/* ============================================================
   portfolio/css/style.css — ALL styling lives here.
   Light tokens under :root, dark tokens under [data-theme="dark"].
   Accent: indigo. Mobile-first, 768px = nav breakpoint.
   ============================================================ */

/* ---------- Design tokens ---------- */
:root {
  /* colors — light */
  --color-accent: #4f46e5;
  --color-accent-hover: #4338ca;
  --color-on-accent: #ffffff;
  --color-bg: #ffffff;
  --color-surface: #f8fafc;
  --color-text: #0f172a;
  --color-text-muted: #475569;
  --color-border: #e2e8f0;
  --color-tag-bg: #eef2ff;
  --color-tag-text: #3730a3;

  /* typography */
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

  /* shape & motion */
  --radius: 12px;
  --shadow: 0 1px 3px rgba(15, 23, 42, 0.08);
  --shadow-hover: 0 8px 24px rgba(15, 23, 42, 0.12);
  --transition: 150ms ease;

  /* layout — 8px spacing scale */
  --container: 1100px;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 40px;
  --space-6: 48px;
  --space-7: 56px;
  --space-8: 64px;
}

/* colors — dark (applied by JS on <html>) */
[data-theme="dark"] {
  --color-accent: #818cf8;
  --color-accent-hover: #a5b4fc;
  --color-on-accent: #0f172a;
  --color-bg: #0f172a;
  --color-surface: #1e293b;
  --color-text: #f1f5f9;
  --color-text-muted: #94a3b8;
  --color-border: #334155;
  --color-tag-bg: #312e81;
  --color-tag-text: #c7d2fe;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.5);
}

/* ---------- Base ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
  transition: background-color var(--transition), color var(--transition);
}

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

h1,
h2,
h3 {
  line-height: 1.2;
  margin: 0 0 var(--space-2);
}

p {
  margin: 0 0 var(--space-2);
}

a {
  color: var(--color-accent);
  transition: color var(--transition);
}

:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-2);
}

@media (min-width: 768px) {
  .container {
    padding-inline: var(--space-3);
  }
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: 12px 24px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font: inherit;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition:
    background-color var(--transition),
    color var(--transition),
    border-color var(--transition),
    transform var(--transition),
    box-shadow var(--transition);
}

.btn-primary {
  background: var(--color-accent);
  color: var(--color-on-accent);
}

.btn-primary:hover {
  background: var(--color-accent-hover);
}

.btn-secondary {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border);
}

.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* ---------- Sections ---------- */
.section {
  padding-block: var(--space-6);
}

@media (min-width: 768px) {
  .section {
    padding-block: var(--space-8);
  }
}

.section-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin-bottom: var(--space-4);
}

/* ---------- Header / nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}

.nav {
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  min-height: 64px;
}

.logo {
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--color-text);
  text-decoration: none;
  margin-right: auto;
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-text);
  border-radius: 1px;
  transition: transform var(--transition), opacity var(--transition);
}

.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-menu {
  list-style: none;
  display: flex;
  align-items: center;
  gap: var(--space-1);
  margin: 0;
  padding: 0;
}

.nav-menu a {
  display: block;
  padding: 8px 12px;
  color: var(--color-text-muted);
  text-decoration: none;
  font-weight: 500;
  border-radius: 8px;
  transition: color var(--transition), background-color var(--transition);
}

.nav-menu a:hover {
  color: var(--color-accent);
  background: var(--color-tag-bg);
}

.nav-menu a[aria-current="page"] {
  color: var(--color-accent);
  font-weight: 600;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  padding: 0;
  font-size: 1.125rem;
  line-height: 1;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  color: var(--color-text);
  cursor: pointer;
  transition: border-color var(--transition), color var(--transition);
}

.theme-toggle:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* hamburger + dropdown under 768px */
@media (max-width: 767px) {
  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: var(--space-2);
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-hover);
  }

  .nav-menu.open {
    display: flex;
  }
}

/* ---------- Hero ---------- */
.hero {
  padding-block: var(--space-8);
}

.hero h1 {
  font-size: clamp(2.25rem, 6vw, 3.5rem);
  margin-bottom: var(--space-1);
}

.hero-role {
  color: var(--color-accent);
  font-weight: 600;
  font-size: 1.125rem;
  margin: 0 0 var(--space-1);
}

.hero-tagline {
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--color-text-muted);
  max-width: 40ch;
  margin: 0;
}

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

/* ---------- Cards ---------- */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-3);
  box-shadow: var(--shadow);
  transition:
    transform var(--transition),
    box-shadow var(--transition),
    border-color var(--transition);
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover);
  border-color: var(--color-accent);
}

.card h3 {
  font-size: 1.125rem;
}

.card p {
  color: var(--color-text-muted);
  margin: 0;
}

.card-grid {
  display: grid;
  gap: var(--space-3);
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

/* banded section on home page */
.what-i-do {
  background: var(--color-surface);
  border-block: 1px solid var(--color-border);
}

/* ---------- Projects ---------- */
.project-grid {
  display: grid;
  gap: var(--space-3);
  grid-template-columns: 1fr;
}

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

@media (min-width: 960px) {
  .project-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.project-card {
  display: flex;
  flex-direction: column;
  padding: 0;
  overflow: hidden;
}

.project-card > *:not(.project-image) {
  margin-inline: var(--space-3);
}

.project-card h3 {
  margin-top: var(--space-3);
  font-size: 1.0625rem;
}

.project-card p {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
}

/* placeholder block until you drop real screenshots into assets/ */
.project-image {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  background: var(--color-accent);
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
}

.tag {
  display: inline-block;
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  font-size: 0.8125rem;
  font-weight: 500;
  line-height: 1.5;
  padding: 2px 10px;
  border-radius: 999px;
}

.project-links {
  display: flex;
  gap: var(--space-3);
  margin-top: auto;
  padding-bottom: var(--space-3);
}

.project-links a {
  font-weight: 600;
  font-size: 0.9375rem;
  text-decoration: none;
}

.project-links a:hover {
  text-decoration: underline;
}

/* ---------- About ---------- */
.about-intro {
  max-width: 65ch;
  color: var(--color-text-muted);
  font-size: 1.0625rem;
}

.skills {
  margin-top: var(--space-5);
}

.skills-grid {
  display: grid;
  gap: var(--space-3);
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.skill-tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  margin: 0;
  padding: 0;
}

.timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 var(--space-3);
  border-left: 2px solid var(--color-border);
  display: grid;
  gap: var(--space-4);
}

.timeline-item {
  position: relative;
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: calc(-1 * var(--space-3) - 5px);
  top: 6px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-accent);
}

.timeline-date {
  display: block;
  color: var(--color-accent);
  font-weight: 600;
  font-size: 0.875rem;
  margin-bottom: 2px;
}

.timeline-item h3 {
  margin-bottom: 4px;
  font-size: 1.0625rem;
}

.timeline-item p {
  color: var(--color-text-muted);
  margin: 0;
  font-size: 0.9375rem;
}

/* ---------- Contact ---------- */
.contact-layout {
  display: grid;
  gap: var(--space-5);
}

@media (min-width: 768px) {
  .contact-layout {
    grid-template-columns: 1fr 1.4fr;
  }
}

.contact-info ul {
  list-style: none;
  display: grid;
  gap: var(--space-2);
  margin: 0;
  padding: 0;
}

.contact-info li {
  color: var(--color-text-muted);
}

.contact-info a {
  font-weight: 600;
  text-decoration: none;
}

.contact-info a:hover {
  text-decoration: underline;
}

.form-field {
  display: grid;
  gap: 6px;
  margin-bottom: var(--space-3);
}

.form-field label {
  font-weight: 600;
  font-size: 0.9375rem;
}

input,
textarea {
  font: inherit;
  color: var(--color-text);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 10px 12px;
  width: 100%;
  transition: border-color var(--transition);
}

input:focus,
textarea:focus {
  border-color: var(--color-accent);
}

textarea {
  min-height: 140px;
  resize: vertical;
}

.form-hint {
  color: var(--color-text-muted);
  font-size: 0.875rem;
}

/* ---------- 404 ---------- */
.error-page {
  text-align: center;
  padding-block: var(--space-8);
  max-width: 560px;
  margin-inline: auto;
}

.error-code {
  font-size: clamp(4rem, 15vw, 7rem);
  font-weight: 800;
  color: var(--color-accent);
  line-height: 1;
  margin: 0 0 var(--space-2);
}

.error-page p {
  color: var(--color-text-muted);
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding-block: var(--space-4);
  margin-top: var(--space-6);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}

.copyright {
  color: var(--color-text-muted);
  font-size: 0.875rem;
  margin: 0;
}

.social-links {
  list-style: none;
  display: flex;
  gap: var(--space-3);
  margin: 0;
  padding: 0;
}

.social-links a {
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: 0.9375rem;
}

.social-links a:hover {
  color: var(--color-accent);
}

.back-to-top {
  position: fixed;
  right: var(--space-3);
  bottom: var(--space-3);
  z-index: 90;
  padding: 10px 14px;
  border: none;
  border-radius: var(--radius);
  background: var(--color-accent);
  color: var(--color-on-accent);
  font: inherit;
  font-weight: 600;
  font-size: 0.875rem;
  cursor: pointer;
  box-shadow: var(--shadow-hover);
  transition: background-color var(--transition), transform var(--transition);
}

.back-to-top:hover {
  background: var(--color-accent-hover);
  transform: translateY(-2px);
}

/* JS toggles the `hidden` attribute; keep it authoritative */
.back-to-top[hidden] {
  display: none;
}

/* ---------- Accessibility ---------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}