/* MCU AI Cloud Lab - unified UI refresh
   Scope: visual polish only. Do not change business layout or protocol behavior. */
:root {
    --mcu-primary: #4f46a5;
    --mcu-primary-strong: #332e78;
    --mcu-primary-soft: #efedff;
    --mcu-cyan: #008c95;
    --mcu-cyan-soft: #e3f7f6;
    --mcu-amber: #b96b05;
    --mcu-amber-soft: #fff4dd;
    --mcu-green: #16835f;
    --mcu-green-soft: #e5f7ef;
    --mcu-red: #c33d3a;
    --mcu-ink: #172033;
    --mcu-muted: #647083;
    --mcu-line: #d9dfeb;
    --mcu-line-strong: #bfc8d8;
    --mcu-surface: #ffffff;
    --mcu-surface-2: #f6f8fc;
    --mcu-shell: #eef2f7;
    --mcu-radius-sm: 6px;
    --mcu-radius: 8px;
    --mcu-radius-lg: 10px;
    --mcu-shadow-sm: 0 2px 8px rgba(23, 32, 51, 0.08);
    --mcu-shadow: 0 10px 28px rgba(23, 32, 51, 0.12);
    --mcu-shadow-lg: 0 18px 48px rgba(23, 32, 51, 0.16);
    --mcu-focus: 0 0 0 3px rgba(0, 140, 149, 0.22);
}

html {
    scroll-behavior: smooth;
    background: var(--mcu-shell);
}

body {
    color: var(--mcu-ink);
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
}

body:not([style*="overflow: hidden"]) {
    background:
        linear-gradient(180deg, rgba(239, 237, 255, 0.82), rgba(246, 248, 252, 0.96) 38%, #fff 100%);
}

a {
    text-underline-offset: 3px;
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible,
[role="button"]:focus-visible {
    outline: none !important;
    box-shadow: var(--mcu-focus) !important;
}

button,
.btn,
.btn-main,
.btn-login,
.nav-btn,
.price-btn,
.path-btn,
.enter-btn,
.submit-btn,
.code-btn,
.learning-analysis-btn,
.ai-report-btn,
.chat-send-btn,
.file-button,
.btn-submit,
.btn-circuit {
    min-height: 40px;
    border-radius: var(--mcu-radius) !important;
    letter-spacing: 0 !important;
    transition: transform 160ms ease, box-shadow 160ms ease, background-color 160ms ease, border-color 160ms ease, color 160ms ease !important;
}

button:hover,
.btn-main:hover,
.nav-btn:hover,
.price-btn:hover,
.path-btn:hover,
.enter-btn:hover,
.submit-btn:hover,
.code-btn:hover,
.learning-analysis-btn:hover,
.ai-report-btn:hover,
.chat-send-btn:hover,
.file-button:hover,
.btn-submit:hover,
.btn-circuit:hover {
    transform: translateY(-1px);
}

button:active,
.btn-main:active,
.nav-btn:active,
.price-btn:active,
.path-btn:active,
.enter-btn:active,
.submit-btn:active,
.code-btn:active,
.learning-analysis-btn:active,
.ai-report-btn:active,
.chat-send-btn:active,
.file-button:active,
.btn-submit:active,
.btn-circuit:active {
    transform: translateY(0);
}

/* Public landing pages */
.header {
    top: 0 !important;
    border-bottom: 1px solid rgba(217, 223, 235, 0.9);
    box-shadow: 0 8px 28px rgba(23, 32, 51, 0.08) !important;
}

body:has(#betaBanner) {
    padding-top: 58px !important;
}

#betaBanner {
    height: 58px !important;
    line-height: 58px !important;
    font-size: 18px !important;
    box-shadow: 0 5px 18px rgba(192, 57, 43, 0.45) !important;
}

#betaBanner > div {
    line-height: 58px !important;
}

#betaBanner span {
    font-size: 18px !important;
}

#betaBanner span[style*="font-size:17px"] {
    font-size: 20px !important;
}

#betaBanner span[style*="font-size:13px"] {
    font-size: 16px !important;
    padding: 3px 14px !important;
}

#betaBanner button {
    width: 30px !important;
    height: 30px !important;
    font-size: 18px !important;
}

body:has(#betaBanner) .header {
    top: 58px !important;
}

.header .container {
    max-width: 1180px;
}

.logo,
.nav-logo {
    color: var(--mcu-primary) !important;
}

.header-links a,
.top-nav a {
    border-radius: var(--mcu-radius);
}

.hero {
    padding-top: 116px !important;
    background:
        radial-gradient(circle at 18% 16%, rgba(0, 140, 149, 0.28), transparent 28%),
        radial-gradient(circle at 82% 20%, rgba(255, 180, 73, 0.25), transparent 24%),
        linear-gradient(135deg, #2f2a72 0%, #4f46a5 48%, #0f7680 100%) !important;
}

.hero h1 {
    letter-spacing: 0 !important;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}

.hero-subtitle {
    color: rgba(255, 255, 255, 0.9) !important;
}

.btn-main,
.btn-login,
.nav-btn.primary,
.price-btn.filled,
.submit-btn,
.code-btn-compile,
.code-btn-run:not(:disabled),
.btn-submit,
.chat-send-btn {
    background: linear-gradient(135deg, var(--mcu-cyan), var(--mcu-primary)) !important;
    color: #fff !important;
    border: 1px solid rgba(255, 255, 255, 0.18) !important;
    box-shadow: 0 10px 24px rgba(0, 140, 149, 0.22) !important;
}

.btn-main {
    animation: none !important;
    border-radius: 999px !important;
}

.video-link,
.back-link {
    border-radius: 999px;
}

.tag,
.badge,
.nav-badge {
    border-radius: 999px !important;
    letter-spacing: 0 !important;
}

.steps-section,
.beginner-path,
.selling-points,
.experiments-section,
.ai-section,
.audience-section,
.pricing-section,
.faq-section {
    background: transparent !important;
}

.section-header h2 {
    color: var(--mcu-ink) !important;
    letter-spacing: 0 !important;
}

.step-card,
.path-card,
.point-card,
.exp-card,
.price-card,
.faq-item,
.audience-card,
.ai-chat-demo,
.mcu-card,
.dest-card,
.container > .card,
.card,
.exp-category,
.na-info-panel,
.ai-report-panel,
.chat-panel,
.learning-analysis-panel {
    border-radius: var(--mcu-radius-lg) !important;
    border: 1px solid var(--mcu-line) !important;
    box-shadow: var(--mcu-shadow-sm) !important;
}

.path-card:hover,
.point-card:hover,
.exp-card:hover,
.price-card:hover,
.mcu-card:hover,
.dest-card:hover {
    transform: translateY(-3px) !important;
    box-shadow: var(--mcu-shadow) !important;
    border-color: var(--mcu-line-strong) !important;
}

.featured,
.recommended {
    border-color: rgba(0, 140, 149, 0.38) !important;
    box-shadow: 0 14px 32px rgba(0, 140, 149, 0.14) !important;
}

.audience-icon {
    font-size: 0 !important;
}

.audience-card h3,
.audience-card p {
    color: var(--mcu-ink) !important;
}

.audience-card p {
    color: var(--mcu-muted) !important;
}

.audience-icon::before {
    display: inline-flex;
    width: 48px;
    height: 48px;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: var(--mcu-cyan-soft);
    color: var(--mcu-cyan);
    font: normal normal normal 22px/1 "Font Awesome 6 Free";
    font-weight: 900;
}

.audience-card:nth-child(1) .audience-icon::before { content: "\f19d"; }
.audience-card:nth-child(2) .audience-icon::before { content: "\f121"; }
.audience-card:nth-child(3) .audience-icon::before { content: "\f51c"; }

/* Platform selector */
.mcu-options {
    align-items: stretch;
}

body:has(.mcu-options) {
    background:
        radial-gradient(circle at 18% 16%, rgba(0, 140, 149, 0.28), transparent 28%),
        radial-gradient(circle at 82% 20%, rgba(255, 180, 73, 0.24), transparent 24%),
        linear-gradient(135deg, #2f2a72 0%, #4f46a5 48%, #0f7680 100%) !important;
}

body:has(.mcu-options) h1,
body:has(.mcu-options) .subtitle,
body:has(.mcu-options) .back-link,
body:has(.mcu-options) #modeHint span {
    color: #fff !important;
}

body:has(.mcu-options) .subtitle,
body:has(.mcu-options) .back-link {
    opacity: 0.9;
}

.mcu-card {
    display: flex !important;
    min-height: 260px;
    flex-direction: column;
    justify-content: space-between;
}

.mcu-card p {
    color: var(--mcu-muted) !important;
}

.mcu-card.mcu-arduino::before {
    background: linear-gradient(90deg, var(--mcu-cyan), #23b7aa) !important;
}

.mcu-card.mcu-stm32::before {
    background: linear-gradient(90deg, #1d4f91, var(--mcu-primary)) !important;
}

/* Experiment workbench pages */
.top-nav,
.upgrade-banner {
    border-bottom: 1px solid var(--mcu-line);
}

.top-banner {
    display: flex !important;
    flex-wrap: wrap !important;
    align-items: center !important;
    justify-content: space-between !important;
    gap: 8px 14px !important;
    min-height: 58px;
    padding: 10px 14px !important;
    border: 1px solid rgba(255, 255, 255, 0.22) !important;
}

.top-banner-left,
.top-banner-right {
    display: flex !important;
    flex-wrap: wrap !important;
    align-items: center !important;
    gap: 8px !important;
    min-width: 0;
}

.top-banner-left {
    flex: 1 1 410px;
}

.top-banner-title {
    flex: 1 1 300px;
    min-width: 260px;
    text-align: center !important;
    white-space: normal !important;
    line-height: 1.25 !important;
    font-size: clamp(18px, 2vw, 24px) !important;
}

.top-banner-right {
    flex: 0 1 330px;
    justify-content: flex-end !important;
}

.top-banner button,
.top-banner a,
.btn-recharge,
.experiment-counter {
    margin-left: 0 !important;
    min-height: 34px !important;
    white-space: nowrap;
}

.top-banner button,
.top-banner a {
    font-size: 12px !important;
    padding: 5px 10px !important;
}

.top-nav {
    box-shadow: 0 4px 18px rgba(23, 32, 51, 0.08) !important;
}

.main-container,
.main-layout {
    gap: 12px !important;
}

.card {
    background: var(--mcu-surface) !important;
    transform: none !important;
}

.card-header,
.na-info-header,
.chat-title,
.ai-report-title,
.learning-analysis-title {
    background: linear-gradient(180deg, #fff, var(--mcu-surface-2)) !important;
    color: var(--mcu-ink) !important;
    border-bottom: 1px solid var(--mcu-line) !important;
}

.card-header i,
.na-info-title,
.ai-report-title,
.learning-analysis-title-main {
    color: var(--mcu-primary) !important;
}

.experiment-item,
.experiment-option,
.exp-item,
label.experiment-item {
    display: inline-flex !important;
    align-items: center !important;
    gap: 6px !important;
    border-radius: var(--mcu-radius) !important;
    border: none !important;
    background: transparent !important;
    color: var(--mcu-ink) !important;
    min-height: 36px;
    padding: 4px 8px !important;
    cursor: pointer;
}

.experiment-item:hover,
.experiment-option:hover,
.exp-item:hover,
label.experiment-item:hover {
    border: none !important;
    background: rgba(0, 140, 149, 0.08) !important;
}

.experiment-item input:checked + span,
.experiment-item:has(input:checked),
.experiment-option:has(input:checked),
label.experiment-item:has(input:checked) {
    border: none !important;
    background: rgba(0, 140, 149, 0.12) !important;
    color: var(--mcu-ink) !important;
}

label.experiment-item input[type="radio"],
.experiment-item input[type="radio"] {
    margin-right: 8px !important;
}

.stat-item,
.score-box,
.na-score-box,
.file-info,
.status-msg,
.compile-status {
    border-radius: var(--mcu-radius) !important;
}

.na-score-value,
.stat-value {
    color: var(--mcu-green) !important;
    font-variant-numeric: tabular-nums;
}

.ai-report-body,
.chat-messages,
.learning-analysis-content,
.code-input,
.code-highlight,
.code-gutter,
textarea,
pre {
    border-radius: var(--mcu-radius) !important;
}

.code-editor-wrap,
.code-merged-box {
    border-radius: var(--mcu-radius-lg) !important;
    border-color: var(--mcu-line) !important;
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.9);
}

.code-input,
.chat-input,
textarea,
input,
select {
    border: 1px solid var(--mcu-line) !important;
}

.code-input:focus,
.chat-input:focus,
textarea:focus,
input:focus,
select:focus {
    border-color: var(--mcu-cyan) !important;
}

.file-button,
.btn-circuit,
.learning-analysis-btn,
.ai-report-btn {
    background: #fff !important;
    color: var(--mcu-primary) !important;
    border: 1px solid var(--mcu-line-strong) !important;
}

.file-button:hover,
.btn-circuit:hover,
.learning-analysis-btn:hover,
.ai-report-btn:hover {
    background: var(--mcu-primary-soft) !important;
}

.debug-btn {
    min-width: 28px;
    min-height: 28px;
    border-radius: 6px !important;
}

.learning-analysis-actions {
    gap: 10px !important;
    align-items: center !important;
}

#generateLearningBtn,
#exportLearningBtn,
#downloadTextPdfBtn {
    position: relative;
    isolation: isolate;
    display: inline-flex !important;
    align-items: center !important;
    justify-content: center !important;
    gap: 8px !important;
    min-height: 46px !important;
    min-width: 142px !important;
    padding: 0 18px !important;
    border: 0 !important;
    border-radius: 12px !important;
    color: #fff !important;
    font-weight: 800 !important;
    line-height: 1 !important;
    white-space: nowrap !important;
    text-shadow: 0 1px 1px rgba(12, 22, 56, 0.2);
    box-shadow: 0 10px 22px rgba(46, 55, 148, 0.22), inset 0 1px 0 rgba(255, 255, 255, 0.28) !important;
    overflow: hidden;
}

#generateLearningBtn {
    background: linear-gradient(135deg, #0f9f8f 0%, #4038a8 100%) !important;
}

#exportLearningBtn {
    background: linear-gradient(135deg, #6a5bd8 0%, #34278f 100%) !important;
}

#downloadTextPdfBtn {
    background: linear-gradient(135deg, #16835f 0%, #008a9a 100%) !important;
}

#generateLearningBtn::before,
#exportLearningBtn::before,
#downloadTextPdfBtn::before {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.18);
    box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.25);
    font-size: 11px;
    font-weight: 900;
    line-height: 1;
    color: rgba(255, 255, 255, 0.96);
}

#generateLearningBtn::before {
    content: "AI";
}

#exportLearningBtn::before {
    content: "PDF";
    font-size: 9px;
}

#downloadTextPdfBtn::before {
    content: "\2193";
    font-size: 16px;
}

#generateLearningBtn::after,
#exportLearningBtn::after,
#downloadTextPdfBtn::after {
    content: "";
    position: absolute;
    inset: 0;
    z-index: -1;
    background: linear-gradient(120deg, rgba(255, 255, 255, 0.26), rgba(255, 255, 255, 0) 42%);
    opacity: 0.95;
}

#generateLearningBtn:hover,
#exportLearningBtn:hover,
#downloadTextPdfBtn:hover {
    transform: translateY(-2px) !important;
    color: #fff !important;
    box-shadow: 0 14px 28px rgba(46, 55, 148, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.34) !important;
    filter: saturate(1.08);
}

#generateLearningBtn:active,
#exportLearningBtn:active,
#downloadTextPdfBtn:active {
    transform: translateY(0) !important;
}

#generateLearningBtn:disabled,
#exportLearningBtn:disabled,
#downloadTextPdfBtn:disabled {
    cursor: not-allowed !important;
    opacity: 0.58 !important;
    filter: grayscale(0.22) saturate(0.85);
    box-shadow: none !important;
}

.clear-chat-btn,
#clearLearningBtn,
#undoCodeBtn,
#redoCodeBtn {
    min-width: 36px !important;
    min-height: 32px !important;
}

/* Auth and forms */
.tabs {
    border-color: var(--mcu-line) !important;
}

.tab.active {
    color: var(--mcu-primary) !important;
    border-color: var(--mcu-cyan) !important;
}

.message.success {
    background: var(--mcu-green-soft) !important;
    color: #0f5c43 !important;
}

.message.error {
    background: #fff0f0 !important;
    color: var(--mcu-red) !important;
}

/* Density and mobile safety */
@media (max-width: 1180px) {
    .main-container {
        width: 100% !important;
        padding-left: 12px !important;
        padding-right: 12px !important;
        grid-template-columns: minmax(260px, 330px) minmax(0, 1fr) minmax(360px, 460px) !important;
    }
}

@media (max-width: 900px) {
    body {
        overflow-x: hidden;
    }

    .header-links,
    .nav-stats {
        gap: 6px !important;
        flex-wrap: wrap;
        justify-content: flex-end;
    }

    .hero h1 {
        font-size: clamp(28px, 8vw, 42px) !important;
    }

    .hero-subtitle {
        font-size: 16px !important;
    }

    .steps-grid,
    .points-grid,
    .exp-grid,
    .pricing-grid,
    .audience-grid,
    .mcu-options {
        grid-template-columns: 1fr !important;
    }

    .main-container,
    .main-layout {
        display: flex !important;
        flex-direction: column !important;
        height: auto !important;
        max-height: none !important;
        overflow: visible !important;
    }

    .exp-sidebar,
    .main-left,
    .main-right,
    .main-third {
        width: 100% !important;
        min-width: 0 !important;
    }

    .top-nav {
        padding-left: 14px !important;
        padding-right: 14px !important;
        align-items: flex-start !important;
        gap: 10px;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        scroll-behavior: auto !important;
        transition-duration: 0.01ms !important;
    }
}