:root {
    /* Backgrounds */
    --bg-dark: #0a0a0c;
    --bg-panel: rgba(20, 20, 25, 0.7);
    --bg-elevated: #1e1e24;
    --bg-input: #202028;
    --bg-tooltip: rgba(16, 20, 24, 0.9);

    /* Borders */
    --border-subtle: rgba(255, 255, 255, 0.1);
    --border-medium: rgba(255, 255, 255, 0.2);

    /* Signal Colors */
    --color-voltage: #00ff55;
    --color-voltage-glow: rgba(0, 255, 85, 0.2);
    --color-voltage-border: rgba(0, 255, 85, 0.3);
    --color-voltage-bg: rgba(0, 255, 85, 0.05);

    --color-current: #ffcc00;
    --color-current-glow: rgba(255, 204, 0, 0.2);
    --color-current-border: rgba(255, 204, 0, 0.3);
    --color-current-bg: rgba(255, 204, 0, 0.05);

    --color-power: #a0a0b0;
    --color-power-border: rgba(160, 160, 176, 0.3);

    /* Danger */
    --color-danger: #ff5555;
    --color-danger-bg: rgba(255, 50, 50, 0.1);
    --color-danger-bg-hover: rgba(255, 50, 50, 0.2);
    --color-danger-border: rgba(255, 50, 50, 0.3);

    /* Text */
    --text-main: #ffffff;
    --text-muted: #888899;

    /* Misc */
    --color-dot-disconnected: #555555;
    --shadow-md: rgba(0, 0, 0, 0.5);
    --shadow-heavy: rgba(0, 0, 0, 0.8);

    /* Button surfaces */
    --btn-bg: rgba(255, 255, 255, 0.1);
    --btn-bg-hover: rgba(255, 255, 255, 0.2);
    --btn-border: rgba(255, 255, 255, 0.2);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    overflow-x: hidden;
    /* Prevent tooltip and absolute elements from causing horizontal scroll */
}

body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: 'Inter', sans-serif;
    height: 100vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

/* Background Effect (Subtle mesh gradient) */
body::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 15% 50%, var(--color-voltage-bg), transparent 40%),
        radial-gradient(circle at 85% 30%, var(--color-current-bg), transparent 40%);
    z-index: -1;
}

.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    padding: 24px;
    gap: 24px;
}

/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--bg-panel);
    border: 1px solid var(--border-subtle);
    border-radius: 12px;
    padding: 16px 24px;
    backdrop-filter: blur(10px);
}

.header-left h1 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.header-left .accent {
    color: var(--text-muted);
}

.status-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background-color: var(--color-dot-disconnected);
}

.dot.connected {
    background-color: var(--color-voltage);
    box-shadow: 0 0 10px var(--color-voltage);
}

/* Button */
.btn {
    background: var(--btn-bg);
    border: 1px solid var(--btn-border);
    color: var(--text-main);
    padding: 10px 20px;
    border-radius: 8px;
    font-family: inherit;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn:hover {
    background: var(--btn-bg-hover);
    transform: translateY(-1px);
}

.btn-primary {
    background: var(--bg-input);
}

.btn-secondary {
    background: var(--btn-bg);
}

.btn-sm {
    padding: 6px 12px;
    font-size: 12px;
}

.btn-danger {
    background: var(--color-danger-bg);
    border-color: var(--color-danger-border);
    color: var(--color-danger);
}

.btn-danger:hover {
    background: var(--color-danger-bg-hover);
}

/* Dashboard Grid */
.dashboard {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.panel {
    background: var(--bg-panel);
    border: 1px solid var(--border-subtle);
    border-radius: 16px;
    padding: 24px;
    backdrop-filter: blur(10px);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-width: 0;
    /* Prevent grid blowout */
    overflow: hidden;
}

.voltage-panel {
    border-color: var(--color-voltage-border);
}

.current-panel {
    border-color: var(--color-current-border);
}

.power-panel {
    border-color: var(--color-power-border);
}

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 20px;
}

.panel-header h2 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.stats {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    font-family: 'Share Tech Mono', monospace;
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Typography for Values */
.panel-value {
    display: flex;
    align-items: baseline;
    justify-content: flex-end;
    font-family: 'Share Tech Mono', monospace;
}

.big-text {
    font-size: clamp(1.8rem, 4.2vw, 5.5rem);
    line-height: 1;
}

.unit {
    font-size: clamp(0.9rem, 1.8vw, 2.5rem);
    margin-left: 8px;
    opacity: 0.8;
}

.voltage-panel .panel-value {
    color: var(--color-voltage);
}

.current-panel .panel-value {
    color: var(--color-current);
}

.power-panel .panel-value {
    color: var(--color-power);
}

.voltage-panel .stat span {
    color: var(--color-voltage);
}

.current-panel .stat span {
    color: var(--color-current);
}

/* Graph Section */
.graph-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 12px;
    min-height: 0;
}

.graph-controls {
    display: flex;
    gap: 20px;
    background: var(--bg-panel);
    border: 1px solid var(--border-subtle);
    border-radius: 8px;
    padding: 10px 16px;
    font-size: 0.9rem;
}

.control-group {
    display: flex;
    align-items: center;
    gap: 8px;
}

.control-group label {
    color: var(--text-muted);
}

.control-group select {
    background: var(--bg-input);
    color: var(--text-main);
    border: 1px solid var(--border-medium);
    border-radius: 4px;
    padding: 6px 10px;
    font-family: inherit;
    outline: none;
}

/* Marker Editor Popup */
.marker-editor {
    position: absolute;
    background: var(--bg-elevated);
    border: 1px solid var(--border-subtle);
    border-radius: 6px;
    padding: 12px;
    box-shadow: 0 8px 24px var(--shadow-heavy);
    display: flex;
    flex-direction: column;
    gap: 12px;
    z-index: 1000;
    transition: opacity 0.1s ease, transform 0.1s ease;
    transform: translateY(0);
}

.marker-editor.hidden {
    opacity: 0;
    pointer-events: none;
    transform: translateY(-5px);
}

.marker-editor input {
    background: var(--bg-dark);
    color: var(--text-main);
    border: 1px solid var(--border-subtle);
    border-radius: 4px;
    padding: 6px 10px;
    font-family: inherit;
    font-size: 14px;
    outline: none;
    min-width: 200px;
}

.marker-editor input:focus {
    border-color: var(--color-voltage);
}

.marker-editor-controls {
    display: flex;
    gap: 8px;
    justify-content: flex-end;
}

.graph-container {
    flex: 1;
    background: var(--bg-panel);
    border: 1px solid var(--border-subtle);
    border-radius: 12px;
    position: relative;
    overflow: hidden;
}

/* uPlot Overrides */
.uplot {
    font-family: 'Share Tech Mono', monospace;
}

.u-legend {
    color: var(--text-muted);
}

.u-axis-text {
    fill: var(--text-muted) !important;
}

.u-label {
    fill: var(--text-muted) !important;
}

/* Custom Tooltip */
.u-tooltip {
    position: absolute;
    display: none;
    background: var(--bg-tooltip);
    border: 1px solid var(--border-subtle);
    border-radius: 4px;
    padding: 8px 12px;
    font-size: 14px;
    color: var(--text-main);
    pointer-events: none;
    z-index: 100;
    box-shadow: 0 4px 12px var(--shadow-md);
    backdrop-filter: blur(4px);
    transition: opacity 0.1s ease-out;
    max-width: calc(100vw - 24px);
    /* Never wider than the viewport */
}

.u-tooltip.visible {
    display: block;
}

.u-tooltip-row {
    display: flex;
    justify-content: space-between;
    gap: 12px;
}

.u-tooltip-val-v {
    color: var(--color-voltage);
    font-weight: bold;
}

.u-tooltip-val-i {
    color: var(--color-current);
    font-weight: bold;
}

.u-tooltip-time {
    color: var(--text-muted);
    font-size: 12px;
    margin-bottom: 4px;
    border-bottom: 1px solid var(--border-subtle);
    padding-bottom: 4px;
}

canvas {
    width: 100%;
    height: 100%;
    display: block;
}

/* Auto-Annotate button — hidden until Konami code is entered */
#annotate-btn {
    display: none;
}

#annotate-btn.konami-unlocked {
    display: inline-flex;
    animation: konami-pop 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

@keyframes konami-pop {
    from {
        opacity: 0;
        transform: scale(0.6);
    }

    to {
        opacity: 1;
        transform: scale(1);
    }
}

/* Drag and Drop Overlay */
.drag-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(10, 10, 12, 0.85);
    backdrop-filter: blur(8px);
    z-index: 9999;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: opacity 0.3s ease;
}

.drag-overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

.drag-content {
    border: 3px dashed var(--color-voltage);
    border-radius: 20px;
    padding: 60px 100px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    background: rgba(0, 255, 85, 0.05);
    box-shadow: 0 0 40px var(--color-voltage-glow);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    pointer-events: none;
}

.drag-overlay.drag-active .drag-content {
    transform: scale(1.05);
    box-shadow: 0 0 80px var(--color-voltage-glow);
    background: rgba(0, 255, 85, 0.1);
}

.drag-icon {
    color: var(--color-voltage);
    animation: bounce 2s infinite ease-in-out;
}

.drag-content h2 {
    font-size: 2rem;
    color: var(--text-main);
    font-weight: 600;
}

@keyframes bounce {

    0%,
    100% {
        transform: translateY(0);
    }

    50% {
        transform: translateY(-10px);
    }
}

/* Responsive Layout */

/* Tablet / narrow desktop (≤ 1000px) */
@media (max-width: 1000px) {
    .app-container {
        padding: 16px;
        gap: 16px;
    }

    header {
        flex-wrap: wrap;
        gap: 12px;
        padding: 14px 18px;
    }

    .header-controls {
        flex-wrap: wrap;
        gap: 8px;
    }

    .dashboard {
        grid-template-columns: 1fr 1fr;
        gap: 16px;
    }

    .power-panel {
        grid-column: 1 / -1;
    }

    .panel {
        padding: 18px;
    }

    .big-text {
        font-size: 4rem;
    }

    .unit {
        font-size: 2rem;
    }
}

/* Mobile landscape / small tablet (≤ 640px) */
@media (max-width: 640px) {
    .app-container {
        padding: 12px;
        gap: 12px;
    }

    header {
        padding: 12px 14px;
    }

    .header-left h1 {
        font-size: 1.2rem;
    }

    .header-controls {
        width: 100%;
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 8px;
    }

    #connect-btn {
        grid-column: 1 / -1;
    }

    .header-controls .btn {
        padding: 10px 8px;
        font-size: 0.82rem;
        text-align: center;
        justify-content: center;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .dashboard {
        grid-template-columns: 1fr;
        gap: 10px;
    }

    .power-panel {
        grid-column: auto;
    }

    .panel {
        padding: 14px 16px;
    }

    .panel-header {
        margin-bottom: 12px;
    }

    .big-text {
        font-size: 3.5rem;
    }

    .unit {
        font-size: 1.6rem;
    }

    .graph-section {
        min-height: 240px;
    }
}

/* Mobile portrait (≤ 480px) */
@media (max-width: 480px) {
    body {
        overflow-y: auto;
        height: auto;
        min-height: 100vh;
    }

    .app-container {
        height: auto;
        padding: 10px;
        gap: 10px;
    }

    .big-text {
        font-size: 2.8rem;
    }

    .unit {
        font-size: 1.4rem;
    }

    .panel {
        padding: 12px 14px;
    }

    .panel-header h2 {
        font-size: 1rem;
    }

    .stats {
        font-size: 0.8rem;
    }

    .graph-section {
        min-height: 200px;
    }

    .drag-content {
        padding: 40px 30px;
    }

    .drag-content h2 {
        font-size: 1.4rem;
        text-align: center;
    }
}

/* Recording duration badge */
.recording-duration {
    font-family: 'Share Tech Mono', monospace;
    font-size: 0.75rem;
    color: #ff5555;
    opacity: 0.85;
    letter-spacing: 0.05em;
    margin-left: 8px;
    animation: rec-pulse 1.4s ease-in-out infinite;
}

@keyframes rec-pulse {

    0%,
    100% {
        opacity: 0.85;
    }

    50% {
        opacity: 0.35;
    }
}

/* Status error state */
.status-error {
    color: var(--color-danger) !important;
    transition: color 0.2s ease;
}

.dot-error {
    background-color: var(--color-danger) !important;
}