/* ═══════════════════════════════════════════════════════════
   RIAN Co., Ltd. — Homepage Stylesheet
   ═══════════════════════════════════════════════════════════ */

/* ── TOKENS ──────────────────────────────────────────────── */
:root {
  --bg:         #05060a;
  --bg2:        #0a0b14;
  --bg3:        #0f101d;
  --bg4:        #161829;
  --text:       #f0f2fa;
  --text-dim:   #a0a8c8;
  --text-xdim:  #5a6288;
  --accent:     #5c8df6;
  --accent2:    #9b6ef6;
  --accent3:    #0dc9e6;
  --border:     rgba(92, 141, 246, 0.2);
  --border2:    rgba(255,255,255,0.08);
  --radius-sm:  8px;
  --radius:     14px;
  --radius-lg:  24px;
  --shadow:     0 12px 32px rgba(0,0,0,0.5);
  --shadow-lg:  0 20px 60px rgba(0,0,0,0.6);
  --font:       'Inter', system-ui, -apple-system, sans-serif;
  --mono:       'JetBrains Mono', 'Fira Code', monospace;
  --nav-h:      72px;
  --max-w:      1100px;
  --transition: 0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
}

/* ── RESET ───────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  word-break: keep-all;
  overflow-wrap: break-word;
}
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img, svg { display: block; }
button { cursor: pointer; border: none; background: none; font: inherit; color: inherit; }
input, textarea, select {
  font: inherit;
  color: inherit;
  background: transparent;
  border: none;
  outline: none;
  width: 100%;
}

/* ── UTILITY ─────────────────────────────────────────────── */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}
.section {
  padding: 140px 0;
}
.section-label {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 24px;
}
.section-title {
  font-size: clamp(32px, 5vw, 48px);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 24px;
  color: #fff;
  letter-spacing: -0.02em;
}
.section-desc {
  font-size: 18px;
  color: var(--text-dim);
  max-width: 600px;
  margin-bottom: 72px;
}
em { font-style: italic; color: var(--accent); }

/* ── BUTTONS ─────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 600;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}
.btn--primary {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff;
  box-shadow: 0 4px 20px rgba(79, 127, 247, 0.35);
}
.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(79, 127, 247, 0.5);
}
.btn--ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border2);
}
.btn--ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(79, 127, 247, 0.05);
}
.btn--full { width: 100%; justify-content: center; }

/* ── NAV ─────────────────────────────────────────────────── */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 100;
  transition: background var(--transition), border-color var(--transition);
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: rgba(8, 9, 15, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-color: var(--border2);
}
.nav__inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav__logo {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: 0.08em;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.nav__links {
  display: flex;
  align-items: center;
  gap: 40px;
}
.nav__links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-dim);
  transition: color var(--transition);
}
.nav__links a:hover { color: #fff; }
.nav__cta {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-weight: 600 !important;
}
.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
}
.nav__toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: var(--transition);
}
.nav__toggle[aria-expanded="true"] span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.nav__toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}
.nav__toggle[aria-expanded="true"] span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ── HERO ────────────────────────────────────────────────── */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding: var(--nav-h) 24px 80px;
}
.hero__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(79,127,247,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(79,127,247,0.04) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse at center, black 30%, transparent 80%);
}
.hero__glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  pointer-events: none;
}
.hero__glow--1 {
  width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(79,127,247,0.12), transparent 70%);
  top: 10%; left: 20%;
}
.hero__glow--2 {
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(139,92,246,0.1), transparent 70%);
  bottom: 20%; right: 15%;
}
.hero__content {
  position: relative;
  text-align: center;
  max-width: 820px;
}
.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: rgba(79,127,247,0.1);
  border: 1px solid rgba(79,127,247,0.25);
  color: var(--accent);
  margin-bottom: 32px;
  font-family: var(--mono);
}
.hero__title {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  margin-bottom: 24px;
}
.hero__title-main {
  font-size: clamp(72px, 12vw, 120px);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1;
  background: linear-gradient(135deg, #fff 0%, rgba(255,255,255,0.7) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero__title-sub {
  font-size: clamp(16px, 2.5vw, 22px);
  font-weight: 400;
  color: var(--text-dim);
  letter-spacing: 0.15em;
}
.hero__tagline {
  font-size: clamp(14px, 2vw, 18px);
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 24px;
  font-family: var(--mono);
}
.hero__desc {
  font-size: clamp(15px, 1.8vw, 18px);
  color: var(--text-dim);
  line-height: 1.7;
  margin-bottom: 48px;
}
.hero__actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}
.hero__scroll {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-xdim);
  font-size: 11px;
  font-family: var(--mono);
  letter-spacing: 0.1em;
  animation: scroll-hint 3s ease infinite;
}
.hero__scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, var(--text-xdim), transparent);
}
@keyframes scroll-hint {
  0%, 100% { opacity: 0.4; transform: translateX(-50%) translateY(0); }
  50%       { opacity: 1;   transform: translateX(-50%) translateY(6px); }
}

/* ── ABOUT ───────────────────────────────────────────────── */
.about { background: var(--bg2); }
.about__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: start;
}
.about__heading {
  font-size: clamp(24px, 3.5vw, 38px);
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 24px;
  color: #fff;
}
.about__text p {
  color: var(--text-dim);
  margin-bottom: 16px;
  font-size: 16px;
}
.about__stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border2);
}
.stat {
  background: var(--bg3);
  padding: 40px 28px;
  text-align: center;
  border: 1px solid var(--border2);
  transition: background var(--transition);
}
.stat:hover { background: var(--bg4); }
.stat__num {
  font-size: 42px;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 8px;
  line-height: 1;
}
.stat__label {
  font-size: 13px;
  color: var(--text-dim);
  font-weight: 500;
}

/* ── TECH GRID ───────────────────────────────────────────── */
.tech__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.tech-card {
  background: var(--bg2);
  border: 1px solid var(--border2);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  position: relative;
  overflow: hidden;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}
.tech-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(79,127,247,0.04), rgba(139,92,246,0.04));
  opacity: 0;
  transition: opacity var(--transition);
}
.tech-card:hover {
  transform: translateY(-4px);
  border-color: var(--border);
  box-shadow: var(--shadow);
}
.tech-card:hover::before { opacity: 1; }
.tech-card--featured {
  grid-column: span 1;
  background: linear-gradient(135deg, rgba(79,127,247,0.08), rgba(139,92,246,0.08));
  border-color: rgba(79,127,247,0.3);
}
.tech-card__icon {
  width: 44px; height: 44px;
  color: var(--accent);
  margin-bottom: 20px;
}
.tech-card__icon svg { width: 100%; height: 100%; }
.tech-card__num {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--text-xdim);
  margin-bottom: 10px;
  letter-spacing: 0.1em;
}
.tech-card__title {
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 12px;
  line-height: 1.3;
}
.tech-card__desc {
  font-size: 14px;
  color: var(--text-dim);
  line-height: 1.65;
  margin-bottom: 20px;
}
.tech-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.tech-card__tags span {
  font-size: 11px;
  font-weight: 500;
  font-family: var(--mono);
  padding: 3px 10px;
  border-radius: 999px;
  background: rgba(79,127,247,0.1);
  color: var(--accent3);
  border: 1px solid rgba(6,182,212,0.2);
}

/* ── IP ──────────────────────────────────────────────────── */
.ip { background: var(--bg2); }
.ip__cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-bottom: 40px;
}
.ip-card {
  background: var(--bg3);
  border: 1px solid var(--border2);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  transition: transform var(--transition), border-color var(--transition);
}
.ip-card:hover {
  transform: translateY(-3px);
  border-color: var(--border);
}
.ip-card__icon {
  font-size: 28px;
  margin-bottom: 16px;
}
.ip-card h3 {
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 12px;
}
.ip-card p {
  font-size: 14px;
  color: var(--text-dim);
  line-height: 1.65;
}
.ip__notice {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  padding: 24px 28px;
  background: rgba(79,127,247,0.05);
  border: 1px solid rgba(79,127,247,0.15);
  border-radius: var(--radius);
}
.ip__notice-icon {
  font-size: 32px;
  font-weight: 900;
  color: var(--accent);
  flex-shrink: 0;
  line-height: 1;
  font-family: var(--mono);
}
.ip__notice p {
  font-size: 13px;
  color: var(--text-dim);
  line-height: 1.65;
}

/* ── PROJECTS ────────────────────────────────────────────── */
.projects__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.project-card {
  background: var(--bg2);
  border: 1px solid var(--border2);
  border-radius: var(--radius-lg);
  padding: 28px;
  position: relative;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}
.project-card:hover {
  transform: translateY(-4px);
  border-color: var(--border);
  box-shadow: var(--shadow);
}
.project-card__status {
  display: inline-block;
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 16px;
}
.project-card__status--active {
  background: rgba(6,182,212,0.12);
  color: var(--accent3);
  border: 1px solid rgba(6,182,212,0.25);
}
.project-card__status--research {
  background: rgba(139,92,246,0.12);
  color: var(--accent2);
  border: 1px solid rgba(139,92,246,0.25);
}
.project-card__status--mvp {
  background: rgba(245,158,11,0.12);
  color: #f59e0b;
  border: 1px solid rgba(245,158,11,0.25);
}
.project-card h3 {
  font-size: 17px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 12px;
  line-height: 1.3;
}
.project-card p {
  font-size: 14px;
  color: var(--text-dim);
  margin-bottom: 20px;
  line-height: 1.65;
}
.project-card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.project-card__meta span {
  font-size: 11px;
  font-family: var(--mono);
  font-weight: 500;
  padding: 3px 10px;
  border-radius: 999px;
  background: rgba(255,255,255,0.05);
  color: var(--text-dim);
  border: 1px solid var(--border2);
}

/* ── CONTACT ─────────────────────────────────────────────── */
.contact { background: var(--bg2); }
.contact__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: start;
}
.contact__info {
  display: flex;
  flex-direction: column;
  gap: 32px;
}
.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}
.contact-item__icon {
  width: 44px; height: 44px;
  flex-shrink: 0;
  background: var(--bg3);
  border: 1px solid var(--border2);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
}
.contact-item__icon svg { width: 20px; height: 20px; }
.contact-item__label {
  font-size: 11px;
  font-family: var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-xdim);
  margin-bottom: 4px;
}
.contact-item__value {
  font-size: 15px;
  color: var(--text);
  font-weight: 500;
}
.contact__note {
  font-size: 13px;
  color: var(--text-dim);
  line-height: 1.65;
  padding: 20px;
  background: var(--bg3);
  border-radius: var(--radius);
  border: 1px solid var(--border2);
  border-left: 3px solid var(--accent);
}
.contact__form {
  background: var(--bg3);
  border: 1px solid var(--border2);
  border-radius: var(--radius-lg);
  padding: 36px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.form-group label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-dim);
  letter-spacing: 0.05em;
}
.form-group input,
.form-group select,
.form-group textarea {
  background: var(--bg4);
  border: 1px solid var(--border2);
  border-radius: var(--radius);
  padding: 12px 16px;
  font-size: 15px;
  color: var(--text);
  transition: border-color var(--transition);
  resize: vertical;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(79,127,247,0.12);
}
.form-group select option { background: var(--bg3); }
.form-note {
  font-size: 12px;
  color: var(--text-xdim);
  text-align: center;
  font-family: var(--mono);
}

/* ── FOOTER ──────────────────────────────────────────────── */
.footer {
  border-top: 1px solid var(--border2);
  padding: 48px 0;
}
.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}
.footer__brand {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.footer__logo {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: 0.08em;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.footer__corp {
  font-size: 12px;
  color: var(--text-xdim);
  letter-spacing: 0.05em;
}
.footer__copy {
  font-size: 12px;
  color: var(--text-xdim);
  text-align: center;
  line-height: 1.65;
}
.footer__nav {
  display: flex;
  gap: 28px;
}
.footer__nav a {
  font-size: 13px;
  color: var(--text-dim);
  transition: color var(--transition);
}
.footer__nav a:hover { color: var(--accent); }

/* ── MOBILE ──────────────────────────────────────────────── */
@media (max-width: 900px) {
  .tech__grid     { grid-template-columns: 1fr 1fr; }
  .projects__grid { grid-template-columns: 1fr 1fr; }
  .about__inner   { grid-template-columns: 1fr; gap: 48px; }
  .contact__inner { grid-template-columns: 1fr; gap: 48px; }
  .ip__cards      { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .section        { padding: 100px 0; }
  .nav__links     { gap: 24px; }
  .hero__tagline  { letter-spacing: 0.1em; font-size: 13px; }
  .section-desc   { margin-bottom: 52px; }
  .about__inner   { gap: 40px; }
  .contact__inner { gap: 40px; }
}

@media (max-width: 640px) {
  .section        { padding: 80px 0; }
  .container      { padding: 0 20px; }
  .tech__grid     { grid-template-columns: 1fr; }
  .projects__grid { grid-template-columns: 1fr; }
  .ip__cards      { grid-template-columns: 1fr; }
  .footer__inner  { flex-direction: column; text-align: center; }
  .footer__nav    { flex-wrap: wrap; justify-content: center; gap: 16px; }
  .nav__links     { display: none; }
  .nav__toggle    { display: flex; }
  .hero__content  { padding: 0 10px; }
  .hero__title-main { font-size: clamp(56px, 15vw, 80px); }
  .hero__tagline  { font-size: 12px; letter-spacing: 0.06em; }
  .hero__desc     { font-size: 16px; margin-bottom: 32px; }
  .contact__form  { padding: 24px 20px; }
  .ip__notice     { flex-direction: column; gap: 12px; }
  .section-title  { letter-spacing: -0.01em; }
  .nav__links.open {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: var(--nav-h);
    left: 0; right: 0;
    background: rgba(5,6,10,0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 32px 24px;
    gap: 24px;
    border-bottom: 1px solid var(--border2);
    height: calc(100vh - var(--nav-h));
    overflow-y: auto;
  }
}

/* ── ANIMATIONS ──────────────────────────────────────────── */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}