/* ============================================================
   YueDa — style.css
   Light theme · violet accent · camera lens nav · iris aperture
   ============================================================ */

:root {
  --paper: #F7F5FB;
  --surface: #FFFFFF;
  --ink: #1E1A2E;
  --ink-soft: #4B4460;
  --ink-muted: #6C6584;
  --violet: #7C3AED;
  --violet-deep: #6D28D9;
  --violet-dark: #5B21B6;
  --lavender: #EDE9FE;
  --lavender-soft: #F4F0FE;
  --line: #E6E0F4;
  --line-strong: #D8D0EC;
  --good: #2E7D5B;
}

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

html {
  scroll-behavior: smooth;
  overflow-x: hidden;
}

body {
  font-family: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: var(--ink);
  background-color: var(--paper);
  overflow-x: hidden;
}

a {
  color: var(--violet);
  text-decoration: none;
}

a:hover {
  color: var(--violet-dark);
}

img {
  max-width: 100%;
  display: block;
}

h1, h2, h3, h4 {
  line-height: 1.2;
  color: var(--ink);
  font-weight: 700;
}

/* ============ CAMERA LENS NAVIGATION ============ */

.lens-nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--surface);
  border-bottom: 1px solid var(--line);
  box-shadow: 0 1px 0 rgba(124, 58, 237, 0.06);
}

.nav-inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.brand-word {
  font-weight: 800;
  letter-spacing: 0.18em;
  font-size: 18px;
  color: var(--ink);
}

/* CSS-drawn camera lens */
.lens-mark {
  position: relative;
  width: 40px;
  height: 40px;
  display: inline-block;
}

.lens-mark .lens-outer {
  position: absolute;
  inset: 0;
  border: 6px solid var(--violet);
  border-radius: 50%;
  background-color: var(--surface);
}

.lens-mark .lens-core {
  position: absolute;
  inset: 13px;
  border: 2px solid var(--violet-deep);
  border-radius: 50%;
  background-color: var(--lavender);
}

.lens-mark .lens-glint {
  position: absolute;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: #FFFFFF;
  top: 6px;
  right: 9px;
  box-shadow: 0 0 0 1px var(--violet-deep);
}

.lens-mark-sm {
  width: 32px;
  height: 32px;
}

.lens-mark-sm .lens-outer {
  border-width: 5px;
}

.lens-mark-sm .lens-core {
  inset: 10px;
}

.lens-mark-sm .lens-glint {
  width: 5px;
  height: 5px;
  top: 5px;
  right: 7px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 26px;
  margin: 0 auto;
}

.nav-links a {
  color: var(--ink-soft);
  font-weight: 600;
  font-size: 15px;
  position: relative;
  padding: 6px 0;
}

.nav-links a:hover {
  color: var(--violet);
}

.nav-cta {
  flex-shrink: 0;
  background-color: var(--violet);
  color: #FFFFFF !important;
  font-weight: 700;
  font-size: 15px;
  padding: 11px 22px;
  border-radius: 8px;
  transition: background-color 0.2s ease;
}

.nav-cta:hover {
  background-color: var(--violet-dark);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  margin-left: auto;
}

.toggle-bar {
  display: block;
  width: 26px;
  height: 3px;
  border-radius: 2px;
  background-color: var(--ink);
  transition: transform 0.25s ease, opacity 0.25s ease;
}

/* ============ IRIS APERTURE HERO ============ */

.iris-hero {
  background-color: var(--paper);
  border-bottom: 1px solid var(--line);
}

.hero-inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 88px 24px 96px;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 48px;
  align-items: center;
}

.hero-eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--violet-deep);
  background-color: var(--lavender);
  padding: 7px 14px;
  border-radius: 999px;
  margin-bottom: 22px;
}

.hero-title {
  font-size: 46px;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 22px;
}

.hero-sub {
  font-size: 18px;
  color: var(--ink-soft);
  max-width: 540px;
  margin-bottom: 30px;
}

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

.hero-facts {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 26px;
  color: var(--ink-soft);
  font-size: 14px;
}

.hero-facts strong {
  display: block;
  font-size: 20px;
  color: var(--violet-dark);
  font-weight: 800;
}

/* CSS-drawn iris aperture */
.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.aperture {
  position: relative;
  width: 420px;
  height: 420px;
}

.aperture-glow {
  position: absolute;
  inset: 30px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--lavender) 0%, rgba(237, 233, 254, 0) 70%);
  filter: blur(2px);
}

.aperture .ring {
  position: absolute;
  border-radius: 50%;
  border: 2px solid var(--line-strong);
}

.aperture .ring-1 { inset: 4px; border-color: var(--line-strong); }
.aperture .ring-2 { inset: 44px; border-color: var(--violet); }
.aperture .ring-3 { inset: 92px; border-color: var(--violet-deep); }
.aperture .ring-4 { inset: 140px; border-color: var(--violet-dark); }
.aperture .ring-5 { inset: 178px; border: 1px solid var(--lavender); background-color: var(--lavender); }

.aperture .blade {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 4px;
  height: 34px;
  margin: -17px 0 0 -2px;
  border-radius: 2px;
  background-color: var(--violet);
}

.blade-1 { transform: rotate(0deg) translateY(-118px); }
.blade-2 { transform: rotate(45deg) translateY(-118px); }
.blade-3 { transform: rotate(90deg) translateY(-118px); }
.blade-4 { transform: rotate(135deg) translateY(-118px); }
.blade-5 { transform: rotate(180deg) translateY(-118px); }
.blade-6 { transform: rotate(225deg) translateY(-118px); }
.blade-7 { transform: rotate(270deg) translateY(-118px); }
.blade-8 { transform: rotate(315deg) translateY(-118px); }

.aperture-dot {
  position: absolute;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background-color: #FFFFFF;
  top: 16%;
  right: 24%;
  box-shadow: 0 0 0 3px var(--violet);
}

/* ============ BUTTONS ============ */

.btn {
  display: inline-block;
  font-weight: 700;
  font-size: 16px;
  padding: 14px 28px;
  border-radius: 8px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn-primary {
  background-color: var(--violet);
  color: #FFFFFF;
}

.btn-primary:hover {
  background-color: var(--violet-dark);
  color: #FFFFFF;
}

.btn-ghost {
  background-color: transparent;
  color: var(--violet-dark);
  border-color: var(--violet);
}

.btn-ghost:hover {
  background-color: var(--lavender);
}

.btn-light {
  background-color: #FFFFFF;
  color: var(--violet-dark);
}

.btn-light:hover {
  background-color: var(--lavender);
}

.btn-outline-light {
  background-color: transparent;
  color: #FFFFFF;
  border-color: #FFFFFF;
}

.btn-outline-light:hover {
  background-color: #6D28D9;
}

/* ============ SECTION SHARED ============ */

.section-head {
  max-width: 760px;
  margin: 0 auto 48px;
  text-align: center;
}

.section-tag {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--violet-deep);
  margin-bottom: 14px;
}

.section-head h2 {
  font-size: 34px;
  margin-bottom: 14px;
}

.section-intro {
  color: var(--ink-soft);
  font-size: 17px;
}

/* ============ STATEMENT ROW ============ */

.statement {
  background-color: var(--surface);
  border-bottom: 1px solid var(--line);
}

.statement-inner {
  max-width: 1000px;
  margin: 0 auto;
  padding: 84px 24px;
  text-align: center;
}

.statement-title {
  font-size: 40px;
  font-weight: 800;
  margin-bottom: 22px;
}

.statement-lead {
  font-size: 20px;
  color: var(--ink-soft);
  max-width: 800px;
  margin: 0 auto 30px;
}

.statement-cols {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 30px;
  text-align: left;
  color: var(--ink-soft);
}

/* ============ SERVICES ============ */

.services-section {
  background-color: var(--paper);
  padding: 84px 24px;
}

.services-grid {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.service-item {
  background-color: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 30px 28px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.service-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 30px rgba(124, 58, 237, 0.10);
}

.service-num {
  display: inline-block;
  font-weight: 800;
  font-size: 14px;
  color: var(--violet);
  background-color: var(--lavender);
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 16px;
}

.service-item h3 {
  font-size: 20px;
  margin-bottom: 10px;
}

.service-item p {
  color: var(--ink-soft);
  font-size: 15px;
}

/* ============ STAT COLUMNS ============ */

.stats-section {
  background-color: var(--violet-dark);
  background-image: linear-gradient(135deg, var(--violet-dark) 0%, var(--violet-deep) 100%);
  padding: 56px 24px;
}

.stats-inner {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}

.stat-value {
  display: block;
  font-size: 44px;
  font-weight: 800;
  color: #FFFFFF;
  letter-spacing: -0.02em;
}

.stat-label {
  display: block;
  color: var(--lavender);
  font-size: 15px;
  font-weight: 600;
}

/* ============ PROCESS LIST ============ */

.process-section {
  background-color: var(--surface);
  padding: 84px 24px;
  border-top: 1px solid var(--line);
}

.process-list {
  list-style: none;
  max-width: 860px;
  margin: 0 auto;
  counter-reset: none;
}

.process-step {
  display: flex;
  gap: 28px;
  padding: 26px 0;
  position: relative;
}

.process-step::after {
  content: "";
  position: absolute;
  left: 34px;
  top: 74px;
  bottom: -8px;
  width: 2px;
  background-color: var(--line);
}

.process-step:last-child::after {
  display: none;
}

.process-index {
  flex-shrink: 0;
  width: 70px;
  height: 70px;
  border-radius: 50%;
  background-color: var(--lavender);
  color: var(--violet-dark);
  font-weight: 800;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px solid var(--violet);
  z-index: 1;
}

.process-body h3 {
  font-size: 20px;
  margin-bottom: 8px;
}

.process-body p {
  color: var(--ink-soft);
}

/* ============ COMPARISON TABLE ============ */

.comparison-section {
  background-color: var(--paper);
  padding: 84px 24px;
  border-top: 1px solid var(--line);
}

.table-wrap {
  max-width: 1000px;
  margin: 0 auto;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 14px;
  background-color: var(--surface);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 720px;
}

.comparison-table th,
.comparison-table td {
  padding: 18px 20px;
  text-align: left;
  font-size: 15px;
  border-bottom: 1px solid var(--line);
}

.comparison-table thead th {
  background-color: var(--violet);
  color: #FFFFFF;
  font-weight: 700;
}

.comparison-table thead th.col-feature {
  background-color: var(--violet-dark);
}

.comparison-table tbody th {
  color: var(--violet-dark);
  font-weight: 700;
  white-space: nowrap;
}

.comparison-table tbody tr:last-child th,
.comparison-table tbody tr:last-child td {
  border-bottom: none;
}

.comparison-table tbody tr:nth-child(even) {
  background-color: var(--lavender-soft);
}

.comparison-table td {
  color: var(--ink-soft);
}

/* ============ TIMELINE ============ */

.timeline-section {
  background-color: var(--surface);
  padding: 84px 24px;
  border-top: 1px solid var(--line);
}

.timeline {
  list-style: none;
  max-width: 820px;
  margin: 0 auto;
  position: relative;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 90px;
  top: 0;
  bottom: 0;
  width: 2px;
  background-color: var(--line-strong);
}

.timeline-item {
  display: flex;
  align-items: flex-start;
  gap: 28px;
  margin-bottom: 34px;
  position: relative;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-dot {
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background-color: var(--violet);
  border: 4px solid var(--lavender);
  margin-top: 6px;
  position: relative;
  left: 82px;
}

.timeline-year {
  flex-shrink: 0;
  width: 80px;
  text-align: right;
  font-weight: 800;
  font-size: 18px;
  color: var(--violet-dark);
}

.timeline-card {
  flex: 1;
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 20px 24px;
}

.timeline-card h3 {
  font-size: 19px;
  margin-bottom: 6px;
}

.timeline-card p {
  color: var(--ink-soft);
}

/* ============ CONTACT ============ */

.contact-section {
  background-color: var(--paper);
  padding: 84px 24px;
  border-top: 1px solid var(--line);
}

.contact-grid {
  max-width: 1080px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 40px;
  align-items: start;
}

.contact-details {
  background-color: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 32px;
}

.contact-details h3 {
  margin-bottom: 18px;
  font-size: 22px;
}

.contact-line {
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin-bottom: 16px;
  color: var(--ink-soft);
  font-size: 15px;
}

.contact-label {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--violet-deep);
}

.contact-form {
  background-color: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 32px;
}

.form-row {
  margin-bottom: 18px;
}

.form-row label {
  display: block;
  font-weight: 700;
  font-size: 14px;
  margin-bottom: 6px;
  color: var(--ink);
}

.form-row input,
.form-row textarea {
  width: 100%;
  padding: 12px 14px;
  font-size: 15px;
  font-family: inherit;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  background-color: #FFFFFF;
  color: var(--ink);
}

.form-row input:focus,
.form-row textarea:focus {
  outline: none;
  border-color: var(--violet);
  box-shadow: 0 0 0 3px var(--lavender);
}

.form-status {
  margin-top: 14px;
  font-weight: 600;
  min-height: 24px;
}

.form-status.ok {
  color: var(--good);
}

.form-status.err {
  color: #B3261E;
}

/* ============ SPLIT CTA BAND ============ */

.cta-band {
  background-color: var(--violet-dark);
  background-image: linear-gradient(120deg, var(--violet-dark) 0%, var(--violet) 100%);
  padding: 64px 24px;
}

.cta-band-inner {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 40px;
  align-items: center;
}

.cta-left h2 {
  color: #FFFFFF;
  font-size: 34px;
  margin-bottom: 12px;
}

.cta-left p {
  color: var(--lavender);
  font-size: 17px;
}

.cta-right {
  display: flex;
  flex-direction: column;
  gap: 14px;
  justify-content: center;
}

.cta-right .btn {
  text-align: center;
}

/* ============ FOOTER ============ */

.site-footer {
  background-color: var(--ink);
  color: var(--lavender);
  border-top: 4px solid var(--violet);
}

.footer-inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 56px 24px 32px;
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 36px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
}

.footer-brand .brand-word {
  color: #FFFFFF;
}

.footer-about p {
  color: var(--lavender);
  font-size: 14px;
  line-height: 1.6;
}

.footer-col h3 {
  color: #FFFFFF;
  font-size: 15px;
  margin-bottom: 16px;
  letter-spacing: 0.04em;
}

.footer-col ul {
  list-style: none;
}

.footer-col ul li {
  margin-bottom: 10px;
  font-size: 14px;
  color: var(--lavender);
}

.footer-col ul a {
  color: var(--lavender);
}

.footer-col ul a:hover {
  color: #FFFFFF;
}

.footer-bottom {
  border-top: 1px solid rgba(237, 233, 254, 0.16);
  padding: 20px 24px;
  text-align: center;
  font-size: 13px;
  color: var(--lavender);
}

/* ============ SCROLL REVEAL ============ */

.fade-up,
.fade-left {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-up.visible,
.fade-left.visible {
  opacity: 1;
  transform: none;
}

/* ============ RESPONSIVE ============ */

@media (max-width: 960px) {
  .hero-inner {
    grid-template-columns: 1fr;
    padding: 56px 24px 64px;
  }

  .hero-title {
    font-size: 38px;
  }

  .hero-visual {
    order: -1;
  }

  .aperture {
    width: 300px;
    height: 300px;
  }

  .aperture .ring-2 { inset: 30px; }
  .aperture .ring-3 { inset: 64px; }
  .aperture .ring-4 { inset: 98px; }
  .aperture .ring-5 { inset: 124px; }

  .blade-1 { transform: rotate(0deg) translateY(-84px); }
  .blade-2 { transform: rotate(45deg) translateY(-84px); }
  .blade-3 { transform: rotate(90deg) translateY(-84px); }
  .blade-4 { transform: rotate(135deg) translateY(-84px); }
  .blade-5 { transform: rotate(180deg) translateY(-84px); }
  .blade-6 { transform: rotate(225deg) translateY(-84px); }
  .blade-7 { transform: rotate(270deg) translateY(-84px); }
  .blade-8 { transform: rotate(315deg) translateY(-84px); }

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

  .statement-cols {
    grid-template-columns: 1fr;
  }

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

  .cta-band-inner {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 720px) {
  .nav-inner {
    flex-wrap: wrap;
    gap: 14px;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-links {
    display: none;
    flex-basis: 100%;
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
    padding: 8px 0;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links a {
    padding: 10px 0;
    font-size: 16px;
  }

  .nav-cta {
    display: none;
  }

  .nav-cta.mobile-visible {
    display: inline-block;
  }

  .hero-title {
    font-size: 32px;
  }

  .hero-sub {
    font-size: 16px;
  }

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

  .stats-inner {
    grid-template-columns: 1fr 1fr;
    gap: 28px;
  }

  .section-head h2 {
    font-size: 28px;
  }

  .statement-title {
    font-size: 30px;
  }

  .timeline::before {
    left: 14px;
  }

  .timeline-item {
    flex-direction: column;
    gap: 10px;
    padding-left: 44px;
  }

  .timeline-dot {
    position: absolute;
    left: 5px;
    top: 4px;
  }

  .timeline-year {
    text-align: left;
    width: auto;
  }

  .footer-inner {
    grid-template-columns: 1fr;
  }
}