:root {
  --white: #f8f8f6;
  --paper: #ecebe8;
  --ink: #111111;
  --slate: #707070;
  --silver: #c7c9cc;
  --steel: #a0a4aa;
  --dark: #16181c;
  --max: 1200px;
  --radius: 22px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--white);
  color: var(--ink);
  font-family: "Smiley Sans Oblique", "PingFang SC", "Microsoft YaHei", sans-serif;
  scroll-behavior: smooth;
}

body {
  overflow-x: hidden;
}

a {
  -webkit-tap-highlight-color: transparent;
}

a:focus-visible {
  outline: 2px solid #d4d7dd;
  outline-offset: 3px;
}

h1,
h2,
h3,
h4,
.brand-cn {
  font-family: "Smiley Sans Oblique", "PingFang SC", "Microsoft YaHei", sans-serif;
  letter-spacing: 0.02em;
}

.topbar {
  position: fixed;
  z-index: 50;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 28px;
  mix-blend-mode: difference;
  color: #ffffff;
}

.side-nav {
  position: fixed;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 45;
  display: grid;
  gap: 10px;
}

.side-nav a {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.55);
  border: 1px solid rgba(0, 0, 0, 0.35);
  transition: transform 0.25s ease, background-color 0.25s ease;
}

.side-nav a:hover,
.side-nav a.active {
  transform: scale(1.35);
  background: #ffffff;
}

.brand {
  display: grid;
  gap: 3px;
}

.brand-cn {
  font-size: 1rem;
  font-weight: 600;
}

.brand-en {
  font-size: 0.72rem;
  opacity: 0.75;
  letter-spacing: 0.13em;
}

.panel {
  min-height: 100svh;
  display: grid;
  place-items: center;
  padding: 110px 20px 80px;
  position: relative;
}

.content {
  width: min(var(--max), 100%);
}

.hero {
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(120deg, rgba(20, 21, 24, 0.5), rgba(20, 21, 24, 0.2)),
    url("images/hero-main.jpg") center/cover no-repeat;
  transform: scale(1.02);
  filter: grayscale(100%);
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 10% 30%, rgba(255, 255, 255, 0.22), transparent 50%),
    linear-gradient(0deg, rgba(10, 10, 10, 0.58), rgba(10, 10, 10, 0.25));
}

.hero-content {
  position: relative;
  z-index: 2;
  width: min(1050px, 100%);
  color: #f5f5f5;
}

.eyebrow {
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  margin: 0 0 16px;
  opacity: 0.75;
}

.hero h1 {
  font-size: clamp(4rem, 15vw, 10rem);
  line-height: 0.9;
  margin: 0;
}

.hero-en {
  margin: 8px 0 0;
  font-size: clamp(1rem, 2vw, 1.4rem);
  letter-spacing: 0.38em;
  text-transform: uppercase;
  opacity: 0.78;
}

.hero h2 {
  margin: 18px 0 10px;
  font-size: clamp(1.4rem, 2.6vw, 2.2rem);
  font-weight: 600;
}

.quote {
  margin: 20px 0 36px;
  font-size: clamp(1rem, 1.8vw, 1.24rem);
  opacity: 0.88;
}

.badge {
  display: inline-block;
  margin-bottom: 18px;
  padding: 6px 16px;
  border: 1px solid rgba(245, 245, 245, 0.55);
  border-radius: 999px;
  font-size: 0.72rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  opacity: 0.85;
}

.btn {
  display: inline-block;
  border: 1px solid currentColor;
  border-radius: 999px;
  padding: 11px 22px;
  text-decoration: none;
  color: inherit;
  font-size: 0.95rem;
  transition: transform 0.28s ease, background-color 0.28s ease, color 0.28s ease;
}

.btn:hover {
  transform: translateY(-2px);
  background: #f3f3f1;
  color: #0e0e0e;
}

.btn-ghost {
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  padding: 9px 14px;
}

.section-light {
  background:
    radial-gradient(circle at 80% 10%, #ffffff 0%, transparent 40%),
    linear-gradient(180deg, var(--white), var(--paper));
}

.section-silver {
  background:
    linear-gradient(140deg, #d4d7db 0%, #f3f4f6 45%, #c7cbd2 100%);
}

.section-dark {
  color: #f5f5f5;
  background:
    radial-gradient(circle at 90% 15%, rgba(255, 255, 255, 0.08), transparent 45%),
    linear-gradient(130deg, #0f1114 0%, #1f242b 55%, #111318 100%);
}

.section-final {
  color: #fff;
  background: #0f1114;
  overflow: hidden;
}

#hero,
#definition,
#era,
#core,
#system,
#value,
#future {
  scroll-margin-top: 76px;
}

.section-era {
  color: #f5f5f5;
  background: radial-gradient(circle at 50% 0%, #232629 0%, #0b0c0e 70%);
  text-align: center;
  overflow: hidden;
}

.era-video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: grayscale(45%) brightness(0.8);
}

.era-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(8, 9, 10, 0.55), rgba(8, 9, 10, 0.75));
}

.era-content {
  position: relative;
  z-index: 2;
  margin: 0 auto;
  max-width: 780px;
}

.section-era .eyebrow {
  opacity: 0.6;
}

.section-era h3 {
  line-height: 1.25;
}

.era-lines {
  margin-top: 30px;
  display: grid;
  gap: 10px;
  font-size: clamp(1.05rem, 2.2vw, 1.4rem);
  color: #cfd2d8;
}

.era-strong {
  margin-top: 6px;
  font-size: clamp(1.3rem, 3vw, 1.9rem);
  color: #ffffff;
  font-weight: 600;
}

.accent-line {
  margin: 16px 0 0;
  font-size: clamp(1.05rem, 2vw, 1.3rem);
  color: #1c1c1c;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.future-bg {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(115deg, rgba(255, 255, 255, 0.08), transparent 40%),
    repeating-linear-gradient(
      120deg,
      rgba(255, 255, 255, 0.03) 0,
      rgba(255, 255, 255, 0.03) 2px,
      transparent 2px,
      transparent 16px
    );
  opacity: 0.8;
}

h3 {
  margin: 0;
  font-size: clamp(2rem, 5vw, 4rem);
  line-height: 1.06;
}

.split-title {
  margin-top: 18px;
  display: grid;
  gap: 4px;
  font-size: clamp(1.55rem, 3.8vw, 3.2rem);
  font-family: "Smiley Sans Oblique", "PingFang SC", "Microsoft YaHei", sans-serif;
}

.lead {
  margin-top: 22px;
  max-width: 740px;
  color: #3b3b3b;
  font-size: clamp(1rem, 2vw, 1.2rem);
  line-height: 1.8;
}

.section-dark .lead,
.section-final .lead {
  color: #d8d8d8;
}

.checks {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  max-width: 620px;
}

.checks li {
  border: 1px solid #c4c4c4;
  border-radius: var(--radius);
  padding: 14px 16px;
  background: rgba(255, 255, 255, 0.5);
}

.grid-2 {
  display: grid;
  gap: 30px;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
}

.keyword-list {
  margin-top: 24px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.keyword-list article:last-child {
  grid-column: 1 / -1;
}

.keyword-list article {
  background: rgba(255, 255, 255, 0.65);
  border: 1px solid rgba(17, 17, 17, 0.08);
  border-radius: var(--radius);
  padding: 20px;
}

.keyword-list h4 {
  margin: 0;
  font-size: clamp(1.05rem, 2.4vw, 1.3rem);
}

.keyword-list p {
  margin: 8px 0 0;
  color: #2d3137;
}

.silhouette-wrap {
  display: grid;
  gap: 14px;
}

.body-photo {
  display: block;
  width: 100%;
  height: auto;
}

.muted {
  color: #2e333c;
  margin: 0;
  line-height: 1.6;
}

.timeline {
  margin-top: 30px;
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  gap: 14px;
  align-items: center;
}

.phase {
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.05);
  padding: 20px;
}

.phase h4 {
  margin: 0;
  font-size: 1.65rem;
}

.phase p {
  margin: 7px 0 0;
  color: #dbdde2;
}

.arrow {
  font-size: 1.8rem;
  opacity: 0.8;
}

.contrast {
  margin-top: 22px;
  display: grid;
  gap: 8px;
  font-size: clamp(1.1rem, 2vw, 1.35rem);
}

.contrast span {
  color: #666;
  margin-right: 8px;
}

.farewell-lines {
  margin-top: 20px;
  display: grid;
  gap: 6px;
  font-size: clamp(1.05rem, 2.2vw, 1.5rem);
  color: #2a2a2a;
  font-weight: 600;
}

.core-slogan {
  position: relative;
  margin: 0 0 40px;
  max-width: 760px;
  padding-top: 22px;
  font-size: clamp(1.3rem, 3.2vw, 2.1rem);
  line-height: 1.5;
  color: #ffffff;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.core-slogan::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 46px;
  height: 2px;
  background: rgba(255, 255, 255, 0.6);
}

.future-list {
  list-style: none;
  margin: 24px 0 30px;
  padding: 0;
  display: grid;
  gap: 9px;
}

.future-list li {
  width: fit-content;
  border-bottom: 1px solid rgba(255, 255, 255, 0.28);
  padding-bottom: 4px;
}

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

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

@media (prefers-reduced-motion: reduce) {
  html,
  body {
    scroll-behavior: auto;
  }

  .reveal,
  .btn,
  .side-nav a {
    transition: none;
  }
}

@media (max-width: 920px) {
  .side-nav {
    display: none;
  }

  .grid-2 {
    grid-template-columns: 1fr;
  }

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

  .arrow {
    text-align: center;
    transform: rotate(90deg);
  }
}

@media (max-width: 640px) {
  .topbar {
    padding: 14px 15px;
  }

  .brand-en {
    display: none;
  }

  .btn-ghost {
    font-size: 0.72rem;
    padding: 8px 11px;
  }

  .checks,
  .keyword-list {
    grid-template-columns: 1fr;
  }

  .panel {
    padding: 96px 16px 64px;
  }

  .hero h2 {
    max-width: 12em;
  }
}

.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  background: rgba(10, 10, 10, 0.6);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.25s ease, visibility 0.25s ease;
}

.modal-overlay.is-open {
  opacity: 1;
  visibility: visible;
}

.modal {
  position: relative;
  width: min(420px, 100%);
  max-height: 88vh;
  overflow-y: auto;
  background: var(--white);
  border-radius: var(--radius);
  padding: 36px 28px 28px;
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.35);
  transform: translateY(16px) scale(0.98);
  transition: transform 0.25s ease;
}

.modal-overlay.is-open .modal {
  transform: translateY(0) scale(1);
}

.modal-close {
  position: absolute;
  top: 14px;
  right: 14px;
  width: 32px;
  height: 32px;
  border: none;
  border-radius: 50%;
  background: rgba(17, 17, 17, 0.06);
  color: var(--ink);
  font-size: 1.2rem;
  line-height: 1;
  cursor: pointer;
  transition: background-color 0.2s ease;
}

.modal-close:hover {
  background: rgba(17, 17, 17, 0.12);
}

.modal h3 {
  font-size: clamp(1.4rem, 3vw, 1.8rem);
  margin: 6px 0 0;
}

.modal-desc {
  margin: 10px 0 22px;
  color: #4a4a4a;
  font-size: 0.95rem;
  line-height: 1.6;
}

.waitlist-form {
  display: grid;
  gap: 16px;
}

.field {
  display: grid;
  gap: 6px;
  font-size: 0.85rem;
  color: #4a4a4a;
}

.field input {
  font: inherit;
  padding: 12px 14px;
  border: 1px solid rgba(17, 17, 17, 0.15);
  border-radius: 12px;
  background: #fff;
  color: var(--ink);
}

.field input:focus {
  outline: none;
  border-color: rgba(17, 17, 17, 0.5);
}

.hp-field {
  position: absolute;
  left: -9999px;
  top: -9999px;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

.form-error {
  margin: -4px 0 0;
  font-size: 0.82rem;
  color: #b3261e;
  min-height: 1.1em;
}

.modal-submit {
  width: 100%;
  text-align: center;
  background: var(--ink);
  color: #fff;
  border-color: var(--ink);
}

.modal-submit:hover {
  background: #2a2a2a;
  color: #fff;
}

.modal-step-success {
  text-align: center;
}

.modal-step-success .modal-done {
  width: 100%;
  text-align: center;
}