(--color-primary);
  text-decoration: underline;
}


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

.section-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;

  min-height: 44px;
  padding: 10px 28px;

  border: 2px solid var(--color-primary);
  border-radius: var(--radius);

  background: var(--color-primary);
  color: var(--color-white);

  font-weight: 600;
  text-align: center;

  transition:
    background-color var(--transition),
    border-color var(--transition),
    color var(--transition),
    transform var(--transition);
}

.section-button:hover {
  border-color: var(--color-primary-dark);
  background: var(--color-primary-dark);
  color: var(--color-white);

  transform: translateY(-1px);
}


/* =========================================================
   ABOUT / DISCLAIMER
   ========================================================= */

.disclaimer-text {
  margin-bottom: 18px;
  color: var(--color-text-muted);
}

.announcement {
  margin-bottom: 25px;
  color: var(--color-text-muted);
}

.announcement-email {
  color: var(--color-primary);
  font-weight: 700;
}

.announcement-email:hover {
  color: var(--color-accent);
}


/* =========================================================
   EDUCATIONAL SERVICES
   ========================================================= */

.education-links {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
}

.education-links .section-button {
  margin: 0;
}


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

.site-footer {
  background: var(--color-footer);
  color: var(--color-white);
}

.footer-top {
  display: flex;
  align-items: center;

  padding: 45px 0 35px;
}

.footer-brand {
  display: inline-flex;

  padding: 16px 28px;

  background: var(--color-white);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 50px;

  padding-bottom: 45px;
}

.footer-heading {
  position: relative;

  margin-bottom: 22px;
  padding-left: 22px;

  color: var(--color-white);

  font-family: var(--font-heading);
  font-size: 1.05rem;
  text-transform: uppercase;
}

.footer-heading::before {
  content: "";

  position: absolute;
  top: 50%;
  left: 0;

  width: 13px;
  height: 13px;

  background: var(--color-accent);

  transform: translateY(-50%);
}

.footer-contact {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-contact-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;

  color: #eee;
}

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

.footer-contact-item .icon {
  margin-top: 4px;
  color: var(--color-accent);
}


.footer-nav {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-nav a {
  color: #eee;
  transition: color var(--transition);
}

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


/* ---------- Social links ---------- */

.social-links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;

  margin-top: 25px;
}

.social-links a {
  color: var(--color-white);
  font-weight: 600;

  transition: color var(--transition);
}

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


/* ---------- Copyright ---------- */

.footer-bottom {
  padding: 20px 0;

  border-top: 1px solid rgba(255, 255, 255, 0.12);

  color: #bbb;
  font-size: 0.9rem;
  text-align: center;
}

.footer-bottom p {
  margin: 0;
}


/* =========================================================
   REDUCED MOTION
   ========================================================= */

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
  }
}