:root {
  --bg: #f6fbf5;
  --surface: #ffffff;
  --text: #2f3e35;
  --muted: #5e7568;
  --primary: #7abf9b;
  --primary-deep: #4f9271;
  --accent: #8ed2df;
  --line: #d6eadf;
  --shadow: 0 14px 30px rgba(78, 121, 101, 0.14);
}

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

html,
body {
  margin: 0;
  padding: 0;
}

body {
  font-family: "Nunito", "Segoe UI", sans-serif;
  background: linear-gradient(180deg, #f3fbff 0%, var(--bg) 55%, #f9fff8 100%);
  color: var(--text);
  line-height: 1.6;
}

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

.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100dvh;
  padding: 1.2rem clamp(1rem, 3vw, 2.4rem) 2rem;
  display: grid;
  grid-template-rows: auto 1fr;
  align-items: center;
  overflow: hidden;
}

.hero-media {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-color: #f7fcf9;
  background-image: url("assets/spring_hero.png");
  background-size: cover;
  background-position: center;
  transform: scale(1.06);
  transform-origin: center;
  filter: brightness(1.38) saturate(0.74);
  -webkit-mask-image: radial-gradient(
    ellipse 105% 95% at 50% 44%,
    #000 22%,
    rgba(0, 0, 0, 0.72) 52%,
    transparent 88%
  );
  mask-image: radial-gradient(
    ellipse 105% 95% at 50% 44%,
    #000 22%,
    rgba(0, 0, 0, 0.72) 52%,
    transparent 88%
  );
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 15% 20%, rgba(142, 210, 223, 0.1), transparent 42%),
    radial-gradient(circle at 85% 85%, rgba(122, 191, 155, 0.18), transparent 40%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.2), rgba(255, 255, 255, 0.07));
  z-index: 1;
}

.top-nav,
.hero-content {
  position: relative;
  z-index: 3;
}

.top-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.brand {
  font-weight: 800;
  font-size: clamp(1.05rem, 2.4vw, 1.35rem);
  letter-spacing: 0.02em;
}

.nav-links {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.28rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.8);
}

.nav-links a {
  font-weight: 700;
  color: #446053;
  padding: 0.35rem 0.72rem;
  border-radius: 999px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.nav-links a:hover {
  background: var(--surface);
  color: var(--primary-deep);
}

.nav-links .studio-link {
  background: linear-gradient(130deg, rgba(122, 191, 155, 0.24) 0%, rgba(142, 210, 223, 0.24) 100%);
  color: #2f5d4a;
}

.nav-links .studio-link:hover {
  background: linear-gradient(130deg, rgba(122, 191, 155, 0.34) 0%, rgba(142, 210, 223, 0.34) 100%);
  color: #1f4937;
}

.lang-switcher {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: rgba(255, 255, 255, 0.8);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.25rem;
}

.lang-btn {
  border: none;
  background: transparent;
  color: var(--muted);
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
  padding: 0.38rem 0.68rem;
  border-radius: 999px;
  cursor: pointer;
}

.lang-btn.active {
  background: var(--surface);
  color: var(--primary-deep);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.08);
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(
      180deg,
      transparent 0%,
      transparent 56%,
      rgba(246, 251, 245, 0.55) 78%,
      var(--bg) 100%
    ),
    linear-gradient(
      180deg,
      rgba(249, 251, 250, 0.02),
      rgba(249, 251, 250, 0.02)
    );
  z-index: 2;
}

.hero-content {
  max-width: 680px;
  margin-top: clamp(1rem, 6vh, 5rem);
}

.eyebrow {
  display: inline-block;
  margin: 0 0 0.5rem;
  padding: 0.2rem 0.62rem;
  border-radius: 999px;
  background: rgba(122, 191, 155, 0.2);
  color: var(--primary-deep);
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-size: 0.8rem;
}

.hero .eyebrow {
  background: rgba(255, 255, 255, 0.82);
  border: 1px solid rgba(122, 191, 155, 0.42);
  color: #2d6a4d;
  text-shadow:
    0 0 6px rgba(252, 253, 252, 0.98),
    0 0 14px rgba(248, 252, 249, 0.88),
    0 0 24px rgba(248, 252, 249, 0.62),
    0 1px 0 rgba(255, 255, 255, 0.82),
    0 1px 3px rgba(38, 52, 44, 0.14);
}

.hero h1 {
  margin: 0;
  font-size: clamp(2rem, 6vw, 4rem);
  line-height: 1.1;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: #15251c;
  text-shadow:
    0 0 12px rgba(252, 253, 252, 0.98),
    0 0 28px rgba(248, 252, 249, 0.92),
    0 0 52px rgba(248, 252, 249, 0.68),
    0 2px 0 rgba(255, 255, 255, 0.85),
    0 2px 10px rgba(38, 52, 44, 0.18),
    0 3px 14px rgba(38, 52, 44, 0.1);
}

.hero .hero-subtitle {
  margin: 1.2rem 0 1.75rem;
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: #2a3d34;
  font-weight: 600;
  max-width: 58ch;
  line-height: 1.65;
  text-shadow:
    0 0 6px rgba(252, 253, 252, 0.97),
    0 0 16px rgba(248, 252, 249, 0.85),
    0 0 30px rgba(248, 252, 249, 0.58),
    0 1px 0 rgba(255, 255, 255, 0.75),
    0 1px 4px rgba(38, 52, 44, 0.16);
}

.subtitle-item,
.subtitle-sep {
  display: inline;
}

.hero .cta-btn {
  color: #071912;
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.42),
    0 0 18px rgba(252, 253, 252, 0.92),
    0 0 38px rgba(248, 252, 249, 0.52),
    var(--shadow);
}

.hero .cta-btn:hover {
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.48),
    0 0 22px rgba(252, 253, 252, 0.95),
    0 0 46px rgba(248, 252, 249, 0.58),
    0 16px 28px rgba(78, 121, 101, 0.22);
}

.subtitle-sep {
  white-space: nowrap;
}

.cta-btn {
  display: inline-block;
  background: linear-gradient(130deg, var(--primary) 0%, #89c8a9 100%);
  color: #113524;
  padding: 0.78rem 1.25rem;
  border-radius: 999px;
  font-weight: 800;
  box-shadow: var(--shadow);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.cta-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 16px 28px rgba(78, 121, 101, 0.22);
}

.section {
  width: min(1100px, calc(100% - 2rem));
  margin: 0 auto;
  padding: clamp(2.6rem, 6vw, 5rem) 0;
}

.core-intro {
  padding-top: clamp(2rem, 5vw, 3.4rem);
}

.core-intro-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 1rem;
}

.core-intro-card {
  grid-column: span 4;
  background: rgba(255, 255, 255, 0.82);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 1rem 1rem 1.1rem;
  box-shadow: var(--shadow);
}

.core-intro-card h3 {
  margin: 0 0 0.4rem;
}

.core-intro-card p {
  margin: 0;
  color: #496052;
}

.section-heading {
  margin-bottom: 1.4rem;
}

.section h2 {
  margin: 0 0 0.4rem;
  font-size: clamp(1.5rem, 4vw, 2.2rem);
}

.section-heading p {
  margin: 0;
  color: var(--muted);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 1rem;
}

.feature-card {
  grid-column: span 6;
  background: rgba(255, 255, 255, 0.8);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 1rem 1rem 1.1rem;
  box-shadow: var(--shadow);
}

.feature-card h3 {
  margin: 0 0 0.4rem;
}

.feature-card p {
  margin: 0;
  color: #496052;
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.gallery-item {
  margin: 0;
  min-height: 180px;
  border: 2px dashed #b9ddd0;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.7);
  display: grid;
  place-items: center;
  color: var(--muted);
  font-weight: 700;
  text-align: center;
  padding: 0.8rem;
  cursor: pointer;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.gallery-item:hover,
.gallery-item:focus-visible {
  transform: translateY(-2px);
  border-color: var(--primary);
  outline: none;
}

.lightbox {
  position: fixed;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 40;
}

.lightbox.is-open {
  display: flex;
}

.lightbox-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(16, 32, 26, 0.7);
}

.lightbox-panel {
  position: relative;
  z-index: 1;
  width: min(900px, calc(100% - 2rem));
  background: rgba(255, 255, 255, 0.97);
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: var(--shadow);
  padding: 0.8rem;
}

.lightbox-close {
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--primary-deep);
  border-radius: 999px;
  font-weight: 800;
  padding: 0.35rem 0.8rem;
  cursor: pointer;
  margin: 0 0 0.5rem auto;
  display: block;
}

.lightbox-image {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 12px;
  border: 1px solid var(--line);
}

.lightbox-caption {
  margin: 0.65rem 0 0.2rem;
  color: #3f584b;
  font-weight: 700;
}

.devlog-list {
  background: rgba(255, 255, 255, 0.84);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 1rem 1.2rem;
  box-shadow: var(--shadow);
  margin: 0;
  color: #496052;
}

.devlog-list li + li {
  margin-top: 0.7rem;
}

.devlog-preview-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.devlog-preview-card {
  background: rgba(255, 255, 255, 0.86);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 1rem;
}

.devlog-preview-date {
  margin: 0 0 0.4rem;
  color: var(--primary-deep);
  font-weight: 800;
  font-size: 0.9rem;
}

.devlog-preview-card h3 {
  margin: 0 0 0.45rem;
  font-size: 1.04rem;
}

.devlog-preview-card p {
  margin: 0;
  color: #496052;
}

.devlog-preview-card a {
  display: inline-block;
  margin-top: 0.8rem;
  font-weight: 800;
  color: var(--primary-deep);
}

.devlog-more-link {
  display: inline-block;
  margin-top: 1rem;
  font-weight: 800;
  color: var(--primary-deep);
}

.blog-body {
  min-height: 100vh;
}

.blog-nav {
  width: min(1100px, calc(100% - 2rem));
  margin: 1rem auto 0;
}

.blog-main {
  width: min(860px, calc(100% - 2rem));
  margin: 0 auto;
  padding: clamp(2rem, 5vw, 4rem) 0;
}

.blog-header {
  margin-bottom: 1.4rem;
}

.blog-header h1 {
  margin: 0 0 0.4rem;
  font-size: clamp(1.8rem, 4vw, 2.7rem);
}

.blog-header p {
  margin: 0;
  color: var(--muted);
}

.blog-list {
  display: grid;
  gap: 1rem;
}

.blog-timeline-layout {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 1rem;
  align-items: start;
}

.blog-timeline {
  position: sticky;
  top: 1rem;
  background: rgba(255, 255, 255, 0.88);
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: var(--shadow);
  padding: 1rem;
}

.blog-timeline h2 {
  margin: 0 0 0.6rem;
  font-size: 1rem;
}

.blog-timeline ul {
  margin: 0;
  padding: 0;
  list-style: none;
  border-left: 2px solid #b9ddd0;
}

.blog-timeline li {
  margin: 0;
  padding: 0.35rem 0 0.35rem 0.8rem;
  position: relative;
}

.blog-timeline li::before {
  content: "";
  position: absolute;
  left: -0.37rem;
  top: 0.9rem;
  width: 0.55rem;
  height: 0.55rem;
  border-radius: 999px;
  background: var(--primary);
  border: 2px solid #fff;
}

.blog-timeline a {
  font-weight: 700;
  color: #446053;
}

.blog-post {
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 1rem 1.1rem;
  scroll-margin-top: 1rem;
}

.blog-post time {
  color: var(--primary-deep);
  font-weight: 800;
}

/* Dev log multilingual blocks switch with <html lang="..."> (see script.js setLanguage). */
.devlog-lang {
  display: none;
}

html[lang="zh-CN"] .devlog-lang[data-devlog-lang="zh"],
html[lang="en"] .devlog-lang[data-devlog-lang="en"],
html[lang="fr"] .devlog-lang[data-devlog-lang="fr"] {
  display: block;
}

.blog-post h2 {
  margin: 0.3rem 0 0.6rem;
}

.blog-post p {
  margin: 0;
  color: #496052;
}

.blog-back {
  display: inline-block;
  margin-top: 1.2rem;
  font-weight: 800;
  color: var(--primary-deep);
}

.site-footer {
  border-top: 1px solid var(--line);
  width: min(1100px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 1.4rem 0 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--muted);
  gap: 1rem;
}

.site-footer a {
  font-weight: 700;
}

.footer-links {
  display: inline-flex;
  align-items: center;
  gap: 0.9rem;
  flex-wrap: wrap;
}

.footer-links a:first-child {
  color: var(--primary-deep);
}

@media (max-width: 900px) {
  .hero {
    padding-bottom: 1rem;
  }

  .hero-content {
    margin-top: 2.2rem;
  }

  .feature-card {
    grid-column: span 12;
  }

  .core-intro-card {
    grid-column: span 12;
  }

  .gallery-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .devlog-preview-list {
    grid-template-columns: 1fr;
  }

  .blog-timeline-layout {
    grid-template-columns: 1fr;
  }

  .blog-timeline {
    position: static;
  }

  .top-nav {
    justify-content: center;
  }
}

@media (max-width: 640px) {
  .nav-links,
  .lang-switcher {
    width: 100%;
    justify-content: center;
  }

  .gallery-grid {
    grid-template-columns: 1fr;
  }

  .site-footer {
    flex-direction: column;
    align-items: flex-start;
  }
}