:root {
  --bg: #0f0f0f;
  --bg-elevated: #1a1a1a;
  --bg-card: #1f1f1f;
  --border: #2e2e2e;
  --text: #f1f1f1;
  --text-dim: #a0a0a0;
  --accent: #ff0033;
  --accent-hover: #e0002e;
  color-scheme: dark;
}

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

html {
  scroll-behavior: smooth;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: "Segoe UI", Roboto, Arial, sans-serif;
  line-height: 1.6;
}

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

a:hover {
  text-decoration: underline;
}

/* Nav */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 24px;
  background: rgba(15, 15, 15, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 600;
  font-size: 15px;
}

.nav-brand:hover {
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 18px;
  margin-left: auto;
}

.nav-links a {
  color: var(--text-dim);
  font-size: 14px;
}

.nav-links a:hover {
  color: var(--text);
  text-decoration: none;
}

/* Buttons */
.btn {
  display: inline-block;
  border-radius: 8px;
  font-weight: 600;
  text-align: center;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.1s ease;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff;
}

.btn-secondary {
  background: var(--bg-elevated);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: #262626;
  color: var(--text);
}

.btn-lg {
  padding: 12px 26px;
  font-size: 16px;
}

.btn-sm {
  padding: 6px 14px;
  font-size: 13px;
}

/* Hero */
.hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 18px;
  padding: 80px 24px 64px;
  background: radial-gradient(ellipse at top, #261016 0%, var(--bg) 60%);
}

.hero-icon {
  border-radius: 20px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
}

.hero h1 {
  font-size: clamp(32px, 6vw, 56px);
  line-height: 1.15;
}

.accent {
  color: var(--accent);
}

.hero-sub {
  max-width: 640px;
  font-size: 18px;
  color: var(--text-dim);
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  justify-content: center;
}

.hero-note {
  max-width: 560px;
  font-size: 13px;
  color: var(--text-dim);
}

/* Sections */
.section {
  padding: 64px 24px;
  max-width: 980px;
  margin: 0 auto;
}

.section-alt {
  max-width: none;
  background: var(--bg-elevated);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section h2 {
  font-size: 30px;
  margin-bottom: 12px;
  text-align: center;
}

.section-sub {
  text-align: center;
  color: var(--text-dim);
  margin-bottom: 32px;
}

.badge {
  display: inline-block;
  padding: 2px 12px;
  border-radius: 999px;
  background: var(--accent);
  color: #fff;
  font-size: 13px;
  font-weight: 700;
  vertical-align: middle;
  margin-right: 6px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
  margin-top: 28px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
}

.card h3 {
  font-size: 16px;
  margin-bottom: 6px;
}

.card p {
  font-size: 14px;
  color: var(--text-dim);
}

/* Steps */
.steps {
  list-style: none;
  max-width: 640px;
  margin: 28px auto 0;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.steps li {
  display: flex;
  gap: 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px;
}

.step-num {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

.steps h3 {
  font-size: 16px;
  margin-bottom: 4px;
}

.steps p {
  font-size: 14px;
  color: var(--text-dim);
}

.tip {
  max-width: 640px;
  margin: 20px auto 0;
  font-size: 14px;
  color: var(--text-dim);
  background: rgba(255, 0, 51, 0.08);
  border: 1px solid rgba(255, 0, 51, 0.35);
  border-radius: 10px;
  padding: 14px 16px;
}

/* Guide */
.guide {
  list-style: none;
  max-width: 720px;
  margin: 28px auto 0;
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.guide-step h3 {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  margin-bottom: 6px;
}

.guide-step p {
  color: var(--text-dim);
  font-size: 14px;
  margin-bottom: 12px;
}

.guide-step img {
  display: block;
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.45);
}

.guide-step img + img {
  margin-top: 12px;
}

/* Shortcuts */
.shortcuts {
  margin: 28px auto 0;
  border-collapse: collapse;
  max-width: 640px;
  width: 100%;
}

.shortcuts th,
.shortcuts td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
  text-align: left;
}

.shortcuts th {
  color: var(--text-dim);
  font-weight: 600;
  border-bottom-color: var(--border);
}

kbd {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  border-radius: 5px;
  padding: 1px 7px;
  font-family: Consolas, "Courier New", monospace;
  font-size: 13px;
}

code {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 1px 6px;
  font-size: 13px;
}

/* Footer */
.footer {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  flex-wrap: wrap;
  padding: 28px 24px;
  border-top: 1px solid var(--border);
  font-size: 13px;
  color: var(--text-dim);
}

.footer-note {
  opacity: 0.7;
}

@media (max-width: 640px) {
  .nav-links {
    display: none;
  }

  .hero {
    padding: 56px 20px 48px;
  }

  .hero-actions {
    flex-direction: column;
  }

  .btn-lg {
    width: 100%;
  }
}