/* ============================================================
   style.css — Sylvain Masclin Personal Academic Website
   smasclin.com
   ============================================================ */

/* ── Google Fonts ─────────────────────────────────────────── */
@import url('https://fonts.googleapis.com/css2?family=Lora:ital,wght@0,400;0,600;0,700;1,400;1,600&family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;0,9..40,600;1,9..40,400&display=swap');

/* ── CSS Custom Properties ────────────────────────────────── */
:root {
  /* Brand palette */
  --accent:        #FF7E00;
  --accent-dark:   #cc6500;
  --accent-light:  #ffaa44;
  --accent-tint:   #fff0e0;

  /* Backgrounds */
  --bg-page:       #f0f8ff;
  --bg-surface:    #e8f4ff;
  --bg-card:       #f8fcff;
  --bg-dark:       #0d2233;

  /* Text */
  --text-primary:  #0d2233;
  --text-body:     #1a3a52;
  --text-muted:    #4a6d8c;
  --text-light:    #7a9ab5;
  --text-on-dark:  #f0f8ff;

  /* Borders */
  --border-light:  #d6e8f5;
  --border-mid:    #b8d4e8;

  /* Typography */
  --font-serif:    'Lora', Georgia, serif;
  --font-sans:     'DM Sans', system-ui, sans-serif;

  /* Spacing scale */
  --space-xs:  0.5rem;
  --space-sm:  1rem;
  --space-md:  1.5rem;
  --space-lg:  2.5rem;
  --space-xl:  4rem;
  --space-2xl: 6rem;

  /* Layout */
  --content-width:     1100px;
  --content-narrow:    720px;
  --radius-sm:   6px;
  --radius-md:   12px;
  --radius-lg:   20px;
  --radius-pill: 100px;

  /* Transitions */
  --transition-fast: 180ms ease;
  --transition-mid:  300ms ease;
}

/* ── Reset & Base ──────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--bg-page);
  color: var(--text-body);
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.75;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--accent-dark);
}

ul, ol {
  padding-left: 1.4rem;
}

/* ── Typography Scale ──────────────────────────────────────── */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  color: var(--text-primary);
  line-height: 1.2;
  font-weight: 700;
}

h1 { font-size: clamp(2rem,    5vw, 3.25rem); }
h2 { font-size: clamp(1.5rem,  3vw, 2.25rem); }
h3 { font-size: clamp(1.2rem, 2.5vw, 1.6rem); }
h4 { font-size: 1.15rem; font-weight: 600; }
h5 { font-size: 1rem;    font-weight: 600; }
h6 { font-size: 0.9rem;  font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; }

p {
  margin-bottom: 1.25rem;
  color: var(--text-body);
}

p:last-child {
  margin-bottom: 0;
}

blockquote {
  border-left: 3px solid var(--accent);
  padding: 0.75rem 0 0.75rem 1.5rem;
  margin: var(--space-md) 0;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 1.15rem;
  color: var(--text-muted);
}

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

em {
  font-style: italic;
}

small {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ── Layout Utilities ──────────────────────────────────────── */
.container {
  width: 100%;
  max-width: var(--content-width);
  margin-inline: auto;
  padding-inline: clamp(1.25rem, 5vw, 2.5rem);
}

.container--narrow {
  max-width: var(--content-narrow);
}

.section {
  padding-block: var(--space-xl);
}

.section--lg {
  padding-block: var(--space-2xl);
}

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

.section--dark {
  background-color: var(--bg-dark);
  color: var(--text-on-dark);
}

.section--dark h1,
.section--dark h2,
.section--dark h3,
.section--dark h4 {
  color: var(--text-on-dark);
}

.section--dark p {
  color: rgba(250, 246, 240, 0.85);
}

/* ── Grid helpers ──────────────────────────────────────────── */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 440px), 1fr));
  gap: var(--space-lg);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr));
  gap: var(--space-md);
}

/* ── Flex helpers ──────────────────────────────────────────── */
.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

.flex-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
}

/* ── Navigation ────────────────────────────────────────────── */
.site-nav {
  background-color: var(--bg-page);
  border-bottom: 1px solid var(--border-light);
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: var(--space-sm);
}

/* Site name / logo */
.site-nav__name {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  white-space: nowrap;
  flex-shrink: 0;
}

.site-nav__name:hover {
  color: var(--accent);
}

/* Nav links */
.site-nav__links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
  padding: 0;
}

.site-nav__links a {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-pill);
  position: relative;
  transition: color var(--transition-fast), background var(--transition-fast);
  letter-spacing: 0.01em;
}

/* Animated underline effect */
.site-nav__links a::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 0.75rem;
  right: 0.75rem;
  height: 1.5px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-mid);
  border-radius: 1px;
}

.site-nav__links a:hover {
  color: var(--text-primary);
  background: transparent;
}

.site-nav__links a:hover::after {
  transform: scaleX(1);
}

.site-nav__links a.active {
  color: var(--accent);
}

.site-nav__links a.active::after {
  transform: scaleX(1);
}

/* Mobile hamburger */
.site-nav__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  flex-shrink: 0;
}

.site-nav__toggle span {
  display: block;
  width: 22px;
  height: 1.5px;
  background-color: var(--text-primary);
  border-radius: 2px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

/* ── Page Header (used on inner pages) ─────────────────────── */
.page-header {
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-light);
  padding-block: var(--space-xl);
}

.page-header__eyebrow {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.75rem;
  display: block;
}

.page-header__title {
  margin-bottom: 0.75rem;
}

.page-header__subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 60ch;
}

/* ── Hero ──────────────────────────────────────────────────── */
.hero {
  background-color: var(--bg-surface);
  padding-block: var(--space-xl);
}

.hero__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: center;
}

.hero__eyebrow {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1rem;
  display: block;
}

.hero__title {
  margin-bottom: 1.25rem;
}

.hero__title em {
  font-style: italic;
  color: var(--accent);
}

.hero__lead {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 52ch;
  margin-bottom: var(--space-md);
}

/* ── Buttons ───────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 0.65rem 1.4rem;
  border-radius: var(--radius-pill);
  border: 1.5px solid transparent;
  cursor: pointer;
  transition: background var(--transition-fast),
              color var(--transition-fast),
              border-color var(--transition-fast),
              transform var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}

.btn:hover {
  transform: translateY(-1px);
}

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

.btn--primary:hover {
  background: var(--accent-dark);
  border-color: var(--accent-dark);
  color: #fff;
}

.btn--outline {
  background: transparent;
  color: var(--accent);
  border-color: var(--accent);
}

.btn--outline:hover {
  background: var(--accent-tint);
  color: var(--accent-dark);
}

.btn--ghost {
  background: transparent;
  color: var(--text-muted);
  border-color: var(--border-mid);
}

.btn--ghost:hover {
  background: var(--bg-surface);
  color: var(--text-primary);
  border-color: var(--border-mid);
}

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: var(--space-md);
}

/* ── Cards ─────────────────────────────────────────────────── */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  transition: box-shadow var(--transition-mid), transform var(--transition-mid);
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 28px rgba(43, 35, 24, 0.08);
}

.card__tag {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-tint);
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-pill);
  margin-bottom: 0.75rem;
}

.card__title {
  font-size: 1.15rem;
  margin-bottom: 0.5rem;
}

.card__body {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ── Dividers & Decorative ─────────────────────────────────── */
.divider {
  border: none;
  border-top: 1px solid var(--border-light);
  margin-block: var(--space-lg);
}

.section-label {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-family: var(--font-sans);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-light);
  margin-bottom: var(--space-md);
}

.section-label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border-light);
}

.section-heading {
  margin-bottom: var(--space-md);
}

.section-heading__title {
  margin-bottom: 0.5rem;
}

.section-heading__sub {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 55ch;
}

/* ── Tag / Pill ────────────────────────────────────────────── */
.tag {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-muted);
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  padding: 0.2rem 0.65rem;
  border-radius: var(--radius-pill);
}

.tag--accent {
  color: var(--accent);
  background: var(--accent-tint);
  border-color: transparent;
}

/* ── Slideshow ─────────────────────────────────────────────── */
.slideshow {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  background: var(--bg-surface);
  aspect-ratio: 4 / 3;
}

.slideshow__slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 1s ease;
}

.slideshow__slide.active {
  opacity: 1;
}

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

.slideshow__caption {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 1rem 1.25rem;
  background: linear-gradient(to top, rgba(43,35,24,0.72) 0%, transparent 100%);
  color: rgba(250,246,240,0.9);
  font-size: 0.8rem;
  font-family: var(--font-sans);
}

.slideshow__dots {
  position: absolute;
  bottom: 0.75rem;
  right: 1rem;
  display: flex;
  gap: 6px;
}

.slideshow__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: rgba(250,246,240,0.45);
  transition: background var(--transition-fast), width var(--transition-fast);
  cursor: pointer;
  border: none;
}

.slideshow__dot.active {
  background: rgba(250,246,240,0.95);
  width: 18px;
  border-radius: 3px;
}

/* ── Timeline ──────────────────────────────────────────────── */
.timeline {
  position: relative;
  padding-left: 2.5rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0.5rem;
  top: 6px;
  bottom: 6px;
  width: 1px;
  background: var(--border-mid);
}

.timeline__item {
  position: relative;
  margin-bottom: var(--space-lg);
}

.timeline__item:last-child {
  margin-bottom: 0;
}

.timeline__dot {
  position: absolute;
  left: -2.15rem;
  top: 0.35rem;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--bg-page);
  border: 2px solid var(--accent);
  transition: background var(--transition-fast);
}

.timeline__item:hover .timeline__dot {
  background: var(--accent);
}

.timeline__date {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.35rem;
}

.timeline__title {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
}

.timeline__body {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ── Course Card ───────────────────────────────────────────── */
.course-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-top: 3px solid var(--accent);
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  padding: var(--space-md);
}

.course-card__code {
  font-family: var(--font-sans);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.4rem;
}

.course-card__title {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.6rem;
}

.course-card__desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: var(--space-sm);
}

/* ── Contact Strip ─────────────────────────────────────────── */
.contact-strip {
  background: var(--bg-dark);
  color: var(--text-on-dark);
  padding-block: var(--space-lg);
}

.contact-strip__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
}

.contact-strip__text h3 {
  color: var(--text-on-dark);
  margin-bottom: 0.4rem;
}

.contact-strip__text p {
  color: rgba(250,246,240,0.7);
  font-size: 0.95rem;
  margin: 0;
}

.contact-strip a {
  color: var(--accent-light);
}

.contact-strip a:hover {
  color: var(--text-on-dark);
}

/* ── Footer ────────────────────────────────────────────────── */
.site-footer {
  background-color: var(--bg-dark);
  border-top: 1px solid rgba(250,246,240,0.08);
  padding-block: var(--space-md);
  margin-top: auto;
}

.site-footer__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
}

.site-footer__copy {
  font-size: 0.8rem;
  color: rgba(250,246,240,0.45);
}

.site-footer__affil {
  font-size: 0.8rem;
  color: rgba(250,246,240,0.45);
  text-align: right;
}

/* ── Resource Hub ──────────────────────────────────────────── */
.resource-section {
  margin-bottom: var(--space-xl);
}

.resource-section__header {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: var(--space-md);
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-light);
}

.resource-section__header h3 {
  flex: 1;
}

.resource-section__meta {
  font-size: 0.8rem;
  color: var(--text-light);
}

/* ── Tip Card (Resources newsletter) ──────────────────────── */
.tip-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: var(--space-sm) var(--space-md);
  margin-bottom: 0.75rem;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.tip-card:hover {
  transform: translateX(3px);
  box-shadow: 2px 4px 16px rgba(43,35,24,0.07);
}

.tip-card__meta {
  font-size: 0.75rem;
  color: var(--text-light);
  margin-bottom: 0.25rem;
}

.tip-card__title {
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* ── Academic / CV Section ─────────────────────────────────── */
.doc-link {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: var(--space-sm) var(--space-md);
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  margin-bottom: 0.75rem;
  transition: border-color var(--transition-fast), transform var(--transition-fast);
  text-decoration: none;
}

.doc-link:hover {
  border-color: var(--accent);
  transform: translateX(3px);
}

.doc-link__icon {
  width: 40px;
  height: 40px;
  background: var(--accent-tint);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.doc-link__title {
  font-family: var(--font-serif);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.15rem;
}

.doc-link__meta {
  font-size: 0.8rem;
  color: var(--text-light);
}

/* ── Prose content (About, Teaching philosophy) ────────────── */
.prose {
  max-width: 68ch;
}

.prose p {
  margin-bottom: 1.35rem;
}

.prose h2 {
  margin-top: var(--space-lg);
  margin-bottom: var(--space-sm);
}

.prose h3 {
  margin-top: var(--space-md);
  margin-bottom: 0.75rem;
}

.prose ul,
.prose ol {
  margin-bottom: 1.25rem;
}

.prose li {
  margin-bottom: 0.4rem;
  color: var(--text-body);
}

/* ── Responsive — tablet ───────────────────────────────────── */
@media (max-width: 900px) {
  .hero__inner {
    grid-template-columns: 1fr;
  }

  .hero__lead {
    max-width: 100%;
  }
}

/* ── Responsive — mobile ───────────────────────────────────── */
@media (max-width: 600px) {
  :root {
    --space-xl:  2.5rem;
    --space-2xl: 4rem;
  }

  /* Mobile nav: hide links, show hamburger */
  .site-nav__links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--bg-page);
    border-bottom: 1px solid var(--border-light);
    padding: var(--space-sm) var(--space-md);
    gap: 0.1rem;
    z-index: 99;
  }

  .site-nav__links.open {
    display: flex;
  }

  .site-nav__links a {
    padding: 0.65rem 0.5rem;
    font-size: 1rem;
  }

  .site-nav__links a::after {
    display: none;
  }

  .site-nav {
    position: sticky;
    top: 0;
  }

  .site-nav__toggle {
    display: flex;
  }

  .contact-strip__inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .site-footer__inner {
    flex-direction: column;
    text-align: center;
  }

  .site-footer__affil {
    text-align: center;
  }
}

/* ── Accessibility ─────────────────────────────────────────── */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 3px;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }

  html {
    scroll-behavior: auto;
  }
}

/* ── Skip link ─────────────────────────────────────────────── */
.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  background: var(--accent);
  color: #fff;
  padding: 0.5rem 1rem;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
  z-index: 200;
}

.skip-link:focus {
  top: 0;
}