Doc redesign

docs/_static/custom.css

@@ -10,3 +10,25 @@
 .fixed-table td {
     white-space: normal !important;
 }
+
+/* Card styling for sphinx-design grid cards */
+.sd-card {
+    transition: box-shadow 0.2s ease, transform 0.2s ease;
+}
+
+.sd-card:hover {
+    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
+    transform: translateY(-2px);
+}
+
+/* Horizontal rule styling */
+hr {
+    border: none;
+    border-top: 1px solid #e0e0e0;
+    margin: 2rem 0;
+}
+
+/* Quick start code block on landing page */
+.highlight-python .highlight {
+    border-radius: 4px;
+}

docs/guide/index.rst

@@ -1,27 +1,65 @@
 Guides
 ======
 
+These guides cover the core concepts you need to build and simulate models
+with NEURON. Start with :doc:`what_is_neuron` for an overview, or jump to
+:doc:`how_to_get_started` if you are ready to dive in.
+
+.. grid:: 1 1 2 2
+   :gutter: 3
+
+   .. grid-item-card:: :octicon:`info` What is NEURON?
+      :link: what_is_neuron
+      :link-type: doc
+
+      An overview of NEURON's capabilities, design philosophy, and
+      advantages for computational neuroscience.
+
+   .. grid-item-card:: :octicon:`rocket` How to Get Started
+      :link: how_to_get_started
+      :link-type: doc
+
+      Installation, first steps, key resources, and pointers to
+      tutorials and the discussion board.
+
+   .. grid-item-card:: :octicon:`meter` Units in NEURON
+      :link: units
+      :link-type: doc
+
+      Default units for time, voltage, current, length, and
+      conductance --- plus how to use ``neuron.units``.
+
+   .. grid-item-card:: :octicon:`question` FAQ
+      :link: faq
+      :link-type: doc
+
+      Answers to frequently asked questions about running,
+      troubleshooting, and configuring NEURON.
+
 .. toctree::
    :maxdepth: 2
+   :caption: Getting Started
 
    what_is_neuron
    how_to_get_started
    bio_faq
    units
+   faq
+
+.. toctree::
+   :maxdepth: 2
+   :caption: GUI Tools & Model Building
+
    saveses
    cellbuilder
    import3d
    network_builder_tutorials
    optimization
 
 .. toctree::
-   :maxdepth: 1 
+   :maxdepth: 1
+   :caption: Advanced Topics
 
    modelview_compact_display
-
-.. toctree::
-   :maxdepth: 2
-
    randomness
-   porting_mechanisms_to_cpp
-   faq
+   porting_mechanisms_to_cpp