/* ===================================
   CSS Variables & Design Tokens
   =================================== */
:root {
  /* Colors */
  --emerald-50: #ecfdf5;
  --emerald-100: #d1fae5;
  --emerald-200: #a7f3d0;
  --emerald-300: #6ee7b7;
  --emerald-400: #34d399;
  --emerald-500: #10b981;
  --emerald-600: #059669;
  --emerald-700: #047857;
  --emerald-800: #065f46;
  --emerald-900: #064e3b;
  --emerald-950: #022c22;

  --amber-50: #fffbeb;
  --amber-100: #fef3c7;
  --amber-400: #fbbf24;
  --amber-500: #f59e0b;
  --amber-600: #d97706;

  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;

  --white: #ffffff;
  --black: #000000;

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;

  /* Spacing */
  --spacing-1: 0.25rem;
  --spacing-2: 0.5rem;
  --spacing-3: 0.75rem;
  --spacing-4: 1rem;
  --spacing-5: 1.25rem;
  --spacing-6: 1.5rem;
  --spacing-8: 2rem;
  --spacing-10: 2.5rem;
  --spacing-12: 3rem;
  --spacing-16: 4rem;
  --spacing-20: 5rem;

  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.375rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.75rem;
  --radius-2xl: 1rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  --shadow-2xl: 0 25px 50px -12px rgb(0 0 0 / 0.25);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 200ms ease;
  --transition-slow: 300ms ease;

  /* Theme Variables - Light Mode (Default) */
  --bg-body: linear-gradient(to bottom right, var(--emerald-50), var(--white), var(--amber-50));
  --bg-white: var(--white);
  --bg-gradient: linear-gradient(to bottom right, var(--emerald-50), var(--white));
  --bg-card: var(--white);
  --bg-card-hover: var(--white);
  --border-card: var(--emerald-100);
  --text-primary: var(--gray-900);
  --text-secondary: var(--gray-700);
  --text-muted: var(--gray-600);
  --text-light: var(--gray-500);
  --nav-bg: rgba(255, 255, 255, 0.95);
  --nav-border: var(--gray-200);
  --input-bg: rgba(255, 255, 255, 0.2);
  --input-border: rgba(255, 255, 255, 0.3);
}

/* Dark Mode Theme */
[data-theme="dark"] {
  --bg-body: linear-gradient(to bottom right, #0f1419, #1a2332, #0f1419);
  --bg-white: #1a2332;
  --bg-gradient: linear-gradient(to bottom right, #1a2332, #0f1419);
  --bg-card: #1e293b;
  --bg-card-hover: #243244;
  --border-card: #334155;
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --text-light: #64748b;
  --nav-bg: rgba(15, 20, 25, 0.95);
  --nav-border: #334155;
  --input-bg: rgba(0, 0, 0, 0.3);
  --input-border: rgba(255, 255, 255, 0.1);

  /* Override some base colors for dark mode */
  --gray-50: #1e293b;
  --gray-100: #334155;
  --gray-200: #475569;
  --emerald-50: #064e3b;
  --emerald-100: #065f46;
  --amber-50: #451a03;
  --amber-100: #78350f;
}

/* ===================================
   Dark Mode Component Overrides
   =================================== */

/* Thesis Card in Education */
[data-theme="dark"] .thesis-card {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .thesis-title,
[data-theme="dark"] .thesis-description {
  color: #e2e8f0;
}

/* Research Cards */
[data-theme="dark"] .research-title {
  color: #f1f5f9;
}

[data-theme="dark"] .research-meta p {
  color: #cbd5e1;
}

[data-theme="dark"] .research-meta strong {
  color: #10b981;
}

[data-theme="dark"] .research-description {
  color: #94a3b8;
}

/* Certification Cards */
[data-theme="dark"] .card-cert h3 {
  color: #f1f5f9;
}

[data-theme="dark"] .cert-issuer {
  color: #34d399;
}

[data-theme="dark"] .cert-description {
  color: #cbd5e1;
}

/* Conference Cards */
[data-theme="dark"] .card-conference h3 {
  color: #f1f5f9;
}

[data-theme="dark"] .card-conference p {
  color: #cbd5e1;
}

[data-theme="dark"] .conference-meta {
  color: #94a3b8;
}

/* Honors Cards */
[data-theme="dark"] .card-honor h3,
[data-theme="dark"] .honor-body h3 {
  color: #f1f5f9;
}

[data-theme="dark"] .honor-org {
  color: #34d399;
}

[data-theme="dark"] .honor-description {
  color: #cbd5e1;
}

/* Volunteering Cards */
[data-theme="dark"] .card-volunteering h3 {
  color: #f1f5f9;
}

[data-theme="dark"] .volunteering-org {
  color: #34d399;
}

[data-theme="dark"] .volunteering-location {
  color: #94a3b8;
}

[data-theme="dark"] .volunteering-description {
  color: #cbd5e1;
}

/* Experience Cards */
[data-theme="dark"] .card-experience .card-header-experience {
  background: linear-gradient(to right, #1e293b, #0f1419);
}

[data-theme="dark"] .card-experience h3 {
  color: #f1f5f9;
}

[data-theme="dark"] .card-experience .card-subtitle {
  color: #94a3b8;
}

[data-theme="dark"] .responsibility-list li {
  color: #cbd5e1;
}

/* Skills Cards */
[data-theme="dark"] .skill-header span:first-child {
  color: #e2e8f0;
}

/* Coursework items */
[data-theme="dark"] .coursework h4,
[data-theme="dark"] .thesis h4 {
  color: #f1f5f9;
}

[data-theme="dark"] .coursework-item {
  color: #cbd5e1;
}

/* About section */
[data-theme="dark"] .about-text p {
  color: #cbd5e1;
}

[data-theme="dark"] .about-text strong {
  color: #34d399;
}

/* Buttons in dark mode */
[data-theme="dark"] .btn-outline {
  border-color: #10b981;
  color: #34d399;
}

[data-theme="dark"] .btn-outline:hover {
  background: rgba(16, 185, 129, 0.1);
}

/* Contact Section Intro */
[data-theme="dark"] .contact-intro {
  color: #cbd5e1;
}

[data-theme="dark"] .section-header h2 {
  color: #f1f5f9;
}

/* Active Nav Links in dark mode */
[data-theme="dark"] .nav-link.active {
  background: #065f46;
  color: #34d399;
}

[data-theme="dark"] .nav-link:hover {
  background: #064e3b;
}

[data-theme="dark"] .mobile-nav-link.active {
  background: #065f46;
  color: #34d399;
}

[data-theme="dark"] .mobile-nav-link:hover {
  background: #064e3b;
}

/* Hamburger Menu Icon */
[data-theme="dark"] .mobile-menu-btn {
  color: #f1f5f9;
}

[data-theme="dark"] .mobile-menu-btn:hover {
  background: #334155;
}

[data-theme="dark"] .mobile-menu-btn svg {
  stroke: #f1f5f9;
}

/* ===================================
   Reset & 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);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--text-secondary);
  background: var(--bg-body);
  min-height: 100vh;
  transition: background var(--transition-slow), color var(--transition-slow);
}

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

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  line-height: 1.3;
  color: var(--text-primary);
}

h1 {
  font-size: var(--font-size-4xl);
  font-weight: 700;
}

h2 {
  font-size: var(--font-size-3xl);
  font-weight: 600;
}

h3 {
  font-size: var(--font-size-xl);
  font-weight: 600;
}

h4 {
  font-size: var(--font-size-lg);
  font-weight: 600;
}

strong {
  font-weight: 600;
}

/* ===================================
   Layout Utilities
   =================================== */
.container {
  max-width: 80rem;
  margin: 0 auto;
  padding: 0 var(--spacing-4);
}

@media (min-width: 640px) {
  .container {
    padding: 0 var(--spacing-6);
  }
}

@media (min-width: 1024px) {
  .container {
    padding: 0 var(--spacing-8);
  }
}

.hidden {
  display: none !important;
}

/* ===================================
   Navigation
   =================================== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  transition: all var(--transition-slow);
}

.nav.scrolled {
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-lg);
}

.nav-container {
  max-width: 80rem;
  margin: 0 auto;
  padding: 0 var(--spacing-4);
}

@media (min-width: 640px) {
  .nav-container {
    padding: 0 var(--spacing-6);
  }
}

@media (min-width: 1024px) {
  .nav-container {
    padding: 0 var(--spacing-8);
  }
}

.nav-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 5rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
}

.logo-circle {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-full);
  background: linear-gradient(to bottom right, var(--emerald-600), var(--emerald-800));
  display: flex;
  align-items: center;
  justify-content: center;
}

.logo-circle span {
  color: var(--white);
  font-weight: 700;
  font-size: var(--font-size-sm);
}

.nav-links {
  display: none;
  align-items: center;
  gap: var(--spacing-1);
}

@media (min-width: 768px) {
  .nav-links {
    display: flex;
  }
}

.nav-link {
  padding: var(--spacing-2) var(--spacing-4);
  border-radius: var(--radius-lg);
  color: var(--text-secondary);
  font-weight: 500;
  transition: all var(--transition-normal);
}

.nav-link:hover {
  background: var(--emerald-50);
}

.nav-link.active {
  background: var(--emerald-100);
  color: var(--emerald-900);
}

.mobile-menu-btn {
  display: flex;
  padding: var(--spacing-2);
  border-radius: var(--radius-lg);
  transition: background var(--transition-normal);
}

.mobile-menu-btn:hover {
  background: var(--emerald-50);
}

@media (min-width: 768px) {
  .mobile-menu-btn {
    display: none;
  }
}

.mobile-menu-btn svg {
  width: 1.5rem;
  height: 1.5rem;
}

.mobile-nav {
  background: var(--bg-card);
  border-top: 1px solid var(--border-card);
  box-shadow: var(--shadow-lg);
}

@media (min-width: 768px) {
  .mobile-nav {
    display: none !important;
  }
}

.mobile-nav-links {
  padding: var(--spacing-4);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-2);
}

.mobile-nav-link {
  width: 100%;
  text-align: left;
  padding: var(--spacing-3) var(--spacing-4);
  border-radius: var(--radius-lg);
  color: var(--text-secondary);
  font-weight: 500;
  transition: all var(--transition-normal);
}

.mobile-nav-link:hover {
  background: var(--emerald-50);
}

.mobile-nav-link.active {
  background: var(--emerald-100);
  color: var(--emerald-900);
}

/* ===================================
   Hero Section
   =================================== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 5rem var(--spacing-4) var(--spacing-4);
}

@media (min-width: 640px) {
  .hero {
    padding: 5rem var(--spacing-6) var(--spacing-6);
  }
}

@media (min-width: 1024px) {
  .hero {
    padding: 5rem var(--spacing-8) var(--spacing-8);
  }
}

.hero-container {
  max-width: 80rem;
  width: 100%;
}

.hero-grid {
  display: grid;
  gap: var(--spacing-12);
  align-items: center;
}

@media (min-width: 768px) {
  .hero-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.hero-image-wrapper {
  display: flex;
  justify-content: center;
  position: relative;
  order: 1;
}

@media (min-width: 768px) {
  .hero-image-wrapper {
    justify-content: flex-end;
    order: 1;
  }
}

.hero-image-glow {
  position: absolute;
  inset: 0;
  background: linear-gradient(to bottom right, var(--emerald-400), var(--amber-400));
  border-radius: var(--radius-full);
  filter: blur(2rem);
  opacity: 0.2;
  animation: pulse 2s infinite;
}

@keyframes pulse {

  0%,
  100% {
    opacity: 0.2;
    transform: scale(1);
  }

  50% {
    opacity: 0.3;
    transform: scale(1.05);
  }
}

.hero-image {
  position: relative;
  width: 16rem;
  height: 16rem;
  border-radius: var(--radius-full);
  overflow: hidden;
  border: 8px solid var(--white);
  box-shadow: var(--shadow-2xl);
}

@media (min-width: 640px) {
  .hero-image {
    width: 20rem;
    height: 20rem;
  }
}

.hero-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-content {
  text-align: center;
  order: 2;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-6);
}

@media (min-width: 768px) {
  .hero-content {
    text-align: left;
    order: 2;
  }
}

.hero-text {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-2);
}

.hero-subtitle {
  color: var(--emerald-700);
  font-size: var(--font-size-lg);
  font-weight: 500;
}

.hero-description {
  color: var(--gray-600);
  max-width: 32rem;
}

@media (min-width: 768px) {
  .hero-description {
    margin: 0;
  }
}

.hero-buttons {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-4);
  justify-content: center;
}

@media (min-width: 640px) {
  .hero-buttons {
    flex-direction: row;
  }
}

@media (min-width: 768px) {
  .hero-buttons {
    justify-content: flex-start;
  }
}

.scroll-indicator {
  display: none;
  justify-content: center;
  margin-top: var(--spacing-16);
  animation: bounce 1s infinite;
}

@media (min-width: 768px) {
  .scroll-indicator {
    display: flex;
  }
}

.scroll-indicator svg {
  width: 1.5rem;
  height: 1.5rem;
  color: var(--emerald-600);
}

@keyframes bounce {

  0%,
  100% {
    transform: translateY(0);
  }

  50% {
    transform: translateY(-0.5rem);
  }
}

/* ===================================
   Sections
   =================================== */
.section {
  padding: var(--spacing-20) var(--spacing-4);
}

@media (min-width: 640px) {
  .section {
    padding: var(--spacing-20) var(--spacing-6);
  }
}

@media (min-width: 1024px) {
  .section {
    padding: var(--spacing-20) var(--spacing-8);
  }
}

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

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

.section-contact {
  background: linear-gradient(to bottom right, var(--emerald-600), var(--emerald-800));
  color: var(--white);
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-16);
}

.section-header h2 {
  margin-bottom: var(--spacing-4);
}

.section-divider {
  width: 6rem;
  height: 0.25rem;
  background: linear-gradient(to right, var(--emerald-600), var(--amber-500));
  margin: 0 auto;
  border-radius: var(--radius-full);
}

.divider-light {
  background: linear-gradient(to right, var(--white), var(--amber-400));
  margin-bottom: var(--spacing-4);
}

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

/* ===================================
   Badges
   =================================== */
.badge {
  display: inline-flex;
  align-items: center;
  padding: var(--spacing-1) var(--spacing-3);
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.025em;
}

.badge-outline {
  border: 1px solid var(--emerald-300);
  color: var(--emerald-700);
  background: transparent;
}

.badge-emerald {
  background: var(--emerald-600);
  color: var(--white);
}

.badge-amber {
  background: var(--amber-500);
  color: var(--white);
}

.badge-light {
  background: rgba(255, 255, 255, 0.2);
  color: var(--white);
  border: 1px solid rgba(255, 255, 255, 0.4);
}

/* ===================================
   Buttons
   =================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-3) var(--spacing-6);
  border-radius: var(--radius-lg);
  font-weight: 500;
  font-size: var(--font-size-base);
  transition: all var(--transition-normal);
  gap: var(--spacing-2);
}

.btn-primary {
  background: linear-gradient(to right, var(--emerald-600), var(--emerald-700));
  color: var(--white);
  box-shadow: var(--shadow-lg);
}

.btn-primary:hover {
  background: linear-gradient(to right, var(--emerald-700), var(--emerald-800));
}

.btn-outline {
  border: 1px solid var(--emerald-300);
  color: var(--emerald-700);
  background: transparent;
}

.btn-outline:hover {
  background: var(--emerald-50);
}

.btn-white {
  background: var(--white);
  color: var(--emerald-700);
}

.btn-white:hover {
  background: var(--emerald-50);
}

.btn-social {
  background: rgba(255, 255, 255, 0.2);
  color: var(--white);
  border: 1px solid rgba(255, 255, 255, 0.3);
  padding: var(--spacing-2) var(--spacing-4);
}

.btn-social:hover {
  background: rgba(255, 255, 255, 0.3);
}

.btn-social svg {
  width: 1rem;
  height: 1rem;
}

.btn-full {
  width: 100%;
}

.btn-icon {
  width: 1rem;
  height: 1rem;
}

.btn-icon-right {
  width: 1rem;
  height: 1rem;
  margin-left: var(--spacing-1);
}

.btn-disabled {
  opacity: 0.6;
  cursor: not-allowed;
  pointer-events: none;
  background: var(--gray-400);
}

.btn-disabled:hover {
  background: var(--gray-400);
  transform: none;
}

/* ===================================
   Cards
   =================================== */
.card {
  background: var(--bg-card);
  border: 2px solid var(--border-card);
  border-radius: var(--radius-xl);
  overflow: hidden;
  transition: all var(--transition-slow);
}

.card-hover:hover {
  border-color: var(--emerald-300);
  box-shadow: var(--shadow-2xl);
}

.card-header {
  padding: var(--spacing-6);
}

.card-header-primary {
  background: linear-gradient(to right, var(--emerald-600), var(--emerald-700));
  color: var(--white);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.card-header-experience {
  background: linear-gradient(to right, var(--emerald-50), var(--white));
}

.card-header-content {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-4);
}

.card-header-text {
  flex: 1;
}

.card-header-text h3 {
  color: inherit;
  margin-bottom: var(--spacing-2);
}

.card-header-primary .card-header-text h3 {
  color: var(--white);
}

.card-subtitle {
  color: var(--emerald-50);
  font-size: var(--font-size-sm);
}

.card-header-experience .card-subtitle {
  color: var(--gray-600);
}

.card-grade {
  color: var(--emerald-100);
  margin-top: var(--spacing-2);
  font-size: var(--font-size-sm);
}

.card-body {
  padding: var(--spacing-6);
}

/* ===================================
   Icon Boxes
   =================================== */
.icon-box {
  padding: var(--spacing-3);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
}

.icon-box svg {
  width: 2rem;
  height: 2rem;
}

.icon-box-light {
  background: rgba(255, 255, 255, 0.2);
  color: var(--white);
}

.icon-box-primary {
  background: var(--emerald-600);
  color: var(--white);
}

.icon-box-primary svg {
  width: 1.5rem;
  height: 1.5rem;
}

/* ===================================
   About Section
   =================================== */
.about-grid {
  display: grid;
  gap: var(--spacing-12);
  align-items: center;
}

@media (min-width: 768px) {
  .about-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.about-text {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-6);
}

.about-image-wrapper {
  display: flex;
  justify-content: center;
  position: relative;
}

.about-image-bg {
  position: absolute;
  inset: 0;
  background: linear-gradient(to bottom right, var(--emerald-200), var(--amber-200));
  border-radius: var(--radius-2xl);
  transform: rotate(3deg);
}

.about-image {
  position: relative;
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-2xl);
  width: 100%;
  max-width: 28rem;
}

/* ===================================
   Education Section
   =================================== */
.card-education {
  box-shadow: var(--shadow-xl);
}

.coursework {
  margin-bottom: var(--spacing-6);
}

.coursework h4 {
  color: var(--gray-900);
  margin-bottom: var(--spacing-4);
}

.coursework-grid {
  display: grid;
  gap: var(--spacing-3);
}

@media (min-width: 640px) {
  .coursework-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.coursework-item {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-2);
}

.dot {
  width: 0.5rem;
  height: 0.5rem;
  background: var(--emerald-600);
  border-radius: var(--radius-full);
  margin-top: 0.5rem;
  flex-shrink: 0;
}

.separator {
  border: none;
  border-top: 1px solid var(--gray-200);
  margin: var(--spacing-6) 0;
}

.thesis h4 {
  color: var(--gray-900);
  margin-bottom: var(--spacing-4);
}

.thesis-card {
  background: linear-gradient(to bottom right, var(--amber-50), var(--emerald-50));
  border-left: 4px solid var(--amber-500);
  padding: var(--spacing-6);
  border-radius: var(--radius-lg);
}

.thesis-title {
  color: var(--gray-900);
  margin-bottom: var(--spacing-3);
}

.thesis-description {
  color: var(--gray-600);
}

/* ===================================
   Research Section
   =================================== */
.research-grid {
  display: grid;
  gap: var(--spacing-8);
}

@media (min-width: 768px) {
  .research-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.research-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  margin-bottom: var(--spacing-3);
}

.research-icon {
  width: 1.25rem;
  height: 1.25rem;
}

.research-icon.emerald {
  color: var(--emerald-600);
}

.research-icon.amber {
  color: var(--amber-600);
}

.research-title {
  color: var(--gray-900);
  margin-bottom: var(--spacing-4);
  transition: color var(--transition-normal);
}

.card-hover:hover .research-title {
  color: var(--emerald-700);
}

.research-meta {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-2);
  color: var(--gray-600);
  font-size: var(--font-size-sm);
  margin-bottom: var(--spacing-4);
}

.research-description {
  color: var(--gray-700);
  margin-bottom: var(--spacing-4);
}

/* ===================================
   Experience Section
   =================================== */
.experience-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-8);
}

.card-experience:hover {
  box-shadow: var(--shadow-xl);
}

.responsibility-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-3);
}

.responsibility-list li {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-3);
}

.responsibility-list .dot {
  width: 0.375rem;
  height: 0.375rem;
  margin-top: 0.5rem;
}

/* ===================================
   Skills Section
   =================================== */
.skills-grid {
  display: grid;
  gap: var(--spacing-8);
}

@media (min-width: 768px) {
  .skills-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card-skills .card-header-primary {
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
}

.skills-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
}

.skills-header svg {
  width: 1.5rem;
  height: 1.5rem;
}

.skills-header h3 {
  color: var(--white);
  font-size: var(--font-size-lg);
}

.skill-item {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-2);
}

.skill-item+.skill-item {
  margin-top: var(--spacing-6);
}

.skill-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.skill-header span:first-child {
  color: var(--gray-700);
  font-size: var(--font-size-sm);
}

.skill-percent {
  color: var(--emerald-700);
  font-weight: 500;
  font-size: var(--font-size-sm);
}

.progress {
  width: 100%;
  height: 0.5rem;
  background: var(--gray-200);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(to right, var(--emerald-500), var(--emerald-600));
  border-radius: var(--radius-full);
  transition: width 1s ease-out;
}

/* ===================================
   Certifications Section
   =================================== */
.certifications-grid {
  display: grid;
  gap: var(--spacing-6);
}

@media (min-width: 640px) {
  .certifications-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .certifications-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card-cert {
  overflow: hidden;
}

.card-cert:hover {
  box-shadow: var(--shadow-xl);
}

.cert-image {
  overflow: hidden;
  background: linear-gradient(to bottom right, var(--emerald-100), var(--amber-100));
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-2);
}

.cert-image img {
  width: 100%;
  height: auto;
  max-height: 16rem;
  object-fit: contain;
  transition: transform var(--transition-slow);
}

.card-cert:hover .cert-image img {
  transform: scale(1.1);
}

.card-cert .card-body {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-2);
}

.card-cert h3 {
  font-size: var(--font-size-lg);
  color: var(--gray-900);
}

.cert-issuer {
  color: var(--emerald-700);
  font-size: var(--font-size-sm);
}

.cert-description {
  color: var(--gray-600);
  font-size: var(--font-size-sm);
  margin-top: var(--spacing-2);
}

/* ===================================
   Conferences Section
   =================================== */
.conferences-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-6);
}

.card-conference {
  border-left-width: 4px;
}

.card-conference:hover {
  box-shadow: var(--shadow-xl);
}

.border-emerald {
  border-left-color: var(--emerald-600);
}

.border-amber {
  border-left-color: var(--amber-600);
}

.conference-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--spacing-2);
  margin-bottom: var(--spacing-3);
}

.conference-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-2);
  color: var(--gray-600);
  font-size: var(--font-size-sm);
}

.conference-location {
  display: flex;
  align-items: center;
  gap: var(--spacing-1);
}

.conference-location svg {
  width: 1rem;
  height: 1rem;
}

.card-conference h3 {
  color: var(--gray-900);
  margin-bottom: var(--spacing-3);
}

.card-conference p {
  color: var(--gray-700);
}

/* ===================================
   Honors Section
   =================================== */
.honors-grid {
  display: grid;
  gap: var(--spacing-6);
}

@media (min-width: 768px) {
  .honors-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card-honor {
  position: relative;
  overflow: hidden;
}

.card-honor:hover {
  box-shadow: var(--shadow-xl);
}

.honor-gradient {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 0.25rem;
  background: linear-gradient(to right, var(--emerald-600), var(--amber-500));
}

.honor-body {
  text-align: center;
  padding-top: var(--spacing-8);
}

.honor-icon {
  width: 5rem;
  height: 5rem;
  margin: 0 auto var(--spacing-4);
  border-radius: var(--radius-full);
  background: linear-gradient(to bottom right, var(--amber-400), var(--amber-600));
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  transition: transform var(--transition-normal);
}

.card-honor:hover .honor-icon {
  transform: scale(1.1);
}

.honor-icon svg {
  width: 2.5rem;
  height: 2.5rem;
  color: var(--white);
}

.honor-body h3 {
  color: var(--gray-900);
  margin: var(--spacing-2) 0;
}

.honor-org {
  color: var(--emerald-700);
  font-size: var(--font-size-sm);
  margin-bottom: var(--spacing-4);
}

.honor-description {
  color: var(--gray-600);
  font-size: var(--font-size-sm);
}

/* ===================================
   Volunteering Section
   =================================== */
.volunteering-grid {
  display: grid;
  gap: var(--spacing-8);
}

@media (min-width: 768px) {
  .volunteering-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.card-volunteering {
  overflow: hidden;
}

.card-volunteering:hover {
  box-shadow: var(--shadow-xl);
}

.volunteering-image {
  overflow: hidden;
  background: linear-gradient(to bottom right, var(--emerald-100), var(--amber-100));
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-2);
}

.volunteering-image img {
  width: 100%;
  height: auto;
  max-height: 20rem;
  object-fit: contain;
  transition: transform var(--transition-slow);
}

.card-volunteering:hover .volunteering-image img {
  transform: scale(1.1);
}

.card-volunteering h3 {
  color: var(--gray-900);
  margin: var(--spacing-2) 0;
}

.volunteering-org {
  color: var(--emerald-700);
  font-size: var(--font-size-sm);
  margin-bottom: var(--spacing-2);
}

.volunteering-location {
  color: var(--gray-500);
  font-size: var(--font-size-sm);
  margin-bottom: var(--spacing-4);
}

.volunteering-description {
  color: var(--gray-700);
}

/* ===================================
   Contact Section
   =================================== */
.contact-intro {
  color: var(--emerald-100);
  max-width: 42rem;
  margin: 0 auto;
}

.contact-grid {
  display: grid;
  gap: var(--spacing-12);
}

@media (min-width: 768px) {
  .contact-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.card-contact-form {
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(12px);
  border-color: rgba(255, 255, 255, 0.2);
}

.card-contact-form h3 {
  color: var(--white);
  margin-bottom: var(--spacing-4);
}

.form-group {
  margin-bottom: var(--spacing-4);
}

.form-group label {
  display: block;
  color: var(--white);
  margin-bottom: var(--spacing-2);
  font-weight: 500;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: var(--spacing-3) var(--spacing-4);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: var(--white);
  font-size: var(--font-size-base);
  font-family: inherit;
  transition: all var(--transition-normal);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: rgba(255, 255, 255, 0.6);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  box-shadow: 0 0 0 2px rgba(255, 255, 255, 0.5);
}

.form-group textarea {
  resize: vertical;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-6);
}

.card-contact-info {
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(12px);
  border-color: rgba(255, 255, 255, 0.2);
}

.contact-item {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-4);
}

.contact-icon {
  padding: var(--spacing-3);
  background: rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-lg);
}

.contact-icon svg {
  width: 1.5rem;
  height: 1.5rem;
  color: var(--white);
}

.contact-item h4 {
  color: var(--white);
  margin-bottom: var(--spacing-2);
}

.contact-item p {
  color: var(--emerald-100);
}

.connect-title {
  color: var(--white);
  margin-bottom: var(--spacing-4);
}

.social-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-3);
}

/* ===================================
   Footer
   =================================== */
.footer {
  background: var(--emerald-950);
  color: var(--white);
  padding: var(--spacing-8) var(--spacing-4);
  text-align: center;
}

.footer p {
  margin-bottom: var(--spacing-2);
}

.footer-tagline {
  color: var(--emerald-300);
}

/* ===================================
   Toast Notifications
   =================================== */
#toast-container {
  position: fixed;
  bottom: var(--spacing-6);
  right: var(--spacing-6);
  z-index: 100;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-3);
}

.toast {
  padding: var(--spacing-4) var(--spacing-6);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  animation: slideIn 0.3s ease-out;
  max-width: 24rem;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(100%);
  }

  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.toast-loading {
  background: var(--gray-800);
  color: var(--white);
}

.toast-success {
  background: var(--emerald-600);
  color: var(--white);
}

.toast-error {
  background: #dc2626;
  color: var(--white);
}

/* ===================================
   Responsive Typography
   =================================== */
@media (max-width: 640px) {
  h1 {
    font-size: var(--font-size-3xl);
  }

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

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

/* ===================================
   Theme Toggle Button
   =================================== */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-full);
  background: var(--emerald-100);
  color: var(--emerald-700);
  transition: all var(--transition-normal);
  margin-left: var(--spacing-2);
}

.theme-toggle:hover {
  background: var(--emerald-200);
  transform: rotate(15deg);
}

.theme-toggle svg {
  width: 1.25rem;
  height: 1.25rem;
}

.theme-toggle .icon-sun,
.theme-toggle .icon-moon {
  display: none;
}

/* Light mode: show moon icon (to switch to dark) */
:root .theme-toggle .icon-moon,
[data-theme="light"] .theme-toggle .icon-moon {
  display: block;
}

/* Dark mode: show sun icon (to switch to light) */
[data-theme="dark"] .theme-toggle .icon-sun {
  display: block;
}

[data-theme="dark"] .theme-toggle .icon-moon {
  display: none;
}

[data-theme="dark"] .theme-toggle {
  background: #334155;
  color: #fbbf24;
}

[data-theme="dark"] .theme-toggle:hover {
  background: #475569;
}