/* ============================================================
   Tyler Ton — Portfolio Stylesheet
   ============================================================ */

/* ============================================================
   Custom Properties
   ============================================================ */
:root {
  --color-bg: #0d0f14;
  --color-surface: #161920;
  --color-surface-2: #1e2230;
  --color-border: #2a2f3e;
  --color-accent: #00d4aa;
  --color-accent-dim: #00a882;
  --color-accent-glow: rgba(0, 212, 170, 0.15);
  --color-text-primary: #e8eaf0;
  --color-text-secondary: #9aa0b4;
  --color-text-muted: #5a6078;
  --color-tag-bg: rgba(0, 212, 170, 0.1);
  --color-tag-text: #00d4aa;

  --font-sans: 'Inter', 'Segoe UI', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;

  --weight-normal: 400;
  --weight-medium: 500;
  --weight-semibold: 600;
  --weight-bold: 700;

  --leading-tight: 1.2;
  --leading-normal: 1.6;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-24: 6rem;
  --space-32: 8rem;

  --container-max: 1100px;
  --nav-height: 64px;
  --section-pad-y: var(--space-24);
  --border-radius: 8px;
  --border-radius-lg: 16px;

  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;
  --transition-spring: 400ms cubic-bezier(0.34, 1.56, 0.64, 1);

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.4);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.5);
  --shadow-glow: 0 0 20px var(--color-accent-glow);
}

/* ============================================================
   Global Reset & Base
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: var(--font-sans); background: var(--color-bg); color: var(--color-text-secondary); line-height: var(--leading-normal); font-size: var(--text-base); }
body.scroll-locked { overflow: hidden; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
button { border: none; background: none; font-family: inherit; cursor: pointer; }
img { max-width: 100%; display: block; }

/* ============================================================
   Utility — Container
   ============================================================ */
.container { max-width: var(--container-max); margin-inline: auto; padding-inline: var(--space-6); }

/* ============================================================
   Utility — Section Labels & Headings
   ============================================================ */
.section-label {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-accent);
  letter-spacing: 0.1em;
  display: block;
  margin-bottom: var(--space-2);
}
.section-label--sm { font-size: var(--text-xs); margin-bottom: var(--space-3); }

.section-heading {
  font-size: clamp(var(--text-2xl), 4vw, var(--text-4xl));
  color: var(--color-text-primary);
  font-weight: var(--weight-bold);
  margin-bottom: var(--space-8);
  line-height: var(--leading-tight);
}

/* ============================================================
   Utility — Buttons
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--border-radius);
  font-weight: var(--weight-semibold);
  font-size: var(--text-sm);
  transition: all var(--transition-base);
  cursor: pointer;
  text-decoration: none;
  border: 1.5px solid transparent;
}
.btn--primary { background: var(--color-accent); color: var(--color-bg); border-color: var(--color-accent); }
.btn--primary:hover { background: var(--color-accent-dim); border-color: var(--color-accent-dim); box-shadow: var(--shadow-glow); }
.btn--outline { background: transparent; color: var(--color-accent); border-color: var(--color-accent); }
.btn--outline:hover { background: var(--color-tag-bg); }
.btn--ghost { background: transparent; color: var(--color-text-secondary); border-color: transparent; }
.btn--ghost:hover { color: var(--color-text-primary); }
.btn--full { width: 100%; justify-content: center; }
.btn--loading .btn__label { opacity: 0.5; }
.btn__spinner {
  display: none;
  width: 16px;
  height: 16px;
  border: 2px solid currentColor;
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}
.btn--loading .btn__spinner { display: inline-block; }

/* ============================================================
   Utility — Tags & Badges
   ============================================================ */
.tag {
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  padding: var(--space-1) var(--space-3);
  border-radius: 4px;
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  border: 1px solid rgba(0, 212, 170, 0.2);
}
.badge {
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
  padding: var(--space-1) var(--space-3);
  border-radius: 20px;
}
.badge--in-progress {
  background: rgba(255, 184, 0, 0.15);
  color: #ffb800;
  border: 1px solid rgba(255, 184, 0, 0.3);
}

/* ============================================================
   Utility — Reveal Animation
   ============================================================ */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity var(--transition-slow), transform var(--transition-slow); }
.reveal--visible { opacity: 1; transform: translateY(0); }

/* ============================================================
   Navigation
   ============================================================ */
.nav {
  position: fixed;
  top: 0;
  inset-inline: 0;
  z-index: 100;
  height: var(--nav-height);
  transition: background var(--transition-base), border-color var(--transition-base);
}
.nav--scrolled {
  background: rgba(13, 15, 20, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}
.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  gap: var(--space-6);
}
.nav__logo {
  font-family: var(--font-mono);
  font-size: var(--text-xl);
  font-weight: var(--weight-bold);
  color: var(--color-accent);
  letter-spacing: 0.05em;
}
.nav__links { display: flex; align-items: center; gap: var(--space-6); }
.nav__link {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  font-weight: var(--weight-medium);
  transition: color var(--transition-fast);
  position: relative;
}
.nav__link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width var(--transition-base);
}
.nav__link:hover { color: var(--color-text-primary); }
.nav__link:hover::after { width: 100%; }
.nav__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 32px;
  height: 32px;
}
.nav__toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text-primary);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}
.nav__toggle[aria-expanded="true"] .nav__toggle-bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__toggle[aria-expanded="true"] .nav__toggle-bar:nth-child(2) { opacity: 0; }
.nav__toggle[aria-expanded="true"] .nav__toggle-bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
.nav__mobile {
  display: none;
  position: fixed;
  top: var(--nav-height);
  inset-inline: 0;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-4) var(--space-6);
}
.nav__mobile-links { display: flex; flex-direction: column; gap: var(--space-4); }
.nav__mobile-link {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  font-weight: var(--weight-medium);
  transition: color var(--transition-fast);
}
.nav__mobile-link:hover { color: var(--color-accent); }

/* ============================================================
   Hero
   ============================================================ */
.hero {
  min-height: 100svh;
  display: grid;
  place-items: center;
  position: relative;
  overflow: hidden;
  background: var(--color-bg);
  padding-top: var(--nav-height);
}
.hero__bg-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(42, 47, 62, 0.3) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 47, 62, 0.3) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
}
.hero__particle-canvas { position: absolute; inset: 0; pointer-events: none; }
.hero__content {
  position: relative;
  z-index: 1;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-6);
}
.hero__eyebrow {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-accent);
  letter-spacing: 0.1em;
}
.hero__name {
  font-size: clamp(var(--text-4xl), 8vw, 5rem);
  font-weight: var(--weight-bold);
  color: var(--color-text-primary);
  line-height: var(--leading-tight);
}
.hero__tagline {
  font-size: clamp(var(--text-lg), 3vw, var(--text-2xl));
  color: var(--color-text-secondary);
  font-family: var(--font-mono);
  min-height: 2em;
  display: flex;
  align-items: center;
  gap: 2px;
}
.hero__cursor {
  color: var(--color-accent);
  animation: blink 0.8s step-end infinite;
}
.hero__location {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}
.hero__location-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 0 0 var(--color-accent-glow);
  animation: pulse 2s ease-out infinite;
}
.hero__cta-group { display: flex; gap: var(--space-4); flex-wrap: wrap; justify-content: center; }
.hero__scroll-hint {
  position: absolute;
  bottom: var(--space-8);
  left: 50%;
  transform: translateX(-50%);
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  animation: bounce 2s ease-in-out infinite;
}

/* ============================================================
   Keyframes
   ============================================================ */
@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}
@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 rgba(0, 212, 170, 0.4); }
  70%  { box-shadow: 0 0 0 10px rgba(0, 212, 170, 0); }
  100% { box-shadow: 0 0 0 0 rgba(0, 212, 170, 0); }
}
@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50%       { transform: translateX(-50%) translateY(6px); }
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ============================================================
   About
   ============================================================ */
.about { padding-block: var(--section-pad-y); }
.about__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-16);
  align-items: start;
}
.about__bio { color: var(--color-text-secondary); line-height: var(--leading-normal); margin-bottom: var(--space-6); }
.about__meta { display: flex; flex-direction: column; gap: var(--space-3); }
.about__meta-item { display: flex; align-items: center; gap: var(--space-3); font-size: var(--text-sm); color: var(--color-text-secondary); }
.about__meta-icon { font-size: var(--text-base); }
.about__stats { display: flex; flex-direction: column; gap: var(--space-4); }
.stat-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  padding: var(--space-6) var(--space-8);
  text-align: center;
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
}
.stat-card:hover { border-color: var(--color-accent); box-shadow: var(--shadow-glow); }
.stat-card__number {
  display: block;
  font-size: var(--text-4xl);
  font-weight: var(--weight-bold);
  color: var(--color-accent);
  font-family: var(--font-mono);
  line-height: 1;
  margin-bottom: var(--space-2);
}
.stat-card__label { font-size: var(--text-sm); color: var(--color-text-muted); }

/* ============================================================
   Skills
   ============================================================ */
.skills { padding-block: var(--section-pad-y); background: var(--color-surface); }
.skills__inner > .section-heading { /* inherits */ }
.skills__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--space-8);
}
.skill-category {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  padding: var(--space-6);
}
.skill-category__title {
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: var(--space-4);
  font-family: var(--font-mono);
}
.skill-list { display: flex; flex-direction: column; gap: var(--space-4); }
.skill-item { display: flex; flex-direction: column; gap: var(--space-2); }
.skill-item__name { font-size: var(--text-sm); color: var(--color-text-secondary); display: flex; justify-content: space-between; }
.skill-item__bar { height: 4px; background: var(--color-border); border-radius: 2px; overflow: hidden; }
.skill-item__fill {
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--color-accent), var(--color-accent-dim));
  border-radius: 2px;
  transition: width 1s var(--transition-spring);
}

/* ============================================================
   Experience / Timeline
   ============================================================ */
.experience { padding-block: var(--section-pad-y); }
.timeline {
  position: relative;
  padding-left: var(--space-8);
  border-left: 2px solid var(--color-border);
  display: flex;
  flex-direction: column;
  gap: var(--space-12);
}
.timeline__item { position: relative; }
.timeline__marker {
  position: absolute;
  left: calc(-1 * var(--space-8) - 1px);
  top: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  width: var(--space-8);
}
.timeline__dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 0 4px var(--color-accent-glow);
  flex-shrink: 0;
}
.timeline__header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-3);
  flex-wrap: wrap;
}
.timeline__role { font-size: var(--text-lg); font-weight: var(--weight-semibold); color: var(--color-text-primary); }
.timeline__company { font-size: var(--text-sm); color: var(--color-accent); font-family: var(--font-mono); }
.timeline__period { font-size: var(--text-xs); color: var(--color-text-muted); font-family: var(--font-mono); white-space: nowrap; }
.timeline__description { font-size: var(--text-sm); color: var(--color-text-secondary); line-height: var(--leading-normal); margin-bottom: var(--space-4); }
.timeline__tags { display: flex; flex-wrap: wrap; gap: var(--space-2); }
.timeline__tag {
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  padding: var(--space-1) var(--space-3);
  border-radius: 4px;
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  border: 1px solid rgba(0, 212, 170, 0.2);
}

/* ============================================================
   Projects
   ============================================================ */
.projects { padding-block: var(--section-pad-y); background: var(--color-surface); }
.projects__filter {
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
  margin-bottom: var(--space-8);
}
.filter-btn {
  font-size: var(--text-sm);
  font-family: var(--font-mono);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--border-radius);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  background: transparent;
  transition: all var(--transition-fast);
}
.filter-btn:hover { color: var(--color-text-primary); border-color: var(--color-text-muted); }
.filter-btn--active { color: var(--color-accent); border-color: var(--color-accent); background: var(--color-tag-bg); }
.projects__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-6);
  position: relative;
}
.project-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
  display: flex;
  flex-direction: column;
}
.project-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-glow); border-color: var(--color-accent); }
.project-card--hidden { opacity: 0; pointer-events: none; position: absolute; visibility: hidden; }
.project-card__top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-6) var(--space-6) 0;
}
.project-card__icon { font-size: 2rem; }
.project-card__link {
  font-size: var(--text-xl);
  color: var(--color-text-muted);
  transition: color var(--transition-fast), transform var(--transition-fast);
  display: inline-flex;
}
.project-card__link:hover { color: var(--color-accent); transform: translate(2px, -2px); }
.project-card__body { padding: var(--space-6); display: flex; flex-direction: column; gap: var(--space-4); flex: 1; }
.project-card__title { font-size: var(--text-lg); font-weight: var(--weight-semibold); color: var(--color-text-primary); }
.project-card__description { font-size: var(--text-sm); color: var(--color-text-secondary); line-height: var(--leading-normal); flex: 1; }
.project-card__tags { display: flex; flex-wrap: wrap; gap: var(--space-2); }

/* ============================================================
   Research
   ============================================================ */
.research { padding-block: var(--section-pad-y); }
.research__card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  position: relative;
  overflow: hidden;
  max-width: 800px;
}
.research__card-accent-bar {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), transparent);
}
.research__card-body { padding: var(--space-8); }
.research__card-header { display: flex; align-items: center; gap: var(--space-4); flex-wrap: wrap; margin-bottom: var(--space-4); }
.research__title { font-size: var(--text-2xl); font-weight: var(--weight-bold); color: var(--color-text-primary); }
.research__institution { font-size: var(--text-sm); color: var(--color-accent); font-family: var(--font-mono); margin-bottom: var(--space-1); }
.research__timeline { font-size: var(--text-xs); color: var(--color-text-muted); font-family: var(--font-mono); margin-bottom: var(--space-6); }
.research__description { color: var(--color-text-secondary); line-height: var(--leading-normal); margin-bottom: var(--space-6); }
.research__topics { display: flex; flex-wrap: wrap; gap: var(--space-3); margin-bottom: var(--space-6); }
.research__topic {
  font-size: var(--text-sm);
  font-family: var(--font-mono);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--border-radius);
  background: var(--color-surface-2);
  color: var(--color-text-primary);
  border: 1px solid var(--color-border);
}
.research__tool-list { display: flex; flex-wrap: wrap; gap: var(--space-2); margin-top: var(--space-3); }

/* ============================================================
   Contact
   ============================================================ */
.contact { padding-block: var(--section-pad-y); background: var(--color-surface); }
.contact__inner {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: var(--space-16);
  align-items: start;
}
.contact__subtitle { color: var(--color-text-secondary); margin-bottom: var(--space-8); line-height: var(--leading-normal); }
.contact__links { display: flex; flex-direction: column; gap: var(--space-4); }
.contact__link { display: flex; align-items: center; gap: var(--space-3); color: var(--color-text-secondary); transition: color var(--transition-fast); font-size: var(--text-sm); }
.contact__link:hover { color: var(--color-accent); }
.contact__link-icon { font-size: var(--text-base); }
.form-group { display: flex; flex-direction: column; gap: var(--space-2); margin-bottom: var(--space-6); }
.form-label { font-size: var(--text-sm); font-weight: var(--weight-medium); color: var(--color-text-secondary); }
.form-input,
.form-textarea {
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  color: var(--color-text-primary);
  border-radius: var(--border-radius);
  padding: var(--space-3) var(--space-4);
  width: 100%;
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.form-input::placeholder,
.form-textarea::placeholder { color: var(--color-text-muted); }
.form-input:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-glow);
}
.form-textarea { resize: vertical; min-height: 120px; }
.form-error { color: #ff5f5f; font-size: var(--text-xs); margin-top: var(--space-1); display: none; }
.form-error--visible { display: block; }
.contact-form__success { padding: var(--space-8); text-align: center; color: var(--color-accent); font-size: var(--text-lg); }

/* ============================================================
   Footer
   ============================================================ */
.footer {
  padding-block: var(--space-8);
  border-top: 1px solid var(--color-border);
  background: var(--color-bg);
}
.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-4);
}
.footer__copy { font-size: var(--text-sm); color: var(--color-text-muted); }
.footer__nav { display: flex; gap: var(--space-6); }
.footer__nav-link { font-size: var(--text-sm); color: var(--color-text-muted); transition: color var(--transition-fast); }
.footer__nav-link:hover { color: var(--color-accent); }
.footer__built { font-size: var(--text-xs); color: var(--color-text-muted); font-family: var(--font-mono); }

/* ============================================================
   Responsive — 768px
   ============================================================ */
@media (max-width: 768px) {
  .nav__links, .nav__cta { display: none; }
  .nav__toggle { display: flex; }
  .nav__mobile { display: block; }
  .nav__mobile[aria-hidden="true"] { display: none; }
  .about__inner { grid-template-columns: 1fr; gap: var(--space-8); }
  .about__stats { flex-direction: row; }
  .contact__inner { grid-template-columns: 1fr; gap: var(--space-8); }
  .projects__grid { grid-template-columns: 1fr; }
  .hero__cta-group { flex-direction: column; align-items: center; }
}

/* ============================================================
   Responsive — 480px
   ============================================================ */
@media (max-width: 480px) {
  :root { --section-pad-y: var(--space-16); }
  .about__stats { flex-direction: column; }
  .timeline { padding-left: var(--space-6); }
  .footer__inner { flex-direction: column; text-align: center; }
}

/* ============================================================
   Reduced Motion
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms;
    animation-iteration-count: 1;
    transition-duration: 0.01ms;
  }
}