:root {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-card: #21262d;
    --border-color: #30363d;
    --text-primary: #f0f6fc;
    --text-secondary: #8b949e;
    --accent-color: #238636;
    --accent-hover: #2ea043;
    --accent-glow: rgba(46, 160, 67, 0.35);
    --danger-color: #da3633;
    --danger-hover: #f85149;
    --warning-color: #d29922;
    --info-color: #58a6ff;
    --font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-mono: "SF Mono", "Fira Code", Monaco, Consolas, "Liberation Mono", Menlo, monospace;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --shadow: 0 4px 14px rgba(0, 0, 0, 0.45);
    --shadow-sm: 0 2px 6px rgba(0, 0, 0, 0.3);
}

[data-theme="light"] {
    --bg-primary: #f6f8fa;
    --bg-secondary: #ffffff;
    --bg-card: #f0f3f6;
    --border-color: #d0d7de;
    --text-primary: #1f2328;
    --text-secondary: #656d76;
    --accent-color: #1f883d;
    --accent-hover: #1a7f37;
    --accent-glow: rgba(31, 136, 61, 0.25);
    --danger-color: #cf222e;
    --danger-hover: #a40e26;
    --warning-color: #9a6700;
    --info-color: #0969da;
    --shadow: 0 4px 14px rgba(0, 0, 0, 0.08);
    --shadow-sm: 0 2px 6px rgba(0, 0, 0, 0.05);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-tap-highlight-color: transparent;
}

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-family);
    line-height: 1.5;
    padding: max(1rem, env(safe-area-inset-top)) max(1rem, env(safe-area-inset-right)) max(1.5rem, env(safe-area-inset-bottom)) max(1rem, env(safe-area-inset-left));
    min-height: 100vh;
    min-height: 100dvh;
    overflow-x: hidden;
    transition: background-color 0.2s ease, color 0.2s ease;
}

.container {
    max-width: 1080px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.hidden {
    display: none !important;
}

/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
    flex-wrap: wrap;
    gap: 1rem;
}

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

.header-logo-group {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.app-logo {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    flex-shrink: 0;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.45), 0 0 16px var(--accent-glow);
    border: 1.5px solid var(--border-color);
    background: #0a0e14;
    display: block;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.app-logo:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.6), 0 0 22px var(--accent-glow);
}

.pwa-banner-logo {
    width: 42px;
    height: 42px;
    border-radius: var(--radius-sm);
    flex-shrink: 0;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    border: 1px solid var(--border-color);
    background: #0a0e14;
}

.header-brand h1 {
    font-size: clamp(1.25rem, 3.5vw, 1.6rem);
    font-weight: 700;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    line-height: 1.2;
}

.header-brand h1 .badge {
    font-size: 0.7rem;
    background: var(--info-color);
    color: #fff;
    padding: 0.15rem 0.45rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    vertical-align: middle;
}

.header-brand p {
    font-size: clamp(0.8rem, 2vw, 0.9rem);
    color: var(--text-secondary);
    margin-top: 0.2rem;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.header-select-wrapper {
    position: relative;
}

select, button, input {
    font-family: inherit;
    font-size: 0.9rem;
}

select {
    background-color: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 0.45rem 0.8rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    outline: none;
    transition: border-color 0.15s ease;
    min-height: 38px;
}

select:focus-visible, button:focus-visible, input:focus-visible {
    outline: 2px solid var(--info-color);
    outline-offset: 1px;
}

/* PWA Install Button */
.btn-install {
    background: linear-gradient(135deg, var(--accent-color) 0%, #1c742e 100%);
    color: #ffffff;
    border: 1px solid var(--accent-hover);
    box-shadow: 0 0 10px var(--accent-glow);
    animation: install-pulse 2.5s infinite;
}

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

@keyframes install-pulse {
    0%, 100% { box-shadow: 0 0 6px var(--accent-glow); }
    50% { box-shadow: 0 0 14px var(--accent-glow); }
}

/* PWA Install Banner */
.pwa-banner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: linear-gradient(135deg, rgba(35, 134, 54, 0.15) 0%, var(--bg-secondary) 100%);
    border: 1px solid var(--accent-color);
    border-radius: var(--radius-md);
    padding: 0.9rem 1.25rem;
    gap: 1rem;
    flex-wrap: wrap;
}

.pwa-banner-content {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex: 1;
    min-width: 260px;
}

.pwa-banner-icon {
    font-size: 1.6rem;
}

.pwa-banner-text {
    display: flex;
    flex-direction: column;
    gap: 0.15rem;
    font-size: 0.88rem;
}

.pwa-banner-text strong {
    color: var(--text-primary);
    font-weight: 600;
}

.pwa-banner-text span {
    color: var(--text-secondary);
    font-size: 0.82rem;
}

.pwa-banner-actions {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

/* Cards & Grid Layout */
.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.25rem;
}

@media (max-width: 768px) {
    .grid-2 {
        grid-template-columns: 1fr;
    }
}

.card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.25rem;
    box-shadow: var(--shadow);
}

.card-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    color: var(--text-primary);
    flex-wrap: wrap;
    gap: 0.5rem;
}

/* Primary Action Bar */
.action-panel {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-card) 100%);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.25rem 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    box-shadow: var(--shadow);
}

.clock-display-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.clock-wrapper {
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
}

.digital-clock {
    font-family: var(--font-mono);
    font-size: clamp(1.8rem, 6vw, 2.75rem);
    font-weight: 700;
    color: var(--info-color);
    letter-spacing: 1px;
    font-variant-numeric: tabular-nums;
    line-height: 1.1;
}

.digital-clock-sub {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.status-wrapper {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
    align-items: flex-start;
}

@media (min-width: 769px) {
    .status-wrapper {
        align-items: flex-end;
    }
}

.main-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn {
    padding: 0.75rem 1.5rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: all 0.15s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    user-select: none;
    min-height: 44px;
}

.btn:active {
    transform: scale(0.98);
}

.btn-action {
    flex: 1;
    min-width: 200px;
}

.btn-primary {
    background-color: var(--accent-color);
    color: #ffffff;
    font-size: 1.05rem;
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    box-shadow: 0 4px 12px var(--accent-glow);
}

.btn-danger {
    background-color: var(--danger-color);
    color: #ffffff;
    font-size: 1.05rem;
}

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

.btn-secondary {
    background-color: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

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

.btn-sm {
    padding: 0.4rem 0.8rem;
    font-size: 0.82rem;
    min-height: 36px;
}

.btn-xs {
    padding: 0.2rem 0.5rem;
    font-size: 0.75rem;
    min-height: 28px;
    border-radius: 4px;
}

.btn-icon-only {
    width: 38px;
    height: 38px;
    padding: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

/* Transmit Indicator */
.btn-indicator {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.8);
    display: inline-block;
}

.btn-danger .btn-indicator {
    background-color: #ffffff;
    animation: transmitting-pulse 0.8s infinite;
}

@keyframes transmitting-pulse {
    0%, 100% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.4); opacity: 0.4; }
}

/* Status Pills */
.ntp-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    font-size: 0.82rem;
    padding: 0.3rem 0.65rem;
    border-radius: 20px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    flex-wrap: wrap;
}

.wake-lock-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    font-size: 0.78rem;
    padding: 0.25rem 0.6rem;
    border-radius: 20px;
    background: rgba(35, 134, 54, 0.15);
    border: 1px solid var(--accent-color);
    color: var(--text-primary);
}

.wake-lock-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background-color: var(--accent-color);
    animation: pulse 1.2s infinite;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--text-secondary);
    flex-shrink: 0;
}

.status-dot.synced { background-color: var(--accent-color); box-shadow: 0 0 6px var(--accent-color); }
.status-dot.syncing { background-color: var(--warning-color); animation: pulse 1s infinite; }
.status-dot.error { background-color: var(--danger-color); }

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.3; }
}

/* Form Controls & Toggles */
.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
    margin-bottom: 0.75rem;
}

.form-group label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.form-input {
    padding: 0.5rem 0.75rem;
    background: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    width: 100%;
    min-height: 40px;
}

.toggle-label {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    cursor: pointer;
    user-select: none;
    font-size: 0.88rem;
    min-height: 36px;
}

.toggle-label input[type="checkbox"] {
    width: 20px;
    height: 20px;
    accent-color: var(--accent-color);
    cursor: pointer;
    flex-shrink: 0;
}

.setting-desc {
    font-size: 0.78rem;
    color: var(--text-secondary);
    margin-left: 1.85rem;
    margin-top: -0.15rem;
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.slider-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.slider-value {
    font-family: var(--font-mono);
    font-weight: 600;
    color: var(--info-color);
    font-size: 0.9rem;
}

.slider-container {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-top: 0.2rem;
}

.slider-container input[type="range"] {
    flex: 1;
    height: 8px;
    accent-color: var(--accent-color);
    cursor: pointer;
}

/* Visualizer & Oscilloscope */
.visualizer-card {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.visualizer-title {
    margin-bottom: 0.25rem;
}

.telemetry-info {
    font-size: 0.78rem;
    font-weight: normal;
    color: var(--text-secondary);
    font-family: var(--font-mono);
}

.canvas-wrapper {
    background-color: #05070a;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    position: relative;
    width: 100%;
    aspect-ratio: 1000 / 90;
    min-height: 70px;
}

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

.inspector-hint {
    font-size: 0.76rem;
    color: var(--text-secondary);
    text-align: right;
    font-style: italic;
    margin-top: -0.3rem;
}

/* Responsive Frame Inspector Grid */
.frame-inspector {
    display: grid;
    grid-template-columns: repeat(30, 1fr);
    gap: 3px;
    width: 100%;
}

@media (max-width: 900px) {
    .frame-inspector {
        grid-template-columns: repeat(20, 1fr);
    }
}

@media (max-width: 640px) {
    .frame-inspector {
        grid-template-columns: repeat(15, 1fr);
    }
}

@media (max-width: 440px) {
    .frame-inspector {
        grid-template-columns: repeat(10, 1fr);
        gap: 3px;
    }
}

.cell {
    height: 30px;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.68rem;
    font-family: var(--font-mono);
    font-weight: 700;
    color: #ffffff;
    background-color: #21262d;
    transition: transform 0.12s ease, box-shadow 0.12s ease;
    cursor: pointer;
    user-select: none;
}

.cell:hover {
    transform: scale(1.1);
    z-index: 3;
    box-shadow: 0 0 8px rgba(255, 255, 255, 0.4);
}

.cell.marker { background-color: #da3633; }
.cell.bit1 { background-color: #d29922; }
.cell.bit0 { background-color: #238636; }
.cell.missing { background-color: #484f58; }

.cell.current {
    box-shadow: 0 0 12px #58a6ff, 0 0 4px #ffffff;
    border: 2px solid #ffffff;
    transform: scale(1.18);
    z-index: 4;
}

.cell.inspected {
    border: 2px solid #e3b341;
    box-shadow: 0 0 8px #e3b341;
}

.symbol-legend {
    display: flex;
    gap: 0.9rem;
    font-size: 0.78rem;
    margin-top: 0.2rem;
    flex-wrap: wrap;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.legend-color {
    width: 12px;
    height: 12px;
    border-radius: 3px;
    flex-shrink: 0;
}

.legend-color.marker { background-color: #da3633; }
.legend-color.bit1 { background-color: #d29922; }
.legend-color.bit0 { background-color: #238636; }
.legend-color.missing { background-color: #484f58; }

/* Status Bar Info Strip */
.info-strip {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.75rem;
    font-size: 0.85rem;
    background-color: var(--bg-card);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
}

@media (max-width: 600px) {
    .info-strip {
        grid-template-columns: 1fr;
        gap: 0.4rem;
    }
}

.info-cell {
    display: flex;
    gap: 0.35rem;
    align-items: baseline;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.info-cell strong {
    color: var(--text-secondary);
    font-size: 0.8rem;
}

/* Safety Callout */
.alert-box {
    border-radius: var(--radius-md);
    padding: 1rem 1.25rem;
    border-left: 4px solid var(--danger-color);
    background-color: rgba(218, 54, 51, 0.1);
    font-size: 0.88rem;
}

.alert-box h4 {
    color: var(--danger-color);
    margin-bottom: 0.3rem;
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

/* Accordion / Info Details */
details {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 0.85rem 1.15rem;
    transition: background-color 0.2s ease;
}

details summary {
    cursor: pointer;
    font-weight: 600;
    outline: none;
    color: var(--text-primary);
    list-style: none;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

details summary::-webkit-details-marker {
    display: none;
}

details summary::after {
    content: "▾";
    font-size: 1rem;
    transition: transform 0.2s ease;
    color: var(--text-secondary);
}

details[open] summary::after {
    transform: rotate(180deg);
}

.accordion-list {
    margin-top: 0.75rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
    padding-left: 1.2rem;
}

.accordion-list li {
    margin-bottom: 0.45rem;
    line-height: 1.45;
}

details p {
    margin-top: 0.75rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.compat-list .not-supported-item {
    color: var(--warning-color);
    margin-top: 0.5rem;
}

/* Footer */
footer {
    text-align: center;
    font-size: 0.82rem;
    color: var(--text-secondary);
    padding: 1.5rem 0 0.5rem;
    border-top: 1px solid var(--border-color);
}

.footer-links {
    margin-top: 0.4rem;
}

footer a {
    color: var(--info-color);
    text-decoration: none;
    padding: 0.3rem 0.4rem;
}

footer a:hover {
    text-decoration: underline;
}

/* iOS PWA Install Modal */
.modal-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.65);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 1rem;
}

.modal-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.6);
    width: 100%;
    max-width: 440px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    animation: modal-pop 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modal-pop {
    0% { opacity: 0; transform: scale(0.95); }
    100% { opacity: 1; transform: scale(1); }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.1rem 1.25rem;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-primary);
}

.modal-close {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1.4rem;
    cursor: pointer;
    line-height: 1;
    padding: 0.2rem 0.5rem;
    border-radius: var(--radius-sm);
}

.modal-close:hover {
    color: var(--text-primary);
    background: var(--bg-card);
}

.modal-body {
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.ios-step-item {
    display: flex;
    align-items: flex-start;
    gap: 0.85rem;
    font-size: 0.9rem;
    color: var(--text-primary);
    line-height: 1.45;
}

.ios-step-num {
    width: 26px;
    height: 26px;
    border-radius: 50%;
    background: var(--accent-color);
    color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.8rem;
    flex-shrink: 0;
}

.modal-footer {
    padding: 0.9rem 1.25rem;
    border-top: 1px solid var(--border-color);
    background: var(--bg-card);
}

/* Responsive Breakpoints & Mobile Polish */
@media (max-width: 480px) {
    header {
        flex-direction: column;
        align-items: stretch;
    }
    
    .header-brand {
        width: 100%;
    }

    .header-controls {
        width: 100%;
        justify-content: space-between;
    }

    .header-select-wrapper {
        flex: 1;
    }

    .header-select-wrapper select {
        width: 100%;
    }

    .action-panel {
        padding: 1rem;
    }

    .main-buttons {
        flex-direction: column;
    }

    .btn-action {
        width: 100%;
    }

    .pwa-banner {
        flex-direction: column;
        align-items: stretch;
    }

    .pwa-banner-actions {
        width: 100%;
    }

    .pwa-banner-actions .btn {
        flex: 1;
    }
}