/* ============================================================
   FEEN Wave Engine — Design System
   Dark-mode, CSS-custom-property–driven UI
   ============================================================ */

/* ---- Custom properties ---- */
:root {
    --clr-bg:          #0d0d0f;
    --clr-surface:     #141417;
    --clr-surface-2:   #1c1c21;
    --clr-surface-3:   #242429;
    --clr-border:      rgba(255, 255, 255, 0.07);
    --clr-border-hi:   rgba(255, 255, 255, 0.14);

    --clr-accent:      #03dac6;
    --clr-accent-dim:  rgba(3, 218, 198, 0.12);
    --clr-purple:      #bb86fc;
    --clr-purple-dim:  rgba(187, 134, 252, 0.15);
    --clr-danger:      #cf6679;
    --clr-danger-dim:  rgba(207, 102, 121, 0.15);

    --clr-text:        #e2e2e6;
    --clr-text-muted:  #8a8a96;
    --clr-text-faint:  #44444c;

    --radius-sm:  6px;
    --radius-md:  10px;
    --radius-lg:  16px;

    --shadow-card: 0 1px 3px rgba(0,0,0,0.4), 0 4px 16px rgba(0,0,0,0.3);

    --font-sans: 'Inter', 'Segoe UI', system-ui, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;

    --transition: 0.18s ease;
}

/* ---- Reset / base ---- */
*, *::before, *::after { box-sizing: border-box; }

body {
    margin: 0;
    background: var(--clr-bg);
    color: var(--clr-text);
    font-family: var(--font-sans);
    font-size: 15px;
    line-height: 1.55;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--clr-purple);
    text-decoration: none;
    transition: color var(--transition);
}
a:hover { color: #d0aaff; text-decoration: underline; }

/* ============================================================
   App shell
   ============================================================ */
.app-shell {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* ---- Topbar ---- */
.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 52px;
    padding: 0 24px;
    background: var(--clr-surface);
    border-bottom: 1px solid var(--clr-border);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(8px);
}

.topbar-brand {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    letter-spacing: 0.04em;
}

.brand-icon {
    font-size: 1.3rem;
    color: var(--clr-accent);
    line-height: 1;
}

.brand-name {
    font-size: 1.05rem;
    color: var(--clr-text);
}

.topbar-links {
    display: flex;
    gap: 4px;
}

.nav-link {
    padding: 5px 13px;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--clr-text-muted);
    transition: background var(--transition), color var(--transition);
}
.nav-link:hover {
    background: var(--clr-surface-3);
    color: var(--clr-text);
    text-decoration: none;
}
.nav-link.active {
    background: var(--clr-accent-dim);
    color: var(--clr-accent);
}

/* ---- Page content ---- */
.page-content {
    flex: 1;
    max-width: 1080px;
    width: 100%;
    margin: 0 auto;
    padding: 28px 24px 16px;
}

/* ---- Page header ---- */
.page-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 24px;
}

.page-header-text h1 {
    margin: 0 0 4px;
    font-size: 1.75rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--clr-accent);
}

.page-header-text p {
    margin: 0;
    font-size: 0.9rem;
    color: var(--clr-text-muted);
}

.header-badge {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 3px 10px;
    border-radius: 20px;
    background: var(--clr-accent-dim);
    border: 1px solid rgba(3, 218, 198, 0.3);
    color: var(--clr-accent);
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    margin-top: 4px;
}

.header-badge::before {
    content: '';
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--clr-accent);
    animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
    0%, 100% { opacity: 1; }
    50%       { opacity: 0.35; }
}

/* ---- Stat cards ---- */
.stat-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
    margin-bottom: 20px;
}

.stat-card {
    background: var(--clr-surface);
    border: 1px solid var(--clr-border);
    border-radius: var(--radius-md);
    padding: 14px 18px;
    display: flex;
    flex-direction: column;
    gap: 4px;
    transition: border-color var(--transition);
}
.stat-card:hover { border-color: var(--clr-border-hi); }

.stat-label {
    font-size: 0.72rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--clr-text-muted);
}

.stat-value {
    font-size: 1.6rem;
    font-weight: 600;
    color: var(--clr-text);
    line-height: 1.1;
}

.stat-unit {
    font-size: 0.9rem;
    color: var(--clr-text-muted);
    font-weight: 400;
}

/* ---- Main grid ---- */
.main-grid {
    display: grid;
    grid-template-columns: 280px 1fr;
    grid-template-rows: auto 1fr;
    gap: 16px;
}

/* ---- Card ---- */
.card {
    background: var(--clr-surface);
    border: 1px solid var(--clr-border);
    border-radius: var(--radius-lg);
    padding: 20px;
    box-shadow: var(--shadow-card);
}

.card-title {
    margin: 0 0 16px;
    font-size: 0.78rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--clr-text-muted);
}

/* ---- Controls card ---- */
.controls-card {
    grid-column: 1;
    grid-row: 1 / 3;
}

.btn-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-bottom: 20px;
}

/* ---- Buttons ---- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 9px 16px;
    border-radius: var(--radius-md);
    border: 1px solid var(--clr-border-hi);
    background: var(--clr-surface-2);
    color: var(--clr-text);
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: background var(--transition), border-color var(--transition),
                transform 0.1s ease, box-shadow var(--transition);
    white-space: nowrap;
}
.btn:hover {
    background: var(--clr-surface-3);
    border-color: var(--clr-border-hi);
    transform: translateY(-1px);
    box-shadow: 0 3px 10px rgba(0,0,0,0.3);
}
.btn:active { transform: translateY(0); box-shadow: none; }

.btn-icon { font-style: normal; font-size: 0.9em; opacity: 0.8; }

.btn-primary {
    background: linear-gradient(135deg, #7c3aed 0%, #9b5de5 100%);
    border-color: transparent;
    color: #fff;
    box-shadow: 0 2px 8px rgba(124, 58, 237, 0.35);
}
.btn-primary:hover {
    background: linear-gradient(135deg, #6d28d9 0%, #8b4fe0 100%);
    border-color: transparent;
    box-shadow: 0 4px 14px rgba(124, 58, 237, 0.45);
}
.btn-primary.active {
    background: linear-gradient(135deg, #059669 0%, #10b981 100%);
    box-shadow: 0 2px 8px rgba(5, 150, 105, 0.4);
}

.btn-danger {
    background: var(--clr-danger-dim);
    border-color: rgba(207, 102, 121, 0.3);
    color: var(--clr-danger);
}
.btn-danger:hover {
    background: rgba(207, 102, 121, 0.25);
    border-color: rgba(207, 102, 121, 0.5);
}

/* ---- Speed slider ---- */
.speed-row {
    display: flex;
    align-items: center;
    gap: 10px;
    padding-top: 4px;
    border-top: 1px solid var(--clr-border);
}

.speed-label {
    font-size: 0.78rem;
    color: var(--clr-text-muted);
    white-space: nowrap;
    min-width: 80px;
}

.speed-val {
    font-size: 0.82rem;
    color: var(--clr-accent);
    min-width: 20px;
    text-align: right;
}

.slider {
    flex: 1;
    -webkit-appearance: none;
    appearance: none;
    height: 3px;
    background: var(--clr-surface-3);
    border-radius: 2px;
    outline: none;
    cursor: pointer;
}
.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--clr-accent);
    cursor: pointer;
    transition: transform var(--transition);
}
.slider::-webkit-slider-thumb:hover { transform: scale(1.25); }
.slider::-moz-range-thumb {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--clr-accent);
    border: none;
    cursor: pointer;
}

/* ---- Chart card ---- */
.chart-card {
    grid-column: 2;
    grid-row: 1;
}

.chart-wrap {
    position: relative;
    height: 340px;
    background: #08080b;
    border-radius: var(--radius-md);
    padding: 8px;
    border: 1px solid var(--clr-border);
}

/* ---- Log card ---- */
.log-card {
    grid-column: 2;
    grid-row: 2;
    padding: 16px 20px;
}

#log-console {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    max-height: 110px;
    overflow-y: auto;
}

.log-entry {
    margin: 3px 0;
    color: var(--clr-accent);
    border-left: 2px solid var(--clr-accent-dim);
    padding-left: 8px;
}

/* ---- Footer ---- */
.app-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 24px;
    border-top: 1px solid var(--clr-border);
    font-size: 0.78rem;
    color: var(--clr-text-faint);
}
.app-footer a { color: var(--clr-text-muted); }
.app-footer a:hover { color: var(--clr-text); }

/* ---- Mono utility ---- */
.mono { font-family: var(--font-mono); }

/* ============================================================
   Dashboard — homepage tile grid
   ============================================================ */

.dashboard-intro {
    margin-bottom: 28px;
}

.dashboard-intro p {
    margin: 0;
    font-size: 0.9rem;
    color: var(--clr-text-muted);
    max-width: 640px;
}

.tile-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.tile {
    background: var(--clr-surface);
    border: 1px solid var(--clr-border);
    border-radius: var(--radius-lg);
    padding: 20px;
    box-shadow: var(--shadow-card);
    display: flex;
    flex-direction: column;
    gap: 12px;
    text-decoration: none;
    color: inherit;
    cursor: pointer;
    transition: border-color var(--transition), box-shadow var(--transition),
                transform var(--transition);
    position: relative;
    overflow: hidden;
}

.tile:hover {
    border-color: var(--clr-accent);
    box-shadow: 0 0 0 1px var(--clr-accent), 0 6px 24px rgba(0,0,0,0.45);
    transform: translateY(-2px);
    text-decoration: none;
    color: inherit;
}

.tile-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.tile-title {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--clr-text-muted);
}

.tile-badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 2px 8px;
    border-radius: 20px;
    background: var(--clr-accent-dim);
    border: 1px solid rgba(3, 218, 198, 0.3);
    color: var(--clr-accent);
    font-size: 0.65rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.tile-badge::before {
    content: '';
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--clr-accent);
    animation: pulse-dot 2s infinite;
}

.tile-preview {
    flex: 1;
    min-height: 90px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #08080b;
    border: 1px solid var(--clr-border);
    border-radius: var(--radius-md);
    overflow: hidden;
    position: relative;
}

.tile-preview canvas {
    display: block;
    width: 100%;
    height: 90px;
}

.tile-meta {
    display: flex;
    gap: 12px;
}

.tile-stat {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.tile-stat-label {
    font-size: 0.68rem;
    text-transform: uppercase;
    letter-spacing: 0.07em;
    color: var(--clr-text-muted);
}

.tile-stat-value {
    font-family: var(--font-mono);
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--clr-accent);
    line-height: 1.1;
}

/* Static tiles (API Ref has no live chart) */
.tile-preview-static {
    flex: 1;
    min-height: 90px;
    background: #08080b;
    border: 1px solid var(--clr-border);
    border-radius: var(--radius-md);
    padding: 14px 16px;
    display: flex;
    flex-direction: column;
    gap: 6px;
    justify-content: center;
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--clr-text-muted);
}

.tile-preview-static .ep-row {
    display: flex;
    gap: 8px;
    align-items: center;
}

.tile-preview-static .ep-method {
    font-size: 0.65rem;
    font-weight: 600;
    padding: 1px 6px;
    border-radius: 3px;
    min-width: 36px;
    text-align: center;
}

.ep-get  { background: var(--clr-accent-dim);  color: var(--clr-accent); }
.ep-post { background: var(--clr-purple-dim);  color: var(--clr-purple); }

/* Node-list preview */
.tile-node-list {
    flex: 1;
    min-height: 90px;
    background: #08080b;
    border: 1px solid var(--clr-border);
    border-radius: var(--radius-md);
    padding: 10px 14px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    gap: 5px;
    justify-content: flex-start;
}

.tile-node-row {
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-mono);
    font-size: 0.75rem;
}

.tile-node-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #00ff9d;
    flex-shrink: 0;
}

.tile-node-label {
    color: var(--clr-text-muted);
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.tile-node-val {
    color: var(--clr-accent);
}

.tile-empty-hint {
    font-size: 0.78rem;
    color: var(--clr-text-faint);
    text-align: center;
    width: 100%;
}

/* Wiring preview */
.tile-wiring-state {
    flex: 1;
    min-height: 90px;
    background: #08080b;
    border: 1px solid var(--clr-border);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.tile-wiring-state canvas {
    display: block;
    width: 100%;
    height: 90px;
}

/* Observer tile: VCP Connectivity observes an external system, not FEEN's own network.
   Purple accent signals the architectural boundary (read-only external view). */
.tile--observer {
    border-color: var(--clr-purple-dim);
}

.tile--observer:hover {
    border-color: var(--clr-purple);
    box-shadow: 0 0 0 1px var(--clr-purple), 0 6px 24px rgba(0,0,0,0.45);
}

.tile--observer .tile-badge {
    background: var(--clr-purple-dim);
    border-color: rgba(187, 134, 252, 0.3);
    color: var(--clr-purple);
}

.tile--observer .tile-badge::before {
    background: var(--clr-purple);
}

.tile--observer .tile-stat-value {
    color: var(--clr-purple);
}

/* API Reference tile: single-width, sits beside HLV tile in the last row */

/* ---- Responsive ---- */
@media (max-width: 700px) {
    .tile-grid {
        grid-template-columns: 1fr;
    }
}

@media (min-width: 701px) and (max-width: 900px) {
    .tile-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* ---- Responsive ---- */
@media (max-width: 700px) {
    .page-content  { padding: 16px 12px; }
    .stat-grid     { grid-template-columns: 1fr; }
    .main-grid     { grid-template-columns: 1fr; grid-template-rows: auto; }
    .controls-card { grid-column: 1; grid-row: auto; }
    .chart-card    { grid-column: 1; grid-row: auto; }
    .log-card      { grid-column: 1; grid-row: auto; }
    .btn-group     { flex-direction: row; flex-wrap: wrap; }
}