/* =============================================================
   sections.css — Per-section layout and component styles
   Phase 2/3: Implement section-specific styles
   ============================================================= */

/* --- Navigation --- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--space-6);
  gap: var(--space-6);
}

.nav__logo {
  font-family: var(--font-heading);
  font-size: var(--font-lg);
  font-weight: 700;
  color: var(--color-text);
  white-space: nowrap;
  flex-shrink: 0;
  text-decoration: none;
}

.nav__logo:hover {
  color: var(--color-primary);
  text-decoration: none;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  flex-wrap: nowrap;
  overflow: hidden;
}

.nav__link {
  font-size: var(--font-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--border-radius);
  transition: color var(--transition-fast), background-color var(--transition-fast);
  white-space: nowrap;
  text-decoration: none;
}

.nav__link:hover,
.nav__link.active {
  color: var(--color-primary);
  background-color: color-mix(in srgb, var(--color-primary) 8%, transparent);
  text-decoration: none;
}

.nav__controls {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-shrink: 0;
}

.nav__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: var(--space-2);
}

.hamburger-bar {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 2px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

/* Mobile nav drawer */
.nav__drawer {
  position: fixed;
  top: var(--nav-height);
  right: 0;
  bottom: 0;
  width: min(280px, 80vw);
  background-color: var(--color-surface);
  box-shadow: var(--shadow-lg);
  padding: var(--space-6);
  transform: translateX(100%);
  transition: transform var(--transition-normal);
  z-index: 99;
  overflow-y: auto;
}

.nav__drawer.open {
  transform: translateX(0);
}

.nav__drawer-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.nav__drawer-links .nav__link {
  font-size: var(--font-base);
  padding: var(--space-3) var(--space-4);
}

/* Dark mode toggle */
.icon-moon { display: none; }
.icon-sun  { display: inline; }

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

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .icon-moon { display: inline; }
  :root:not([data-theme="light"]) .icon-sun  { display: none; }
}

/* Medium screens: compress nav link padding/font before hamburger kicks in */
@media (max-width: 1200px) and (min-width: 1025px) {
  .nav__logo {
    font-size: var(--font-base);
  }
  .nav__link {
    font-size: 0.75rem;
    padding: var(--space-1) var(--space-2);
  }
}

/* Tablet and below: hide links, show hamburger */
@media (max-width: 1024px) {
  .nav__links {
    display: none;
  }
  .nav__hamburger {
    display: flex;
  }
}

/* --- Hero Section --- */
.section--hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding-top: calc(var(--nav-height) + var(--space-12));
  padding-bottom: var(--space-20);
  background: linear-gradient(
    132deg,
    var(--color-bg) 0%,
    color-mix(in srgb, var(--color-primary) 7%, var(--color-bg)) 56%,
    color-mix(in srgb, var(--color-accent) 5%, var(--color-bg)) 100%
  );
}

.section--hero::before,
.section--hero::after {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}

.section--hero::before {
  background: url('../assets/images/hero/arc-field-a.svg') center / cover no-repeat;
  opacity: 0.52;
  transform: translate3d(0, 0, 0);
  animation: hero-arcfield-drift-a 40s ease-in-out infinite;
}

.section--hero::after {
  background: url('../assets/images/hero/arc-field-b.svg') center / cover no-repeat;
  opacity: 0.46;
  transform: translate3d(0, 0, 0);
  animation: hero-arcfield-drift-b 34s ease-in-out infinite;
}

.hero__inner {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  gap: var(--space-16);
  position: relative;
  z-index: 1;
}

.hero__image-wrap {
  flex-shrink: 0;
}

.hero__photo {
  width: 260px;
  height: 260px;
  border-radius: 50%;
  object-fit: cover;
  border: 4px solid var(--color-surface);
  box-shadow: var(--shadow-lg);
}

.hero__text {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.hero__name {
  font-family: var(--font-heading);
  font-size: var(--font-5xl);
  line-height: 1.1;
  color: var(--color-text);
}

.hero__credential {
  font-size: var(--font-lg);
  color: var(--color-primary);
  font-weight: 600;
}

.hero__tagline {
  font-size: var(--font-xl);
  color: var(--color-text-secondary);
  max-width: 50ch;
}

.hero__ctas {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
  margin-top: var(--space-2);
}

/* Tablet range: tighten hero gap before single-column kicks in */
@media (max-width: 1024px) and (min-width: 641px) {
  .hero__inner {
    gap: var(--space-8);
  }
  .hero__photo {
    width: 180px;
    height: 180px;
  }
  .hero__name {
    font-size: var(--font-4xl);
  }
}

@media (max-width: 640px) {
  .hero__inner {
    grid-template-columns: 1fr;
    text-align: center;
    gap: var(--space-8);
  }
  .hero__image-wrap {
    display: flex;
    justify-content: center;
  }
  .hero__photo {
    width: 200px;
    height: 200px;
  }
  .section--hero::before {
    opacity: 0.4;
  }
  .section--hero::after {
    opacity: 0.34;
  }
  .hero__name {
    font-size: var(--font-4xl);
  }
  .hero__ctas {
    justify-content: center;
  }
}

@keyframes hero-arcfield-drift-a {
  0%,
  100% {
    transform: translate3d(0, 0, 0);
  }
  50% {
    transform: translate3d(16px, -10px, 0);
  }
}

@keyframes hero-arcfield-drift-b {
  0%,
  100% {
    transform: translate3d(0, 0, 0);
  }
  50% {
    transform: translate3d(-14px, 8px, 0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .section--hero::before,
  .section--hero::after {
    animation: none;
  }
}

/* Dark mode: increase arc field visibility */
@media (prefers-color-scheme: dark) {
  .section--hero::before {
    opacity: 0.85;
  }
  .section--hero::after {
    opacity: 0.78;
  }
}

/* --- About Section --- */
.section--about {
  background-color: var(--color-surface);
}

.about__bio {
  max-width: 75ch;
  margin-bottom: var(--space-10);
}

.about__bio p + p {
  margin-top: var(--space-4);
}

.about__stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: var(--space-4);
  margin-bottom: var(--space-8);
}

.stat-card {
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  padding: var(--space-6);
  text-align: center;
  transition: box-shadow var(--transition-fast);
}

.stat-card:hover {
  box-shadow: var(--shadow-md);
}

.stat-card__number {
  display: block;
  font-family: var(--font-heading);
  font-size: var(--font-4xl);
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.1;
}

.stat-card__label {
  display: block;
  font-size: var(--font-sm);
  color: var(--color-text-secondary);
  margin-top: var(--space-1);
}

.about__tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

/* --- Education Section --- */
.section--education {
  background-color: var(--color-bg);
}

.degree-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  padding: var(--space-8);
  margin-bottom: var(--space-6);
  box-shadow: var(--shadow-sm);
}

.degree-card--primary {
  border-left: 4px solid var(--color-primary);
}

.degree-card--upcoming {
  border-left: 4px solid var(--color-accent);
  opacity: 0.9;
}

.degree-card__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}

.degree-card__logo {
  width: 64px;
  height: 64px;
  flex-shrink: 0;
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-border);
  background-color: #ffffff;
  padding: 4px;
  object-fit: contain;
}

.degree-card__school-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  flex: 1;
  min-width: 0;
}

.degree-card__school {
  font-family: var(--font-heading);
  font-size: var(--font-2xl);
  color: var(--color-text);
}

.degree-card__location {
  font-size: var(--font-sm);
  color: var(--color-text-secondary);
}

@media (max-width: 640px) {
  .degree-card__header {
    gap: var(--space-3);
  }

  .degree-card__logo {
    width: 52px;
    height: 52px;
  }
}

.degree-card__degrees {
  list-style: disc;
  padding-left: var(--space-5);
  margin-bottom: var(--space-6);
}

.degree-card__degrees li {
  margin-bottom: var(--space-1);
  font-weight: 500;
}

.degree-card__gpa {
  color: var(--color-primary);
  font-weight: 700;
}

.degree-card__note {
  color: var(--color-text-secondary);
  font-weight: 400;
  font-size: var(--font-sm);
}

.degree-card__honors-heading,
.degree-card__coursework-heading {
  font-size: var(--font-sm);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-3);
}

.degree-card__honors {
  margin-bottom: var(--space-6);
}

.degree-card__honors ul {
  list-style: disc;
  padding-left: var(--space-5);
}

.degree-card__honors li {
  margin-bottom: var(--space-1);
  font-size: var(--font-sm);
}

.degree-card__program {
  font-size: var(--font-xl);
  font-weight: 600;
  color: var(--color-text);
}

/* Chip list (coursework) */
.chip-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  overflow-x: auto;
  padding-bottom: var(--space-1);
}

.chip-list li {
  background-color: color-mix(in srgb, var(--color-primary) 10%, transparent);
  color: var(--color-primary-dark);
  font-size: var(--font-xs);
  font-weight: 600;
  padding: var(--space-1) var(--space-3);
  border-radius: 999px;
  white-space: nowrap;
}

/* --- Experience & Research Timeline --- */
.section--experience {
  background-color: var(--color-surface);
}

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

.timeline {
  position: relative;
  padding-left: var(--space-8);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 11px;
  top: 0;
  bottom: 0;
  width: 2px;
  background-color: var(--color-border);
}

.timeline__entry {
  position: relative;
  margin-bottom: var(--space-8);
}

.timeline__marker {
  position: absolute;
  left: calc(-1 * var(--space-8) + 3px);
  top: 4px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background-color: var(--color-primary);
  border: 3px solid var(--color-surface);
  box-shadow: 0 0 0 2px var(--color-primary);
}

.timeline__card {
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow-sm);
}

.timeline__card-header {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}

.timeline__role {
  font-size: var(--font-lg);
  font-weight: 700;
  color: var(--color-text);
  width: 100%;
}

.timeline__org {
  font-weight: 600;
  color: var(--color-primary);
}

.timeline__location,
.timeline__dates,
.timeline__hours {
  font-size: var(--font-sm);
  color: var(--color-text-secondary);
}

.timeline__bullets {
  list-style: disc;
  padding-left: var(--space-5);
  margin-top: var(--space-3);
}

.timeline__bullets li {
  margin-bottom: var(--space-1);
  font-size: var(--font-sm);
  color: var(--color-text-secondary);
}

/* --- Skills Section --- */
.section--skills {
  background-color: var(--color-bg);
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-6);
}

.skill-group {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  padding: var(--space-6);
}

.skill-group__heading {
  font-size: var(--font-sm);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-4);
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.tag-list li {
  background-color: color-mix(in srgb, var(--color-primary) 10%, transparent);
  color: var(--color-primary-dark);
  font-size: var(--font-xs);
  font-weight: 500;
  padding: var(--space-1) var(--space-3);
  border-radius: 4px;
}

/* --- Certifications Section --- */
.section--certifications {
  background-color: var(--color-bg);
}

.cert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-4);
}

.cert-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow-sm);
  position: relative;
}

.cert-card--active {
  border-left: 3px solid var(--color-primary);
}

.cert-card--upcoming {
  border-left: 3px solid var(--color-accent);
  opacity: 0.85;
}

.cert-card__name {
  font-size: var(--font-base);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.cert-card__issuer {
  font-size: var(--font-sm);
  color: var(--color-primary);
  font-weight: 500;
  margin-bottom: var(--space-1);
}

.cert-card__dates {
  font-size: var(--font-xs);
  color: var(--color-text-secondary);
}

/* --- Volunteer Section --- */
.section--volunteer {
  background-color: var(--color-bg);
}

.volunteer-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-6);
}

.volunteer-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow-sm);
}

.volunteer-card__org {
  font-size: var(--font-xl);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-1);
}

.volunteer-card__role {
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-1);
}

.volunteer-card__location,
.volunteer-card__dates {
  font-size: var(--font-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-1);
}

.volunteer-card__description {
  margin-top: var(--space-3);
  font-size: var(--font-sm);
  color: var(--color-text-secondary);
  font-style: italic;
}

/* --- Athletics & Interests Card Grid --- */
.section--athletics,
.section--interests {
  background-color: var(--color-surface);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-6);
}

.activity-card {
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-fast), transform var(--transition-fast);
}

.activity-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.activity-card__image-wrap {
  aspect-ratio: 4 / 3;
  overflow: hidden;
  background-color: var(--color-border);
}

.activity-card__image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.activity-card:hover .activity-card__image {
  transform: scale(1.04);
}

.activity-card__body {
  padding: var(--space-5);
}

.activity-tag {
  display: inline-block;
  font-size: var(--font-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: var(--space-1) var(--space-2);
  border-radius: 4px;
  margin-bottom: var(--space-2);
}

.activity-tag--former {
  background-color: color-mix(in srgb, var(--color-text-secondary) 15%, transparent);
  color: var(--color-text-secondary);
}

.activity-tag--current {
  background-color: color-mix(in srgb, var(--color-success) 15%, transparent);
  color: var(--color-success);
}

.activity-card__name {
  font-size: var(--font-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-1);
}

.activity-card__org,
.activity-card__dates {
  font-size: var(--font-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-1);
}

.activity-card__desc {
  font-size: var(--font-sm);
  color: var(--color-text-secondary);
  margin-top: var(--space-3);
  line-height: 1.5;
}

/* --- Conference Presentations --- */
.presentation-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.presentation-card {
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
}

.presentation-card--upcoming {
  opacity: 0.8;
  border-style: dashed;
}

.presentation-card__title {
  font-size: var(--font-base);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-2);
  font-style: italic;
}

.presentation-card__event {
  font-size: var(--font-sm);
  color: var(--color-primary);
  font-weight: 500;
}

.presentation-card__date {
  font-size: var(--font-xs);
  color: var(--color-text-secondary);
  margin-top: var(--space-1);
}

/* --- Philosophy Quote --- */
.philosophy-quote {
  margin-top: var(--space-16);
  padding: var(--space-10) var(--space-12);
  background: linear-gradient(
    135deg,
    color-mix(in srgb, var(--color-primary) 8%, var(--color-bg)),
    color-mix(in srgb, var(--color-accent) 8%, var(--color-bg))
  );
  border-radius: var(--border-radius-lg);
  text-align: center;
  position: relative;
}

.philosophy-quote::before {
  content: '\201C';
  font-family: var(--font-heading);
  font-size: 6rem;
  color: var(--color-primary);
  opacity: 0.2;
  position: absolute;
  top: -1rem;
  left: var(--space-8);
  line-height: 1;
}

.philosophy-quote__text {
  font-family: var(--font-heading);
  font-size: var(--font-2xl);
  font-style: italic;
  color: var(--color-text);
  max-width: 70ch;
  margin-inline: auto;
  line-height: 1.5;
}

/* --- Contact Section --- */
.section--contact {
  background-color: var(--color-bg);
}

.contact-form {
  max-width: 600px;
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.form-label {
  font-size: var(--font-sm);
  font-weight: 600;
  color: var(--color-text);
}

.form-label--optional {
  font-weight: 400;
  color: var(--color-text-secondary);
}

.form-input,
.form-select,
.form-textarea {
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  font-family: var(--font-body);
  font-size: var(--font-base);
  color: var(--color-text);
  background-color: var(--color-surface);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-primary) 20%, transparent);
}

.form-input.invalid,
.form-select.invalid,
.form-textarea.invalid {
  border-color: var(--color-error);
}

.form-textarea {
  resize: vertical;
  min-height: 120px;
}

.form-error {
  font-size: var(--font-xs);
  color: var(--color-error);
  min-height: 1em;
}

.btn--submit {
  align-self: flex-start;
}

.btn__spinner {
  width: 16px;
  height: 16px;
  border: 2px solid rgba(255 255 255 / 0.4);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 600ms linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.form-feedback {
  padding: var(--space-4) var(--space-5);
  border-radius: var(--border-radius);
  font-weight: 500;
}

.form-feedback--success {
  background-color: color-mix(in srgb, var(--color-success) 15%, transparent);
  color: var(--color-success);
  border: 1px solid var(--color-success);
}

.form-feedback--error {
  background-color: color-mix(in srgb, var(--color-error) 12%, transparent);
  color: var(--color-error);
  border: 1px solid var(--color-error);
}

.contact__social {
  margin-top: var(--space-8);
  display: flex;
  gap: var(--space-4);
}

.social-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 600;
  color: var(--color-primary);
  transition: color var(--transition-fast);
}

.social-link:hover {
  color: var(--color-primary-dark);
}

.social-icon {
  width: 24px;
  height: 24px;
  fill: var(--color-primary);
  transition: fill var(--transition-fast);
}

.social-link:hover .social-icon {
  fill: var(--color-primary-dark);
}

/* --- Footer --- */
.site-footer {
  background-color: var(--color-text);
  color: #E8EFF5;
  padding-block: var(--space-10);
}

.footer__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-4);
  text-align: center;
}

.footer__name {
  font-family: var(--font-heading);
  font-size: var(--font-lg);
  font-weight: 700;
}

.footer__credential {
  font-weight: 400;
  font-size: var(--font-sm);
  color: #8FA6BB;
}

.footer__nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-1) var(--space-4);
}

.footer__nav a {
  font-size: var(--font-sm);
  color: #8FA6BB;
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer__nav a:hover {
  color: #fff;
}

.footer__links a {
  font-size: var(--font-sm);
  color: var(--color-accent);
  font-weight: 600;
}

.footer__links a:hover {
  color: #fff;
}

.footer__copy {
  font-size: var(--font-xs);
  color: #8FA6BB;
}

/* Offset anchors for fixed nav */
.section {
  scroll-margin-top: var(--nav-height);
}