marcus/marcus-skills/stereo-design-system

Stereo Design System

Skeuomorphic component system inspired by high-end stereo receivers. Pure CSS — no images required. All textures achieved through layered gradients.

Design Principles

1. Physical metaphor — every element references real hardware (machined brass, etched metal, backlit displays)
2. Warm palette — dark brown/charcoal chassis, brushed brass controls, warm amber indicators
3. Consistent lighting — single overhead light source from top-left, all specular highlights at ~10 o'clock
4. Tactile depth — panels have brushed texture and beveled edges, controls cast shadows, indicators glow
5. Sans-serif only — system font stack throughout, no monospace or serif
6. Etched, not painted — position indicators and labels look stamped into the panel surface

Color Tokens

/* Brass palette — brushed/satin finish */
--brass-light: #c0a050;
--brass-mid: #a08838;
--brass-dark: #7a6828;
--brass-shadow: #54481a;
--brass-highlight: #d0b860;
--brass-shine: #ddc878;
 
/* Chassis */
--chassis-bg: #181715;
--chassis-surface: #24221e;
--chassis-border: #332f28;
--chassis-inset: #100f0d;
--chassis-text: #8a8a90;
--chassis-text-light: #b0b0b6;
 
/* Indicators */
--led-green: #4aff6a;
--led-red: #ff4a4a;
--led-amber: #ffaa2a;
 
/* Active/On state accent */
--active-amber: #e8a020;
--active-label: #d0a030;

Components

Rotary Knobs

Cylindrical flat-front brass knobs with:

• Circular brushed texture via repeating-conic-gradient
• Edge darkening via radial-gradient (flat center, dark rim = cylindrical)
• Separate gloss overlay (.knob-gloss div) — stays fixed when knob rotates
• Position indicator line (dark groove, not painted)
• Etched tick marks on panel surface (lighter than panel, not black: #3a3630 / #48423a)
• Sizes: standard (100px), small (64px), custom via inline styles

Toggle Switches

Vertical and horizontal (rocker) variants:

• Recessed plate with illuminated brass border (rgba(160,136,56,0.25))
• Brass toggle with specular highlight
• On state label: warm amber #d0a030 (not green)

Fader/Slider Controls

Blocky brass thumbs (2px border-radius) with:

• Top-face specular gradient
• Horizontal brushed texture
• Center groove detail
• Lit track fill (brass gradient)

VU Meters

Dark-face analog meters:

• Background: warm dark vignette (#2a2218 → #100c08)
• Amber/gold scale numbers with subtle glow
• Gold-to-red gradient needle
• Dark brass bezel (3-ring shadow)

LED Indicators

Brass-bezeled indicator lights:

• Green, amber, red variants
• On state: radial gradient with glow bloom via box-shadow
• Off state: dark muted version of same hue

Display/Readout

Backlit amber displays:

• Dark warm background (#0c0a06 → #080602)
• Amber text #e8a020 with glow halo
• Scanline overlay effect
• Dark brass bezel (3-ring)
• Sans-serif font

Source Selector Buttons

Recessed button group:

• 2×2 grid layout
• Illuminated border on active state
• Brass glow on selection

Panels

Dark warm chassis panels:

• Brushed horizontal texture (repeating-linear-gradient at 0.8% opacity)
• Diagonal grain (second gradient at 127°)
• Overhead light gradient (lighter top, darker bottom)
• Beveled edges (bright top border, inner highlight top/left, shadow bottom)
• Corner radius: 5px

Key Techniques

Brushed Metal Texture (CSS only)

/* Circular brushed (for knobs) */
repeating-conic-gradient(from 0deg,
  rgba(255,255,255,0.04) 0deg,
  rgba(0,0,0,0.02) 0.4deg,
  transparent 0.8deg, transparent 1.2deg)
 
/* Linear brushed (for panels) */
repeating-linear-gradient(180deg,
  rgba(255,255,255,0.008) 0px,
  transparent 1px, transparent 2px)

Specular Highlight (rotation-safe)

Gloss is a separate overlay div (not part of the knob background) so it stays fixed when the knob rotates:

<div class="knob-container">
  <div class="knob pos-mid"></div>
  <div class="knob-gloss"></div>  <!-- stays fixed -->
</div>

.knob-gloss {
  position: absolute;
  inset: 14px; /* match knob inset */
  border-radius: 50%;
  pointer-events: none;
  z-index: 2;
  background:
    radial-gradient(ellipse 60% 50% at 32% 28%,
      rgba(255,248,220,0.55) 0%,
      rgba(255,240,200,0.25) 25%, transparent 60%),
    radial-gradient(ellipse 40% 35% at 70% 72%,
      rgba(255,240,200,0.08) 0%, transparent 50%);
}

Etched Position Indicators

/* Lighter than panel surface, not black */
background: #3a3630;
box-shadow: 0 1px 0 rgba(255,248,220,0.06); /* light edge = stamped feel */

Illuminated Button Bezel

border: 1px solid rgba(160,136,56,0.25);
box-shadow: 0 0 4px rgba(160,136,56,0.1),
            0 -1px 0 rgba(208,184,96,0.15);

Page Background

Warm radial vignette (not flat):

background: radial-gradient(
  ellipse 70% 60% at 50% 35%,
  #22201c 0%, #1a1816 30%, #121110 60%, #0a0908 100%);

Reference Implementation

Full working showcase with all components: assets/showcase.html

• Interactive: clickable switches, source selector, animated VU needles
• Mobile responsive (breakpoints at 680px and 480px)
• Zero dependencies, single HTML file