@import url('https://fonts.googleapis.com/css2?family=Be+Vietnam+Pro:ital,wght@0,300;0,400;0,500;0,600;0,700;0,800;1,400&family=Outfit:wght@300;400;500;600;700;800&display=swap');

/* Language switcher hiding logic */
html[lang="vi"] *[lang="en"] {
    display: none !important;
}

html[lang="en"] *[lang="vi"] {
    display: none !important;
}

:root {
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-glass: rgba(255, 255, 255, 0.8);
    --border-glass: rgba(15, 23, 42, 0.08);
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --accent-color: #0A4699;
    --accent-gradient: linear-gradient(135deg, #3D8EFF 0%, #0A4699 100%);
    --accent-hover: #073574;
    --success-color: #059669;
    --success-gradient: linear-gradient(135deg, #059669 0%, #047857 100%);
    --card-shadow: 0 10px 30px -10px rgba(15, 23, 42, 0.08), 0 1px 3px rgba(15, 23, 42, 0.03);
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Be Vietnam Pro', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

.parallax-hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 140%;
    background-image: url('assets/img/keyboard_drafting_bg.jpg');
    background-size: cover;
    background-position: center;
    filter: blur(1px);
    z-index: -1;
    pointer-events: none;
    will-change: transform;
}

h1,
h2,
h3,
h4,
.brand-name {
    font-family: 'Be Vietnam Pro', sans-serif;
    font-weight: 700;
}

/* Glassmorphism utility */
.glass-panel {
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-glass);
    border-radius: 16px;
    box-shadow: var(--card-shadow);
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Navigation */
nav {
    padding: 1.5rem 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 100;
    transition: var(--transition-smooth);
}

nav.scrolled {
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-glass);
    padding: 1rem 0;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-wrapper {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: var(--accent-gradient);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 800;
    font-size: 1.5rem;
    font-family: 'Be Vietnam Pro', sans-serif;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.2);
}

.brand-name {
    font-size: 1.5rem;
    color: var(--text-primary);
    letter-spacing: -0.5px;
}

.brand-name span {
    color: var(--text-primary);
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
    align-items: center;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition-smooth);
    font-size: 0.95rem;
}

.nav-links a:hover {
    color: var(--text-primary);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 10px;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition-smooth);
    cursor: pointer;
    border: none;
    font-size: 0.95rem;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.2);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.35);
}

.btn-secondary {
    background: rgba(15, 23, 42, 0.04);
    color: var(--text-primary);
    border: 1px solid var(--border-glass);
}

.btn-secondary:hover {
    background: rgba(15, 23, 42, 0.08);
    transform: translateY(-2px);
}

.btn-google {
    background: white;
    color: #1f2937;
    border: 1px solid var(--border-glass);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
}

.btn-google:hover {
    background: #f9fafb;
    transform: translateY(-2px);
}

/* Hero Section */
.hero {
    padding: 10rem 0 6rem 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -20%;
    right: -10%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.08) 0%, rgba(255, 255, 255, 0) 70%);
    z-index: -1;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -10%;
    left: -10%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(139, 92, 246, 0.05) 0%, rgba(255, 255, 255, 0) 70%);
    z-index: -1;
}

.hero-fade-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 180px;
    background: linear-gradient(to bottom, rgba(248, 250, 252, 0) 0%, var(--bg-primary) 100%);
    pointer-events: none;
    z-index: 1;
}

.hero-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.badge {
    background: rgba(59, 130, 246, 0.06);
    border: 1px solid rgba(59, 130, 246, 0.15);
    color: var(--accent-color);
    padding: 0.35rem 1rem;
    border-radius: 9999px;
    font-size: 0.85rem;
    font-weight: 600;
    display: inline-block;
    margin-bottom: 1.5rem;
}

.hero-title {
    font-size: 3.5rem;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    letter-spacing: -1.5px;
}

.hero-title span {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-description {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    font-weight: 400;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.hero-brew-install {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    background: rgba(15, 23, 42, 0.03);
    border: 1px solid var(--border-glass);
    padding: 0.6rem 1.2rem;
    border-radius: 10px;
    font-size: 0.9rem;
    margin-top: 0.5rem;
    box-shadow: 0 2px 8px rgba(15, 23, 42, 0.02);
}

.hero-brew-install span {
    color: var(--text-secondary);
    font-weight: 500;
}

.hero-brew-install code {
    font-family: Menlo, Monaco, Consolas, monospace;
    font-weight: 700;
    color: var(--accent-color);
    background: rgba(15, 23, 42, 0.03);
    padding: 0.2rem 0.5rem;
    border-radius: 6px;
    border: 1px solid rgba(15, 23, 42, 0.05);
}


/* Interactive Simulator */
.simulator-section {
    padding: 4rem 0;
}

.simulator-card {
    max-width: 700px;
    margin: 0 auto;
    padding: 2rem;
}

.simulator-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-glass);
    padding-bottom: 1rem;
}

.dot-indicators {
    display: flex;
    gap: 6px;
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.dot-red {
    background: #ef4444;
}

.dot-yellow {
    background: #f59e0b;
}

.dot-green {
    background: #10b981;
}

.simulator-title {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 600;
}

.simulator-body {
    position: relative;
}

.simulator-input {
    width: 100%;
    min-height: 120px;
    background: rgba(255, 255, 255, 0.8);
    border: 1px solid var(--border-glass);
    border-radius: 8px;
    padding: 1rem;
    color: var(--text-primary);
    font-size: 1.1rem;
    resize: none;
    outline: none;
    font-family: inherit;
    transition: var(--transition-smooth);
}

.simulator-input:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 15px rgba(59, 130, 246, 0.15);
}

.simulator-tips {
    display: flex;
    justify-content: space-between;
    margin-top: 1rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* Features Grid */
.features {
    padding: 6rem 0;
}

.section-header {
    text-align: center;
    max-width: 600px;
    margin: 0 auto 4rem auto;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    letter-spacing: -1px;
}

.section-desc {
    color: var(--text-secondary);
    font-size: 1.05rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.feature-card {
    padding: 2.5rem;
    transition: var(--transition-smooth);
}

.feature-card:hover {
    transform: translateY(-5px);
    border-color: rgba(59, 130, 246, 0.2);
    box-shadow: 0 12px 30px rgba(15, 23, 42, 0.06);
}

.feature-icon {
    width: 50px;
    height: 50px;
    background: rgba(59, 130, 246, 0.06);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
    transition: var(--transition-smooth);
}

.feature-icon svg {
    width: 28px;
    height: 28px;
    stroke: var(--accent-color);
    transition: var(--transition-smooth);
}

/* Idle Loop Animations for SVG Icons */
.feature-icon.mac-fix svg {
    animation: idle-pulse 3s ease-in-out infinite;
}

.feature-icon.spellcheck svg {
    animation: idle-rotate 6s ease-in-out infinite;
}

.feature-icon.coding svg {
    animation: idle-wiggle 4s ease-in-out infinite;
}

.feature-icon.clipboard svg {
    animation: idle-float 3s ease-in-out infinite;
}

.feature-icon.macro svg {
    animation: idle-pulse-opacity 2.5s ease-in-out infinite;
}

.feature-icon.app-mode svg {
    animation: idle-window-breathe 4s ease-in-out infinite;
}

.feature-icon.cloud svg {
    animation: cloud-float 3s ease-in-out infinite alternate;
}

@keyframes idle-pulse {

    0%,
    100% {
        transform: scale(1);
        opacity: 0.85;
    }

    50% {
        transform: scale(1.05);
        opacity: 1;
    }
}

@keyframes idle-rotate {

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

    50% {
        transform: rotate(6deg);
    }
}

@keyframes idle-wiggle {

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

    50% {
        transform: translateX(2px);
    }
}

@keyframes idle-float {

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

    50% {
        transform: translateY(-3px);
    }
}

@keyframes idle-pulse-opacity {

    0%,
    100% {
        opacity: 0.8;
        transform: scale(1);
    }

    50% {
        opacity: 1;
        transform: scale(1.06);
    }
}

@keyframes idle-window-breathe {
    0%, 100% {
        transform: scale(1) translateY(0);
    }
    50% {
        transform: scale(1.03) translateY(-1px);
    }
}

/* Feature Icon Hover Micro-Animations */
.feature-card:hover .feature-icon.mac-fix svg {
    animation: mac-glow 0.8s ease-in-out infinite alternate;
}

.feature-card:hover .feature-icon.spellcheck svg {
    animation: spell-shake 0.4s ease-in-out;
}

.feature-card:hover .feature-icon.coding svg {
    animation: code-wiggle 0.5s ease-in-out;
}

.feature-card:hover .feature-icon.clipboard svg {
    animation: clip-bounce 0.5s ease-in-out;
}

.feature-card:hover .feature-icon.macro svg {
    animation: bolt-strike 0.5s ease-in-out;
}

.feature-card:hover .feature-icon.app-mode svg {
    animation: window-switch 0.6s ease-in-out;
}

.simulator-section:hover .feature-icon.cloud svg {
    animation: cloud-float-fast 1.5s ease-in-out infinite alternate;
}

@keyframes mac-glow {
    0% {
        filter: drop-shadow(0 0 2px rgba(10, 70, 153, 0.3));
        transform: scale(1.1);
    }

    100% {
        filter: drop-shadow(0 0 8px rgba(10, 70, 153, 0.8));
        transform: scale(1.1);
    }
}

@keyframes spell-shake {

    0%,
    100% {
        transform: rotate(0) scale(1.1);
    }

    25% {
        transform: rotate(-12deg) scale(1.15);
    }

    75% {
        transform: rotate(12deg) scale(1.15);
    }
}

@keyframes code-wiggle {

    0%,
    100% {
        transform: translateX(0) scale(1.1);
    }

    33% {
        transform: translateX(-4px) scale(1.15);
    }

    66% {
        transform: translateX(4px) scale(1.15);
    }
}

@keyframes clip-bounce {

    0%,
    100% {
        transform: translateY(0) scale(1.1);
    }

    50% {
        transform: translateY(-5px) scale(1.2);
    }
}

@keyframes bolt-strike {
    0% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.3) rotate(-15deg);
    }

    100% {
        transform: scale(1.1);
    }
}

@keyframes window-switch {
    0%, 100% {
        transform: scale(1) translateX(0);
    }
    30% {
        transform: scale(0.92) translateX(-2px);
    }
    70% {
        transform: scale(1.1) translateX(2px);
    }
}

@keyframes cloud-float {
    0% {
        transform: translateY(0);
    }

    100% {
        transform: translateY(-5px);
    }
}

@keyframes cloud-float-fast {
    0% {
        transform: translateY(0) scale(1.1);
    }

    100% {
        transform: translateY(-8px) scale(1.15);
    }
}


.feature-card h3 {
    margin-bottom: 0.75rem;
    font-size: 1.25rem;
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Deep Dive Section */
.deep-dive {
    padding: 6rem 0;
    background: #ffffff;
    border-top: 1px solid var(--border-glass);
    border-bottom: 1px solid var(--border-glass);
}

.deep-dive-item {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    margin-bottom: 6rem;
}

.deep-dive-item:last-child {
    margin-bottom: 0;
}

.deep-dive-item:nth-child(even) {
    direction: rtl;
}

.deep-dive-item:nth-child(even) .deep-dive-text {
    direction: ltr;
}

.deep-dive-text h3 {
    font-size: 2rem;
    margin-bottom: 1.2rem;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.deep-dive-text p {
    color: var(--text-secondary);
    font-size: 1.05rem;
    margin-bottom: 1.2rem;
    line-height: 1.7;
}

.deep-dive-tech-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-top: 1.5rem;
}

.tech-tag {
    background: rgba(59, 130, 246, 0.05);
    color: var(--accent-color);
    font-size: 0.8rem;
    font-weight: 600;
    padding: 0.3rem 0.8rem;
    border-radius: 6px;
    border: 1px solid rgba(59, 130, 246, 0.1);
}

.deep-dive-visual {
    width: 100%;
    direction: ltr;
}

.visual-mockup {
    background: #0f172a;
    color: #f8fafc;
    border-radius: 12px;
    padding: 1.5rem;
    font-family: Menlo, Monaco, Consolas, Courier New, monospace;
    font-size: 0.85rem;
    box-shadow: 0 20px 40px rgba(15, 23, 42, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.05);
    line-height: 1.5;
}

.logo-img {
    width: 38px;
    height: 38px;
    border-radius: 10px;
    object-fit: contain;
    box-shadow: 0 4px 10px rgba(10, 70, 153, 0.15);
    transition: var(--transition-smooth);
}

.logo-img:hover {
    transform: scale(1.05);
}

.feature-screenshot {
    width: 100%;
    object-fit: contain;
    border-radius: 14px;
    transition: transform 0.5s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

.feature-screenshot:hover {
    transform: translateY(-6px);
}

.feature-screenshot.shadowed {
    box-shadow: 0 10px 30px rgba(10, 70, 153, 0.06);
    border: 1px solid rgba(10, 70, 153, 0.08);
    background: #ffffff;
    padding: 6px;
}

.feature-screenshot.shadowed:hover {
    box-shadow: 0 20px 40px rgba(10, 70, 153, 0.12);
}

/* Auth Page layout */
.auth-wrapper {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    position: relative;
    overflow: hidden;
}

.auth-wrapper::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(139, 92, 246, 0.05) 0%, rgba(255, 255, 255, 0) 70%);
    z-index: -1;
}

.auth-card {
    width: 100%;
    max-width: 480px;
    padding: 3rem 2.5rem;
    text-align: center;
}

.auth-logo {
    margin-bottom: 2rem;
    display: inline-flex;
}

.auth-title {
    font-size: 1.75rem;
    margin-bottom: 0.75rem;
}

.auth-desc {
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    font-size: 0.95rem;
}

.user-profile {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.user-avatar {
    width: 96px;
    height: 96px;
    border-radius: 50%;
    border: 3px solid var(--accent-color);
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.15);
    object-fit: cover;
}

.user-name {
    font-size: 1.35rem;
    font-weight: 600;
}

.user-email {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-top: -0.5rem;
}

.token-box {
    margin-top: 1.5rem;
    background: rgba(15, 23, 42, 0.02);
    border: 1px solid var(--border-glass);
    border-radius: 10px;
    padding: 1.25rem;
    text-align: left;
}

.token-box-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
}

.token-box-title {
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-secondary);
}

.token-area {
    width: 100%;
    background: transparent;
    border: none;
    color: var(--success-color);
    font-family: monospace;
    font-size: 0.85rem;
    resize: none;
    outline: none;
    word-break: break-all;
    height: 90px;
}

/* Alert styles */
.alert {
    padding: 1rem;
    border-radius: 10px;
    margin-bottom: 1.5rem;
    text-align: left;
    font-size: 0.9rem;
    border: 1px solid transparent;
}

.alert-warning {
    background: rgba(245, 158, 11, 0.08);
    border-color: rgba(245, 158, 11, 0.15);
    color: #b45309;
}

.alert-error {
    background: rgba(239, 68, 68, 0.08);
    border-color: rgba(239, 68, 68, 0.15);
    color: #b91c1c;
}

/* Footer */
footer {
    padding: 4rem 0 2rem 0;
    border-top: 1px solid var(--border-glass);
    background: rgba(15, 23, 42, 0.02);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1.5rem;
}

.copyright {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.footer-links {
    display: flex;
    gap: 1.5rem;
    list-style: none;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition-smooth);
    font-size: 0.9rem;
}

.footer-links a:hover {
    color: var(--text-primary);
}

/* Responsive */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .nav-links {
        display: none;
    }

    .hero-actions {
        flex-direction: column;
        padding: 0 2rem;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }

    .deep-dive-item {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .deep-dive-item:nth-child(even) {
        direction: ltr;
    }
}

/* Language Switcher Styling */
.lang-switcher {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    background: rgba(15, 23, 42, 0.04);
    border: 1px solid var(--border-glass);
    padding: 0.25rem 0.5rem;
    border-radius: 8px;
    margin-left: 1rem;
}

.lang-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 0.8rem;
    font-weight: 700;
    padding: 0.2rem 0.5rem;
    cursor: pointer;
    border-radius: 6px;
    transition: var(--transition-smooth);
}

.lang-btn:hover {
    color: var(--text-primary);
}

.lang-btn.active {
    background: var(--accent-gradient);
    color: white;
    box-shadow: 0 2px 8px rgba(10, 70, 153, 0.15);
}

/* Donation Section */
.donation-section {
    padding: 6rem 0;
    border-top: 1px solid var(--border-glass);
    background: var(--bg-secondary);
}

.donation-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2.5rem;
    max-width: 800px;
    margin: 3rem auto 0 auto;
}

.donation-card {
    padding: 2.5rem 2rem;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-between;
    min-height: 340px;
}

.donation-card h3 {
    margin-bottom: 0.75rem;
    font-size: 1.25rem;
}

.donation-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
}

.momo-qr {
    width: 150px;
    height: 150px;
    object-fit: contain;
    border-radius: 12px;
    border: 1px solid var(--border-glass);
    box-shadow: 0 4px 15px rgba(15, 23, 42, 0.05);
    margin: 0.5rem 0 1.5rem 0;
    transition: var(--transition-smooth);
}

.momo-qr:hover {
    transform: scale(1.05);
}

/* Q&A Section */
.qa-section {
    padding: 6rem 0;
    border-top: 1px solid var(--border-glass);
    background: var(--bg-secondary);
}

.qa-list {
    max-width: 800px;
    margin: 3rem auto 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.qa-item {
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    border-radius: 12px;
    padding: 1.25rem 1.5rem;
    transition: var(--transition-smooth);
}

.qa-item[open] {
    box-shadow: 0 4px 20px rgba(59, 130, 246, 0.05);
    border-color: rgba(59, 130, 246, 0.2);
}

.qa-item summary {
    font-weight: 600;
    font-size: 1.05rem;
    cursor: pointer;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-primary);
    user-select: none;
}

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

.qa-item summary::after {
    content: '+';
    font-size: 1.25rem;
    font-weight: 300;
    color: var(--text-secondary);
    transition: transform var(--transition-smooth);
}

.qa-item[open] summary::after {
    content: '−';
    transform: rotate(180deg);
}

.qa-content {
    margin-top: 1rem;
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    border-top: 1px solid var(--border-glass);
    padding-top: 1rem;
}

.qa-content p {
    margin-bottom: 0.75rem;
}

.qa-content p:last-child {
    margin-bottom: 0;
}

.qa-content code {
    background: rgba(59, 130, 246, 0.08);
    color: var(--accent-color);
    padding: 0.15rem 0.4rem;
    border-radius: 4px;
    font-family: monospace;
    font-size: 0.85rem;
}