/* CSS Reset & Baseline */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 62.5%;
    scroll-behavior: smooth;
}

:root {
    --bg-color: #0d1117;
    --primary-color: #161b22;
    --secondary-color: #30363d;
    --accent-color: #8b949e;
    --text-color: #e6edf3;
    --highlight-color: #f59e0b;
    --highlight-hover: #d97706;

    --border-radius: 0.8rem;
    --transition: 0.3s ease;
    --shadow: 0 1rem 3rem rgba(0, 0, 0, 0.4);

    --nav-height: 6rem;
}

body.light-theme {
    --bg-color: #f8f9fa;
    --primary-color: #e9ecef;
    --secondary-color: #dee2e6;
    --accent-color: #6c757d;
    --text-color: #212529;
    --highlight-color: #d97706;
    --highlight-hover: #b45309;
    --shadow: 0 0.5rem 1.5rem rgba(0, 0, 0, 0.1);
}

body {
    font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    font-size: 1.6rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 0;
    padding-top: var(--nav-height);
}

/* =========================================================================
   NAVBAR
   ========================================================================= */

.main-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(13, 17, 23, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(48, 54, 61, 0.6);
    z-index: 1000;
    transition: background var(--transition);
}

body.light-theme .main-nav {
    background: rgba(248, 249, 250, 0.95);
    border-bottom-color: rgba(222, 226, 230, 0.6);
}

.nav-container {
    max-width: 120rem;
    height: 100%;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    flex-shrink: 0;
    transition: transform var(--transition);
}

.nav-logo:hover {
    transform: scale(1.08);
}

.nav-logo img {
    filter: drop-shadow(0 0 6px rgba(245, 158, 11, 0.3));
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    flex-direction: column;
    gap: 0.5rem;
    z-index: 1001;
}

.hamburger-line {
    display: block;
    width: 2.4rem;
    height: 2px;
    background-color: var(--text-color);
    transition: all var(--transition);
    border-radius: 2px;
}

.nav-menu {
    display: flex;
    align-items: center;
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 3rem;
    align-items: center;
}

.nav-link {
    color: var(--accent-color);
    text-decoration: none;
    font-size: 1.5rem;
    font-weight: 500;
    padding: 0.6rem 0;
    position: relative;
    transition: color var(--transition);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--highlight-color);
    transition: width var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--highlight-color);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.theme-toggle {
    background: var(--primary-color);
    border: 1px solid var(--secondary-color);
    color: var(--text-color);
    width: 3.8rem;
    height: 3.8rem;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: all var(--transition);
    flex-shrink: 0;
    margin-left: 2rem;
}

.theme-toggle:hover {
    background: var(--secondary-color);
    transform: scale(1.05);
}

.theme-toggle svg {
    width: 1.8rem;
    height: 1.8rem;
    fill: currentColor;
}

.light-icon {
    display: none;
}

body.light-theme .dark-icon {
    display: none;
}

body.light-theme .light-icon {
    display: block;
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background: var(--primary-color);
        border-bottom: 1px solid var(--secondary-color);
        padding: 2rem;
        transform: translateY(-120%);
        transition: transform var(--transition);
        z-index: 999;
    }

    .nav-menu.open {
        transform: translateY(0);
    }

    .nav-links {
        flex-direction: column;
        gap: 2rem;
        width: 100%;
    }

    .nav-link {
        font-size: 1.8rem;
    }
}

/* =========================================================================
   MAIN LAYOUT
   ========================================================================= */

.app-container {
    width: 100%;
    max-width: 70rem;
    padding: 2rem;
}

.app-header {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 2rem;
    margin-top: 3rem;
    width: 100%;
    text-align: center;
}

h1 {
    font-size: 2.8rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
    letter-spacing: -0.5px;
    font-weight: 800;
}

.app-header p {
    color: var(--accent-color);
    font-size: 1.4rem;
}

/* =========================================================================
   QR TOOL BOX
   ========================================================================= */

.qr-box {
    background-color: var(--primary-color);
    border-radius: var(--border-radius);
    padding: 3rem;
    box-shadow: var(--shadow);
}

/* Input */
.input-group {
    margin-bottom: 2rem;
}

.input-label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 0.8rem;
}

.char-count {
    font-size: 1.2rem;
    color: var(--accent-color);
    font-weight: 400;
}

.qr-textarea {
    width: 100%;
    background-color: var(--bg-color);
    border: 2px solid var(--secondary-color);
    color: var(--text-color);
    font-size: 1.5rem;
    font-family: inherit;
    padding: 1.2rem 1.4rem;
    border-radius: var(--border-radius);
    outline: none;
    resize: vertical;
    min-height: 9rem;
    max-height: 20rem;
    transition: border-color var(--transition);
}

.qr-textarea::placeholder {
    color: var(--secondary-color);
}

.qr-textarea:focus {
    border-color: var(--highlight-color);
}

/* Options row */
.options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.option-group {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.option-label {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--accent-color);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.qr-select {
    background-color: var(--bg-color);
    border: 2px solid var(--secondary-color);
    color: var(--text-color);
    font-size: 1.4rem;
    font-family: inherit;
    padding: 0.8rem 1rem;
    border-radius: var(--border-radius);
    outline: none;
    cursor: pointer;
    transition: border-color var(--transition);
}

.qr-select:focus,
.qr-select:hover {
    border-color: var(--highlight-color);
}

/* Color pickers row */
.colors-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-bottom: 2.5rem;
}

.color-group {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.color-picker-wrapper {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: var(--bg-color);
    border: 2px solid var(--secondary-color);
    border-radius: var(--border-radius);
    padding: 0.6rem 1rem;
    transition: border-color var(--transition);
}

.color-picker-wrapper:hover {
    border-color: var(--highlight-color);
}

.color-input {
    width: 2.8rem;
    height: 2.8rem;
    border: none;
    border-radius: 0.4rem;
    cursor: pointer;
    background: none;
    padding: 0;
}

.color-input::-webkit-color-swatch-wrapper {
    padding: 0;
}

.color-input::-webkit-color-swatch {
    border: 1px solid var(--secondary-color);
    border-radius: 0.4rem;
}

.color-hex {
    font-size: 1.3rem;
    font-family: monospace;
    color: var(--accent-color);
}

/* QR Preview */
.qr-preview-area {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 2rem;
    background: #ffffff;
    border-radius: var(--border-radius);
    min-height: 20rem;
    padding: 1.5rem;
    overflow: hidden;
}

#qr-container canvas {
    display: block;
    max-width: 100%;
    height: auto;
    border-radius: 0.4rem;
}

/* qrcodejs also injects an img; hide it */
#qr-container img {
    display: none;
}

.qr-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.2rem;
    color: #9ca3af;
}

.qr-placeholder svg {
    opacity: 0.3;
}

.qr-placeholder p {
    font-size: 1.4rem;
    color: #9ca3af;
    text-align: center;
}

/* Action buttons */
.action-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.2rem;
}

.btn-primary {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.8rem;
    padding: 1.4rem;
    background-color: var(--highlight-color);
    color: #000000;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1.5rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
}

.btn-primary:hover:not(:disabled) {
    background-color: var(--highlight-hover);
    transform: translateY(-2px);
    box-shadow: 0 0.5rem 1.5rem rgba(245, 158, 11, 0.4);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
}

.btn-primary:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.btn-secondary {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.8rem;
    padding: 1.4rem;
    background-color: transparent;
    color: var(--text-color);
    border: 2px solid var(--secondary-color);
    border-radius: var(--border-radius);
    font-size: 1.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.btn-secondary:hover:not(:disabled) {
    border-color: var(--highlight-color);
    color: var(--highlight-color);
    transform: translateY(-2px);
}

.btn-secondary:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.btn-icon {
    width: 1.8rem;
    height: 1.8rem;
    flex-shrink: 0;
}

/* Toast */
.toast-container {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    z-index: 2000;
}

.toast {
    background-color: #06d6a0;
    color: #000000;
    padding: 0.8rem 1.8rem;
    border-radius: 2rem;
    font-size: 1.3rem;
    font-weight: 700;
    box-shadow: var(--shadow);
    white-space: nowrap;
    opacity: 0;
    transform: translateY(1rem);
    animation: slideUpFade 0.3s forwards;
}

@keyframes slideUpFade {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* =========================================================================
   INFORMATIONAL SECTIONS
   ========================================================================= */

.info-section {
    margin-top: 4rem;
    width: 100%;
    max-width: 80rem;
}

.section-title {
    text-align: center;
    font-size: 2.4rem;
    margin-bottom: 3rem;
    color: var(--text-color);
    font-weight: 700;
}

.section-divider {
    border: none;
    border-top: 1px solid var(--secondary-color);
    margin: 4rem auto;
    width: 60%;
    opacity: 0.3;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
}

.info-card {
    background: var(--primary-color);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--border-radius);
    padding: 2.5rem 2rem;
    text-align: center;
    transition: transform var(--transition);
    display: flex;
    flex-direction: column;
    align-items: center;
}

body.light-theme .info-card {
    border: 1px solid var(--secondary-color);
}

.info-card:hover {
    transform: translateY(-0.5rem);
}

.card-icon {
    width: 4.5rem;
    height: 4.5rem;
    border-radius: 1.2rem;
    background: rgba(245, 158, 11, 0.15);
    color: var(--highlight-color);
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 1.5rem;
}

.icon-svg {
    width: 2.2rem;
    height: 2.2rem;
}

.info-card h3 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    color: var(--text-color);
    font-weight: 600;
}

.info-card p {
    font-size: 1.4rem;
    color: var(--accent-color);
    line-height: 1.5;
}

/* Steps */
.step-card {
    align-items: flex-start;
    text-align: left;
}

.step-card .step-header {
    display: flex;
    align-items: center;
    gap: 1.2rem;
    margin-bottom: 1.5rem;
    width: 100%;
}

.step-card .card-icon {
    margin-bottom: 0;
    width: 3.5rem;
    height: 3.5rem;
    flex-shrink: 0;
}

.step-card .icon-svg {
    width: 1.8rem;
    height: 1.8rem;
}

.step-number {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--highlight-color);
    font-family: monospace;
}

.step-card h3 {
    margin-bottom: 0;
}

/* =========================================================================
   FAQ
   ========================================================================= */

.faq-container {
    margin-top: 4rem;
    padding: 3rem;
    background-color: var(--primary-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    border: 1px solid rgba(255, 255, 255, 0.05);
    width: 100%;
    max-width: 80rem;
}

.faq-container h2 {
    font-size: 2.2rem;
    margin-bottom: 2.5rem;
    color: var(--highlight-color);
    text-align: center;
    letter-spacing: -0.5px;
}

.faq-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.faq-item {
    background-color: var(--bg-color);
    border-radius: 0.6rem;
    border: 1px solid rgba(139, 148, 158, 0.2);
    overflow: hidden;
    transition: var(--transition);
}

.faq-item:hover {
    border-color: rgba(245, 158, 11, 0.4);
}

.faq-item summary {
    padding: 1.8rem 5rem 1.8rem 1.8rem;
    font-weight: 600;
    font-size: 1.6rem;
    color: var(--text-color);
    cursor: pointer;
    list-style: none;
    position: relative;
    user-select: none;
    transition: color var(--transition);
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::after {
    content: '+';
    position: absolute;
    right: 2rem;
    top: 50%;
    transform: translateY(-50%);
    font-size: 2.4rem;
    font-weight: 300;
    color: var(--highlight-color);
    transition: transform var(--transition);
}

.faq-item[open] summary {
    color: var(--highlight-color);
    border-bottom: 1px solid rgba(139, 148, 158, 0.1);
}

.faq-item[open] summary::after {
    content: '−';
    transform: translateY(-50%);
}

.faq-answer {
    padding: 2rem 1.8rem;
    color: var(--accent-color);
    line-height: 1.6;
    font-size: 1.45rem;
    animation: fadeInDown 0.3s ease forwards;
}

@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-10px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* =========================================================================
   FOOTER
   ========================================================================= */

.app-footer {
    width: 100%;
    margin-top: 5rem;
    background: var(--primary-color);
    border-top: 1px solid var(--secondary-color);
}

.footer-main {
    max-width: 120rem;
    margin: 0 auto;
    padding: 4rem 3rem 3rem;
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 4rem;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
}

.footer-logo {
    opacity: 0.8;
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.footer-logo:hover {
    opacity: 1;
    transform: scale(1.05);
}

.footer-tagline {
    font-size: 1.4rem;
    color: var(--accent-color);
    line-height: 1.6;
    max-width: 36rem;
}

.footer-disclaimer {
    font-size: 1.2rem;
    color: var(--accent-color);
    line-height: 1.5;
    max-width: 36rem;
    margin-top: 1.2rem;
}

.footer-disclaimer a {
    color: var(--highlight-color);
    text-decoration: none;
    font-weight: 600;
}

.footer-disclaimer a:hover {
    text-decoration: underline;
    text-underline-offset: 3px;
}

.footer-copy {
    font-size: 1.2rem;
    color: var(--accent-color);
    margin-top: 0.6rem;
}

.footer-col {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
}

.footer-heading {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-color);
    text-transform: uppercase;
    letter-spacing: 0.8px;
    margin-bottom: 0.5rem;
}

.footer-col-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.footer-col-links a {
    color: var(--accent-color);
    text-decoration: none;
    font-size: 1.4rem;
    transition: color var(--transition);
}

.footer-col-links a:hover {
    color: var(--highlight-color);
}

@media (max-width: 768px) {
    .footer-main {
        grid-template-columns: 1fr;
        gap: 3rem;
        text-align: center;
    }

    .footer-brand {
        align-items: center;
    }

    .footer-tagline {
        max-width: 100%;
    }

    .footer-col {
        align-items: center;
    }

    .footer-disclaimer,
    .footer-copy {
        max-width: 100%;
        text-align: center;
    }
}

/* =========================================================================
   ARTICLE PAGE
   ========================================================================= */

.article-container {
    width: 100%;
    max-width: 80rem;
    padding: 4rem 2rem;
    margin: 0 auto;
}

.article-container h1 {
    font-size: 3.2rem;
    margin-bottom: 1rem;
    line-height: 1.3;
}

.article-meta {
    font-size: 1.3rem;
    color: var(--accent-color);
    margin-bottom: 3rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid rgba(139, 148, 158, 0.2);
}

.article-container h2 {
    font-size: 2.2rem;
    margin: 3rem 0 1.5rem;
    color: var(--highlight-color);
    font-weight: 700;
}

.article-container h3 {
    font-size: 1.8rem;
    margin: 2rem 0 1rem;
    color: var(--text-color);
    font-weight: 600;
}

.article-container p {
    font-size: 1.6rem;
    line-height: 1.8;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
}

.article-container ul,
.article-container ol {
    margin: 1.5rem 0;
    padding-left: 3rem;
}

.article-container li {
    font-size: 1.5rem;
    line-height: 1.7;
    color: var(--accent-color);
    margin-bottom: 0.8rem;
}

.article-container strong {
    color: var(--text-color);
}

.article-cta {
    margin-top: 3rem;
    padding: 3rem;
    background: var(--primary-color);
    border-radius: var(--border-radius);
    border: 1px solid rgba(245, 158, 11, 0.2);
    text-align: center;
}

.article-cta p {
    margin-bottom: 1.5rem;
}

.article-cta .cta-btn {
    display: inline-block;
    padding: 1.4rem 3rem;
    background: var(--highlight-color);
    color: #000000;
    text-decoration: none;
    border-radius: var(--border-radius);
    font-size: 1.6rem;
    font-weight: 700;
    transition: var(--transition);
}

.article-cta .cta-btn:hover {
    background: var(--highlight-hover);
    transform: translateY(-2px);
}

/* =========================================================================
   COOKIE BANNER
   ========================================================================= */

#cookie-banner {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--primary-color);
    border-top: 1px solid var(--secondary-color);
    padding: 1.6rem 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
    z-index: 9999;
    flex-wrap: wrap;
    box-shadow: 0 -0.4rem 1.5rem rgba(0, 0, 0, 0.3);
}

#cookie-banner p {
    font-size: 1.3rem;
    color: var(--accent-color);
    line-height: 1.5;
    flex: 1;
    min-width: 24rem;
}

#cookie-banner p a {
    color: var(--highlight-color);
    text-decoration: underline;
    text-underline-offset: 2px;
}

.cookie-buttons {
    display: flex;
    gap: 1rem;
    flex-shrink: 0;
}

.cookie-btn {
    padding: 0.8rem 1.8rem;
    border-radius: 0.6rem;
    font-size: 1.3rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: var(--transition);
    white-space: nowrap;
}

.cookie-btn--accept {
    background: var(--highlight-color);
    color: #000000;
}

.cookie-btn--accept:hover {
    background: var(--highlight-hover);
}

.cookie-btn--reject {
    background: transparent;
    color: var(--accent-color);
    border: 1px solid var(--secondary-color);
}

.cookie-btn--reject:hover {
    border-color: var(--accent-color);
    color: var(--text-color);
}

@media (max-width: 600px) {
    .options-grid,
    .colors-row,
    .action-row {
        grid-template-columns: 1fr;
    }

    h1 {
        font-size: 2.2rem;
    }
}