@import url("https://cdn.jsdelivr.net/npm/@fontsource/noto-serif-sc@5.2.9/500.css");
@import url("https://cdn.jsdelivr.net/npm/@fontsource/noto-serif-sc@5.2.9/600.css");
@import url("https://cdn.jsdelivr.net/npm/@fontsource/noto-serif-sc@5.2.9/800.css");

:root {
  --font-text:
    "Noto Serif SC", "Source Han Serif SC", "Source Han Serif SC VF",
    "Noto Serif CJK SC", "Songti SC", STSong, SimSun, serif;
  --font-code: Consolas, "Liberation Mono", Menlo, monospace;

  --color-text-prime: rgb(0, 0, 0);
  --color-text-high: rgb(175, 175, 175);
  --color-text-max: rgb(255, 255, 255);

  --color-background: rgb(0, 0, 0);

  --color-card-prime: rgb(20, 20, 20);
  --color-card-mid: rgb(40, 40, 40);
  --color-card-high: rgb(60, 60, 60);
  --color-card-max: rgb(255, 255, 255);

  --border-card: 1px solid var(--color-line);
  --radius-card: calc(var(--radius) + 4px);

  --color-line: rgba(80, 80, 80);

  --container: 1200px;
  --content-readable: 620px;
  --content-wide: 760px;
  --glow: rgba(255, 255, 255, 0.2);
  --line-strong: rgba(255, 255, 255, 0.2);
  --motion-fast: 0.18s ease;
  --motion-medium: 0.28s ease;

  --panel: rgb(15, 15, 15);
  --panel-soft: rgb(20, 20, 20);
  --radius: 10px;
  --radius-panel: calc(var(--radius) + 6px);
  --radius-pill: 999px;
  --shadow: 0 30px 110px rgba(0, 0, 0, 0.5);
  --space-card: 24px;
  --space-card-compact: 22px;
}

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

html {
  min-height: 100%;
  overflow-x: hidden;
  background: var(--color-background);
  scroll-behavior: smooth;

  &.is-page-loading {
    background: #000;

    & body {
      visibility: hidden;
      opacity: 0;
      transition: opacity 0.42s ease;
    }
  }

  &.is-page-ready {
    & body {
      visibility: visible;
      opacity: 1;
      transition: opacity 0.42s ease;
    }
  }

  @media (prefers-reduced-motion: reduce) {
    scroll-behavior: auto;

    &.is-page-loading body,
    &.is-page-ready body {
      transition: none;
    }

  }
}

body {
  min-height: 100%;
  overflow-x: hidden;
  color: var(--color-text-max);
  background: var(--color-background);
  font-family: var(--font-text), serif;
  font-weight: 500;
}

main {
  width: min(var(--container), calc(100% - 40px));
  margin: 0 auto;
  padding: 96px 0 24px;

  @media (width < 800px) {
    width: min(100% - 28px, var(--container));
    padding-top: 84px;
  }
}

header {
  position: fixed;
  top: 14px;
  left: 50%;
  z-index: 40;
  width: min(var(--container), calc(100% - 40px));
  transform: translateX(-50%);

  & > section {
    position: relative;

    & > .desk {
      display: flex;
      gap: 18px;
      align-items: center;
      justify-content: space-between;
      min-height: 58px;
      padding: 8px;
      border: 1px solid var(--color-line);
      border-radius: var(--radius-panel);
      background: var(--color-card-prime);
      backdrop-filter: blur(18px);

      & > figure {
        display: flex;
        gap: 10px;
        align-items: center;
        padding: 0 10px;

        & > img {
          display: inline-flex;
          align-items: center;
          justify-content: center;
          width: 34px;
          height: 34px;
          border-radius: var(--radius);
          font-size: 0.78rem;
          font-weight: 800;
          letter-spacing: 0;
          color: var(--color-text-prime);
          background: var(--color-card-max);
        }

        & > span {
          font-size: 0.94rem;
          font-weight: 600;
          letter-spacing: 0;
          color: var(--color-text-max);
        }
      }

      & > nav {
        display: flex;
        gap: 4px;
        align-items: center;
        padding: 3px;
        border: 1px solid var(--color-line);
        border-radius: var(--radius-pill);
        background: var(--color-card-mid);

        & > a {
          display: inline-flex;
          align-items: center;
          min-height: 34px;
          padding: 0 14px;
          border-radius: var(--radius-pill);
          font-size: 0.92rem;
          font-weight: 600;
          white-space: nowrap;
          color: var(--color-text-high);

          &:hover {
            color: var(--color-text-max);
            background: var(--color-card-high);
          }
        }

        @media (width < 800px) {
          display: none;
        }
      }

      & > .nav-action {
        display: flex;
        gap: 8px;
        align-items: center;

        & > .lang {
          position: relative;
          display: flex;
          align-items: center;

          & > .lang-toggle {
            min-width: 100px;
            height: 36px;
            padding: 0 12px;
            border: 1px solid var(--color-line);
            border-radius: var(--radius);
            font-size: 0.84rem;
            font-weight: 800;
            text-align: center;
            color: var(--color-text-high);
            background: var(--color-card-mid);
            cursor: pointer;

            &:hover {
              color: var(--color-text-max);
              background: var(--color-card-high);
            }
          }

          & > .lang-dropdown {
            position: absolute;
            top: calc(100% + 8px);
            right: 0;
            display: grid;
            visibility: hidden;
            gap: 4px;
            min-width: 132px;
            padding: 6px;
            border: 1px solid var(--color-line);
            border-radius: var(--radius);
            background: var(--color-card-prime);
            opacity: 0;
            transform: translateY(-6px);
            transition:
              opacity var(--motion-fast),
              transform var(--motion-fast),
              visibility 0s 0.18s;
            pointer-events: none;

            & > .lang-btn {
              width: 100%;
              min-height: 32px;
              padding: 0 10px;
              border: 1px solid transparent;
              border-radius: 7px;
              font-size: 0.84rem;
              font-weight: 600;
              text-align: left;
              color: var(--color-text-max);
              background: transparent;
              cursor: pointer;

              &:hover {
                background: var(--color-card-mid);
              }

              &.is-active {
                border-color: var(--color-card-max);
                color: var(--color-text-prime);
                background: var(--color-card-max);
              }
            }
          }

          &.is-open > .lang-dropdown {
            visibility: visible;
            opacity: 1;
            transform: translateY(0);
            transition:
              opacity var(--motion-fast),
              transform var(--motion-fast);
            pointer-events: auto;
          }
        }

        & > .header-cta {
          display: inline-flex;
          align-items: center;
          justify-content: center;
          min-width: 108px;
          min-height: 34px;
          padding: 0 14px;
          border-radius: var(--radius);
          font-size: 0.94rem;
          font-weight: 800;
          color: var(--color-text-prime);
          background: var(--color-card-max);
          transition:
            opacity 0.72s cubic-bezier(0.22, 1, 0.36, 1),
            transform var(--motion-fast),
            background var(--motion-fast),
            border-color var(--motion-fast);

          &:hover {
            transform: translateY(-4px);
          }
        }

        & > .menu-toggle {
          display: none;
          flex-direction: column;
          gap: 4px;
          align-items: center;
          justify-content: center;
          width: 38px;
          height: 38px;
          padding: 0;
          border: 1px solid var(--color-line);
          border-radius: var(--radius);
          background: rgba(255, 255, 255, 0.06);
          cursor: pointer;

          & > span {
            display: block;
            width: 16px;
            height: 2px;
            margin: 0;
            border-radius: var(--radius-pill);
            background: var(--color-card-max);
            transform-origin: center;
            transition:
              opacity 0.2s ease,
              transform 0.2s ease;
          }

          &.is-active > span {
            &:first-child {
              transform: translateY(6px) rotate(45deg);
            }

            &:last-child {
              transform: translateY(-6px) rotate(-45deg);
            }

            &:nth-child(2) {
              opacity: 0;
            }
          }
        }
      }
    }

    & > .mobile {
      position: absolute;
      top: calc(100% + 10px);
      right: 0;
      left: 0;
      display: grid;
      visibility: hidden;
      gap: 6px;
      padding: 8px;
      border: 1px solid var(--color-line);
      border-radius: var(--radius-panel);
      background: rgba(12, 12, 12, 0.96);
      box-shadow: 0 16px 48px rgba(0, 0, 0, 0.08);
      opacity: 0;
      transform: translateY(-8px);
      transition:
        opacity var(--motion-fast),
        transform var(--motion-fast),
        visibility 0s 0.18s;
      pointer-events: none;

      &.is-open {
        visibility: visible;
        opacity: 1;
        transform: translateY(0);
        transition:
          opacity var(--motion-fast),
          transform var(--motion-fast);
        pointer-events: auto;
      }

      & a {
        display: flex;
        align-items: center;
        min-height: 44px;
        padding: 0 12px;
        border-radius: var(--radius);
        font-size: 0.92rem;
        font-weight: 800;
        color: rgb(215, 215, 215);

        &:hover {
          background: rgba(255, 255, 255, 0.08);
        }
      }

      & > strong > .is-strong {
        border-radius: var(--radius);
        color: var(--color-text-prime);
        background: var(--color-card-max);
      }
    }
  }

  @media (width < 800px) {
    top: 10px;
    width: min(100% - 28px, var(--container));

    & > section {
      padding: 0;
    }

    & > section > .desk > .nav-action > .header-cta {
      display: none;
    }

    & > section > .desk > .nav-action > .menu-toggle {
      display: flex;
    }
  }
}

footer {
  --footer-content-gap: clamp(20px, 2.4vw, 40px);
  --footer-content-width: min(1340px, calc(100% - 44px));
  --footer-glow-height: 320px;
  --footer-icon-size: 16px;
  --footer-logo-stage-h: clamp(210px, 24vw, 280px);
  --footer-logo-w: min(920px, 76vw);
  --footer-social-size: 34px;
  position: relative;
  z-index: 0;
  width: 100%;
  overflow: hidden;
  margin: 56px 0 0;
  padding: 0 0 58px;
  color: var(--color-text-high);
  background: transparent;

  &::before {
    content: "";
    position: absolute;
    top: var(--footer-logo-stage-h);
    right: 0;
    left: 0;
    z-index: 0;
    height: var(--footer-glow-height);
    background:
      radial-gradient(
        ellipse at 50% 0%,
        rgba(255, 255, 255, 0.16) 0%,
        rgba(255, 255, 255, 0.11) 12%,
        rgba(255, 255, 255, 0.065) 30%,
        rgba(255, 255, 255, 0.025) 52%,
        transparent 74%
      ),
      radial-gradient(
        ellipse at 24% 12%,
        rgba(255, 255, 255, 0.035) 0%,
        transparent 48%
      ),
      radial-gradient(
        ellipse at 76% 12%,
        rgba(255, 255, 255, 0.035) 0%,
        transparent 48%
      );
    opacity: 0.72;
    pointer-events: none;
  }

  & > #footer {
    position: relative;
    z-index: 1;

    & > figure {
      height: var(--footer-logo-stage-h);
      overflow: visible;
      pointer-events: none;

      & > img {
        position: absolute;
        bottom: -8px;
        left: 50%;
        z-index: 1;
        width: var(--footer-logo-w);
        max-width: none;
        height: auto;
        opacity: 1;
        filter: brightness(0) invert(1) opacity(0.11);
        transform: translateX(-50%);
        pointer-events: none;
        user-select: none;
      }
    }

    & > .divider {
      position: absolute;
      right: 8px;
      top: calc(var(--footer-logo-stage-h) - 1px);
      left: 8px;
      z-index: 2;
      height: 0;
      border-top: 1px solid transparent;
      pointer-events: none;
      border-image: linear-gradient(
        90deg,
        rgba(255, 255, 255, 0.05) 0%,
        rgba(255, 255, 255, 0.2) 12%,
        rgba(255, 255, 255, 0.3) 28%,
        rgba(255, 255, 255, 0.6) 40%,
        rgba(255, 255, 255, 0.9) 50%,
        rgba(255, 255, 255, 0.6) 60%,
        rgba(255, 255, 255, 0.3) 72%,
        rgba(255, 255, 255, 0.2) 88%,
        rgba(255, 255, 255, 0.05) 100%
      ) 1;
    }
  }

  & > section {
    position: relative;
    z-index: 2;
    display: grid;
    grid-template-columns: minmax(220px, 250px) minmax(0, 1fr);
    gap: var(--footer-content-gap);
    width: var(--footer-content-width);
    margin: 0 auto;
    padding-top: 26px;

    & > * {
      position: relative;
      z-index: 1;
    }

    & > .footer-identity {
      display: flex;
      flex-direction: column;
      gap: 16px;
      align-items: flex-start;

      & > .footer-socials {
        display: flex;
        gap: 10px;

        & > a {
          display: inline-flex;
          align-items: center;
          justify-content: center;
          width: var(--footer-social-size);
          height: var(--footer-social-size);
          border: 1px solid rgba(255, 255, 255, 0.12);
          border-radius: var(--radius-pill);
          font-size: 0.8rem;
          font-weight: 800;
          color: var(--color-text-max);
          background: rgba(255, 255, 255, 0.032);
          transition:
            background var(--motion-fast),
            border-color var(--motion-fast),
            transform var(--motion-fast);

          &:hover {
            border-color: rgba(255, 255, 255, 0.28);
            background: rgba(255, 255, 255, 0.09);
            transform: translateY(-1px);
          }
        }

        & > a > img {
          display: block;
          width: var(--footer-icon-size);
          height: var(--footer-icon-size);
        }
      }

      & > p {
        max-width: 24ch;
        font-size: 0.86rem;
        line-height: 1.64;
      }

      & > strong {
        font-size: 0.98rem;
        font-weight: 600;
        color: var(--color-text-max);
      }
    }

    & > .footer-nav {
      display: grid;
      grid-template-columns: repeat(4, minmax(0, 1fr));
      gap: clamp(14px, 3vw, 60px);

      & > .footer-link-group {
        display: flex;
        flex-direction: column;
        gap: 14px;
        align-items: flex-start;

        &:nth-child(2) {
          margin-left: -40px;
        }

        & > a {
          font-size: 0.9rem;
          font-weight: 500;
          line-height: 1.25;
          color: var(--color-text-high);
          transition:
            color var(--motion-fast),
            transform var(--motion-fast);

          &:hover {
            color: var(--color-text-max);
            transform: translateX(2px);
          }
        }

        & > h3 {
          font-size: 0.95rem;
          font-weight: 600;
          color: var(--color-text-max);
        }
      }
    }
  }

  @media (width < 800px) {
    --footer-logo-stage-h: clamp(110px, 31vw, 160px);
    --footer-logo-w: min(760px, 88vw);
    margin-top: 48px;

    & > section {
      grid-template-columns: 1fr;
      gap: 12px;
      padding-top: 30px;

      & > .footer-identity {
        align-items: center;
        text-align: center;

        & > p {
          max-width: 42ch;
        }
      }

      & > .footer-nav {
        grid-template-areas:
          "sections apps"
          "projects more";
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 24px 10px;

        & > .footer-link-group {
          align-items: flex-start;
          min-width: 0;
          text-align: left;

          &:nth-child(1) {
            grid-area: sections;
          }

          &:nth-child(2) {
            grid-area: projects;
            margin-left: 0;
          }

          &:nth-child(3) {
            grid-area: apps;
          }

          &:nth-child(4) {
            grid-area: more;
          }

          &:nth-child(3),
          &:nth-child(4) {
            justify-self: end;
            align-items: flex-end;
            text-align: right;
          }
        }
      }
    }
  }
}

section {
  padding: 2px 0 32px;

  @media (width < 800px) {
    padding-top: 64px;
  }
}

button {
  border: 0;
  font: inherit;
}

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

.primary-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 108px;
  min-height: 46px;
  padding: 0 18px;
  border-radius: var(--radius);
  font-size: 0.94rem;
  font-weight: 800;
  transition:
    opacity 0.72s cubic-bezier(0.22, 1, 0.36, 1),
    transform var(--motion-fast),
    background var(--motion-fast),
    border-color var(--motion-fast);
  color: var(--color-text-prime);
  background: var(--color-card-max);

  &:hover {
    transform: translateY(-4px);
  }
}

.secondary-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 108px;
  min-height: 46px;
  padding: 0 18px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  font-size: 0.94rem;
  font-weight: 800;
  color: var(--color-text-max);
  background: var(--color-card-prime);
  transition:
    opacity 0.72s cubic-bezier(0.22, 1, 0.36, 1),
    transform var(--motion-fast),
    background var(--motion-fast),
    border-color var(--motion-fast);

  &:hover {
    transform: translateY(-4px);
  }
}

#hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, var(--section-hero-aside, 0.82fr));
  gap: 28px;
  align-items: stretch;
  padding: 74px 0 48px;

  & .hero-kicker {
    font-size: 1.28rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--color-text-high);
  }

  & .hero-title {
    max-width: 10ch;
    margin-top: 12px;
    font-size: clamp(2.6rem, 4.2vw, 4.6rem);
    font-weight: 800;
    line-height: 1.2;
    color: var(--color-text-max);
  }

  & .hero-desc {
    max-width: var(--content-readable);
    margin-top: 18px;
    font-size: 1rem;
    line-height: 1.76;
    color: var(--color-text-high);
  }

  & .hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 24px;
  }

  @media (width < 800px) {
    grid-template-columns: 1fr;
    gap: 20px;
    padding: 44px 0 34px;

    & .hero-actions,
    & .primary-btn,
    & .secondary-btn {
      width: 100%;
    }

    & .hero-desc {
      font-size: 0.98rem;
    }

    & .hero-title {
      max-width: 9ch;
      font-size: 2.45rem;
    }
  }
}

#title {
  max-width: 1024px;
  margin: 88px 128px 24px;
  text-align: center;

  & .kicker {
    font-size: 1.28rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--color-text-high);
  }

  & .title {
    margin-top: 8px;
    font-size: clamp(1.8rem, 3.6vw, 2.8rem);
    font-weight: 800;
    line-height: 1.08;
    color: var(--color-text-max);
  }

  & .description {
    max-width: 1440px;
    margin-top: 12px;
    font-size: 1.12rem;
    line-height: 1.75;
    color: var(--color-text-high);
  }

  @media (width < 800px) {
    max-width: 1024px;
    margin: 88px 0 24px;
  }
}