:root {
    --bg: #0a0a0c;
    --bg-elev: #131318;
    --bg-elev-2: #1c1c24;
    --border: #26262f;
    --border-strong: #34343f;
    --text: #f4f4f6;
    --text-dim: #9a9aa6;
    --text-mute: #6a6a76;
    --accent: #ff6b1a;
    --accent-glow: rgba(255, 107, 26, 0.35);
    --accent-soft: rgba(255, 107, 26, 0.12);
    --eco: #4ade80;
    --eco-soft: rgba(74, 222, 128, 0.12);
    --warn: #f59e0b;
    --danger: #ef4444;
    --radius: 16px;
    --radius-sm: 10px;
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
}

* {
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

html, body {
    margin: 0;
    padding: 0;
    background: var(--bg);
    color: var(--text);
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    font-size: 16px;
    line-height: 1.5;
    min-height: 100vh;
    overflow-x: hidden;
}

body {
    padding-bottom: env(safe-area-inset-bottom);
}

.bg-grid {
    position: fixed;
    inset: 0;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.025) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.025) 1px, transparent 1px);
    background-size: 40px 40px;
    mask-image: radial-gradient(ellipse at top, black 30%, transparent 80%);
    -webkit-mask-image: radial-gradient(ellipse at top, black 30%, transparent 80%);
    pointer-events: none;
    z-index: 0;
}

.bg-glow {
    position: fixed;
    top: -200px;
    left: 50%;
    transform: translateX(-50%);
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, var(--accent-glow) 0%, transparent 60%);
    filter: blur(80px);
    pointer-events: none;
    z-index: 0;
    opacity: 0.6;
}

.app {
    position: relative;
    z-index: 1;
    max-width: 560px;
    margin: 0 auto;
    padding: 20px 16px 40px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

/* Header */
.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 8px 4px 4px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.brand-mark {
    width: 42px;
    height: 42px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--accent) 0%, #ff8a3d 100%);
    display: grid;
    place-items: center;
    color: #1a0a00;
    box-shadow: 0 4px 16px var(--accent-glow);
}

.brand-mark svg {
    width: 22px;
    height: 22px;
}

.brand-text h1 {
    margin: 0;
    font-size: 22px;
    font-weight: 800;
    letter-spacing: -0.02em;
    line-height: 1.1;
}

.brand-sub {
    font-size: 11px;
    color: var(--text-mute);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-weight: 600;
}

.season-pill {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    background: var(--bg-elev);
    border: 1px solid var(--border);
    border-radius: 999px;
    font-size: 12px;
    font-weight: 600;
    color: var(--text-dim);
}

.season-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--accent);
    box-shadow: 0 0 8px var(--accent-glow);
}

.season-pill.winter .season-dot {
    background: #60a5fa;
    box-shadow: 0 0 8px rgba(96, 165, 250, 0.5);
}

/* Card */
.card {
    background: var(--bg-elev);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 18px;
    box-shadow: var(--shadow);
}

.card-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

.card-head h2 {
    margin: 0;
    font-size: 13px;
    font-weight: 700;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.meta {
    font-size: 12px;
    color: var(--text-mute);
    font-family: 'JetBrains Mono', monospace;
}

.link-btn {
    background: transparent;
    border: none;
    color: var(--accent);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 6px;
    transition: background 0.15s;
}

.link-btn:hover, .link-btn:active {
    background: var(--accent-soft);
}

/* Presets */
.preset-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.preset-chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 14px;
    background: var(--bg-elev-2);
    border: 1px solid var(--border);
    border-radius: 999px;
    color: var(--text-dim);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.15s;
    user-select: none;
}

.preset-chip:hover {
    border-color: var(--border-strong);
    color: var(--text);
}

.preset-chip.active {
    background: var(--accent-soft);
    border-color: var(--accent);
    color: var(--accent);
}

.preset-chip .edit-pencil {
    width: 14px;
    height: 14px;
    opacity: 0.5;
    transition: opacity 0.15s;
}

.preset-chip:hover .edit-pencil {
    opacity: 1;
}

.preset-empty {
    color: var(--text-mute);
    font-size: 13px;
    font-style: italic;
}

/* Field */
.field {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.field label {
    font-size: 13px;
    font-weight: 600;
    color: var(--text-dim);
}

.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
}

input[type="number"],
input[type="text"],
select {
    width: 100%;
    padding: 14px 14px;
    background: var(--bg-elev-2);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text);
    font-size: 16px;
    font-weight: 600;
    font-family: inherit;
    transition: border-color 0.15s, background 0.15s;
}

input[type="number"]:focus,
input[type="text"]:focus,
select:focus {
    outline: none;
    border-color: var(--accent);
    background: var(--bg-elev);
}

input[type="number"] {
    font-family: 'JetBrains Mono', monospace;
}

/* Hide number spinners */
input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}
input[type="number"] {
    -moz-appearance: textfield;
}

.input-suffix {
    position: relative;
}

.input-suffix input {
    padding-right: 44px;
}

.input-suffix span {
    position: absolute;
    right: 14px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-mute);
    font-size: 14px;
    font-weight: 600;
    pointer-events: none;
}

/* Slider */
.slider-row {
    display: flex;
    align-items: center;
    gap: 14px;
}

.slider-row output {
    min-width: 56px;
    text-align: right;
    font-family: 'JetBrains Mono', monospace;
    font-size: 18px;
    font-weight: 700;
    color: var(--accent);
}

input[type="range"] {
    flex: 1;
    -webkit-appearance: none;
    appearance: none;
    height: 6px;
    background: var(--bg-elev-2);
    border-radius: 3px;
    outline: none;
    background-image: linear-gradient(to right, var(--accent) 0%, var(--accent) var(--val, 50%), var(--bg-elev-2) var(--val, 50%));
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 24px;
    height: 24px;
    background: var(--accent);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 0 0 4px rgba(255, 107, 26, 0.15), 0 2px 8px rgba(0, 0, 0, 0.4);
    transition: transform 0.1s;
}

input[type="range"]::-webkit-slider-thumb:active {
    transform: scale(1.15);
}

input[type="range"]::-moz-range-thumb {
    width: 24px;
    height: 24px;
    background: var(--accent);
    border-radius: 50%;
    cursor: pointer;
    border: none;
    box-shadow: 0 0 0 4px rgba(255, 107, 26, 0.15);
}

/* Bar stepper */
.bar-stepper {
    display: grid;
    grid-template-columns: 56px 1fr 56px;
    gap: 8px;
}

.bar-stepper input {
    text-align: center;
    font-size: 18px;
}

.step-btn {
    width: 56px;
    height: 50px;
    background: var(--bg-elev-2);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text);
    font-size: 22px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.15s;
}

.step-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.step-btn:active {
    transform: scale(0.95);
}

/* Bar visual */
.bar-visual {
    display: flex;
    gap: 3px;
    height: 18px;
    padding: 4px;
    background: var(--bg-elev-2);
    border: 1px solid var(--border);
    border-radius: 8px;
}

.bar-cell {
    flex: 1;
    background: var(--bg-elev);
    border-radius: 2px;
    transition: background 0.2s;
}

.bar-cell.full {
    background: linear-gradient(180deg, var(--accent) 0%, #cc4d0d 100%);
    box-shadow: 0 0 4px var(--accent-glow);
}

.bar-cell.full.low {
    background: linear-gradient(180deg, var(--danger) 0%, #b91c1c 100%);
    box-shadow: 0 0 4px rgba(239, 68, 68, 0.4);
}

/* Segmented */
.seg {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 4px;
    padding: 4px;
    background: var(--bg-elev-2);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
}

.seg-opt {
    padding: 12px 8px;
    background: transparent;
    border: none;
    border-radius: 8px;
    color: var(--text-dim);
    font-size: 14px;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: all 0.15s;
}

.seg-opt:hover:not(.active) {
    color: var(--text);
}

.seg-opt.active {
    background: var(--accent);
    color: #1a0a00;
    box-shadow: 0 2px 8px var(--accent-glow);
}

/* Result */
.result-card {
    border-color: var(--border-strong);
    background: linear-gradient(180deg, var(--bg-elev) 0%, #15151c 100%);
}

.result-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.result-tile {
    background: var(--bg-elev-2);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 18px 14px;
    display: flex;
    flex-direction: column;
    gap: 4px;
    position: relative;
    overflow: hidden;
}

.result-tile::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
}

.result-tile.e85::before {
    background: var(--eco);
}

.result-tile.gas::before {
    background: var(--accent);
}

.result-label {
    font-size: 12px;
    font-weight: 700;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.result-tile.e85 .result-label {
    color: var(--eco);
}

.result-tile.gas .result-label {
    color: var(--accent);
}

.result-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 32px;
    font-weight: 700;
    line-height: 1.1;
    color: var(--text);
    letter-spacing: -0.02em;
}

.result-unit {
    font-size: 12px;
    color: var(--text-mute);
    font-weight: 500;
}

.result-detail {
    font-size: 13px;
    color: var(--text-dim);
    line-height: 1.6;
    padding: 12px 14px;
    background: var(--bg-elev-2);
    border-radius: var(--radius-sm);
    font-family: 'JetBrains Mono', monospace;
}

.result-detail .row {
    display: flex;
    justify-content: space-between;
    gap: 8px;
}

.result-detail .row + .row {
    margin-top: 4px;
}

.result-detail .row .v {
    color: var(--text);
    font-weight: 600;
}

.result-warn {
    padding: 12px 14px;
    background: rgba(245, 158, 11, 0.08);
    border: 1px solid rgba(245, 158, 11, 0.3);
    border-radius: var(--radius-sm);
    color: var(--warn);
    font-size: 13px;
    font-weight: 500;
}

.result-warn.danger {
    background: rgba(239, 68, 68, 0.08);
    border-color: rgba(239, 68, 68, 0.3);
    color: var(--danger);
}

/* Footer */
.footer {
    text-align: center;
    color: var(--text-mute);
    font-size: 11px;
    line-height: 1.6;
    padding: 8px 4px;
}

.footer p {
    margin: 0;
}

/* Modal */
.modal {
    border: 1px solid var(--border-strong);
    background: var(--bg-elev);
    border-radius: var(--radius);
    padding: 0;
    max-width: 440px;
    width: calc(100% - 32px);
    color: var(--text);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.7);
}

.modal::backdrop {
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
}

.modal-form {
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin: 0;
}

.modal-form h3 {
    margin: 0 0 4px;
    font-size: 18px;
    font-weight: 700;
}

.modal-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 8px;
    margin-top: 8px;
}

.modal-actions-end {
    display: flex;
    gap: 8px;
    margin-left: auto;
}

.btn-primary, .btn-ghost {
    padding: 12px 18px;
    border-radius: var(--radius-sm);
    font-family: inherit;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    border: 1px solid transparent;
    transition: all 0.15s;
}

.btn-primary {
    background: var(--accent);
    color: #1a0a00;
}

.btn-primary:hover {
    background: #ff8a3d;
}

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

.btn-ghost:hover {
    color: var(--text);
    border-color: var(--border-strong);
}

#presetDelete {
    color: var(--danger);
    border-color: rgba(239, 68, 68, 0.3);
}

#presetDelete:hover {
    background: rgba(239, 68, 68, 0.08);
}

select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='none' stroke='%239a9aa6' stroke-width='2' d='M2 4l4 4 4-4'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 14px center;
    padding-right: 40px;
}

/* Desktop tweaks */
@media (min-width: 720px) {
    .app {
        max-width: 640px;
        padding: 32px 24px 60px;
        gap: 20px;
    }

    .brand-text h1 {
        font-size: 26px;
    }

    .card {
        padding: 24px;
    }

    .result-value {
        font-size: 38px;
    }
}

@media (prefers-reduced-motion: reduce) {
    * {
        transition: none !important;
        animation: none !important;
    }
}