/* ===== Reset & Base ===== */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg: #ffffff;
  --bg-alt: #fafafa;
  --fg: #18181b;
  --fg-muted: #52525b;
  --fg-faint: #71717a;
  --border: #e4e4e7;
  --card-bg: #ffffff;
  --input-bg: #ffffff;
  --blue: #2563eb;
  --violet: #7c3aed;
  --blue-light: rgba(37, 99, 235, 0.2);
  --btn-bg: #18181b;
  --btn-fg: #ffffff;
  --btn-hover: #3f3f46;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #09090b;
    --bg-alt: #18181b;
    --fg: #f4f4f5;
    --fg-muted: #a1a1aa;
    --fg-faint: #71717a;
    --border: #27272a;
    --card-bg: #09090b;
    --input-bg: #27272a;
    --btn-bg: #ffffff;
    --btn-fg: #18181b;
    --btn-hover: #e4e4e7;
  }
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Geist", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  text-decoration: none;
  color: inherit;
}

/* ===== Navigation ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 50;
  height: 64px;
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

@media (prefers-color-scheme: dark) {
  .nav {
    background: rgba(9, 9, 11, 0.8);
  }
}

.nav-inner {
  max-width: 1152px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.025em;
}

.nav-links {
  display: none;
  gap: 32px;
  font-size: 0.875rem;
  font-weight: 500;
}

.nav-links a {
  color: var(--fg-muted);
  transition: color 0.2s;
}

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

@media (min-width: 640px) {
  .nav-links {
    display: flex;
  }
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 20px;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: 9999px;
  background: var(--btn-bg);
  color: var(--btn-fg);
  border: none;
  cursor: pointer;
  transition: background 0.2s;
}

.btn-primary:hover {
  background: var(--btn-hover);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 32px;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: 9999px;
  background: transparent;
  color: var(--fg);
  border: 1px solid var(--border);
  cursor: pointer;
  transition: background 0.2s;
}

.btn-secondary:hover {
  background: var(--bg-alt);
}

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 80px 24px 64px;
  text-align: center;
}

.hero-inner {
  max-width: 768px;
  margin: 0 auto;
}

.hero-tag {
  margin-bottom: 16px;
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--blue);
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.025em;
}

.gradient-text {
  background: linear-gradient(to right, var(--blue), var(--violet));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  max-width: 576px;
  margin: 24px auto 0;
  font-size: 1.125rem;
  line-height: 1.75;
  color: var(--fg-muted);
}

.hero-actions {
  margin-top: 40px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.hero-actions .btn-primary {
  padding: 12px 32px;
}

@media (min-width: 640px) {
  .hero-actions {
    flex-direction: row;
    justify-content: center;
  }
}

/* ===== Features ===== */
.features {
  background: var(--bg-alt);
  padding: 96px 24px;
}

.features-inner {
  max-width: 1152px;
  margin: 0 auto;
}

.section-title {
  text-align: center;
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.025em;
}

.section-subtitle {
  max-width: 672px;
  margin: 16px auto 0;
  text-align: center;
  color: var(--fg-muted);
}

.features-grid {
  margin-top: 64px;
  display: grid;
  gap: 32px;
}

@media (min-width: 640px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.feature-card {
  padding: 32px;
  border-radius: 16px;
  border: 1px solid var(--border);
  background: var(--card-bg);
  transition: box-shadow 0.2s;
}

.feature-card:hover {
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1),
    0 8px 10px -6px rgba(0, 0, 0, 0.1);
}

@media (prefers-color-scheme: dark) {
  .feature-card:hover {
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.4),
      0 8px 10px -6px rgba(0, 0, 0, 0.3);
  }
}

.feature-card h3 {
  font-size: 1.125rem;
  font-weight: 600;
}

.feature-card p {
  margin-top: 12px;
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--fg-muted);
}

/* ===== About ===== */
.about {
  padding: 96px 24px;
}

.about-inner {
  max-width: 768px;
  margin: 0 auto;
  text-align: center;
}

.about-inner p {
  margin-top: 24px;
  font-size: 1.125rem;
  line-height: 1.75;
  color: var(--fg-muted);
}

/* ===== Contact ===== */
.contact {
  background: var(--bg-alt);
  padding: 96px 24px;
}

.contact-inner {
  max-width: 576px;
  margin: 0 auto;
  text-align: center;
}

.contact-inner > p {
  margin-top: 16px;
  color: var(--fg-muted);
}

.contact-form {
  margin-top: 40px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  text-align: left;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 12px 16px;
  font-size: 0.875rem;
  font-family: inherit;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--input-bg);
  color: var(--fg);
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
  color: var(--fg-faint);
}

.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 3px var(--blue-light);
}

.contact-form textarea {
  resize: vertical;
}

.contact-form .btn-primary {
  margin-top: 8px;
  padding: 12px 32px;
  font-family: inherit;
}

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--border);
  padding: 48px 24px;
}

.footer-inner {
  max-width: 1152px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  font-size: 0.875rem;
  color: var(--fg-faint);
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  color: var(--fg-faint);
  transition: color 0.2s;
}

.footer-links a:hover {
  color: var(--fg);
}

@media (min-width: 640px) {
  .footer-inner {
    flex-direction: row;
    justify-content: space-between;
  }
}