redesigned buttons

frontend/src/styles/global.css

@@ -914,58 +914,98 @@ code, pre, kbd, samp {
     0 14px 40px -24px rgba(0, 0, 0, 0.9);
 }
 
-/* ───── Buttons ───── */
-.btn-stamp {
+/* ───── Buttons — one system ─────
+ * Base .btn = layout + size + focus/disabled. One variant for color
+ * (--primary / --ghost / --danger), one size modifier (--sm / --lg),
+ * shape modifiers (--icon / --block). Never restyle buttons ad-hoc. */
+.btn {
   display: inline-flex;
   align-items: center;
+  justify-content: center;
   gap: 0.5rem;
+  height: 2.5rem;
+  padding: 0 1.2rem;
   font-family: var(--font-display);
   font-style: italic;
   font-weight: 500;
   font-size: 0.95rem;
-  padding: 0.55rem 1.2rem;
+  line-height: 1;
+  letter-spacing: 0.02em;
+  background: transparent;
+  color: var(--text);
+  border: 1px solid transparent;
+  border-radius: 1px;
+  text-decoration: none;
+  white-space: nowrap;
+  cursor: pointer;
+  transition: transform 0.15s ease, background 0.15s ease, color 0.15s ease,
+              border-color 0.15s ease, box-shadow 0.15s ease;
+}
+.btn:focus-visible {
+  outline: none;
+  border-color: var(--mauve);
+  box-shadow: 0 0 0 2px color-mix(in srgb, var(--mauve) 35%, transparent);
+}
+.btn:disabled,
+.btn[aria-disabled="true"] {
+  opacity: 0.55;
+  cursor: default;
+  pointer-events: none;
+}
+.btn svg { width: 1.05em; height: 1.05em; flex-shrink: 0; }
+
+/* Variants */
+.btn--primary {
   background: var(--mauve);
   color: var(--rosewater);
-  border: 1px solid var(--mauve);
-  border-radius: 1px;
-  letter-spacing: 0.02em;
-  text-decoration: none;
-  cursor: pointer;
-  transition: transform 0.15s ease, background 0.15s ease, box-shadow 0.15s ease;
+  border-color: var(--mauve);
   box-shadow: 0 4px 0 -2px color-mix(in srgb, var(--mauve) 60%, black);
 }
-.btn-stamp:hover {
+.btn--primary:hover {
   transform: translateY(-1px);
   background: var(--red);
   border-color: var(--red);
   box-shadow: 0 6px 0 -2px color-mix(in srgb, var(--red) 60%, black);
 }
-.btn-stamp:active {
+.btn--primary:active {
   transform: translateY(1px);
   box-shadow: 0 1px 0 -1px color-mix(in srgb, var(--mauve) 60%, black);
 }
-.btn-ghost {
-  display: inline-flex;
-  align-items: center;
-  gap: 0.5rem;
-  font-family: var(--font-sans);
-  font-size: 0.82rem;
-  padding: 0.4rem 0.85rem;
-  background: transparent;
+.btn--ghost {
   color: var(--subtext1);
-  border: 1px solid var(--surface2);
-  border-radius: 1px;
-  letter-spacing: 0.06em;
-  text-transform: uppercase;
-  text-decoration: none;
-  cursor: pointer;
-  transition: color 0.15s, border-color 0.15s, background 0.15s;
+  border-color: var(--surface2);
+  background: color-mix(in srgb, var(--surface0) 45%, transparent);
 }
-.btn-ghost:hover {
+.btn--ghost:hover {
   color: var(--mauve);
-  border-color: var(--mauve);
-  background: color-mix(in srgb, var(--mauve) 8%, transparent);
+  border-color: color-mix(in srgb, var(--mauve) 50%, var(--surface2));
+  background: color-mix(in srgb, var(--surface0) 80%, transparent);
 }
+.btn--danger {
+  color: var(--red);
+  border-color: color-mix(in srgb, var(--red) 40%, var(--surface2));
+  background: color-mix(in srgb, var(--surface0) 45%, transparent);
+}
+.btn--danger:hover {
+  color: var(--rosewater);
+  background: var(--red);
+  border-color: var(--red);
+}
+/* Pressed/selected state for toggle & tab buttons */
+.btn.is-active {
+  color: var(--mauve);
+  border-color: color-mix(in srgb, var(--mauve) 55%, var(--surface2));
+  background: color-mix(in srgb, var(--mauve) 14%, transparent);
+}
+
+/* Sizes */
+.btn--sm { height: 2rem; padding: 0 0.85rem; font-size: 0.85rem; gap: 0.35rem; }
+.btn--lg { height: 3rem; padding: 0 1.6rem; font-size: 1.05rem; }
+
+/* Shapes */
+.btn--icon { padding: 0; width: 2.5rem; }
+.btn--icon.btn--sm { width: 2rem; }
+.btn--block { width: 100%; }
 
 /* ───── Top-bar controls — one height, one language ───── */
 .topbar-control {