/* ============================================
   LinkedIn QR Code Generator - Styles
   ============================================ */

/* --- Reset & Base --- */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --color-linkedin: #0A66C2;
    --color-linkedin-dark: #004182;
    --color-linkedin-light: #E8F0FE;

    --color-bg: #FFFFFF;
    --color-surface: #F8F9FA;
    --color-border: #E0E0E0;
    --color-text: #1A1A1A;
    --color-text-secondary: #6B7280;
    --color-error: #DC2626;
    --color-error-bg: #FEF2F2;

    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);

    --transition: 150ms ease;
    --max-width: 640px;
}

/* --- Dark Mode --- */
@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #0F0F0F;
        --color-surface: #1A1A1A;
        --color-border: #2D2D2D;
        --color-text: #F0F0F0;
        --color-text-secondary: #9CA3AF;
        --color-linkedin-light: #0A2540;
        --color-error-bg: #1C0A0A;
        --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.2);
        --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
        --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.4);
    }
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100dvh;
    display: flex;
    flex-direction: column;
}

/* --- Accessibility --- */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

:focus-visible {
    outline: 2px solid var(--color-linkedin);
    outline-offset: 2px;
}

/* --- Layout --- */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* --- Header --- */
header {
    padding: 16px 0;
    border-bottom: 1px solid var(--color-border);
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo span {
    font-size: 1.05rem;
    font-weight: 600;
    letter-spacing: -0.01em;
}

/* --- Hero --- */
.hero {
    text-align: center;
    padding: 24px 0 20px;
}

.hero h1 {
    font-size: 1.65rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    line-height: 1.2;
    margin-bottom: 8px;
}

.subtitle {
    color: var(--color-text-secondary);
    font-size: 0.95rem;
    max-width: 480px;
    margin: 0 auto;
}

.hero-tagline {
    font-size: 0.82rem;
    color: var(--color-linkedin);
    font-weight: 600;
    margin-top: 10px;
    letter-spacing: 0.01em;
}

/* --- Sample QR Demo --- */
.qr-demo {
    margin: 24px auto 0;
    text-align: center;
}

.qr-demo-canvas {
    display: inline-block;
    padding: 12px;
    background: #FFFFFF;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.qr-demo-canvas canvas,
.qr-demo-canvas svg {
    display: block;
}

.qr-demo-label {
    font-size: 0.72rem;
    color: var(--color-text-secondary);
    margin-top: 6px;
}

/* --- Generator --- */
.generator {
    padding-bottom: 40px;
}

.input-group {
    display: flex;
    gap: 8px;
}

#linkedin-url {
    flex: 1;
    padding: 12px 16px;
    font-size: 0.95rem;
    font-family: var(--font-family);
    border: 1.5px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-surface);
    color: var(--color-text);
    transition: border-color var(--transition), box-shadow var(--transition);
}

#linkedin-url::placeholder {
    color: var(--color-text-secondary);
    opacity: 0.7;
}

#linkedin-url:focus {
    border-color: var(--color-linkedin);
    box-shadow: 0 0 0 3px rgba(10, 102, 194, 0.15);
    outline: none;
}

#linkedin-url.invalid {
    border-color: var(--color-error);
    box-shadow: 0 0 0 3px rgba(220, 38, 38, 0.1);
}

#generate-btn {
    padding: 12px 24px;
    font-size: 0.95rem;
    font-weight: 600;
    font-family: var(--font-family);
    color: #FFFFFF;
    background: var(--color-linkedin);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: background var(--transition), transform var(--transition), opacity var(--transition);
    white-space: nowrap;
}

#generate-btn:hover:not(:disabled) {
    background: var(--color-linkedin-dark);
}

#generate-btn:active:not(:disabled) {
    transform: scale(0.97);
}

#generate-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.hint {
    margin-top: 8px;
    font-size: 0.8rem;
    color: var(--color-text-secondary);
}

.error {
    margin-top: 8px;
    font-size: 0.85rem;
    color: var(--color-error);
    background: var(--color-error-bg);
    padding: 8px 12px;
    border-radius: var(--radius-sm);
}

/* --- Color Picker --- */
.color-picker {
    margin-top: 16px;
}

.color-label {
    display: block;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    margin-bottom: 8px;
}

.color-options {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.color-swatch {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: 2.5px solid transparent;
    cursor: pointer;
    transition: all var(--transition);
    outline: none;
    padding: 0;
}

.color-swatch:hover {
    transform: scale(1.15);
}

.color-swatch.active {
    border-color: var(--color-linkedin);
    box-shadow: 0 0 0 2px var(--color-bg), 0 0 0 4px var(--color-linkedin);
}

.color-custom-wrap {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    overflow: hidden;
    cursor: pointer;
    border: 2.5px solid var(--color-border);
    transition: all var(--transition);
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.color-custom-wrap.active {
    border-color: var(--color-linkedin);
    box-shadow: 0 0 0 2px var(--color-bg), 0 0 0 4px var(--color-linkedin);
}

.color-custom-wrap input[type="color"] {
    width: 40px;
    height: 40px;
    border: none;
    padding: 0;
    cursor: pointer;
    background: none;
}

.color-custom-wrap input[type="color"]::-webkit-color-swatch-wrapper {
    padding: 0;
}

.color-custom-wrap input[type="color"]::-webkit-color-swatch {
    border: none;
    border-radius: 50%;
}

/* --- Loading State --- */
.qr-loading {
    margin-top: 32px;
    text-align: center;
    animation: fadeIn 300ms ease;
}

.loading-content {
    padding: 32px 0 24px;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-linkedin);
    border-radius: 50%;
    margin: 0 auto 16px;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-text {
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 4px;
}

.loading-countdown {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
}

#countdown-number {
    font-weight: 700;
    color: var(--color-linkedin);
    font-variant-numeric: tabular-nums;
}

/* --- QR Output --- */
.qr-output {
    margin-top: 32px;
    text-align: center;
    animation: fadeIn 300ms ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.qr-canvas {
    display: inline-block;
    padding: 24px;
    background: #FFFFFF;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: 20px;
}

.download-hint-transparent {
    font-size: 0.75rem;
    color: var(--color-text-secondary);
    margin-top: 4px;
    margin-bottom: 12px;
}

.qr-canvas canvas,
.qr-canvas svg {
    display: block;
}

.download-group {
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
}

.btn-download {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 20px;
    font-size: 0.9rem;
    font-weight: 500;
    font-family: var(--font-family);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition);
    border: 1.5px solid transparent;
}

.btn-primary {
    color: #FFFFFF;
    background: var(--color-linkedin);
    border-color: var(--color-linkedin);
}

.btn-primary:hover {
    background: var(--color-linkedin-dark);
    border-color: var(--color-linkedin-dark);
}

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

.btn-secondary:hover {
    background: var(--color-linkedin);
    color: #FFFFFF;
}

.download-hint {
    margin-top: 12px;
    font-size: 0.78rem;
    color: var(--color-text-secondary);
}

/* --- Ad Slots --- */
.ad-slot {
    margin: 16px 0;
    min-height: 0;
    text-align: center;
    overflow: hidden;
    max-height: 0;
    transition: max-height 0.4s ease, margin 0.4s ease;
}

.ad-slot.ad-loaded {
    max-height: 400px;
}

.ad-top {
    margin-top: 16px;
    margin-bottom: 0;
}

.ad-loading {
    margin-top: 20px;
}

.ad-result {
    margin-top: 24px;
}

.ad-bottom {
    margin-top: 8px;
    margin-bottom: 16px;
}

/* --- Features --- */
.features {
    padding: 32px 0;
    border-top: 1px solid var(--color-border);
}

.features h2 {
    font-size: 1.1rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 20px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.feature {
    text-align: center;
    padding: 16px 8px;
}

.feature strong {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.feature span {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    line-height: 1.4;
}

.features-intro {
    text-align: center;
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    max-width: 500px;
    margin: -8px auto 20px;
    line-height: 1.5;
}

/* --- How It Works --- */
.how-it-works {
    padding: 32px 0;
    border-top: 1px solid var(--color-border);
}

.how-it-works h2 {
    font-size: 1.1rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 24px;
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.step {
    text-align: center;
    padding: 16px 8px;
}

.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--color-linkedin);
    color: #fff;
    font-weight: 700;
    font-size: 1rem;
    margin-bottom: 10px;
}

.step strong {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 6px;
}

.step span {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    line-height: 1.4;
}

/* --- Differentiator --- */
.differentiator {
    padding: 32px 0;
    border-top: 1px solid var(--color-border);
}

.differentiator h2 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.differentiator > p {
    font-size: 0.88rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: 16px;
}

.diff-list {
    list-style: none;
    padding: 0;
}

.diff-list li {
    font-size: 0.85rem;
    line-height: 1.5;
    padding: 8px 0;
    border-bottom: 1px solid var(--color-border);
}

.diff-list li:last-child {
    border-bottom: none;
}

.diff-list li strong {
    color: var(--color-linkedin);
}

/* --- FAQ --- */
.faq {
    padding: 32px 0 40px;
    border-top: 1px solid var(--color-border);
}

.faq h2 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.faq-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.faq-item {
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 16px;
    background: var(--color-surface);
}

.faq-item dt {
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 6px;
    color: var(--color-text);
}

.faq-item dd {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.5;
}

/* --- Header Row (with language picker) --- */
.header-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

.logo a {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: inherit;
}

.logo a span {
    font-size: 1.05rem;
    font-weight: 600;
    letter-spacing: -0.01em;
}

/* --- Header Nav --- */
.header-nav a {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: color var(--transition);
}

.header-nav a:hover {
    color: var(--color-linkedin);
}

/* --- Language Picker --- */
.lang-picker {
    position: relative;
}

.lang-current {
    background: none;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    padding: 4px 10px;
    font-size: 0.78rem;
    font-family: var(--font-family);
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: border-color var(--transition);
}

.lang-current:hover {
    border-color: var(--color-linkedin);
    color: var(--color-text);
}

.lang-dropdown {
    display: none;
    position: absolute;
    right: 0;
    top: 100%;
    margin-top: 4px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-md);
    list-style: none;
    min-width: 130px;
    z-index: 100;
}

.lang-picker.open .lang-dropdown {
    display: block;
}

.lang-dropdown li a {
    display: block;
    padding: 8px 14px;
    font-size: 0.82rem;
    color: var(--color-text);
    text-decoration: none;
}

.lang-dropdown li a:hover {
    background: var(--color-surface);
    color: var(--color-linkedin);
}

/* --- Breadcrumb --- */
.breadcrumb {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    padding: 16px 0 8px;
}

.breadcrumb a {
    color: var(--color-text-secondary);
    text-decoration: none;
}

.breadcrumb a:hover {
    color: var(--color-linkedin);
    text-decoration: underline;
}

/* --- Article Content --- */
.article-content {
    padding: 24px 0 32px;
}

.article-content h1 {
    font-size: 1.6rem;
    font-weight: 700;
    line-height: 1.25;
    letter-spacing: -0.02em;
    margin-bottom: 8px;
}

.article-meta {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    margin-bottom: 24px;
}

.article-content h2 {
    font-size: 1.15rem;
    font-weight: 600;
    margin: 28px 0 12px;
}

.article-content h3 {
    font-size: 1rem;
    font-weight: 600;
    margin: 20px 0 8px;
}

.article-content p {
    font-size: 0.92rem;
    line-height: 1.7;
    margin-bottom: 16px;
}

.article-content ul,
.article-content ol {
    font-size: 0.92rem;
    line-height: 1.7;
    margin: 0 0 16px 24px;
}

.article-content li {
    margin-bottom: 6px;
}

.article-content strong {
    font-weight: 600;
}

/* --- CTA Box --- */
.cta-box {
    background: var(--color-linkedin-light);
    border: 1.5px solid var(--color-linkedin);
    border-radius: var(--radius-lg);
    padding: 24px;
    text-align: center;
    margin: 32px 0;
}

.cta-box h3 {
    font-size: 1.05rem;
    margin: 0 0 8px;
}

.cta-box p {
    font-size: 0.88rem;
    color: var(--color-text-secondary);
    margin-bottom: 16px;
}

.cta-box .btn-cta {
    display: inline-block;
    padding: 10px 24px;
    color: #fff;
    background: var(--color-linkedin);
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9rem;
    transition: background var(--transition);
}

.cta-box .btn-cta:hover {
    background: var(--color-linkedin-dark);
}

/* --- Related Articles --- */
.related-articles {
    border-top: 1px solid var(--color-border);
    padding: 24px 0;
}

.related-articles h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.related-articles ul {
    list-style: none;
}

.related-articles li {
    margin-bottom: 8px;
}

.related-articles a {
    font-size: 0.88rem;
    color: var(--color-linkedin);
    text-decoration: none;
}

.related-articles a:hover {
    text-decoration: underline;
}

/* --- Articles Section & Grid --- */
.articles-section {
    padding: 32px 0;
    border-top: 1px solid var(--color-border);
}

.articles-section h2 {
    font-size: 1.1rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 20px;
}

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

.article-card {
    display: block;
    padding: 16px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-surface);
    text-decoration: none;
    color: inherit;
    transition: border-color var(--transition), box-shadow var(--transition);
}

.article-card:hover {
    border-color: var(--color-linkedin);
    box-shadow: var(--shadow-sm);
}

.article-card strong {
    display: block;
    font-size: 0.9rem;
    margin-bottom: 4px;
}

.article-card span {
    font-size: 0.82rem;
    color: var(--color-text-secondary);
    line-height: 1.4;
}

/* --- Article Hub --- */
.article-hub {
    padding: 32px 0 48px;
}

.article-hub h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.article-hub .subtitle {
    margin-bottom: 24px;
}

.article-hub .article-grid {
    gap: 16px;
}

/* --- Mid-article Ad --- */
.ad-mid {
    margin: 24px 0;
}

/* --- Footer --- */
footer {
    margin-top: auto;
    padding: 16px 0;
    border-top: 1px solid var(--color-border);
    text-align: center;
}

footer p {
    font-size: 0.78rem;
    color: var(--color-text-secondary);
}

.footer-links {
    margin-top: 6px;
}

.footer-links a {
    font-size: 0.75rem;
    color: var(--color-text-secondary);
    text-decoration: none;
}

.footer-links a:hover {
    color: var(--color-linkedin);
    text-decoration: underline;
}

/* --- Responsive --- */
@media (max-width: 480px) {
    .logo span {
        font-size: 0.85rem;
    }

    .header-nav a {
        font-size: 0.78rem;
    }

    .hero {
        padding: 16px 0 12px;
    }

    .hero h1 {
        font-size: 1.35rem;
    }

    .input-group {
        flex-direction: column;
    }

    #generate-btn {
        width: 100%;
    }

    .feature-grid {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .feature {
        display: flex;
        align-items: baseline;
        gap: 8px;
        text-align: left;
        padding: 8px 0;
    }

    .feature strong {
        margin-bottom: 0;
        white-space: nowrap;
    }

    .article-content h1 {
        font-size: 1.3rem;
    }

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

    .step {
        display: flex;
        align-items: center;
        gap: 12px;
        text-align: left;
        padding: 8px 0;
    }

    .step-number {
        flex-shrink: 0;
        margin-bottom: 0;
    }

    .step strong {
        margin-bottom: 2px;
    }
}

/* --- Print --- */
@media print {
    header, footer, .input-group, .download-group, .features, .faq,
    .hint, .download-hint, .ad-slot, .qr-loading {
        display: none;
    }

    .qr-output {
        margin-top: 0;
    }

    .qr-canvas {
        box-shadow: none;
        padding: 0;
    }
}