:root {
  --ink: #101316;
  --muted: #606a73;
  --paper: #f7f4ef;
  --line: rgba(16, 19, 22, 0.14);
  --panel: #ffffff;
  --accent: #1fb69a;
  --accent-dark: #0f806f;
  --night: #11171d;
  --cream: #f3eadc;
  --shadow: 0 24px 70px rgba(17, 23, 29, 0.16);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Inter", "Noto Sans SC", system-ui, sans-serif;
}

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

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 20;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  width: 100%;
  padding: 28px clamp(24px, 4.5vw, 68px);
  color: #fff;
  transition:
    background 180ms ease,
    box-shadow 180ms ease,
    color 180ms ease,
    padding 180ms ease;
}

.site-header.scrolled {
  background: rgba(247, 244, 239, 0.92);
  box-shadow: 0 12px 34px rgba(17, 23, 29, 0.1);
  color: var(--ink);
  backdrop-filter: blur(18px);
}

.brand,
.nav-links,
.header-action,
.hero-actions,
.openai-lockup,
.detail-check,
.final-cta {
  display: flex;
  align-items: center;
}

.brand {
  gap: 14px;
  width: max-content;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: 0;
}

.header-logo {
  width: auto;
  height: 32px;
  border-radius: 8px;
}

.brand-mark {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 8px rgba(31, 182, 154, 0.18);
}

.nav-links {
  gap: 38px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 17px;
  font-weight: 700;
  transition: color 180ms ease;
}

.site-header.scrolled .nav-links {
  color: rgba(16, 19, 22, 0.72);
}

.header-action {
  justify-self: end;
  min-height: 52px;
  padding: 0 26px;
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(14px);
  font-size: 16px;
  font-weight: 700;
  transition:
    transform 180ms ease,
    background 180ms ease,
    border-color 180ms ease,
    color 180ms ease;
}

.site-header.scrolled .header-action {
  border-color: rgba(16, 19, 22, 0.16);
  background: rgba(255, 255, 255, 0.64);
  color: var(--ink);
}

.hero {
  position: relative;
  display: flex;
  min-height: 100svh;
  overflow: hidden;
  background: var(--night);
  color: #fff;
}

.hero::after {
  position: absolute;
  inset: 0;
  content: "";
  background:
    linear-gradient(90deg, rgba(17, 23, 29, 0.92) 0%, rgba(17, 23, 29, 0.72) 42%, rgba(17, 23, 29, 0.18) 100%),
    radial-gradient(circle at 80% 22%, rgba(31, 182, 154, 0.2), transparent 28%);
  pointer-events: none;
}

.hero-visual {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(120deg, rgba(255, 255, 255, 0.08), transparent 36%),
    repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.045) 0 1px, transparent 1px 96px);
}

.orbital {
  position: absolute;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 50%;
  animation: drift 12s ease-in-out infinite alternate;
}

.orbital-one {
  right: -14vw;
  top: 13vh;
  width: 48vw;
  height: 48vw;
}

.orbital-two {
  right: 22vw;
  bottom: -20vw;
  width: 34vw;
  height: 34vw;
  animation-delay: -4s;
}

.plus-panel {
  position: absolute;
  right: clamp(24px, 7vw, 110px);
  top: 50%;
  width: min(39vw, 590px);
  min-width: 430px;
  max-width: 100%;
  padding: clamp(28px, 3.2vw, 46px);
  border-radius: 34px;
  background: #fff;
  box-shadow: 0 42px 120px rgba(0, 0, 0, 0.38);
  color: #050608;
  transform: translateY(-45%);
  animation: floatIn 820ms cubic-bezier(0.2, 0.72, 0.2, 1) both;
}

.plus-panel h2 {
  margin: 0 0 34px;
  font-size: clamp(40px, 4.1vw, 56px);
  font-weight: 500;
  line-height: 1;
  letter-spacing: 0;
}

.plus-price {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 34px;
  white-space: nowrap;
}

.plus-price .currency {
  color: #8d9093;
  font-size: clamp(26px, 3vw, 36px);
  font-weight: 500;
}

.plus-price strong {
  font-size: clamp(64px, 5.8vw, 88px);
  font-weight: 600;
  line-height: 0.88;
  letter-spacing: -0.02em;
}

.plus-price span:last-child {
  color: #5f6265;
  font-size: clamp(16px, 1.45vw, 21px);
  font-weight: 500;
}

.plus-tagline {
  margin: 0 0 84px;
  color: #07080a;
  font-size: clamp(24px, 2.5vw, 32px);
  font-weight: 700;
  line-height: 1.2;
}

.current-plan {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 86px;
  margin-bottom: 48px;
  border: 2px solid #e8e8e8;
  border-radius: 999px;
  color: #9a9da0;
  font-size: clamp(22px, 2.5vw, 30px);
  font-weight: 700;
}

.plus-features {
  display: grid;
  gap: 26px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.plus-features li {
  display: grid;
  grid-template-columns: 40px 1fr;
  align-items: center;
  gap: 20px;
  color: #08090b;
  font-size: clamp(19px, 1.9vw, 27px);
  font-weight: 500;
  line-height: 1.32;
}

.plus-features svg {
  width: 34px;
  height: 34px;
  fill: none;
  stroke: currentColor;
  stroke-linejoin: round;
  stroke-width: 1.8;
}

.plus-features path {
  vector-effect: non-scaling-stroke;
}

.hero-content {
  position: relative;
  z-index: 2;
  align-self: center;
  width: min(760px, calc(100% - 40px));
  margin-left: clamp(20px, 8vw, 112px);
  padding-top: 72px;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.openai-lockup {
  gap: 12px;
  width: max-content;
  max-width: 100%;
  margin-bottom: 24px;
  padding: 10px 20px 10px 14px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.1);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.22);
  color: #fff;
  font-size: 20px;
  font-weight: 800;
  line-height: 1;
  backdrop-filter: blur(16px);
}

.openai-lockup svg {
  width: auto;
  height: 32px;
  flex: 0 0 auto;
}

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

h1 {
  max-width: 760px;
  margin-bottom: 20px;
  font-size: clamp(42px, 5.1vw, 68px);
  line-height: 1.05;
  letter-spacing: -0.02em;
}

.hero-copy {
  max-width: 520px;
  color: rgba(255, 255, 255, 0.78);
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.7;
}

.hero-actions {
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 34px;
}

.primary-action,
.secondary-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  padding: 0 24px;
  border-radius: 999px;
  font-weight: 800;
  transition: transform 180ms ease, background 180ms ease, color 180ms ease;
}

.primary-action {
  background: var(--accent);
  color: #06110f;
}

.secondary-action {
  border: 1px solid rgba(255, 255, 255, 0.28);
  color: #fff;
}

.primary-action:hover,
.secondary-action:hover,
.header-action:hover,
.step-button:hover {
  transform: translateY(-2px);
}

.hero-note {
  position: absolute;
  right: clamp(20px, 5vw, 70px);
  bottom: 30px;
  z-index: 2;
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-left: 18px;
  border-left: 2px solid var(--accent);
}

.hero-note span {
  color: rgba(255, 255, 255, 0.58);
  font-size: 12px;
  font-weight: 700;
}

.section {
  padding: clamp(84px, 12vw, 150px) clamp(20px, 6vw, 90px);
}

.section-heading,
.process-heading {
  max-width: 760px;
}

.section-copy {
  max-width: 680px;
  margin: 20px 0 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.8;
}

h2 {
  margin-bottom: 0;
  font-size: clamp(36px, 5vw, 72px);
  line-height: 1.05;
  letter-spacing: 0;
}

.prepare-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  margin-top: 56px;
  background: var(--line);
}

.prepare-item {
  display: flex;
  flex-direction: column;
  min-height: 410px;
  padding: clamp(28px, 4vw, 46px);
  background: var(--paper);
}

.item-index {
  display: block;
  margin-bottom: 44px;
  color: var(--accent-dark);
  font-weight: 800;
}

.prepare-item h3 {
  margin-bottom: 14px;
  font-size: clamp(25px, 3vw, 38px);
}

.prepare-item p,
.notice-copy p,
.faq-list p {
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
}

.prepare-item ul {
  display: grid;
  gap: 10px;
  margin: auto 0 0;
  padding: 28px 0 0;
  list-style: none;
}

.prepare-item li {
  position: relative;
  padding-left: 18px;
  color: rgba(16, 19, 22, 0.78);
  font-size: 15px;
  font-weight: 700;
  line-height: 1.6;
}

.prepare-item li::before {
  position: absolute;
  top: 0.7em;
  left: 0;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  content: "";
}

.process {
  background: #fff;
}

.process-layout {
  display: grid;
  grid-template-columns: minmax(200px, 300px) 1fr;
  gap: clamp(36px, 5vw, 80px);
  margin-top: 60px;
}

.step-list {
  position: sticky;
  top: 96px;
  display: grid;
  gap: 12px;
  align-self: start;
  margin: 0;
  padding: 0;
  list-style: none;
}

.step-button {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 14px;
  align-items: center;
  width: 100%;
  min-height: 76px;
  border: 0;
  border-left: 3px solid var(--line);
  background: transparent;
  color: var(--ink);
  font: inherit;
  text-align: left;
  cursor: pointer;
  transition: transform 180ms ease, border-color 180ms ease, background 180ms ease;
}

.step-button span {
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.step-button strong {
  font-size: 19px;
}

.step-button.active {
  border-color: var(--accent);
  background: linear-gradient(90deg, rgba(31, 182, 154, 0.1), transparent);
}

.step-detail {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(320px, 1.15fr);
  gap: clamp(28px, 4vw, 52px);
  align-items: center;
  min-height: 400px;
  padding: clamp(34px, 7vw, 80px);
  background: var(--night);
  color: #fff;
  box-shadow: var(--shadow);
  border-radius: 16px;
}

.detail-copy-panel {
  min-width: 0;
}

.detail-kicker {
  width: max-content;
  margin-bottom: 24px;
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(31, 182, 154, 0.16);
  color: var(--accent);
  font-weight: 800;
}

.step-detail h3 {
  max-width: 760px;
  margin-bottom: 20px;
  font-size: clamp(30px, 4.4vw, 56px);
  line-height: 1.08;
}

.step-detail p {
  max-width: 680px;
  color: rgba(255, 255, 255, 0.72);
  font-size: 18px;
  line-height: 1.85;
}

.detail-check {
  gap: 14px;
  margin-top: 30px;
  padding-top: 26px;
  border-top: 1px solid rgba(255, 255, 255, 0.16);
}

.detail-check span {
  width: 12px;
  height: 12px;
  flex: 0 0 12px;
  border-radius: 50%;
  background: var(--accent);
}

.detail-check p {
  margin: 0;
  font-size: 15px;
}

.step-visual {
  margin: 0;
}

.step-visual[hidden] {
  display: none;
}

.step-visual img {
  display: block;
  width: 100%;
  border-radius: 14px;
  box-shadow: 0 28px 70px rgba(0, 0, 0, 0.34);
}

.step-detail:has(.step-visual[hidden]) {
  grid-template-columns: 1fr;
}

.notice {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(40px, 6vw, 80px);
  align-items: start;
  background: var(--cream);
}

.notice-copy p {
  max-width: 620px;
  margin-top: 24px;
}

.notice-list {
  display: grid;
  gap: 1px;
  background: rgba(16, 19, 22, 0.14);
}

.notice-list p {
  margin: 0;
  padding: 26px 0;
  background: var(--cream);
  color: var(--muted);
  line-height: 1.7;
}

.notice-list span {
  display: block;
  margin-bottom: 5px;
  color: var(--ink);
  font-weight: 800;
}

.faq-list {
  display: grid;
  gap: 1px;
  margin-top: 54px;
  background: var(--line);
}

details {
  background: var(--paper);
}

summary {
  min-height: 84px;
  padding: 28px 0;
  font-size: clamp(20px, 2.4vw, 28px);
  font-weight: 800;
  cursor: pointer;
}

details p {
  max-width: 820px;
  padding-bottom: 28px;
}

.final-cta {
  justify-content: space-between;
  gap: 16px;
  padding: clamp(24px, 3.5vw, 36px) clamp(20px, 6vw, 90px);
  background: var(--night);
  color: #fff;
}

.final-cta h2 {
  max-width: 480px;
  font-size: clamp(22px, 2.4vw, 32px);
  line-height: 1.15;
}

.final-cta .eyebrow {
  margin-bottom: 6px;
  font-size: 12px;
}

.final-cta .primary-action {
  min-height: 40px;
  padding: 0 16px;
  font-size: 14px;
}

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 700ms ease, transform 700ms ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@keyframes drift {
  to {
    transform: translate3d(-3vw, 2vh, 0) scale(1.05);
  }
}

@keyframes floatIn {
  from {
    opacity: 0;
    transform: translateY(-40%) scale(0.96);
  }

  to {
    opacity: 1;
    transform: translateY(-45%) scale(1);
  }
}

@media (max-width: 900px) {
  .site-header {
    grid-template-columns: 1fr auto;
    padding: 20px 22px;
  }

  .nav-links {
    display: none;
  }

  .hero {
    min-height: 1120px;
    flex-direction: column;
  }

  .hero-visual {
    position: absolute;
    inset: 0;
    z-index: 0;
  }

  .hero-content {
    position: relative;
    z-index: 2;
    align-self: start;
    margin: 0;
    padding: 118px 20px 0;
    width: 100%;
  }

  .plus-panel {
    right: 20px;
    top: auto;
    bottom: 28px;
    width: calc(100% - 40px);
    min-width: 0;
    max-width: 440px;
    padding: 28px;
    transform: translateY(0);
    animation: none;
  }

  .plus-panel h2 {
    margin-bottom: 24px;
  }

  .plus-price {
    margin-bottom: 24px;
  }

  .plus-tagline {
    margin-bottom: 42px;
  }

  .current-plan {
    min-height: 62px;
    margin-bottom: 28px;
  }

  .plus-features {
    gap: 16px;
  }

  .plus-features li {
    grid-template-columns: 32px 1fr;
    gap: 14px;
    font-size: 18px;
  }

  .plus-features svg {
    width: 28px;
    height: 28px;
  }

  .hero-note {
    display: none;
  }

  .process-layout,
  .notice {
    grid-template-columns: 1fr;
  }

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

  .prepare-item {
    min-height: 340px;
  }

  .step-list {
    position: static;
  }

  .step-detail {
    min-height: auto;
    grid-template-columns: 1fr;
    padding: 32px 24px;
  }

  .step-visual img {
    max-width: 620px;
  }

  .final-cta {
    align-items: flex-start;
    flex-direction: column;
    padding-top: 24px;
    padding-bottom: 24px;
  }
}

@media (max-width: 560px) {
  .brand {
    gap: 12px;
    font-size: 18px;
  }

  .brand-mark {
    width: 15px;
    height: 15px;
  }

  .brand span:last-child {
    display: none;
  }

  .header-action {
    min-height: 44px;
    padding: 0 18px;
    font-size: 15px;
  }

  h1 {
    font-size: 36px;
  }

  .hero-copy {
    font-size: 15px;
  }

  .hero-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .openai-lockup {
    margin-bottom: 18px;
    font-size: 16px;
    padding: 8px 16px 8px 12px;
  }

  .openai-lockup svg {
    width: auto;
    height: 26px;
  }

  .primary-action,
  .secondary-action {
    width: 100%;
    min-height: 48px;
    font-size: 15px;
  }

  .final-cta .primary-action {
    min-height: 40px;
  }

  .section {
    padding: 60px 20px;
  }

  .eyebrow {
    font-size: 12px;
  }

  .section-copy {
    font-size: 16px;
  }

  .prepare-grid {
    grid-template-columns: 1fr;
    margin-top: 36px;
  }

  .prepare-item {
    min-height: auto;
    padding: 28px 22px;
  }

  .item-index {
    margin-bottom: 28px;
  }

  .prepare-item ul {
    padding-top: 20px;
  }

  .hero {
    min-height: 980px;
  }

  .plus-panel {
    padding: 22px;
    border-radius: 26px;
  }

  .plus-panel h2 {
    font-size: 34px;
  }

  .plus-price {
    gap: 5px;
  }

  .plus-price .currency {
    font-size: 22px;
  }

  .plus-price strong {
    font-size: 56px;
  }

  .plus-price span:last-child {
    font-size: 14px;
  }

  .plus-tagline {
    margin-bottom: 32px;
    font-size: 20px;
  }

  .current-plan {
    min-height: 52px;
    font-size: 18px;
  }

  .plus-features {
    gap: 13px;
  }

  .plus-features li {
    grid-template-columns: 28px 1fr;
    gap: 12px;
    font-size: 15px;
  }

  .plus-features svg {
    width: 24px;
    height: 24px;
  }
}