:root {
    --bg-deep: #0a0d12;
    --bg-card: #111620;
    --bg-card2: #161c28;
    --border: #1e2a3a;
    --accent: #00e5ff;
    --accent-dim: #00b8cc;
    --accent-glow: rgba(0, 229, 255, 0.15);
    --green: #39ff85;
    --green-dim: rgba(57, 255, 133, 0.12);
    --amber: #ffb830;
    --amber-dim: rgba(255, 184, 48, 0.12);
    --text-primary: #e8f0fe;
    --text-secondary: #6b7fa3;
    --text-muted: #a0b8a8;
}

* {
    box-sizing: border-box;
}

html, body {
    background: var(--bg-deep);
    color: var(--text-primary);
    font-family: 'DM Mono', monospace;
    min-height: 100vh;
    overflow-x: hidden;
}

    /* ── Background grid ── */
    body::before {
        content: '';
        position: fixed;
        inset: 0;
        background-image: linear-gradient(var(--border) 1px, transparent 1px), linear-gradient(90deg, var(--border) 1px, transparent 1px);
        background-size: 48px 48px;
        opacity: 0.35;
        pointer-events: none;
        z-index: 0;
    }

    body::after {
        content: '';
        position: fixed;
        top: -30vh;
        left: 50%;
        transform: translateX(-50%);
        width: 80vw;
        height: 60vh;
        background: radial-gradient(ellipse at center, rgba(0,229,255,0.06) 0%, transparent 70%);
        pointer-events: none;
        z-index: 0;
    }

.page-wrap {
    position: relative;
    z-index: 1;
    max-width: 880px;
    margin: 0 auto;
    padding: 2rem 1.25rem 4rem;
}

/* ── Header ── */
.ev-header {
    text-align: center;
    margin-bottom: 2.5rem;
    padding-top: 1.5rem;
}

    .ev-header .badge {
        display: inline-block;
        font-family: 'Rajdhani', sans-serif;
        font-size: 0.7rem;
        font-weight: 600;
        letter-spacing: 0.2em;
        text-transform: uppercase;
        color: var(--accent);
        border: 1px solid var(--accent);
        border-radius: 2px;
        padding: 2px 10px;
        margin-bottom: 0.75rem;
    }

    .ev-header h1 {
        font-family: 'Rajdhani', sans-serif;
        font-size: clamp(2rem, 6vw, 3.4rem);
        font-weight: 700;
        line-height: 1;
        color: var(--text-primary);
        letter-spacing: -0.02em;
    }

        .ev-header h1 span {
            color: var(--accent);
        }

    .ev-header p {
        color: var(--text-secondary);
        font-size: 0.8rem;
        margin-top: 0.5rem;
        letter-spacing: 0.05em;
    }

/* ── Cards ── */
.ev-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 1.75rem;
    margin-bottom: 1.25rem;
    position: relative;
    overflow: hidden;
}

    .ev-card::before {
        content: '';
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        height: 2px;
        background: linear-gradient(90deg, transparent, var(--accent), transparent);
        opacity: 0.6;
    }

    .ev-card.green-top::before {
        background: linear-gradient(90deg, transparent, var(--green), transparent);
    }

    .ev-card.amber-top::before {
        background: linear-gradient(90deg, transparent, var(--amber), transparent);
    }

    .ev-card.orange-top::before {
        background: linear-gradient(90deg, transparent, #ff8c00, transparent);
    }

.card-label {
    font-family: 'Rajdhani', sans-serif;
    font-size: 0.65rem;
    font-weight: 600;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 1.1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

    .card-label::after {
        content: '';
        flex: 1;
        height: 1px;
        background: var(--border);
    }

/* ── Card sections ── */
.ev-section {
    padding-top: 1.25rem;
    margin-top: 1.25rem;
}

    .ev-section:first-child {
        padding-top: 0;
        margin-top: 0;
    }

/* ── Form elements ── */
.ev-label {
    font-family: 'Rajdhani', sans-serif;
    font-size: 0.7rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--text-secondary);
    margin-bottom: 0.4rem;
    display: block;
}

.ev-input {
    background: var(--bg-deep) !important;
    border: 1px solid var(--border) !important;
    border-radius: 2px !important;
    color: var(--text-primary) !important;
    font-family: 'DM Mono', monospace !important;
    font-size: 1.1rem !important;
    height: 3rem !important;
    padding: 0 1rem !important;
    transition: border-color 0.2s, box-shadow 0.2s;
    width: 100%;
}

    .ev-input:focus {
        outline: none !important;
        border-color: var(--accent) !important;
        box-shadow: 0 0 0 3px var(--accent-glow) !important;
    }

    .ev-input::placeholder {
        color: var(--text-muted) !important;
    }

/* input suffix unit */
.input-wrap {
    position: relative;
}

.input-unit {
    position: absolute;
    right: 0.9rem;
    top: 50%;
    transform: translateY(-50%);
    font-size: 0.7rem;
    letter-spacing: 0.1em;
    color: var(--accent);
    pointer-events: none;
    font-family: 'Rajdhani', sans-serif;
    font-weight: 600;
}

/* battery visual */
.battery-row {
    display: flex;
    align-items: center;
    gap: 1.25rem;
    margin-top: 1rem;
}

.battery-wrap {
    position: relative;
    width: 64px;
    height: 30px;
    flex-shrink: 0;
}

.battery-shell {
    width: 58px;
    height: 30px;
    border: 2px solid var(--accent);
    border-radius: 4px;
    position: absolute;
    left: 0;
    top: 0;
    overflow: hidden;
}

.battery-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-dim), var(--accent));
    transition: width 0.5s cubic-bezier(.4,0,.2,1);
}

.battery-nub {
    position: absolute;
    right: -7px;
    top: 50%;
    transform: translateY(-50%);
    width: 5px;
    height: 14px;
    background: var(--accent);
    border-radius: 0 2px 2px 0;
}

.battery-pct {
    font-family: 'Rajdhani', sans-serif;
    font-weight: 700;
    font-size: 1.4rem;
    color: var(--accent);
}

/* ── Range slider ── */
.ev-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 4px;
    background: var(--border);
    border-radius: 2px;
    outline: none;
    cursor: pointer;
    margin: 0.6rem 0;
    position: relative;
}

    .ev-slider::-webkit-slider-thumb {
        -webkit-appearance: none;
        width: 18px;
        height: 18px;
        border-radius: 50%;
        background: var(--accent);
        border: 2px solid var(--bg-deep);
        box-shadow: 0 0 8px var(--accent);
        cursor: pointer;
        transition: transform 0.15s;
    }

        .ev-slider::-webkit-slider-thumb:hover {
            transform: scale(1.25);
        }

    .ev-slider::-moz-range-thumb {
        width: 18px;
        height: 18px;
        border-radius: 50%;
        background: var(--accent);
        border: 2px solid var(--bg-deep);
        box-shadow: 0 0 8px var(--accent);
    }

.slider-row {
    display: flex;
    justify-content: space-between;
    font-size: 0.65rem;
    color: var(--text-muted);
    letter-spacing: 0.05em;
    margin-top: 0.15rem;
}

.slider-value {
    font-family: 'Rajdhani', sans-serif;
    font-size: 2rem;
    font-weight: 700;
    color: var(--amber);
    line-height: 1;
}

    .slider-value span {
        font-size: 0.85rem;
        font-weight: 400;
        color: var(--text-secondary);
        margin-left: 0.2rem;
    }

/* ── Chart ── */
.chart-container {
    position: relative;
    height: 340px;
}

/* ── Stat cards ── */
.stats-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

@media (max-width: 520px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }
}

.stat-block {
    background: var(--bg-card2);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 1.25rem 1.5rem;
    position: relative;
    overflow: hidden;
}

    .stat-block.green {
        border-left: 3px solid var(--green);
    }

    .stat-block.amber {
        border-left: 3px solid var(--amber);
    }

    .stat-block::after {
        content: '';
        position: absolute;
        inset: 0;
        pointer-events: none;
    }

    .stat-block.green::after {
        background: var(--green-dim);
    }

    .stat-block.amber::after {
        background: var(--amber-dim);
    }

.stat-title {
    font-family: 'Rajdhani', sans-serif;
    font-size: 0.62rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    margin-bottom: 0.3rem;
    position: relative;
    z-index: 1;
}

.stat-block.green .stat-title {
    color: var(--green);
}

.stat-block.amber .stat-title {
    color: var(--amber);
}

.stat-number {
    font-family: 'Rajdhani', sans-serif;
    font-size: 2.4rem;
    font-weight: 700;
    line-height: 1;
    position: relative;
    z-index: 1;
}

.stat-block.green .stat-number {
    color: var(--green);
}

.stat-block.amber .stat-number {
    color: var(--amber);
}

.stat-unit {
    font-size: 0.8rem;
    font-weight: 400;
    color: var(--text-secondary);
    margin-left: 0.25rem;
}

.stat-sub {
    font-size: 0.7rem;
    color: var(--text-secondary);
    margin-top: 0.3rem;
    position: relative;
    z-index: 1;
}

/* ── Section dividers ── */
.section-sep {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin: 0.25rem 0 1.25rem;
    color: var(--text-muted);
    font-size: 0.62rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

    .section-sep::before,
    .section-sep::after {
        content: '';
        flex: 1;
        height: 1px;
        background: var(--border);
    }

/* ── Capacity input row ── */
.fields-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

@media (max-width: 520px) {
    .fields-row {
        grid-template-columns: 1fr;
    }
}

/* ── Toggle switch ── */
.ev-toggle {
    position: relative;
    display: inline-block;
    width: 36px;
    height: 20px;
    flex-shrink: 0;
}

    .ev-toggle input {
        opacity: 0;
        width: 0;
        height: 0;
    }

.ev-toggle-slider {
    position: absolute;
    inset: 0;
    background: var(--border);
    border-radius: 20px;
    cursor: pointer;
    transition: background 0.2s;
}

    .ev-toggle-slider::before {
        content: '';
        position: absolute;
        width: 14px;
        height: 14px;
        left: 3px;
        top: 3px;
        background: var(--text-secondary);
        border-radius: 50%;
        transition: transform 0.2s, background 0.2s;
    }

.ev-toggle input:checked + .ev-toggle-slider {
    background: var(--green-dim);
    border: 1px solid var(--green);
}

    .ev-toggle input:checked + .ev-toggle-slider::before {
        transform: translateX(16px);
        background: var(--green);
    }

/* ── Calculate button ── */
.calc-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.6rem;
    width: 100%;
    padding: 0.85rem 1.5rem;
    background: transparent;
    border: 1px solid var(--accent);
    border-radius: 2px;
    color: var(--accent);
    font-family: 'Rajdhani', sans-serif;
    font-size: 0.9rem;
    font-weight: 700;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    transition: color 0.2s, box-shadow 0.2s;
    margin-top: 1.25rem;
}

    .calc-btn::before {
        content: '';
        position: absolute;
        inset: 0;
        background: var(--accent);
        transform: scaleX(0);
        transform-origin: left;
        transition: transform 0.25s cubic-bezier(.4,0,.2,1);
        z-index: 0;
    }

    .calc-btn:hover::before,
    .calc-btn:focus::before {
        transform: scaleX(1);
    }

    .calc-btn:hover,
    .calc-btn:focus {
        color: var(--bg-deep);
        box-shadow: 0 0 20px var(--accent-glow);
        outline: none;
    }

    .calc-btn span,
    .calc-btn svg {
        position: relative;
        z-index: 1;
    }

    .calc-btn.fired {
        animation: btn-flash 0.35s ease;
    }

@keyframes btn-flash {
    0% {
        box-shadow: 0 0 0px var(--accent-glow);
    }

    50% {
        box-shadow: 0 0 30px rgba(0,229,255,0.5);
    }

    100% {
        box-shadow: 0 0 0px var(--accent-glow);
    }
}

/* glow pulse on accent elements */
@keyframes glow-pulse {
    0%, 100% {
        opacity: 0.7;
    }

    50% {
        opacity: 1;
    }
}
/* ── Nav bar ── */
.ev-nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(10, 13, 18, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

.ev-nav-inner {
    max-width: 880px;
    margin: 0 auto;
    padding: 0 1.25rem;
    display: flex;
    align-items: center;
    gap: 0;
    height: 52px;
}

.ev-nav-logo {
    font-family: 'Rajdhani', sans-serif;
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--accent);
    letter-spacing: 0.08em;
    margin-right: 2rem;
    text-decoration: none;
    flex-shrink: 0;
}

    .ev-nav-logo span {
        color: var(--text-secondary);
    }

.ev-nav-links {
    display: flex;
    align-items: stretch;
    gap: 0;
    height: 100%;
}

.ev-nav-link {
    display: flex;
    align-items: center;
    gap: 0.45rem;
    padding: 0 1.1rem;
    font-family: 'Rajdhani', sans-serif;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--text-secondary);
    text-decoration: none;
    border-bottom: 2px solid transparent;
    transition: color 0.2s, border-color 0.2s;
    white-space: nowrap;
}

    .ev-nav-link:hover {
        color: var(--text-primary);
        border-bottom-color: var(--border);
    }

    .ev-nav-link.active {
        color: var(--accent);
        border-bottom-color: var(--accent);
    }

    .ev-nav-link svg {
        opacity: 0.7;
        flex-shrink: 0;
    }

    .ev-nav-link.active svg {
        opacity: 1;
    }

.nav-pill {
    font-size: 0.55rem;
    letter-spacing: 0.1em;
    background: var(--accent-glow);
    color: var(--accent);
    border: 1px solid rgba(0,229,255,0.3);
    border-radius: 2px;
    padding: 1px 5px;
    margin-left: 0.2rem;
}