body {
  font-family: 'Segoe UI', Arial, sans-serif;
  margin: 0;
  background: #0a0a0a;
  color: #e4e4e7;
}

/* Layout */
.dtb-main {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
  padding: 2.5rem 1rem 2rem 1rem;
  max-width: 1100px;
  margin: 0 auto;
  box-sizing: border-box;
}

/* Header */
.dtb-header {
  background: #0f0f0f;
  border-bottom: 1.5px solid #2a2a2a;
  box-shadow: 0 2px 8px rgba(0,0,0,0.3);
  padding: 2.5rem 1rem 1.5rem 1rem;
  text-align: center;
}
.dtb-header-content {
  max-width: 700px;
  margin: 0 auto;
}
.dtb-title {
  font-size: 2.7rem;
  font-weight: 800;
  color: #ff4757;
  margin: 0 0 0.3rem 0;
  letter-spacing: -1px;
}
.dtb-subtitle {
  font-size: 1.2rem;
  color: #a8a5ff;
  margin: 0;
  font-weight: 500;
  letter-spacing: 0.5px;
}

/* Tabs */
.dtb-tabs {
  display: flex;
  flex-wrap: wrap;
  background: #1a1a1a;
  border-bottom: 2px solid #3a3a3a;
  padding: 0.5rem 1rem 0 1rem;
  gap: 0.5rem;
  justify-content: center;
  position: sticky;
  top: 0;
  z-index: 10;
}
.dtb-tabs button {
  background: #404040;
  color: #e4e4e7;
  border: none;
  border-radius: 18px 18px 0 0;
  padding: 0.6rem 1.6rem;
  cursor: pointer;
  font-size: 1.08rem;
  font-weight: 500;
  margin-bottom: -2px;
  transition: background 0.25s, color 0.25s, box-shadow 0.25s;
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
  outline: none;
}
.dtb-tabs button.active {
  background: #ff4757;
  color: #fff;
  font-weight: 700;
  box-shadow: 0 4px 16px rgba(255,71,87,0.3);
}
.dtb-tabs button:focus {
  outline: 2px solid #a8a5ff;
}

/* Tool Cards */
.dtb-tools-list {
  flex: 2 1 400px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.7rem;
  margin-bottom: 1rem;
}
.tool-card {
  background: #1e1e1e;
  border-radius: 18px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.4);
  padding: 1.3rem 1.1rem 1.1rem 1.1rem;
  cursor: pointer;
  border: 2px solid transparent;
  transition: box-shadow 0.25s, transform 0.22s, border-color 0.22s;
  min-height: 120px;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
}
.tool-card:hover, .tool-card:focus {
  box-shadow: 0 6px 24px rgba(168,165,255,0.3);
  border-color: #a8a5ff;
  transform: translateY(-3px) scale(1.025);
}
.tool-card h3 {
  margin: 0 0 0.5rem 0;
  font-size: 1.15rem;
  color: #5dade2;
  font-weight: 700;
}
.tool-card p {
  margin: 0;
  color: #b0b0b0;
  font-size: 1.01rem;
}

/* Tool Details */
.dtb-tool-details {
  flex: 1 1 320px;
  background: #1e1e1e;
  border-radius: 18px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.4);
  padding: 2rem 1.3rem 1.3rem 1.3rem;
  min-width: 280px;
  max-width: 370px;
  position: sticky;
  top: 2.5rem;
  align-self: flex-start;
  border: 1.5px solid #3a3a3a;
  transition: box-shadow 0.25s, border-color 0.22s, opacity 0.22s;
  opacity: 1;
  z-index: 2;
}
.dtb-tool-details.hidden {
  display: none;
  opacity: 0;
}
.dtb-tool-details h2 {
  margin-top: 0;
  font-size: 1.3rem;
  color: #a8a5ff;
}
.dtb-tool-details h4 {
  margin-bottom: 0.3rem;
  margin-top: 1.1rem;
  color: #ff6b6b;
  font-size: 1.05rem;
}
.dtb-tool-details pre {
  background: #0f0f0f;
  padding: 0.7rem 1rem;
  border-radius: 6px;
  overflow-x: auto;
  font-size: 0.99rem;
  margin: 0 0 0.7rem 0;
  border: 1px solid #3a3a3a;
  color: #e4e4e7;
}
.dtb-tool-details a {
  color: #ff6b6b;
  text-decoration: underline;
  word-break: break-all;
}
.dtb-tool-details ul {
  padding-left: 1.2em;
  margin: 0.5em 0 0 0;
}
.dtb-tool-details button {
  background: none;
  border: none;
  color: #a8a5ff;
  font-size: 1.5em;
  cursor: pointer;
  transition: color 0.2s;
}
.dtb-tool-details button:hover {
  color: #5dade2;
}

/* About & Roadmaps Sections */
.dtb-about-section, .dtb-roadmaps-section {
  background: #1e1e1e;
  border-radius: 18px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.4);
  padding: 2rem 1.3rem 1.3rem 1.3rem;
  margin: 0 auto;
  max-width: 700px;
  border: 1.5px solid #3a3a3a;
  transition: box-shadow 0.25s, border-color 0.22s, opacity 0.22s;
  opacity: 1;
}
.dtb-about-section.hidden, .dtb-roadmaps-section.hidden {
  display: none;
  opacity: 0;
}
.dtb-about-section h2, .dtb-roadmaps-section h2 {
  color: #ff6b6b;
  margin-top: 0;
}
.dtb-about-section h3 {
  color: #a8a5ff;
}
.dtb-about-section ul {
  padding-left: 1.2em;
}
.dtb-roadmaps-section h3 {
  color: #a8a5ff;
  margin-bottom: 0.3em;
}
.roadmap-category ul {
  margin: 0 0 1.2em 0;
  padding-left: 1.2em;
}
.roadmap-category li {
  margin-bottom: 0.3em;
}

/* Transitions */
.dtb-tool-details, .dtb-about-section, .dtb-roadmaps-section, .tool-card, .dtb-tabs button {
  transition: box-shadow 0.25s, border-color 0.22s, background 0.22s, color 0.22s, opacity 0.22s, transform 0.22s;
}

/* Responsive Design */
@media (max-width: 900px) {
  .dtb-main {
    flex-direction: column;
    gap: 1.5rem;
    padding: 1.2rem 0.5rem 1.5rem 0.5rem;
  }
  .dtb-tool-details {
    max-width: 100%;
    position: static;
    margin-top: 1.5rem;
  }
  .dtb-about-section, .dtb-roadmaps-section {
    max-width: 100%;
    padding: 1.2rem 0.7rem 1rem 0.7rem;
  }
}
@media (max-width: 600px) {
  .dtb-title {
    font-size: 2rem;
  }
  .dtb-header {
    padding: 1.2rem 0.5rem 0.7rem 0.5rem;
  }
  .dtb-main {
    padding: 0.5rem 0.1rem 1rem 0.1rem;
  }
  .dtb-tabs {
    padding: 0.3rem 0.2rem 0 0.2rem;
    gap: 0.2rem;
  }
  .dtb-tabs button {
    padding: 0.5rem 0.7rem;
    font-size: 0.98rem;
  }
}