/* ============================================================================
   1. FONTS & CSS VARIABLES — EDIT COLORS HERE
   ============================================================================
   This is the ONE place to change to reskin the whole site. Every color used
   anywhere below is a var(--something) that points back to this block, so
   changing a value here updates it everywhere automatically.
*/
:root {
  /* Light theme colors */
  --primary-color: #4361ee;      /* main buttons, links, active nav underline */
  --primary-color-rgb: 67, 97, 238;
  --secondary-color: #3f37c9;    /* hover state for primary */
  --accent-color: #4895ef;       /* secondary highlights, icons */
  --gradient-start: #4361ee;     /* hero blob gradient */
  --gradient-end: #7209b7;

  --text-color: #2b2d42;         /* main body text */
  --text-color-light: #666a80;   /* secondary/muted text */
  --bg-color: #ffffff;           /* page background */
  --bg-color-alt: #f7f8fc;       /* alternating section background */
  --card-bg: #ffffff;            /* card backgrounds */
  --border-color: #e6e8f0;
  --shadow-color: rgba(43, 45, 66, 0.08);
  --success-color: #2ecc71;
  --error-color: #e63946;

  --font-main: 'Poppins', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 3.5rem;
  --spacing-xl: 6rem;

  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-round: 50%;

  --transition-fast: 0.2s ease;
  --transition-normal: 0.35s ease;
  --transition-slow: 0.6s ease;
}

/* ============================================================================
   2. DARK THEME OVERRIDES
   ============================================================================
   Same variable names, dark values. Because every rule below uses var(--x),
   nothing else in this file ever needs its own dark-mode override.
*/
[data-theme="dark"] {
  --primary-color: #6d8bff;
  --primary-color-rgb: 109, 139, 255;
  --secondary-color: #8fa6ff;
  --accent-color: #5390d9;
  --gradient-start: #6d8bff;
  --gradient-end: #9d4edd;

  --text-color: #e8e9f3;
  --text-color-light: #a6aac2;
  --bg-color: #0f1117;
  --bg-color-alt: #171a23;
  --card-bg: #1b1e28;
  --border-color: #2b2f3d;
  --shadow-color: rgba(0, 0, 0, 0.45);
}

/* ============================================================================
   3. RESET & BASE
   ============================================================================ */
* { margin: 0; padding: 0; box-sizing: border-box; }

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

body {
  font-family: var(--font-main);
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.65;
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

h1, h2, h3, h4 {
  font-family: var(--font-main);
  font-weight: 600;
  line-height: 1.25;
  color: var(--text-color);
}

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

ul { list-style: none; }

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

/* Respect users who've asked for less motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

/* ============================================================================
   4. LAYOUT UTILITIES
   ============================================================================ */
.container {
  width: 90%;
  max-width: 1140px;
  margin: 0 auto;
}

.section { padding: var(--spacing-xl) 0; position: relative; }
.alt-bg { background-color: var(--bg-color-alt); }

.section-heading { text-align: center; margin-bottom: var(--spacing-lg); }
.section-heading h2 { font-size: 2.4rem; margin-bottom: 0.6rem; }
.section-heading .underline {
  height: 4px;
  width: 70px;
  margin: 0 auto;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
}

.sub-heading {
  font-size: 1.4rem;
  margin-bottom: var(--spacing-md);
  padding-left: 1rem;
  border-left: 4px solid var(--primary-color);
}
.projects-subheading-spaced { margin-top: var(--spacing-lg); }

.card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: 0 2px 12px var(--shadow-color);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), background-color var(--transition-normal);
}
.card:hover { transform: translateY(-6px); box-shadow: 0 12px 28px var(--shadow-color); }

.badge {
  display: inline-block;
  font-size: 0.68rem;
  font-weight: 500;
  padding: 0.15rem 0.55rem;
  border-radius: 100px;
  background: rgba(var(--primary-color-rgb), 0.12);
  color: var(--primary-color);
  vertical-align: middle;
  margin-left: 0.4rem;
}

/* Buttons, reused everywhere */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: 100px;
  font-weight: 500;
  font-size: 0.95rem;
  cursor: pointer;
  border: 2px solid transparent;
  transition: all var(--transition-fast);
}
.btn-primary { background: var(--primary-color); color: #fff; }
.btn-primary:hover { background: var(--secondary-color); transform: translateY(-2px); }
.btn-outline { border-color: var(--primary-color); color: var(--primary-color); background: transparent; }
.btn-outline:hover { background: var(--primary-color); color: #fff; transform: translateY(-2px); }
.btn-text { color: var(--text-color); padding: 0.75rem 0.5rem; }
.btn-text:hover { color: var(--primary-color); }
.btn-icon { width: 18px; height: 18px; filter: none; }

/* ============================================================================
   5. HEADER & NAV
   ============================================================================ */
#site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: transparent;
  transition: background-color var(--transition-normal), box-shadow var(--transition-normal);
}
#site-header.scrolled {
  background: var(--bg-color);
  box-shadow: 0 2px 16px var(--shadow-color);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.1rem 0;
}

.logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-color);
  font-family: var(--font-mono);
}
.logo .accent-dot { color: var(--primary-color); }

#main-nav { display: flex; gap: 2rem; }
#main-nav a {
  position: relative;
  color: var(--text-color);
  font-size: 0.95rem;
  font-weight: 500;
  padding-bottom: 4px;
}
#main-nav a::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  height: 2px;
  width: 100%;
  background: var(--primary-color);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-fast);
}
#main-nav a:hover::after,
#main-nav a.active::after { transform: scaleX(1); }
#main-nav a.active { color: var(--primary-color); }

.header-actions { display: flex; align-items: center; gap: 0.75rem; }

#lang-toggle {
  background: none;
  border: 1.5px solid var(--border-color);
  cursor: pointer;
  color: var(--text-color);
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.78rem;
  width: 38px; height: 38px;
  display: flex; align-items: center; justify-content: center;
  border-radius: var(--radius-round);
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}
#lang-toggle:hover { background: var(--bg-color-alt); border-color: var(--primary-color); color: var(--primary-color); }

#theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-color);
  width: 38px; height: 38px;
  display: flex; align-items: center; justify-content: center;
  border-radius: var(--radius-round);
  transition: background-color var(--transition-fast);
}
#theme-toggle:hover { background: var(--bg-color-alt); }
#theme-toggle .icon { width: 20px; height: 20px; }
/* Show sun in dark mode (click to go light), moon in light mode (click to go dark) */
[data-theme="dark"] #theme-toggle .icon-moon,
[data-theme="light"] #theme-toggle .icon-sun { display: none; }

#nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px; height: 32px;
  background: none;
  border: none;
  cursor: pointer;
}
#nav-toggle span {
  display: block;
  height: 2px;
  background: var(--text-color);
  border-radius: 2px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}
#main-nav.open ~ .header-actions #nav-toggle span:nth-child(1),
#nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
#nav-toggle.open span:nth-child(2) { opacity: 0; }
#nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ============================================================================
   6. HERO
   ============================================================================ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding-top: 5rem;
}

.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(70px);
  opacity: 0.35;
  z-index: 0;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  animation: blobDrift 18s ease-in-out infinite alternate;
}
.blob-1 { width: 420px; height: 420px; top: -100px; right: -80px; }
.blob-2 { width: 300px; height: 300px; bottom: -60px; left: -60px; animation-duration: 22s; animation-delay: -4s; }
.blob-3 { width: 220px; height: 220px; top: 40%; left: 55%; animation-duration: 26s; animation-delay: -9s; opacity: 0.25; }

.hero-inner {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  align-items: center;
  gap: var(--spacing-lg);
  position: relative;
  z-index: 1;
}

.hero-greeting {
  font-family: var(--font-mono);
  color: var(--primary-color);
  margin-bottom: 0.5rem;
  font-size: 1rem;
}

.hero-text h1 {
  font-size: 3.2rem;
  margin-bottom: 0.3rem;
}
.hero-text h1 .credential {
  font-size: 1.6rem;
  font-weight: 500;
  color: var(--text-color-light);
}
.hero-text h2 {
  font-size: 1.6rem;
  font-weight: 500;
  color: var(--text-color-light);
  margin-bottom: 1.4rem;
}
#typing-role { color: var(--primary-color); font-weight: 600; }
.cursor { color: var(--primary-color); animation: blink 1s step-end infinite; margin-left: 2px; }

.hero-buttons { display: flex; align-items: center; flex-wrap: wrap; gap: 1rem; margin-top: 1.75rem; }

.hero-photo { display: flex; justify-content: center; }
.photo-frame {
  position: relative;
  width: 300px;
  height: 340px;
  border-radius: 2.25rem;
}
/* Soft blurred glow behind the photo, blending into the background instead
   of a hard ring border */
.photo-frame::before {
  content: "";
  position: absolute;
  inset: -18px;
  border-radius: 2.75rem;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  filter: blur(45px);
  opacity: 0.4;
  z-index: -1;
}
.photo-frame img {
  width: 100%; height: 100%;
  border-radius: 2.25rem;
  object-fit: cover;
  box-shadow: 0 25px 50px var(--shadow-color);
}

/* ============================================================================
   7. ABOUT
   ============================================================================ */
.about-content { max-width: 760px; margin: 0 auto; text-align: left; }
.about-content p { color: var(--text-color-light); font-size: 1.05rem; text-align: justify; hyphens: auto; }

/* ============================================================================
   8. TIMELINE (EXPERIENCE)
   ============================================================================ */
.timeline { position: relative; max-width: 900px; margin: 0 auto; }
.timeline::before {
  content: "";
  position: absolute;
  left: 20px;
  top: 0; bottom: 0;
  width: 2px;
  background: var(--border-color);
}
.timeline-item { position: relative; padding-left: 55px; margin-bottom: var(--spacing-md); }
.timeline-dot {
  position: absolute;
  left: 12px; top: 6px;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: var(--bg-color);
  border: 3px solid var(--primary-color);
}
.timeline-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem 1.75rem;
  box-shadow: 0 2px 12px var(--shadow-color);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
  text-align: left;
}
.timeline-card:hover { transform: translateY(-4px); box-shadow: 0 12px 28px var(--shadow-color); }
.timeline-card h3 { font-size: 1.15rem; }
.timeline-card h4 { font-size: 0.95rem; font-weight: 500; color: var(--primary-color); margin-bottom: 0.3rem; }
.timeline-card .meta { display: block; font-size: 0.82rem; color: var(--text-color-light); margin-bottom: 0.9rem; font-family: var(--font-mono); }
.timeline-card ul { display: flex; flex-direction: column; gap: 0.5rem; }
.timeline-card li { position: relative; padding-left: 1.1rem; color: var(--text-color-light); font-size: 0.93rem; text-align: justify; hyphens: auto; }
.timeline-card li::before { content: "▸"; position: absolute; left: 0; color: var(--primary-color); }

/* ============================================================================
   9. EDUCATION & LANGUAGES
   ============================================================================ */
.education-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-md);
}
.education-card { padding: 1.75rem; }
.education-card h3 { font-size: 1.05rem; margin-bottom: 0.3rem; }
.education-card h4 { font-size: 0.9rem; font-weight: 500; color: var(--primary-color); margin-bottom: 0.4rem; }
.education-card .meta { display: block; font-size: 0.82rem; color: var(--text-color-light); font-family: var(--font-mono); margin-bottom: 0.5rem; }
.education-card p { font-size: 0.88rem; color: var(--text-color-light); margin-bottom: 0.5rem; }
.education-card .thesis-link { margin-top: 0.75rem; padding: 0.5rem 1.1rem; font-size: 0.82rem; }

.languages { margin-top: var(--spacing-lg); text-align: center; }

/* ============================================================================
   10. SKILLS (pill cloud)
   ============================================================================ */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-md);
}
.skill-category h3 { text-align: center; margin-bottom: 1.2rem; font-size: 1.1rem; }

.pill-cloud { display: flex; flex-wrap: wrap; gap: 0.6rem; justify-content: center; }
.pill {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.5rem 1rem;
  border-radius: 100px;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  font-size: 0.85rem;
  color: var(--text-color);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast);
}
.pill:hover { transform: translateY(-3px); box-shadow: 0 6px 16px var(--shadow-color); border-color: var(--primary-color); }
.pill-icon { width: 16px; height: 16px; color: var(--primary-color); flex-shrink: 0; }
.pill-icon + .pill-icon { margin-left: -0.25rem; }

/* ============================================================================
   11. PROJECTS
   ============================================================================ */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-md);
}
.project-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  box-shadow: 0 2px 12px var(--shadow-color);
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
  transform-style: preserve-3d;
  perspective: 800px;
}
.project-card:hover {
  transform: translateY(-8px) rotateX(var(--ry, 0deg)) rotateY(var(--rx, 0deg));
  box-shadow: 0 16px 32px var(--shadow-color);
}
.project-card h4 { font-size: 1.05rem; margin-bottom: 0.7rem; }
.project-card p { color: var(--text-color-light); font-size: 0.92rem; margin-bottom: auto; padding-bottom: 1.2rem; }
.project-card .project-link { align-self: flex-start; padding: 0.55rem 1.2rem; font-size: 0.85rem; }

/* ============================================================================
   12. CONTACT & FORM
   ============================================================================ */
.contact-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: var(--spacing-lg);
  align-items: start;
}

.contact-form-wrap { background: var(--card-bg); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 2rem; box-shadow: 0 2px 12px var(--shadow-color); }

.form-row { margin-bottom: 1.2rem; }
.form-row label { display: block; margin-bottom: 0.4rem; font-size: 0.9rem; font-weight: 500; }
.form-row input, .form-row textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background: var(--bg-color);
  color: var(--text-color);
  font-family: var(--font-main);
  font-size: 0.95rem;
  resize: vertical;
  transition: border-color var(--transition-fast);
}
.form-row input:focus, .form-row textarea:focus { outline: none; border-color: var(--primary-color); }

#form-submit-btn { width: 100%; justify-content: center; }
#form-submit-btn:disabled { opacity: 0.6; cursor: not-allowed; }

#form-status { margin-top: 1rem; font-size: 0.9rem; min-height: 1.2rem; }
#form-status.success { color: var(--success-color); }
#form-status.error { color: var(--error-color); }

.contact-links { display: flex; flex-direction: column; gap: 1rem; }
.contact-link {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  padding: 1rem 1.3rem;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-color);
  font-size: 0.95rem;
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}
.contact-link:hover { transform: translateX(6px); border-color: var(--primary-color); color: var(--primary-color); }
.contact-link .icon { width: 20px; height: 20px; flex-shrink: 0; }

/* ============================================================================
   13. FOOTER
   ============================================================================ */
footer { padding: 2rem 0; border-top: 1px solid var(--border-color); }
.footer-inner { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1rem; }
footer p { color: var(--text-color-light); font-size: 0.85rem; }
.back-to-top { color: var(--text-color-light); font-size: 0.85rem; }
.back-to-top:hover { color: var(--primary-color); }

/* ============================================================================
   14. ANIMATIONS
   ============================================================================ */
@keyframes blink { 50% { opacity: 0; } }

@keyframes blobDrift {
  0%   { transform: translate(0, 0) scale(1); }
  50%  { transform: translate(30px, -40px) scale(1.1); }
  100% { transform: translate(-20px, 20px) scale(0.95); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes slideInFromLeft {
  from { opacity: 0; transform: translateX(-40px); }
  to   { opacity: 1; transform: translateX(0); }
}
@keyframes slideInFromRight {
  from { opacity: 0; transform: translateX(40px); }
  to   { opacity: 1; transform: translateX(0); }
}

/* Elements start hidden; JS adds .is-visible (with the right animation) when scrolled into view */
.reveal { opacity: 0; }
.reveal.is-visible { animation: fadeInUp 0.7s ease forwards; }
.reveal.is-visible[data-animation="slideInFromLeft"] { animation: slideInFromLeft 0.7s ease forwards; }
.reveal.is-visible[data-animation="slideInFromRight"] { animation: slideInFromRight 0.7s ease forwards; }

/* ============================================================================
   15. LANGUAGE SWITCHING (EN / FR)
   ============================================================================
   Every bit of translated text on the site is written twice in the HTML —
   once inside class="lang-en", once inside class="lang-fr" — right next to
   each other. These two rules just hide whichever one doesn't match the
   current language (set on <html data-lang="en|fr"> by js/script.js).
*/
[data-lang="en"] .lang-fr,
html:not([data-lang]) .lang-fr { display: none; }
[data-lang="fr"] .lang-en { display: none; }

/* ============================================================================
   16. RESPONSIVE / MEDIA QUERIES
   ============================================================================ */
@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; text-align: center; }
  .hero-text .tagline { margin-left: auto; margin-right: auto; }
  .hero-buttons { justify-content: center; }
  .hero-photo { order: -1; }
  .photo-frame { width: 220px; height: 250px; }

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

@media (max-width: 768px) {
  #main-nav {
    position: fixed;
    top: 68px; left: 0; right: 0;
    background: var(--bg-color);
    flex-direction: column;
    align-items: center;
    padding: 1.5rem 0;
    gap: 1.2rem;
    box-shadow: 0 8px 20px var(--shadow-color);
    transform: translateY(-150%);
    opacity: 0;
    transition: transform var(--transition-normal), opacity var(--transition-normal);
  }
  #main-nav.open { transform: translateY(0); opacity: 1; }
  #nav-toggle { display: flex; }
}

@media (max-width: 560px) {
  .hero-text h1 { font-size: 2.3rem; }
  .hero-text h2 { font-size: 1.25rem; }
  .education-grid, .skills-grid, .projects-grid { grid-template-columns: 1fr; }
  .section { padding: var(--spacing-lg) 0; }
  .blob { display: none; }
}