:root {
    --bg: #12151f;
    --panel: #1a2030;
    --surface: #20283d;
    --text: #ecf2ff;
    --subtext: #adc2e5;
    --accent: #31c48d;
    --accent-contrast: #0b1f18;
    --border: rgba(255, 255, 255, 0.14);
    --shadow: 0 18px 45px rgba(0, 0, 0, 0.34);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: radial-gradient(circle at 20% 20%, rgba(255, 255, 255, 0.07), transparent 40%), var(--bg);
    color: var(--text);
}

body[data-theme="night-rider"] {
    --bg: #12151f;
    --panel: #1a2030;
    --surface: #20283d;
    --text: #ecf2ff;
    --subtext: #adc2e5;
    --accent: #31c48d;
    --accent-contrast: #0b1f18;
    --border: rgba(255, 255, 255, 0.14);
}

body[data-theme="sunset-burst"] {
    --bg: #1f0f22;
    --panel: #2a1631;
    --surface: #3c1f46;
    --text: #ffe9df;
    --subtext: #ffd6c8;
    --accent: #ff6b5b;
    --accent-contrast: #2b100c;
    --border: rgba(255, 184, 170, 0.28);
}

body[data-theme="arctic-glow"] {
    --bg: #091626;
    --panel: #122a45;
    --surface: #15385e;
    --text: #eaf7ff;
    --subtext: #b7dcf4;
    --accent: #8bd3ff;
    --accent-contrast: #072138;
    --border: rgba(160, 220, 255, 0.32);
}

body[data-theme="lime-punch"] {
    --bg: #0b1613;
    --panel: #10221c;
    --surface: #153328;
    --text: #f4ffe8;
    --subtext: #cae9c4;
    --accent: #b5ff59;
    --accent-contrast: #1d2f07;
    --border: rgba(190, 255, 133, 0.32);
}

body[data-theme="synthwave-pop"] {
    --bg: #1a0c2d;
    --panel: #241040;
    --surface: #33145c;
    --text: #ffeafe;
    --subtext: #f6c8ff;
    --accent: #ff4fd8;
    --accent-contrast: #2a0422;
    --border: rgba(255, 125, 230, 0.35);
}

body[data-theme="bubblegum-blast"] {
    --bg: #2a0f27;
    --panel: #3b1536;
    --surface: #54204c;
    --text: #fff2fb;
    --subtext: #ffd2f0;
    --accent: #ff8fd1;
    --accent-contrast: #3a0f2f;
    --border: rgba(255, 175, 221, 0.38);
}

body[data-theme="lava-lamp"] {
    --bg: #261008;
    --panel: #3b1a0e;
    --surface: #5a2a12;
    --text: #ffefe6;
    --subtext: #ffc9ab;
    --accent: #ff9a3d;
    --accent-contrast: #3b1c04;
    --border: rgba(255, 170, 96, 0.35);
}

body[data-theme="midnight-gold"] {
    --bg: #141414;
    --panel: #1f1f1f;
    --surface: #2d2d2d;
    --text: #fff9e8;
    --subtext: #e6d7ad;
    --accent: #ffd166;
    --accent-contrast: #3a2b05;
    --border: rgba(255, 215, 130, 0.32);
}

.web-app {
    width: min(900px, 100% - 2rem);
    margin: 0 auto;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    padding: 1rem 0;
}

.display-panel,
.app-upsell {
    border: 1px solid var(--border);
    background: linear-gradient(145deg, var(--panel), var(--surface));
    border-radius: 22px;
    box-shadow: var(--shadow);
}

.display-panel {
    display: grid;
    grid-template-rows: auto auto 1fr auto auto auto;
    gap: 0.9rem;
    align-items: center;
    padding: 1.4rem;
}

.app-upsell {
    padding: 1.4rem;
}

.top-banner {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 1rem;
}

.branding {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.branding img {
    border-radius: 8px;
}

.eyebrow {
    margin: 0;
    color: var(--subtext);
    font-size: 0.86rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.eyebrow-link {
    display: inline-block;
    text-decoration: none;
}

.eyebrow-link:hover {
    color: var(--text);
}

h1 {
    margin: 0;
    font-size: clamp(1.2rem, 2vw, 1.65rem);
}

.status {
    margin: 0;
    font-weight: 600;
    color: var(--subtext);
    min-height: 1.5rem;
}

.support-tip {
    margin: 0;
    color: var(--subtext);
    font-size: 0.9rem;
}

.cadence-readout {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border);
    border-radius: 18px;
    min-height: min(52vh, 420px);
    background: rgba(0, 0, 0, 0.12);
}

#cadence-value {
    font-size: clamp(5rem, 16vw, 12rem);
    font-weight: 800;
    line-height: 0.92;
    letter-spacing: -0.05em;
    color: var(--accent);
}

.unit {
    margin-top: 0.3rem;
    font-size: 1.15rem;
    font-weight: 700;
    letter-spacing: 0.12em;
    color: var(--subtext);
}

.sensor-meta {
    margin: 0;
    color: var(--subtext);
    font-size: 0.92rem;
}

.controls {
    display: flex;
    flex-wrap: wrap;
    gap: 0.7rem;
}

.btn {
    border: 1px solid transparent;
    border-radius: 999px;
    font-size: 0.95rem;
    font-weight: 700;
    padding: 0.7rem 1rem;
    cursor: pointer;
    transition: transform 0.2s ease, opacity 0.2s ease, background-color 0.2s ease;
}

.btn:hover:not(:disabled) {
    transform: translateY(-1px);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--accent);
    color: var(--accent-contrast);
}

.btn-secondary {
    background: transparent;
    border-color: var(--border);
    color: var(--text);
}

.auto-reconnect {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--subtext);
    font-size: 0.92rem;
}

.app-upsell h2 {
    margin: 0 0 0.9rem;
}

.theme-label {
    display: block;
    color: var(--subtext);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.theme-picker-inline {
    width: min(100%, 220px);
}

.theme-picker-inline .theme-label {
    margin-bottom: 0.35rem;
    font-size: 0.82rem;
    letter-spacing: 0.03em;
    text-transform: uppercase;
}

.theme-select {
    width: 100%;
    border: 1px solid var(--border);
    border-radius: 12px;
    background: rgba(0, 0, 0, 0.18);
    color: var(--text);
    font-weight: 600;
    font-size: 0.95rem;
    padding: 0.7rem 0.8rem;
}

.upsell-copy {
    margin: 0 0 0.9rem;
    color: var(--subtext);
    font-size: 0.9rem;
}

.app-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.7rem;
    margin-bottom: 0.8rem;
}

.back-link {
    color: var(--accent);
    font-weight: 700;
}

.btn:focus-visible,
.theme-select:focus-visible,
.eyebrow-link:focus-visible,
.back-link:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

@media (max-width: 900px) {
    .top-banner {
        flex-direction: column;
        align-items: stretch;
    }

    .theme-picker-inline {
        width: 100%;
    }

    .cadence-readout {
        min-height: min(45vh, 340px);
    }
}