/* ── Fonts ─────────────────────────────────────────────────── */

@font-face {
  font-family: 'BasicallySerif';
  src: url('/fonts/BasicallySerif-Regular.woff2') format('woff2');
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: 'BasicallySerif';
  src: url('/fonts/BasicallySerif-Bold.woff2') format('woff2');
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: 'BasicallySans';
  src: url('/fonts/BasicallySans-Bold.woff2') format('woff2');
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: 'BaskemoSans';
  src: url('/fonts/BaskemoSans-Regular.woff2') format('woff2');
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

/* ── Base ──────────────────────────────────────────────────── */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* @link https://utopia.fyi/type/calculator?c=360,15,1.2,1400,23,1.25,5,2,&s=0.75|0.5,1.5|2|3|4,s-l&g=s,l,xl,12 */

:root {
  --step--2: clamp(0.651rem, 0.5579rem + 0.4138vw, 0.92rem);
  --step--1: clamp(0.7813rem, 0.6536rem + 0.5673vw, 1.15rem);
  --step-0: clamp(0.9375rem, 0.7644rem + 0.7692vw, 1.4375rem);
  --step-1: clamp(1.125rem, 0.8924rem + 1.0337vw, 1.7969rem);
  --step-2: clamp(1.35rem, 1.0398rem + 1.3786vw, 2.2461rem);
  --step-3: clamp(1.62rem, 1.2089rem + 1.8271vw, 2.8076rem);
  --step-4: clamp(1.944rem, 1.4021rem + 2.4085vw, 3.5095rem);
  --step-5: clamp(2.3328rem, 1.6218rem + 3.1602vw, 4.3869rem);
}

:root {
  --bg: #f0ede8;
  --ink: #1a1a1a;
  --border: #1a1a1a;
  --accent: #00bca4;
  --radius: 8px;
  --font-serif: 'BasicallySerif', Georgia, serif;
  --font-ui: 'BaskemoSans', sans-serif;
  --gap: 1rem;
}

html {
  font-size: 16px;
  background: var(--bg);
  color: var(--ink);
}

body {
  font-family: var(--font-serif);
  font-size: var(--step-0);
  font-weight: 400;
  min-height: 100vh;
  padding: 0 0 4rem;
}

h1, h2, h3, h4 {
  font-family: var(--font-serif);
  font-weight: 700;
}

a {
  color: inherit;
  text-decoration: none;
}

/* ── View transitions ──────────────────────────────────────── */
/* Native cross-document transitions only — the browser performs real
   navigations, so back/forward scroll restoration keeps working. No JS. */

@view-transition {
  navigation: auto;
}

::view-transition-old(root) {
  animation: 150ms ease-in both vt-fade-out;
}

::view-transition-new(root) {
  animation: 200ms ease-out both vt-fade-in;
}

@keyframes vt-fade-out {
  to { opacity: 0; }
}

@keyframes vt-fade-in {
  from { opacity: 0; }
}

@media (prefers-reduced-motion: reduce) {
  ::view-transition-old(root),
  ::view-transition-new(root) {
    animation: none;
  }
}

/* ── Header ────────────────────────────────────────────────── */

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--step-0) var(--step-2);
  position: relative;
}

/* AlgoLit logo */
.logo-wrap {
  display: flex;
  align-items: center;
  gap: 0.2em;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.2em;
  text-decoration: none;
}

.logo-block {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-ui);
  font-size: var(--step-0);
  font-weight: bold;
  letter-spacing: 0.15em;
  padding: 0.45rem 0.9rem;
  border: 0.06em solid var(--border);
  border-radius: 0.2em;
  line-height: 1;
  cursor: pointer;
}

.logo-algo,
.logo-lit {
  background: var(--ink);
  color: var(--bg);
  border-color: var(--ink);
}

.logo-arrow {
  background: var(--bg);
  color: var(--ink);
  border-color: var(--ink);
  padding: 0.45rem 0.6rem;
  font-weight: normal;
  letter-spacing: 0;
}

.logo-sep {
  font-weight: normal;
  letter-spacing: 0;
  padding: 0.45rem 0.6rem;
}

.logo-section {
  background: var(--bg);
  color: var(--ink);
  border-color: var(--ink);
  font-weight: normal;
  letter-spacing: 0.1em;
}

/* Right-side header cluster: language switcher + menu button */
.header-actions {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.lang-switch {
  display: flex;
  align-items: center;
  gap: 0.15em;
  font-family: var(--font-ui);
  font-size: var(--step--1);
}

.lang-switch a,
.lang-switch span {
  padding: 0.25em 0.45em;
  border-radius: 0.2em;
  letter-spacing: 0.05em;
}

.lang-switch-current {
  font-weight: bold;
  background: var(--ink);
  color: var(--bg);
}

.lang-switch a:hover {
  background: var(--accent);
  color: var(--bg);
}

/* Menu button — matches the logo blocks (same height, same border) */
.menu-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-ui);
  font-size: var(--step-0);
  font-weight: bold;
  letter-spacing: 0.15em;
  padding: 0.45rem 0.9rem;
  border: 0.06em solid var(--border);
  border-radius: 0.2em;
  line-height: 1;
  background: var(--bg);
  color: var(--ink);
  cursor: pointer;
}

.menu-btn:hover {
  background: var(--ink);
  color: var(--bg);
}

/* Nav */
.site-nav {
  position: absolute;
  top: calc(100% - 0.25rem);
  right: 2rem;
  background: var(--bg);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  z-index: 100;
}

.site-nav[hidden] {
  display: none;
}

.site-nav a {
  font-family: var(--font-ui);
  font-size: var(--step--1);
  letter-spacing: 0.05em;
  padding: 0.25rem 0;
}

.site-nav a:hover {
  text-decoration: underline;
}

/* ── Intro ─────────────────────────────────────────────────── */

.site-intro {
  padding: 2.5rem 2rem 0;
  max-width: 66ch;
  font-size: var(--step-1);
  line-height: 1.6;
}

/* ── Filter section ────────────────────────────────────────── */

.filters {
  padding: var(--step-2) var(--step-2) var(--step-1);
  max-width: 1200px;
}

.filter-group {
  margin-bottom: 2rem;
}

.filter-label {
  font-size: var(--step-0);
  margin-bottom: 0.75rem;
  font-weight: normal;
}

.filter-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

/* "i" info button next to the learning-goal label */
.info-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.5em;
  height: 1.5em;
  margin-left: 0.4em;
  padding: 0;
  border: 1.5px solid var(--ink);
  border-radius: 50%;
  background: var(--ink);
  color: var(--bg);
  font-family: var(--font-serif);
  font-size: 0.8em;
  line-height: 1;
  cursor: pointer;
  vertical-align: middle;
  transition: background 0.1s, color 0.1s;
}

.info-btn:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--bg);
}

/* Learning-goal descriptions panel — opened from the info button */
.goal-info-popover {
  inset: 0;
  margin: auto;
  width: min(560px, calc(100vw - 2rem));
  max-height: min(80vh, 40rem);
  overflow-y: auto;
  padding: 1.25rem 1.5rem 1.5rem;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--ink);
  box-shadow: 6px 6px 0 rgba(26, 26, 26, 0.18);
}

.goal-info-popover::backdrop {
  background: rgba(26, 26, 26, 0.35);
}

.goal-info-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1rem;
}

.goal-info-title {
  font-family: var(--font-serif);
  font-size: var(--step-1);
  font-weight: 700;
}

.goal-info-close {
  flex: none;
  border: none;
  background: none;
  color: var(--ink);
  font-size: var(--step-1);
  line-height: 1;
  cursor: pointer;
  padding: 0 0.2em;
}

.goal-info-close:hover {
  color: var(--accent);
}

.goal-info-item + .goal-info-item {
  margin-top: 0.9rem;
  padding-top: 0.9rem;
  border-top: 1px solid rgba(26, 26, 26, 0.15);
}

.goal-info-list dt {
  font-family: var(--font-ui);
  font-weight: 700;
  margin-bottom: 0.2rem;
}

.goal-info-list dd {
  font-family: var(--font-ui);
  font-size: var(--step--1);
  line-height: 1.45;
  margin: 0;
}

/* Filter buttons — base (inactive) */
.filter-btn {
  font-family: var(--font-ui);
  font-size: var(--step--1);
  padding: 0.5rem 1rem;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--ink);
  cursor: pointer;
  transition: background 0.1s, color 0.1s;
  white-space: nowrap;
}

.filter-btn:hover {
  border-color: var(--accent);
  outline: 2px solid var(--accent);
  outline-offset: -2px;
}

/* Active / selected state — filled black */
.filter-btn.is-active {
  background: var(--ink);
  color: var(--bg);
  border-color: var(--ink);
}

/* Icon + label filter buttons */
.filter-btn--icon {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
}

.filter-btn--icon > svg {
  display: block;
  height: 1.4em;
  width: auto;
}

.filter-btn--icon.is-active {
  background: var(--bg);
  color: var(--ink);
  border-color: var(--accent);
  outline: 2px solid var(--accent);
  outline-offset: -2px;
}

/* Reset row */
.filter-reset-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 0.5rem;
}

.reset-btn {
  font-family: var(--font-ui);
  font-size: var(--step--1);
  padding: 0.35rem 0.8rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--ink);
  cursor: pointer;
  letter-spacing: 0.05em;
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.2s, visibility 0.2s;
}

.reset-btn.is-visible {
  visibility: visible;
  opacity: 1;
}

.reset-btn:hover {
  background: var(--ink);
  color: var(--bg);
}

.result-count {
  font-size: var(--step--1);
}

.result-count-hint {
  font-style: italic;
}

/* ── Resource grid ─────────────────────────────────────────── */

.resource-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(400px, 100%), 1fr));
  gap: 1.25rem;
  padding: var(--step--2) var(--step-2) var(--step-2);
  max-width: 1740px;
}

.resource-card {
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  background: var(--bg);
  display: grid;
  grid-row: span 5;
  grid-template-rows: subgrid;
}

.resource-card[hidden] {
  display: none;
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 0.5rem;
}

.card-header-right {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-shrink: 0;
}

.card-type {
  font-family: 'BasicallySans', sans-serif;
  font-size: var(--step--1);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.card-tag {
  font-family: var(--font-ui);
  font-size: var(--step--1);
  padding: 0.1rem 0.45rem;
  border-radius: 4px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  font-weight: bold;
  background: var(--ink);
  color: white;
}

.card-title {
  font-size: var(--step-1);
  font-weight: bold;
  line-height: 1.3;
  text-wrap: balance;
}

.card-title a:hover {
  text-decoration: underline;
}

.card-insight {
  font-size: var(--step-0);
  line-height: 1.55;
}

.card-readmore {
  align-self: start;
  justify-self: start;
  font-family: var(--font-ui);
  font-size: var(--step--1);
  font-weight: bold;
  color: var(--accent);
}

.card-readmore:hover {
  text-decoration: underline;
}

.card-footer {
  display: flex;
  flex-direction: row;
  justify-content: space-between;
  align-items: flex-end;
  align-self: end;
  gap: 0.5rem;
}

.card-footer-meta {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  align-items: flex-start;
}

.card-goals,
.card-langs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.goal-tag {
  font-family: var(--font-ui);
  font-size: var(--step--1);
  padding: 0.1rem 0.45rem;
  border: 1.5px solid var(--border);
  border-radius: 4px;
}

.lang-tag {
  font-family: var(--font-ui);
  font-size: var(--step--1);
  display: inline-flex;
  align-items: center;
  border: 1.5px solid var(--ink);
  border-radius: 3px;
  overflow: hidden;
  letter-spacing: 0.06em;
}

.lang-tag svg {
  display: block;
  height: 1.4em;
  width: auto;
}

/* Text fallback for languages without a flag icon */
.lang-tag:not(:has(svg)) {
  padding: 0.1rem 0.35rem;
}

/* Hide lang-tag when empty (e.g. multilingual) */
.lang-tag:empty {
  display: none;
}

/* ── Time investment icon ──────────────────────────────────── */

.time-icon {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
}

.time-icon svg {
  width: 1.2em;
  height: 1.2em;
}

.time-icon .arc-low,
.time-icon .arc-medium,
.time-icon .arc-high { display: none; }

.time-icon[data-level="low"]    .arc-low    { display: block; }
.time-icon[data-level="medium"] .arc-medium { display: block; }
.time-icon[data-level="high"]   .arc-high   { display: block; }

/* ── Resource single page ──────────────────────────────────── */

.resource-page {
  max-width: 760px;
  margin: 0 auto;
  padding: var(--step-2);
}

.breadcrumb {
  margin-bottom: 2rem;
  font-size: var(--step--1);
}

.breadcrumb a:hover {
  text-decoration: underline;
}

.resource-header {
  margin-bottom: 2.5rem;
}

.resource-header-meta {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  align-items: center;
  margin-bottom: 0.75rem;
}

.resource-title {
  font-size: var(--step-2);
  font-weight: bold;
  line-height: 1.25;
  margin-bottom: 1rem;
}

.resource-goals {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.resource-body {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.resource-section h2 {
  font-size: var(--step--2);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: 0.6rem;
}

.resource-section p {
  font-size: var(--step-0);
  line-height: 1.65;
}

.resource-meta-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem 3rem;
}

.resource-section--note {
  border: 2px solid var(--accent);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
}

.examples-list {
  margin-top: 0.75rem;
  padding-left: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.examples-list li {
  font-size: var(--step-0);
  line-height: 1.55;
}

.resource-footer {
  margin-top: 3rem;
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.resource-link-btn {
  display: inline-block;
  font-family: var(--font-ui);
  font-size: var(--step--1);
  padding: 0.6rem 1.4rem;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--ink);
  color: var(--bg);
  transition: background 0.1s, color 0.1s;
}

.resource-link-btn:hover {
  background: var(--bg);
  color: var(--ink);
}

.resource-link-btn--secondary {
  background: var(--bg);
  color: var(--ink);
}

.resource-link-btn--secondary:hover {
  background: var(--ink);
  color: var(--bg);
}


/* ── Save button ───────────────────────────────────────────── */

.save-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2em;
  height: 2em;
  border: 1.5px solid var(--ink);
  border-radius: 50%;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-ui);
  font-size: var(--step--1);
  line-height: 1;
  cursor: pointer;
  flex-shrink: 0;
  transition: background 0.1s, color 0.1s;
}

.save-btn:hover {
  background: var(--ink);
  color: var(--bg);
}

.save-btn.is-saved {
  background: var(--accent);
  color: var(--ink);
  border-color: var(--accent);
}

.save-btn--full {
  width: auto;
  height: auto;
  border-radius: var(--radius);
  padding: 0.6rem 1.2rem;
  gap: 0.5em;
  font-size: var(--step--1);
}

/* ── Learning path page ────────────────────────────────────── */

.lp-page {
  max-width: 760px;
  margin: 0 auto;
  padding: 2rem;
}

.lp-header {
  margin-bottom: 2rem;
}

.lp-title {
  font-size: var(--step-2);
}

.lp-count {
  font-family: var(--font-ui);
  font-size: var(--step--1);
  margin-top: 0.25rem;
}

.lp-section {
  margin-bottom: 2rem;
}

.lp-section-title {
  font-family: var(--font-ui);
  font-size: var(--step--1);
  font-weight: normal;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.75rem;
}

.lp-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.lp-list--done {
  opacity: 0.7;
}

.lp-item {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  border: 1.5px solid var(--ink);
  border-radius: var(--radius);
}

.lp-item.is-done .lp-item-name {
  text-decoration: line-through;
}

.lp-item-info {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.lp-item-type {
  font-family: var(--font-ui);
  font-size: var(--step--2);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.lp-item-name {
  font-size: var(--step-0);
  font-weight: bold;
}

.lp-item-name:hover {
  text-decoration: underline;
}

.lp-item-actions {
  display: flex;
  gap: 0.35rem;
  flex-shrink: 0;
}

/* Hide actions on hover-capable devices; show on hover */
@media (hover: hover) {
  .lp-item-actions {
    opacity: 0;
    transition: opacity 0.15s;
  }
  .lp-item:hover .lp-item-actions,
  .lp-item:focus-within .lp-item-actions {
    opacity: 1;
  }
}

.lp-btn {
  font-family: var(--font-ui);
  font-size: var(--step--1);
  width: 2em;
  height: 2em;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1.5px solid var(--ink);
  border-radius: 4px;
  background: var(--bg);
  color: var(--ink);
  cursor: pointer;
  transition: background 0.1s, color 0.1s;
}

.lp-btn:hover:not(:disabled) {
  background: var(--ink);
  color: var(--bg);
}

.lp-btn:disabled {
  cursor: not-allowed;
  border-color: currentColor;
  opacity: 0.25;
}

.lp-done-btn {
  align-self: center;
}

.lp-done-btn[aria-pressed="true"] {
  background: var(--ink);
  color: var(--bg);
}

/* Drag handle */
.lp-drag-handle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: none;
  background: none;
  padding: 0.4rem 0.2rem;
  color: var(--ink);
  cursor: grab;
  touch-action: none;
  flex-shrink: 0;
  align-self: center;
}

.lp-drag-handle:active,
.lp-item.is-dragging .lp-drag-handle {
  cursor: grabbing;
}

.lp-drag-handle svg {
  width: 0.75em;
  height: 1.125em;
  display: block;
}

.lp-item.is-dragging {
  opacity: 0.5;
}

.lp-empty {
  font-size: var(--step-0);
  line-height: 1.6;
}

.lp-empty a {
  text-decoration: underline;
}

/* ── Sticky learning-path bar ──────────────────────────────── */

.lp-bar {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: var(--step--2) var(--step-2);
  font-family: var(--font-ui);
  font-size: var(--step--1);
  background: var(--accent);
  color: var(--ink);
  text-decoration: none;
  border-top: 2px solid var(--ink);
}

.lp-bar[hidden] {
  display: none;
}

.lp-bar-text {
  letter-spacing: 0.02em;
}

.lp-bar-cta {
  font-weight: bold;
  white-space: nowrap;
}

.lp-bar:hover .lp-bar-cta,
.lp-bar:focus-visible .lp-bar-cta {
  text-decoration: underline;
}