:root {
  --bg: #0f172a;
  --bg-alt: #0b1220;
  --card-bg: #111827;
  --accent: #f97316;
  --accent-soft: rgba(249, 115, 22, 0.15);
  --text-main: #f9fafb;
  --text-sub: #9ca3af;
  --border-soft: #1f2937;
  --shadow-soft: 0 18px 40px rgba(15, 23, 42, 0.7);
  --radius-lg: 18px;
  --radius-md: 12px;
  --radius-sm: 999px;
  --max-width: 1050px;
}

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

html,
body {
  margin: 0;
  padding: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  background: radial-gradient(circle at top left, #1f2937, #020617 55%);
  color: var(--text-main);
}

/* layout */

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.3rem;
}

/* header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(18px);
  background: linear-gradient(
    to bottom,
    rgba(15, 23, 42, 0.95),
    rgba(15, 23, 42, 0.88),
    rgba(15, 23, 42, 0.4)
  );
  border-bottom: 1px solid rgba(148, 163, 184, 0.16);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
}

.logo {
  text-decoration: none;
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.logo-main {
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: 0.03em;
}

.logo-sub {
  font-size: 0.8rem;
  color: var(--text-sub);
}

.nav {
  display: flex;
  gap: 1rem;
  align-items: center;
}

.nav a {
  font-size: 0.9rem;
  color: var(--text-sub);
  text-decoration: none;
  padding: 0.4rem 0.7rem;
  border-radius: var(--radius-sm);
  transition: background 0.15s ease, color 0.15s ease, transform 0.15s ease;
}

.nav a:hover {
  background: rgba(15, 23, 42, 0.9);
  color: var(--text-main);
  transform: translateY(-1px);
}

/* mobile nav toggle */

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.3rem;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text-main);
  border-radius: 999px;
  margin: 3px 0;
}

/* hero */

.hero {
  padding: 3.5rem 0 2.8rem;
}

.hero-content {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(0, 1.2fr);
  gap: 2rem;
  align-items: center;
}

.hero-text h1 {
  font-size: clamp(2.1rem, 3vw + 1rem, 2.9rem);
  margin: 0 0 0.8rem;
}

.hero-text p {
  margin: 0.2rem 0;
  color: var(--text-sub);
  font-size: 0.98rem;
}

.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin: 1.4rem 0 0.6rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.3rem;
  border-radius: 999px;
  font-size: 0.95rem;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease,
    background 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}

.btn.primary {
  background: linear-gradient(135deg, #fb923c, #f97316);
  color: #111827;
  box-shadow: 0 12px 30px rgba(248, 113, 22, 0.6);
}

.btn.primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 18px 40px rgba(248, 113, 22, 0.8);
}

.btn.ghost {
  background: rgba(15, 23, 42, 0.8);
  color: var(--text-main);
  border-color: rgba(148, 163, 184, 0.4);
}

.btn.ghost:hover {
  background: rgba(15, 23, 42, 0.95);
  border-color: rgba(249, 115, 22, 0.7);
}

.hero-note {
  font-size: 0.85rem;
  color: var(--text-sub);
}

.hero-panel {
  background: radial-gradient(circle at top left, #f97316 0, #111827 40%, #020617);
  border-radius: var(--radius-lg);
  padding: 1.6rem 1.5rem;
  box-shadow: var(--shadow-soft);
  position: relative;
  overflow: hidden;
}

.hero-tag {
  position: absolute;
  top: 1.2rem;
  right: 1.2rem;
  font-size: 0.75rem;
  padding: 0.25rem 0.7rem;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.75);
  border: 1px solid rgba(248, 250, 252, 0.1);
}

.hero-panel h2 {
  margin-top: 0.2rem;
}

.hero-list {
  list-style: none;
  padding: 0;
  margin: 0.8rem 0 0;
  font-size: 0.95rem;
}

.hero-list li {
  margin-bottom: 0.4rem;
}

/* sections */

.section {
  padding: 2.5rem 0;
}

.section-alt {
  background: radial-gradient(circle at top right, #1f2937, #020617 60%);
}

.section h2 {
  margin: 0 0 0.4rem;
  font-size: 1.6rem;
}

.section-intro {
  margin: 0.2rem 0 1.4rem;
  color: var(--text-sub);
  font-size: 0.95rem;
}

/* cards */

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.4rem;
}

.card {
  background: var(--card-bg);
  border-radius: var(--radius-md);
  padding: 1.2rem 1.1rem;
  border: 1px solid var(--border-soft);
  box-shadow: 0 12px 26px rgba(15, 23, 42, 0.65);
}

.card h3 {
  margin-top: 0;
  margin-bottom: 0.4rem;
  font-size: 1.05rem;
}

.card p {
  margin: 0.1rem 0 0.4rem;
  color: var(--text-sub);
  font-size: 0.9rem;
}

.card-link-placeholder {
  font-size: 0.8rem;
  color: #fbbf24;
}

/* about */

.about-layout {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 1.4fr);
  gap: 1.5rem;
  align-items: flex-start;
}

.about-highlight {
  background: var(--card-bg);
  border-radius: var(--radius-md);
  padding: 1rem;
  border: 1px solid var(--accent-soft);
  box-shadow: var(--shadow-soft);
}

.about-highlight h3 {
  margin-top: 0;
  margin-bottom: 0.4rem;
}

.about-highlight ul {
  padding-left: 1.1rem;
  margin: 0.2rem 0 0;
  color: var(--text-sub);
  font-size: 0.9rem;
}

/* contact */

.contact-box {
  background: var(--card-bg);
  border-radius: var(--radius-md);
  padding: 1.1rem 1.2rem;
  border: 1px solid var(--border-soft);
  box-shadow: 0 10px 24px rgba(15, 23, 42, 0.6);
}

.contact-box p {
  margin: 0 0 0.5rem;
}

.contact-box ul {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--text-sub);
  font-size: 0.9rem;
}

/* footer */

.site-footer {
  border-top: 1px solid rgba(148, 163, 184, 0.18);
  background: rgba(2, 6, 23, 0.96);
  padding: 1.4rem 0 1.8rem;
}

.footer-content {
  text-align: center;
}

.footer-content p {
  margin: 0.1rem 0;
  font-size: 0.85rem;
  color: var(--text-sub);
}

.footer-small {
  font-size: 0.78rem;
}

/* responsive */

@media (max-width: 900px) {
  .hero-content {
    grid-template-columns: minmax(0, 1fr);
  }

  .hero-panel {
    order: -1;
  }

  .card-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .about-layout {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (max-width: 700px) {
  .nav {
    position: absolute;
    top: 64px;
    right: 0;
    left: 0;
    flex-direction: column;
    background: rgba(15, 23, 42, 0.97);
    padding: 0.6rem 1.3rem 1rem;
    border-bottom: 1px solid rgba(148, 163, 184, 0.2);
    transform: translateY(-110%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.18s ease, opacity 0.18s ease;
  }

  .nav.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-toggle {
    display: block;
  }

  .card-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .hero {
    padding-top: 3rem;
  }
}