:root {
  color-scheme: light;
  --paper: #f7f3ea;
  --paper-strong: #fffaf0;
  --ink: #1d2624;
  --muted: #5e6a66;
  --line: rgba(44, 56, 52, 0.14);
  --cyan: #2fb8c1;
  --green: #5d9f66;
  --amber: #e7a044;
  --coral: #c96f5a;
  --white: #ffffff;
  --shadow: 0 24px 70px rgba(53, 72, 65, 0.14);
  --header-height: 72px;
  font-family:
    Inter,
    ui-sans-serif,
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    "PingFang SC",
    "Hiragino Sans GB",
    "Microsoft YaHei",
    sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  min-width: 320px;
}

body.menu-open {
  overflow: hidden;
}

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

button,
input,
select,
textarea {
  font: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  height: var(--header-height);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 24px;
  padding: 0 clamp(18px, 4vw, 56px);
  background: rgba(247, 243, 234, 0.82);
  border-bottom: 1px solid rgba(44, 56, 52, 0.08);
  backdrop-filter: blur(20px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  width: max-content;
  font-weight: 720;
  letter-spacing: 0;
}

.brand-mark {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background:
    radial-gradient(
      circle at 58% 48%,
      transparent 0 25%,
      var(--paper) 26% 38%,
      transparent 39%
    ),
    conic-gradient(
      from 20deg,
      var(--cyan),
      var(--green),
      var(--amber),
      var(--coral),
      var(--cyan)
    );
  box-shadow: 0 10px 26px rgba(47, 184, 193, 0.25);
}

.primary-nav {
  display: inline-flex;
  align-items: center;
  gap: clamp(18px, 2.4vw, 34px);
  color: rgba(29, 38, 36, 0.72);
  font-size: 0.95rem;
}

.primary-nav a,
.mobile-nav a {
  transition:
    color 160ms ease,
    transform 160ms ease;
}

.primary-nav a:hover,
.mobile-nav a:hover {
  color: var(--ink);
}

.header-controls {
  justify-self: end;
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.header-action {
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 18px;
  border: 1px solid rgba(29, 38, 36, 0.18);
  border-radius: 999px;
  color: var(--ink);
  background: rgba(255, 255, 255, 0.48);
  font-size: 0.92rem;
}

.language-menu {
  position: relative;
}

.language-trigger {
  min-width: 58px;
  height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  border: 1px solid rgba(29, 38, 36, 0.16);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.52);
  color: #1f3935;
  cursor: pointer;
  font-size: 0.84rem;
  font-weight: 760;
}

.language-trigger[aria-expanded="true"] {
  background: #fffaf0;
  box-shadow: 0 12px 28px rgba(53, 72, 65, 0.12);
}

.language-chevron {
  width: 7px;
  height: 7px;
  border-right: 1.6px solid currentColor;
  border-bottom: 1.6px solid currentColor;
  transform: translateY(-2px) rotate(45deg);
}

.language-options {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 132px;
  padding: 6px;
  border: 1px solid rgba(29, 38, 36, 0.12);
  border-radius: 8px;
  background: rgba(255, 250, 240, 0.98);
  box-shadow: var(--shadow);
}

.language-options button {
  width: 100%;
  min-height: 36px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  padding: 0 10px;
  font-size: 0.9rem;
}

.language-options button:hover,
.language-options button[aria-pressed="true"] {
  background: rgba(31, 57, 53, 0.08);
}

.menu-toggle {
  display: none;
  justify-self: end;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(29, 38, 36, 0.16);
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.56);
  color: var(--ink);
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 5px auto;
  background: currentColor;
  transform-origin: center;
  transition: transform 180ms ease;
}

.menu-open .menu-toggle span:first-child {
  transform: translateY(3.5px) rotate(45deg);
}

.menu-open .menu-toggle span:last-child {
  transform: translateY(-3.5px) rotate(-45deg);
}

.mobile-nav {
  position: fixed;
  inset: var(--header-height) 12px auto;
  z-index: 29;
  display: none;
  grid-template-columns: 1fr;
  gap: 6px;
  padding: 14px;
  background: rgba(255, 250, 240, 0.96);
  border: 1px solid rgba(44, 56, 52, 0.12);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.mobile-nav a {
  min-height: 44px;
  display: flex;
  align-items: center;
  padding: 0 10px;
  color: var(--muted);
}

.hero {
  position: relative;
  min-height: clamp(620px, 78svh, 820px);
  overflow: hidden;
  border-bottom: 1px solid rgba(44, 56, 52, 0.08);
}

.hero-backdrop {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(
      90deg,
      rgba(247, 243, 234, 0.98) 0%,
      rgba(247, 243, 234, 0.84) 33%,
      rgba(247, 243, 234, 0.1) 68%
    ),
    url("assets/photonseed-hero.png") center / cover no-repeat;
  transform: scale(1.01);
}

.hero-content {
  position: relative;
  z-index: 1;
  width: min(1120px, calc(100% - 36px));
  min-height: inherit;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
  padding: clamp(42px, 8vw, 86px) 0 clamp(54px, 8vw, 94px);
}

.eyebrow,
.section-kicker {
  margin: 0 0 16px;
  color: var(--green);
  font-size: 0.78rem;
  font-weight: 760;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 720px;
  margin-bottom: 18px;
  font-size: clamp(4.25rem, 15vw, 11rem);
  line-height: 0.9;
  letter-spacing: 0;
}

.hero-lede {
  max-width: 690px;
  margin-bottom: 16px;
  font-size: clamp(1.45rem, 3.4vw, 3.35rem);
  line-height: 1.08;
  font-weight: 720;
  letter-spacing: 0;
}

.hero-copy {
  max-width: 620px;
  margin-bottom: 34px;
  color: var(--muted);
  font-size: clamp(1.02rem, 1.6vw, 1.24rem);
  line-height: 1.76;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: clamp(46px, 7vw, 78px);
}

.button {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 0 20px;
  border: 1px solid transparent;
  border-radius: 999px;
  cursor: pointer;
  font-weight: 680;
  letter-spacing: 0;
  transition:
    transform 160ms ease,
    box-shadow 160ms ease,
    background 160ms ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button[disabled] {
  cursor: wait;
  opacity: 0.72;
  transform: none;
}

.button-primary {
  color: #fffaf0;
  background: #1f3935;
  box-shadow: 0 16px 34px rgba(31, 57, 53, 0.22);
}

.button-primary:hover {
  background: #274842;
}

.button-secondary {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.62);
  border-color: rgba(29, 38, 36, 0.16);
}

.hero-signals {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 150px));
  gap: 18px;
  margin: 0;
}

.hero-signals div {
  border-top: 1px solid rgba(29, 38, 36, 0.18);
  padding-top: 12px;
}

.hero-signals dt {
  color: var(--ink);
  font-weight: 760;
}

.hero-signals dd {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 0.94rem;
}

.section {
  padding: clamp(72px, 10vw, 132px) 0;
}

.section-inner {
  width: min(1120px, calc(100% - 36px));
  margin: 0 auto;
}

.intro-section {
  background: var(--paper-strong);
}

.intro-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 0.72fr);
  gap: clamp(28px, 7vw, 96px);
  align-items: end;
}

h2 {
  font-size: clamp(2rem, 5vw, 4.85rem);
  line-height: 1.02;
  letter-spacing: 0;
}

.intro-grid p:last-child,
.section-heading p,
.surface-copy p,
.access-inner p {
  color: var(--muted);
  font-size: 1.06rem;
  line-height: 1.78;
}

.section-heading {
  max-width: 760px;
  margin-bottom: clamp(32px, 5vw, 56px);
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.tool-card {
  min-height: 300px;
  padding: 24px;
  border: 1px solid rgba(44, 56, 52, 0.12);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.56);
  box-shadow: 0 14px 50px rgba(53, 72, 65, 0.08);
}

.tool-card h3 {
  margin: 22px 0 12px;
  font-size: 1.14rem;
}

.tool-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}

.tool-icon {
  width: 54px;
  height: 54px;
  display: inline-block;
  border-radius: 50%;
  background: var(--cyan);
  position: relative;
}

.tool-icon::before,
.tool-icon::after {
  content: "";
  position: absolute;
  inset: 14px;
  border: 2px solid rgba(255, 255, 255, 0.82);
  border-radius: 50%;
}

.tool-icon::after {
  inset: 23px 12px 12px 23px;
  border-width: 0;
  background: rgba(255, 255, 255, 0.88);
}

.tool-icon-calm {
  background: var(--cyan);
}

.tool-icon-memory {
  background: var(--green);
}

.tool-icon-create {
  background: var(--amber);
}

.tool-icon-flow {
  background: var(--coral);
}

.surfaces-section {
  background: #edf5f1;
}

.surfaces-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 0.75fr);
  gap: clamp(34px, 8vw, 108px);
  align-items: center;
}

.surface-list {
  display: grid;
  gap: 12px;
}

.surface-item {
  display: grid;
  grid-template-columns: 76px 1fr;
  align-items: center;
  gap: 18px;
  padding: 22px;
  border: 1px solid rgba(44, 56, 52, 0.12);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.58);
}

.surface-item span {
  width: 58px;
  height: 58px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  color: #fffaf0;
  background: #1f3935;
  font-weight: 740;
}

.surface-item strong {
  font-size: clamp(1.2rem, 2vw, 1.65rem);
}

.principles-section {
  background: var(--paper);
}

.principle-list {
  display: grid;
  border-top: 1px solid var(--line);
}

.principle-item {
  display: grid;
  grid-template-columns: 80px minmax(180px, 0.42fr) minmax(0, 1fr);
  gap: 28px;
  padding: 28px 0;
  border-bottom: 1px solid var(--line);
  align-items: baseline;
}

.principle-item span {
  color: var(--amber);
  font-weight: 760;
}

.principle-item h3 {
  margin: 0;
  font-size: clamp(1.2rem, 2vw, 1.55rem);
}

.principle-item p {
  margin: 0;
  color: var(--muted);
  line-height: 1.72;
}

.access-section {
  padding: clamp(72px, 10vw, 128px) 0;
  background: #1f3935;
  color: #fffaf0;
}

.access-inner {
  width: min(1120px, calc(100% - 36px));
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 0.68fr);
  gap: clamp(34px, 8vw, 96px);
  align-items: start;
}

.access-section .section-kicker {
  color: #8bd3ca;
}

.access-inner p {
  color: rgba(255, 250, 240, 0.72);
}

.access-form {
  display: grid;
  gap: 14px;
}

.honeypot-field {
  position: absolute;
  left: -100vw;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

.access-form label {
  display: grid;
  gap: 8px;
}

.access-form label span {
  color: rgba(255, 250, 240, 0.72);
  font-size: 0.88rem;
}

.access-form input,
.access-form select,
.access-form textarea {
  width: 100%;
  border: 1px solid rgba(255, 250, 240, 0.18);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
  color: #fffaf0;
  padding: 13px 14px;
  outline: none;
}

.access-form select option {
  color: var(--ink);
}

.access-form textarea {
  resize: vertical;
  min-height: 118px;
}

.access-form input::placeholder,
.access-form textarea::placeholder {
  color: rgba(255, 250, 240, 0.42);
}

.access-form input:focus,
.access-form select:focus,
.access-form textarea:focus {
  border-color: #8bd3ca;
  box-shadow: 0 0 0 3px rgba(139, 211, 202, 0.18);
}

.access-form .button {
  width: 100%;
  background: #fffaf0;
  color: #1f3935;
  margin-top: 4px;
}

.form-status {
  min-height: 24px;
  margin: 0;
  color: rgba(255, 250, 240, 0.72);
  font-size: 0.92rem;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 26px clamp(18px, 4vw, 56px);
  color: rgba(255, 250, 240, 0.74);
  background: #1d2624;
  font-size: 0.94rem;
}

.not-found-page {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 32px;
  background: #f7f3ea;
}

.not-found-panel {
  width: min(560px, 100%);
  display: grid;
  gap: 18px;
}

.not-found-panel h1 {
  margin: 0;
  font-size: clamp(2.4rem, 7vw, 4.8rem);
  line-height: 0.95;
}

.not-found-panel p {
  margin: 0;
  color: #5e6a66;
}

@media (max-width: 980px) {
  .site-header {
    grid-template-columns: 1fr auto auto;
    gap: 10px;
  }

  .primary-nav {
    display: none;
  }

  .header-action {
    display: none;
  }

  .menu-toggle {
    display: inline-block;
  }

  .menu-open .mobile-nav {
    display: grid;
  }

  .tool-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .intro-grid,
  .surfaces-grid,
  .access-inner {
    grid-template-columns: 1fr;
  }

  .principle-item {
    grid-template-columns: 56px 1fr;
  }

  .principle-item p {
    grid-column: 2;
  }
}

@media (max-width: 680px) {
  :root {
    --header-height: 64px;
  }

  .site-header {
    padding: 0 14px;
  }

  .hero {
    min-height: 760px;
  }

  .hero-backdrop {
    background:
      linear-gradient(
        180deg,
        rgba(247, 243, 234, 0.98) 0%,
        rgba(247, 243, 234, 0.92) 44%,
        rgba(247, 243, 234, 0.26) 100%
      ),
      url("assets/photonseed-hero.png") 64% bottom / auto 82% no-repeat;
  }

  .hero-content {
    justify-content: flex-start;
    padding-top: 54px;
  }

  h1 {
    font-size: clamp(2.85rem, 13vw, 3.25rem);
  }

  .hero-copy {
    font-size: 1rem;
  }

  .hero-actions,
  .button {
    width: 100%;
  }

  .hero-signals {
    grid-template-columns: 1fr;
    width: 100%;
    gap: 10px;
  }

  .hero-signals div {
    display: flex;
    justify-content: space-between;
    gap: 18px;
  }

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

  .tool-card {
    min-height: 230px;
  }

  .surface-item {
    grid-template-columns: 58px 1fr;
  }

  .principle-item {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .principle-item p {
    grid-column: auto;
  }

  .site-footer {
    flex-direction: column;
  }
}

@media (max-width: 420px) {
  .brand span:last-child {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition: none !important;
  }
}