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

:root {
    --bg-primary: #1a1a1a;
    --bg-secondary: #252525;
    --bg-card: rgba(37, 37, 37, 0.8);
    --text-primary: #ffffff;
    --text-secondary: #b3b3b3;
    --border-color: rgba(255, 255, 255, 0.1);
    --accent: #ffffff;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 50%, rgba(255, 255, 255, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(255, 255, 255, 0.02) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

body::after {
    content: '';
    position: fixed;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(0, 0, 0, 0.4) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
    z-index: 0;
    animation: floatShadow 20s ease-in-out infinite;
    top: 20%;
    left: 10%;
}

@keyframes floatShadow {
    0%, 100% {
        transform: translate(0, 0) scale(1);
    }
    25% {
        transform: translate(30vw, 10vh) scale(1.2);
    }
    50% {
        transform: translate(20vw, -15vh) scale(0.9);
    }
    75% {
        transform: translate(-10vw, 5vh) scale(1.1);
    }
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
    z-index: 1;
}

/* Header */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(26, 26, 26, 0.9);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    padding: 16px 0;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
    font-size: 16px;
    letter-spacing: 1.5px;
}

.logo-icon {
    width: 24px;
    height: 24px;
    color: var(--text-primary);
}

.logo-text {
    color: var(--text-primary);
}

.nav-links {
    display: flex;
    gap: 28px;
    align-items: center;
}

.nav-links a {
    color: var(--text-primary);
    text-decoration: none;
    font-size: 13px;
    font-weight: 400;
    transition: opacity 0.2s;
}

.nav-links a:hover {
    opacity: 0.7;
}

.btn-primary {
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: var(--text-primary);
    padding: 8px 20px;
    border-radius: 4px;
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.2);
}

.btn-primary.large {
    padding: 14px 32px;
    font-size: 16px;
}

/* Hero Section */
.hero {
    padding: 60px 0 80px;
    text-align: center;
}

.hero-title {
    font-size: 48px;
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 16px;
    letter-spacing: -0.03em;
}

.hero-subtitle {
    font-size: 16px;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 48px;
    line-height: 1.5;
    font-weight: 400;
}

/* Demo Box */
.demo-box {
    background: rgba(37, 37, 37, 0.25);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    padding: 32px;
    max-width: 800px;
    margin: 0 auto;
    position: relative;
    backdrop-filter: blur(16px) saturate(150%);
    -webkit-backdrop-filter: blur(16px) saturate(150%);
    box-shadow: 
        0 4px 24px rgba(0, 0, 0, 0.2),
        inset 0 1px 0 rgba(255, 255, 255, 0.08);
    z-index: 1;
}


.demo-input,
.demo-output {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.tone-selector {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 6px;
}

.tone-selector label {
    font-size: 12px;
    color: var(--text-secondary);
    font-weight: 400;
    white-space: nowrap;
}

.tone-dropdown {
    flex: 1;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 6px;
    padding: 8px 12px;
    color: var(--text-primary);
    font-size: 13px;
    font-family: inherit;
    cursor: pointer;
    transition: all 0.2s;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='10' viewBox='0 0 12 12'%3E%3Cpath fill='%23ffffff' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
    background-size: 10px;
    padding-right: 32px;
}

.tone-dropdown:hover {
    border-color: rgba(255, 255, 255, 0.25);
    background-color: rgba(0, 0, 0, 0.4);
}

.tone-dropdown:focus {
    outline: none;
    border-color: rgba(255, 255, 255, 0.3);
    background-color: rgba(0, 0, 0, 0.4);
    box-shadow: 0 0 0 2px rgba(255, 255, 255, 0.1);
}

.tone-dropdown option {
    background: var(--bg-primary);
    color: var(--text-primary);
    padding: 10px;
}

.demo-input label {
    font-size: 11px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.8px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 6px;
}

.label-icon {
    width: 14px;
    height: 14px;
    color: var(--text-secondary);
}

.demo-text {
    font-size: 15px;
    line-height: 1.5;
    color: var(--text-primary);
    padding: 0;
    background: rgba(0, 0, 0, 0.15);
    border-radius: 8px;
    min-height: 70px;
    position: relative;
    overflow: hidden;
    display: block;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.06);
    box-shadow: 
        0 2px 12px rgba(0, 0, 0, 0.15),
        inset 0 1px 0 rgba(255, 255, 255, 0.04);
}

.demo-text.transcript {
    font-size: 15px;
    line-height: 1.5;
    color: var(--text-primary);
    background: rgba(0, 0, 0, 0.15);
    border-left: 2px solid rgba(255, 255, 255, 0.15);
    padding-left: 16px;
}

.demo-text-content {
    width: calc(100% - 28px);
    display: block;
    position: absolute;
    top: 14px;
    left: 14px;
    padding: 0;
    transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.5s ease;
    transform: translateY(0);
    opacity: 1;
    word-wrap: break-word;
    overflow-wrap: break-word;
    white-space: normal;
    box-sizing: border-box;
}

.demo-text.transcript .demo-text-content {
    width: calc(100% - 32px);
    left: 16px;
}

.demo-text-content.slide-out {
    transform: translateY(100%);
    opacity: 0;
}

.demo-text-content.slide-in {
    transform: translateY(-100%);
    opacity: 0;
}

.demo-text-content.slide-in.active {
    transform: translateY(0);
    opacity: 1;
}

.demo-arrow {
    display: flex;
    justify-content: center;
    margin: 20px 0;
    color: var(--text-secondary);
    opacity: 0.6;
}

.demo-arrow svg {
    width: 24px;
    height: 24px;
}

.demo-output {
    margin-top: 20px;
}

.demo-label {
    font-size: 11px;
    color: var(--text-secondary);
    text-align: left;
    margin-top: -6px;
    opacity: 0.7;
}

.btn-demo {
    margin-top: 24px;
    width: 100%;
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: var(--text-primary);
    padding: 10px 20px;
    border-radius: 4px;
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-demo:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.2);
}

/* Features Section */
.features {
    padding: 80px 0;
}

.section-title {
    font-size: 36px;
    font-weight: 600;
    text-align: center;
    margin-bottom: 16px;
    letter-spacing: -0.03em;
}

.info-hint {
    text-align: center;
    color: var(--text-secondary);
    font-size: 12px;
    margin-bottom: 32px;
    font-style: italic;
    opacity: 0.6;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
    max-width: 900px;
    margin: 0 auto;
}

.feature-card {
    background: rgba(37, 37, 37, 0.25);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    padding: 24px;
    text-align: center;
    backdrop-filter: blur(12px);
    transition: border-color 0.3s ease, transform 0.2s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    isolation: isolate;
}

.feature-card:not(.active) {
    border-color: rgba(255, 255, 255, 0.1);
}

.feature-card:hover:not(.active) {
    border-color: rgba(255, 255, 255, 0.15);
    transform: translateY(-2px);
}

.feature-card.active {
    border-color: rgba(255, 255, 255, 0.3);
    border-width: 1px;
    z-index: 10;
}

.feature-info {
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1), 
                opacity 0.4s ease, 
                padding-top 0.4s ease, 
                margin-top 0.4s ease,
                border-top 0.4s ease;
    margin-top: 0;
    padding-top: 0;
    text-align: left;
    visibility: hidden;
    height: 0;
    pointer-events: none;
}

.feature-card.active .feature-info {
    max-height: 500px;
    opacity: 1;
    padding-top: 20px;
    margin-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    visibility: visible;
    height: auto;
    pointer-events: auto;
}

.feature-info p {
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-secondary);
    margin: 0;
}

.feature-icon {
    width: 36px;
    height: 36px;
    margin: 0 auto 16px;
    color: var(--text-primary);
    opacity: 0.9;
}

.feature-icon svg {
    width: 100%;
    height: 100%;
}

.feature-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 6px;
}

.feature-card p {
    font-size: 13px;
    color: var(--text-secondary);
}

/* Pricing Section */
.pricing {
    padding: 80px 0;
}

.tier-selection-message {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 8px;
    padding: 16px 24px;
    margin: 0 auto 32px auto;
    max-width: 800px;
    text-align: center;
    backdrop-filter: blur(8px);
}

.tier-selection-message p {
    color: var(--text-primary);
    font-size: 14px;
    margin: 0;
    font-weight: 500;
}

.pricing-grid {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 32px;
    max-width: 800px;
    margin: 0 auto;
    align-items: center;
}

.pricing-card {
    background: rgba(37, 37, 37, 0.25);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    padding: 28px;
    text-align: left;
    backdrop-filter: blur(16px) saturate(150%);
    -webkit-backdrop-filter: blur(16px) saturate(150%);
    box-shadow: 
        0 4px 24px rgba(0, 0, 0, 0.2),
        inset 0 1px 0 rgba(255, 255, 255, 0.08);
    transition: all 0.2s;
}

.pricing-card:hover {
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
    box-shadow: 
        0 6px 28px rgba(0, 0, 0, 0.25),
        inset 0 1px 0 rgba(255, 255, 255, 0.1);
}

.pricing-card.featured {
    border-color: rgba(255, 255, 255, 0.2);
    background: rgba(37, 37, 37, 0.3);
}

.pricing-card h3 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 10px;
    text-align: center;
}

.pricing-description {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 24px;
    text-align: center;
    line-height: 1.5;
}

.pricing-features {
    list-style: none;
    margin: 0 0 24px 0;
    padding: 0;
}

.pricing-features li {
    font-size: 13px;
    color: var(--text-primary);
    padding: 8px 0;
    padding-left: 20px;
    position: relative;
    line-height: 1.5;
}

.pricing-features li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--text-secondary);
    font-size: 16px;
    line-height: 1;
}

.pricing-price {
    font-size: 32px;
    font-weight: 600;
    margin: 24px 0;
    text-align: center;
}

.pricing-price span {
    font-size: 16px;
    color: var(--text-secondary);
    font-weight: 400;
}

.pricing-divider {
    width: 1px;
    height: 100%;
    background: linear-gradient(to bottom, transparent, rgba(255, 255, 255, 0.15), transparent);
    min-height: 350px;
}

.btn-pricing {
    width: 100%;
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: var(--text-primary);
    padding: 10px 20px;
    border-radius: 4px;
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    text-align: center;
}

.btn-pricing:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

.btn-pricing.primary {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.15);
}

.btn-pricing.primary:hover {
    background: rgba(255, 255, 255, 0.12);
    border-color: rgba(255, 255, 255, 0.25);
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .hero-title {
        font-size: 40px;
    }

    .hero-subtitle {
        font-size: 18px;
    }

    .demo-box {
        padding: 24px;
    }

    .section-title {
        font-size: 36px;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .pricing-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .pricing-divider {
        width: 100%;
        height: 1px;
        min-height: 1px;
        background: linear-gradient(to right, transparent, rgba(255, 255, 255, 0.2), transparent);
    }
}

/* Footer */
.footer {
    padding: 60px 0 40px;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    margin-top: 80px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 24px;
}

.footer-links {
    display: flex;
    gap: 32px;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 13px;
    font-weight: 400;
    transition: color 0.2s;
}

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

.footer-social {
    display: flex;
    gap: 16px;
    align-items: center;
}

.social-link {
    color: var(--text-secondary);
    transition: color 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.social-link:hover {
    color: var(--text-primary);
}

.social-link svg {
    width: 20px;
    height: 20px;
}

@media (max-width: 768px) {
    .footer-content {
        flex-direction: column;
        text-align: center;
    }

    .footer-links {
        justify-content: center;
        gap: 24px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 32px;
    }

    .demo-text {
        font-size: 16px;
    }
}