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

:root {
  --bg: #0a0a0f;
  --surface: #14141f;
  --surface-hover: #1c1c2e;
  --border: #2a2a3d;
  --text: #f0f0f5;
  --text-muted: #8888a0;
  --accent: #7c5cfc;
  --accent-hover: #6a48e8;
  --accent-glow: rgba(124, 92, 252, 0.25);
  --gradient-1: #7c5cfc;
  --gradient-2: #00c2ff;
  --success: #00e5a0;
  --error: #ff4757;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: var(--bg);
  color: var(--text);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

/* ── Header ── */
.header {
  text-align: center;
  padding: 2.5rem 1rem 1.5rem;
  border-bottom: 1px solid var(--border);
}

.header-title {
  font-size: 1.75rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--gradient-1), var(--gradient-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.35rem;
}

.header-subtitle {
  font-size: 0.95rem;
  color: var(--text-muted);
}

/* ── Container ── */
.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem 1rem 3rem;
}

/* ── Config cards (homepage) ── */
.configs-grid {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.config-card {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.25rem;
  text-decoration: none;
  color: var(--text);
  transition: all 0.25s ease;
}

.config-card:hover {
  background: var(--surface-hover);
  border-color: var(--accent);
  box-shadow: 0 0 20px var(--accent-glow);
  transform: translateY(-2px);
}

.config-card-icon {
  flex-shrink: 0;
  width: 52px;
  height: 52px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--gradient-1), var(--gradient-2));
  display: flex;
  align-items: center;
  justify-content: center;
}

.config-card-content {
  flex: 1;
  min-width: 0;
}

.config-card-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.2rem;
}

.config-card-desc {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.config-card-arrow {
  flex-shrink: 0;
  color: var(--text-muted);
  transition: color 0.25s ease, transform 0.25s ease;
}

.config-card:hover .config-card-arrow {
  color: var(--accent);
  transform: translateX(3px);
}

/* ── Config detail page ── */
.config-hero {
  text-align: center;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 2rem;
}

.config-hero h1 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.config-hero p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.config-content {
  margin-bottom: 2.5rem;
}

.config-content h2 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.config-step {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem;
  margin-bottom: 1rem;
}

.config-step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--gradient-1), var(--gradient-2));
  color: #fff;
  font-size: 0.8rem;
  font-weight: 700;
  margin-right: 0.75rem;
  vertical-align: middle;
}

.config-step-title {
  font-weight: 600;
  font-size: 0.95rem;
  vertical-align: middle;
}

.config-step-body {
  margin-top: 0.75rem;
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.config-step-body code {
  background: rgba(124, 92, 252, 0.1);
  border: 1px solid rgba(124, 92, 252, 0.2);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-size: 0.85rem;
  color: var(--accent);
}

/* ── Video section ── */
.video-section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 2rem;
  text-align: center;
  margin-top: 2rem;
}

.video-section h2 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.video-section p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 1.5rem;
}

.btn-video {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: linear-gradient(135deg, var(--gradient-1), var(--gradient-2));
  color: #fff;
  border: none;
  padding: 0.85rem 2rem;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.btn-video:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

.video-player {
  margin-top: 1.5rem;
  border-radius: 12px;
  overflow: hidden;
  aspect-ratio: 16/9;
}

.video-player iframe {
  width: 100%;
  height: 100%;
  border: none;
}

/* ── Modal overlay ── */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(4px);
  z-index: 100;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.modal-overlay.active {
  display: flex;
}

.modal {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 2rem;
  width: 100%;
  max-width: 420px;
  position: relative;
}

.modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  cursor: pointer;
  line-height: 1;
  transition: color 0.2s;
}

.modal-close:hover {
  color: var(--text);
}

.modal h2 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 0.35rem;
  text-align: center;
}

.modal p {
  color: var(--text-muted);
  font-size: 0.85rem;
  text-align: center;
  margin-bottom: 1.5rem;
}

.form-group {
  margin-bottom: 1rem;
}

.form-group label {
  display: block;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
}

.form-group input {
  width: 100%;
  padding: 0.75rem 1rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  font-size: 0.95rem;
  font-family: inherit;
  transition: border-color 0.2s;
  outline: none;
}

.form-group input:focus {
  border-color: var(--accent);
}

.form-group input::placeholder {
  color: #555570;
}

.form-error {
  font-size: 0.78rem;
  color: var(--error);
  margin-top: 0.3rem;
  display: none;
}

.btn-submit {
  width: 100%;
  padding: 0.85rem;
  background: linear-gradient(135deg, var(--gradient-1), var(--gradient-2));
  color: #fff;
  border: none;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.2s ease;
  margin-top: 0.5rem;
}

.btn-submit:hover {
  opacity: 0.9;
}

.btn-submit:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ── Footer ── */
.footer {
  text-align: center;
  padding: 2rem 1rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  opacity: 0.5;
}

/* ── Empty state ── */
.empty-state {
  text-align: center;
  padding: 4rem 1rem;
  color: var(--text-muted);
}

.empty-state svg {
  margin-bottom: 1rem;
  opacity: 0.3;
}

.empty-state p {
  font-size: 0.95rem;
}

/* ── Responsive ── */
@media (max-width: 480px) {
  .header-title {
    font-size: 1.35rem;
  }

  .config-step {
    padding: 1rem;
  }

  .video-section {
    padding: 1.5rem;
  }

  .modal {
    padding: 1.5rem;
  }
}