/* ========================================
   三角洲行动 · Clay 粘土风格
   ======================================== */

:root {
  --cream: #faf9f7;
  --white: #ffffff;
  --black: #000000;
  --silver: #9f9b93;
  --oat: #dad4c8;
  --ube: #43089f;
  --ube-light: #c1b0ff;
  --slushie: #0089ad;
  --slushie-light: #3bd3fd;
  --matcha: #02492a;
  --lemon: #fbbd41;
  --pom: #fc7981;
  --shadow-subtle: rgba(0,0,0,0.1) 0px 1px 1px, rgba(0,0,0,0.04) 0px -1px 1px inset, rgba(0,0,0,0.05) 0px -0.5px 1px;
  --font: 'DM Sans', 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font);
  background: var(--cream);
  color: var(--black);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: filter 0.5s ease, opacity 0.5s ease;
}

/* ---- Scrollbar ---- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--cream); }
::-webkit-scrollbar-thumb { background: var(--oat); border-radius: 999px; }

/* ---- Navigation ---- */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250,249,247,0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--oat);
}

.nav__inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  height: 58px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--black);
}

.brand__mark {
  width: 34px;
  height: 34px;
  background: var(--lemon);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.85rem;
  color: var(--black);
}

.brand__text {
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.nav__links {
  display: flex;
  gap: 28px;
  align-items: center;
}

.nav__links a {
  color: var(--silver);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s;
}

.nav__links a:hover {
  color: var(--black);
}

.nav__cta {
  background: var(--lemon) !important;
  color: var(--black) !important;
  padding: 8px 20px !important;
  border-radius: 12px !important;
  font-weight: 600 !important;
  font-size: 0.85rem !important;
  transition: transform 0.2s, box-shadow 0.2s !important;
}

.nav__cta:hover {
  transform: rotateZ(-1.5deg) translateY(-1px);
  box-shadow: var(--black) -5px 5px;
}

.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav__toggle span {
  width: 22px;
  height: 2.5px;
  background: var(--black);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}

/* ---- Section ---- */
.section {
  padding: 90px 28px;
  max-width: 1200px;
  margin: 0 auto;
}

.section--wide {
  max-width: none;
}

.section__head {
  text-align: center;
  margin-bottom: 48px;
}

.section-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--silver);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 8px;
}

.section__title {
  font-size: 2.5rem;
  font-weight: 600;
  letter-spacing: -0.04em;
  line-height: 1.15;
  margin-bottom: 12px;
}

.section__intro {
  font-size: 1.05rem;
  color: var(--silver);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ---- Colored dark sections ---- */
.section-dark {
  background: var(--ube);
  border-radius: 40px;
  margin: 0 20px;
  padding: 100px 40px;
  color: #fff;
}

.section-dark .section__title { color: #fff; }
.section-dark .section__intro { color: rgba(255,255,255,0.65); }
.section-dark .section-label { color: var(--ube-light); }

.section-cyan {
  background: var(--slushie);
  border-radius: 40px;
  margin: 0 20px;
  padding: 90px 40px;
  color: #fff;
}

.section-cyan .section__title { color: #fff; }
.section-cyan .section__intro { color: rgba(255,255,255,0.7); }
.section-cyan .section-label { color: var(--slushie-light); }

.section-green {
  background: var(--matcha);
  border-radius: 40px;
  margin: 0 20px;
  padding: 80px 40px;
  color: #fff;
  text-align: center;
}

.section-green .section__title { color: #fff; }
.section-green .section__intro { color: rgba(255,255,255,0.7); }

/* ---- Hero ---- */
.hero {
  text-align: center;
  padding: 100px 28px 80px;
  max-width: 780px;
  margin: 0 auto;
  position: relative;
  overflow: hidden;
}

.hero__glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
  z-index: 0;
}

.hero__glow--ube {
  width: 340px; height: 340px;
  background: var(--ube-light);
  opacity: 0.12;
  top: -60px;
  right: -80px;
}

.hero__glow--cyan {
  width: 260px; height: 260px;
  background: var(--slushie-light);
  opacity: 0.1;
  bottom: -40px;
  left: -60px;
}

.hero__label {
  position: relative;
  z-index: 1;
}

.hero__title {
  position: relative;
  z-index: 1;
  font-size: 4rem;
  font-weight: 600;
  letter-spacing: -0.04em;
  line-height: 1.05;
  margin-bottom: 12px;
}

.hero__title em {
  font-style: normal;
  color: var(--ube);
}

.hero__sub {
  position: relative;
  z-index: 1;
  font-size: 1.15rem;
  color: var(--silver);
  margin-bottom: 28px;
}

.hero__desc {
  position: relative;
  z-index: 1;
  font-size: 1rem;
  color: var(--silver);
  max-width: 520px;
  margin: 0 auto 36px;
  line-height: 1.75;
}

.hero__actions {
  position: relative;
  z-index: 1;
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-size: 0.95rem;
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  border-radius: 12px;
  border: none;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
  font-family: var(--font);
}

.btn:hover {
  transform: rotateZ(-2deg) translateY(-2px);
}

.btn--primary {
  background: var(--lemon);
  color: var(--black);
  font-weight: 600;
}

.btn--primary:hover {
  box-shadow: var(--black) -7px 7px;
}

.btn--outline {
  background: transparent;
  border: 2px solid var(--black);
  color: var(--black);
  font-weight: 500;
}

.btn--outline:hover {
  box-shadow: var(--black) -7px 7px;
}

.btn--red {
  background: var(--pom);
  color: #fff;
  font-weight: 600;
}

.btn--red:hover {
  box-shadow: var(--black) -7px 7px;
}

.btn--full {
  width: 100%;
  justify-content: center;
}

.btn--white {
  background: #fff;
  color: var(--black);
  font-weight: 600;
}

.btn--white:hover {
  box-shadow: var(--black) -7px 7px;
}

/* ---- Stats ---- */
.stats {
  padding: 40px 28px 0;
  max-width: 900px;
  margin: 0 auto;
}

.stats__grid {
  display: flex;
  justify-content: center;
  gap: 60px;
  flex-wrap: wrap;
}

.stat {
  text-align: center;
}

.stat__num {
  display: block;
  font-size: 3rem;
  font-weight: 600;
  letter-spacing: -0.04em;
  line-height: 1;
  margin-bottom: 4px;
}

.stat__unit {
  font-size: 1.1rem;
  font-weight: 600;
}

.stat__label {
  display: block;
  font-size: 0.8rem;
  color: var(--silver);
  margin-top: 4px;
}

/* ---- Feature cards ---- */
.features__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.feature-card {
  background: var(--white);
  border: 1px solid var(--oat);
  border-radius: 24px;
  padding: 36px 28px;
  box-shadow: var(--shadow-subtle);
  transition: transform 0.2s, box-shadow 0.2s;
}

.feature-card:hover {
  transform: rotateZ(-1deg) translateY(-3px);
  box-shadow: rgba(0,0,0,0.12) 0px 4px 12px;
}

.feature-card__icon {
  width: 48px;
  height: 48px;
  border: 1px dashed var(--oat);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  margin-bottom: 20px;
}

.feature-card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 0.9rem;
  color: var(--silver);
  line-height: 1.65;
}

/* ---- Steps ---- */
.steps__list {
  display: flex;
  justify-content: center;
  gap: 60px;
  flex-wrap: wrap;
  max-width: 920px;
  margin: 0 auto;
}

.step {
  text-align: center;
  flex: 1;
  min-width: 150px;
  position: relative;
}

.step:not(:last-child)::after {
  content: '→';
  position: absolute;
  top: 26px;
  right: -34px;
  font-size: 1.3rem;
  color: var(--oat);
  font-weight: 300;
}

.step__num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  border: 2px solid var(--oat);
  border-radius: 50%;
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--ube);
  margin-bottom: 16px;
  background: var(--white);
}

.step h3 {
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 6px;
}

.step p {
  font-size: 0.85rem;
  color: var(--silver);
  line-height: 1.6;
}

/* ---- Gallery ---- */
.image-gallery {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.image-gallery figure {
  border-radius: 20px;
  overflow: hidden;
  background: rgba(255,255,255,0.1);
  backdrop-filter: blur(4px);
  transition: transform 0.2s;
}

.image-gallery figure:hover {
  transform: rotateZ(-1deg) translateY(-4px);
}

.image-gallery img {
  width: 100%;
  height: 220px;
  object-fit: cover;
  display: block;
}

.image-gallery figcaption {
  padding: 14px 18px;
  font-size: 0.8rem;
  color: rgba(255,255,255,0.7);
  font-weight: 500;
}

/* ---- Download cards ---- */
.download-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 920px;
  margin: 0 auto;
}

.download-card {
  background: rgba(255,255,255,0.13);
  backdrop-filter: blur(4px);
  border-radius: 24px;
  padding: 40px 24px;
  text-align: center;
  transition: transform 0.2s;
}

.download-card:hover {
  transform: rotateZ(-1deg) translateY(-3px);
}

.download-card__icon {
  font-size: 2.6rem;
  margin-bottom: 16px;
}

.download-card h3 {
  font-size: 1.2rem;
  font-weight: 600;
  color: #fff;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

.download-card p {
  font-size: 0.9rem;
  color: rgba(255,255,255,0.65);
  margin-bottom: 24px;
  line-height: 1.6;
}

/* ---- FAQ ---- */
.faq__list {
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--white);
  border: 1px solid var(--oat);
  border-radius: 18px;
  padding: 24px 28px;
  box-shadow: var(--shadow-subtle);
  transition: border-color 0.2s;
}

.faq-item:hover {
  border-color: var(--ube-light);
}

.faq-item .q {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 8px;
}

.faq-item .q-mark {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--ube);
  flex-shrink: 0;
}

.faq-item .q-text {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.faq-item .a {
  padding-left: 28px;
  font-size: 0.9rem;
  color: var(--silver);
  line-height: 1.7;
}

/* ---- Refund banner ---- */
.refund-banner {
  background: var(--white);
  border: 1px solid var(--oat);
  border-radius: 28px;
  padding: 40px 36px;
  max-width: 580px;
  margin: 0 auto;
  text-align: center;
  box-shadow: var(--shadow-subtle);
}

.refund-banner__icon {
  font-size: 2.2rem;
  margin-bottom: 12px;
}

.refund-banner h3 {
  font-size: 1.3rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 10px;
}

.refund-banner p {
  font-size: 0.95rem;
  color: var(--silver);
  margin-bottom: 24px;
  line-height: 1.7;
}

/* ---- Footer ---- */
.footer {
  padding: 56px 28px;
  text-align: center;
  border-top: 1px solid var(--oat);
}

.footer__brand {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 20px;
}

.footer__brand .brand__mark {
  width: 30px;
  height: 30px;
  border-radius: 8px;
  font-size: 0.75rem;
}

.footer__nav {
  display: flex;
  justify-content: center;
  gap: 28px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.footer__nav a {
  color: var(--silver);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  transition: color 0.2s;
}

.footer__nav a:hover {
  color: var(--black);
}

.footer__copy {
  font-size: 0.78rem;
  color: var(--silver);
  line-height: 1.8;
}

/* ---- Download page specific ---- */
.download-page {
  padding: 60px 28px;
  max-width: 1100px;
  margin: 0 auto;
}

.download-title {
  font-size: 2.5rem;
  font-weight: 600;
  letter-spacing: -0.04em;
  text-align: center;
  margin-bottom: 8px;
}

.download-sub {
  text-align: center;
  color: var(--silver);
  font-size: 1rem;
  margin-bottom: 48px;
}

/* ---- Refund page specific ---- */
.refund-page {
  padding: 60px 28px;
  max-width: 620px;
  margin: 0 auto;
}

.refund-title {
  font-size: 2.5rem;
  font-weight: 600;
  letter-spacing: -0.04em;
  text-align: center;
  margin-bottom: 8px;
}

.refund-sub {
  text-align: center;
  color: var(--silver);
  font-size: 0.95rem;
  margin-bottom: 40px;
}

.refund-form {
  background: var(--white);
  border: 1px solid var(--oat);
  border-radius: 28px;
  padding: 40px;
  box-shadow: var(--shadow-subtle);
}

.refund-form__group {
  margin-bottom: 24px;
}

.refund-form label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 8px;
}

.refund-form input,
.refund-form textarea,
.refund-form select {
  width: 100%;
  padding: 14px 18px;
  background: var(--cream);
  border: 1px solid var(--oat);
  border-radius: 14px;
  color: var(--black);
  font-family: var(--font);
  font-size: 0.95rem;
  outline: none;
  transition: border-color 0.2s;
}

.refund-form input:focus,
.refund-form textarea:focus,
.refund-form select:focus {
  border-color: var(--ube-light);
}

.refund-form textarea {
  min-height: 120px;
  resize: vertical;
}

.refund-notice {
  background: var(--white);
  border: 1px solid var(--oat);
  border-radius: 24px;
  padding: 28px;
  margin-top: 28px;
  box-shadow: var(--shadow-subtle);
  text-align: center;
}

.refund-notice h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--pom);
  letter-spacing: -0.01em;
  margin-bottom: 8px;
}

.refund-notice p {
  font-size: 0.9rem;
  color: var(--silver);
  line-height: 1.7;
}

/* ---- Page footer ---- */
.page-footer {
  text-align: center;
  padding: 36px 28px;
  border-top: 1px solid var(--oat);
}

.page-footer p {
  font-size: 0.8rem;
  color: var(--silver);
}

.page-footer a {
  color: var(--silver);
  text-decoration: none;
  transition: color 0.2s;
  font-weight: 500;
}

.page-footer a:hover {
  color: var(--black);
}

/* ---- Responsive ---- */
@media (max-width: 768px) {
  .section { padding: 60px 20px; }
  .hero { padding: 60px 20px 50px; }
  .hero__title { font-size: 2.5rem; }
  .section__title { font-size: 1.8rem; }
  .features__grid {
    grid-template-columns: 1fr;
  }
  .image-gallery {
    grid-template-columns: 1fr;
  }
  .download-grid {
    grid-template-columns: 1fr;
    max-width: 380px;
  }
  .stats__grid { gap: 32px; }
  .stat__num { font-size: 2rem; }
  .steps__list { flex-direction: column; align-items: center; gap: 32px; }
  .step:not(:last-child)::after { display: none; }
  .section-dark { border-radius: 28px; margin: 0 12px; padding: 60px 24px; }
  .section-cyan { border-radius: 28px; margin: 0 12px; padding: 60px 24px; }
  .section-green { border-radius: 28px; margin: 0 12px; padding: 60px 24px; }
  .nav__links { display: none; }
  .nav__links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 58px;
    left: 0;
    right: 0;
    background: rgba(250,249,247,0.98);
    padding: 20px;
    gap: 16px;
    border-bottom: 1px solid var(--oat);
  }
  .nav__toggle { display: flex; }
  .download-title { font-size: 1.8rem; }
  .refund-title { font-size: 1.8rem; }
}

@media (max-width: 480px) {
  .hero__title { font-size: 2rem; }
  .section__title { font-size: 1.5rem; }
  .hero__actions { flex-direction: column; align-items: center; }
}

/* ---- Anti-crawl blur ---- */
html:not(.m8w3) body {
    filter: blur(10px);
    -webkit-filter: blur(10px);
}
body {
    transition: filter 0.5s ease, opacity 0.5s ease;
}