:root{--bg:#07090d;--card:#0f131a;--line:#1b222d;--txt:#e8edf5;--dim:#7d8898;--c1:#2a3342;--c2:#3b475c;--glow:transparent;--ok:#22e58b;--bad:#ff2d4d;--warn:#ffb020}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;background:var(--bg);color:var(--txt);font:16px/1.4 system-ui,-apple-system,Segoe UI,Roboto,sans-serif}
body{padding:env(safe-area-inset-top) 0 calc(72px + env(safe-area-inset-bottom));min-height:100vh;background:radial-gradient(900px 500px at 50% -10%,#101826,transparent)}
header{display:flex;justify-content:space-between;align-items:center;padding:14px 18px 4px}
h1{margin:0;font-size:19px;letter-spacing:.3px}
h2{margin:8px 0 0;font-size:13px;text-transform:uppercase;letter-spacing:1.4px;color:var(--dim)}
.conn{display:flex;align-items:center;gap:7px;font-size:12px;color:var(--dim)}
.conn i{width:9px;height:9px;border-radius:50%;background:var(--dim)}
.conn.ok i{background:var(--ok);box-shadow:0 0 8px var(--ok)}.conn.bad i{background:var(--bad);box-shadow:0 0 8px var(--bad)}
main{max-width:560px;margin:0 auto;padding:0 14px}
.tab{display:none}.tab.active{display:block}
/* ring */
.ringwrap{position:relative;width:min(78vw,320px);margin:12px auto 6px;aspect-ratio:1;transition:filter .6s}
.ring{width:100%;height:100%;overflow:visible}
.track,.arc{fill:none;stroke-width:16;stroke-linecap:round}
.track{stroke:#151b25;stroke-dasharray:calc(var(--C)*.75) var(--C)}
.arc{stroke:url(#g);stroke-dasharray:0 var(--C);transition:stroke-dasharray .9s cubic-bezier(.2,.8,.2,1);filter:drop-shadow(0 0 10px var(--glow))}
.ring{--C:678.6}
.center{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;padding-bottom:8%}
.kw{font-size:clamp(52px,17vw,76px);font-weight:700;font-variant-numeric:tabular-nums;line-height:1}
.unit{color:var(--dim);font-size:15px;letter-spacing:2px;margin-top:2px}
.status{margin-top:10px;font-size:13px;font-weight:600;letter-spacing:1.6px;text-transform:uppercase;color:var(--dim)}
body.charging{--c1:#13c27a;--c2:#4dffb8;--glow:#22e58b88}
body.charging .ringwrap{filter:drop-shadow(0 0 28px #22e58b44)}
body.charging .status{color:var(--ok)}
body.plugged{--c1:#d68a00;--c2:#ffc34d;--glow:#ffb02055}
body.plugged .status{color:var(--warn)}
body.offline .ringwrap{opacity:.45}
body.offline .status{color:var(--bad)}
.note{text-align:center;color:var(--bad);font-size:13px;margin:4px 0 8px}
/* tiles */
.tiles{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:14px 0}
.tiles.three{grid-template-columns:repeat(3,1fr)}
.tile{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:12px 14px}
.tile label{display:block;font-size:11px;color:var(--dim);text-transform:uppercase;letter-spacing:1px}
.tile b{font-size:26px;font-variant-numeric:tabular-nums}.tile small{color:var(--dim);margin-left:5px;font-size:12px}
.card{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:14px;margin:12px 0}
.cardhead{display:flex;justify-content:space-between;font-size:13px;margin-bottom:8px}
.dim{color:var(--dim)}.small{font-size:12px}
.alertcard,.banner{display:flex;justify-content:space-between;align-items:center;gap:12px}
#chart svg{width:100%;height:auto;display:block}
.empty{color:var(--dim);text-align:center;padding:30px 0;font-size:14px}
/* controls */
.btn{background:linear-gradient(135deg,#13c27a,#0fa968);color:#04130c;border:0;border-radius:12px;padding:11px 18px;font:600 15px inherit;font-family:inherit;cursor:pointer}
.btn.ghost{background:transparent;color:var(--txt);border:1px solid #2a3342}
.btn.light{background:#fff;color:#a00019;font-size:18px;padding:14px 28px}
.btnrow{display:flex;gap:10px;flex-wrap:wrap}
.chips{display:flex;gap:8px;flex-wrap:wrap}
.chip{border:1px solid #2a3342;background:transparent;color:var(--txt);border-radius:99px;padding:7px 13px;font-size:13px;cursor:pointer}
.chip.on{background:#1b2a3d;border-color:#3d5a80}
.form{display:flex;flex-direction:column;gap:12px}
.form label{display:flex;flex-direction:column;gap:5px;font-size:13px;color:var(--dim)}
.form label.row{flex-direction:row;justify-content:space-between;align-items:center}
input,select{background:#0a0d12;border:1px solid #232c3a;color:var(--txt);border-radius:10px;padding:11px;font:16px inherit;font-family:inherit;width:100%;color-scheme:dark}
input[type=checkbox]{width:22px;height:22px}
fieldset{border:0;padding:0;margin:0;display:flex;flex-direction:column;gap:12px}
fieldset:disabled{opacity:.5}
/* history */
.sess{display:grid;grid-template-columns:1fr auto;gap:2px 10px;padding:11px 0;border-top:1px solid var(--line)}
.sess:first-child{border-top:0}
.sess .d{font-weight:600}.sess .k{font-weight:700;font-variant-numeric:tabular-nums;text-align:right}
.sess .m{color:var(--dim);font-size:12px}
.bar{grid-column:1/-1;height:4px;border-radius:2px;background:#151b25;margin-top:6px;overflow:hidden}.bar i{display:block;height:100%;background:linear-gradient(90deg,#13c27a,#4dffb8)}
/* nav */
nav{position:fixed;left:0;right:0;bottom:0;display:flex;background:#0b0e14ee;backdrop-filter:blur(14px);border-top:1px solid var(--line);padding-bottom:env(safe-area-inset-bottom)}
nav button{flex:1;background:none;border:0;color:var(--dim);padding:9px 0 8px;font:11px inherit;font-family:inherit;display:flex;flex-direction:column;align-items:center;gap:3px}
nav svg{width:23px;height:23px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}
nav button.on{color:var(--ok)}
/* alert overlay */
#alertOverlay{position:fixed;inset:0;z-index:50;display:flex;align-items:center;justify-content:center;text-align:center;color:#fff;animation:flash 1s steps(1) infinite}
#alertOverlay[hidden],#login[hidden]{display:none}
@keyframes flash{0%{background:#ff1030}50%{background:#5a0010}}
.alertbox{padding:24px;max-width:420px}
.alertbox .big{font-size:72px}
.alertbox h1{font-size:clamp(40px,13vw,64px);margin:6px 0 10px;line-height:1.05;letter-spacing:1px}
.alertbox p{font-size:18px;margin:0 0 28px}
#login{position:fixed;inset:0;z-index:60;background:var(--bg);display:flex;align-items:center;justify-content:center;padding:20px}
#login form{width:100%;max-width:360px}
@media(prefers-reduced-motion:reduce){#alertOverlay{animation-duration:2s}.arc{transition:none}}