/* ===== CSS Variables ===== */
:root {
    --primary-color: #10a37f;
    --primary-hover: #0d8a6c;
    --secondary-color: #19c37d;
    --bg-primary: #212121;
    --bg-secondary: #171717;
    --bg-tertiary: #2f2f2f;
    --bg-hover: #2a2a2a;
    --text-primary: #ffffff;
    --text-secondary: #b4b4b4;
    --text-tertiary: #8e8e8e;
    --border-color: #424242;
    --border-light: #565656;
    --error-color: #ef4444;
    --success-color: #22c55e;
    --warning-color: #f59e0b;
    --gradient-start: #10a37f;
    --gradient-end: #19c37d;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    color: var(--primary-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
}

.btn-primary:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-hover);
}

.btn-full {
    width: 100%;
}

.btn-large {
    padding: 14px 28px;
    font-size: 16px;
}

/* ===== Gradient Text ===== */
.gradient-text {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ===== Modal ===== */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
}

.modal.active {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: 24px;
    max-width: 420px;
    width: 90%;
    position: relative;
    border: 1px solid var(--border-color);
}

.close {
    position: absolute;
    right: 16px;
    top: 16px;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-secondary);
    transition: color 0.2s;
}

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

/* ===== Form Styles ===== */
.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-size: 14px;
    color: var(--text-secondary);
}

.form-group input {
    width: 100%;
    padding: 12px 14px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 14px;
    transition: border-color 0.2s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group input::placeholder {
    color: var(--text-tertiary);
}

.error-message {
    color: var(--error-color);
    font-size: 13px;
    margin-bottom: 12px;
    min-height: 18px;
}

/* ===== Landing Page ===== */
.landing-container {
    min-height: 100vh;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 40px;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(23, 23, 23, 0.8);
    backdrop-filter: blur(10px);
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 16px;
}

.nav-link {
    color: var(--text-secondary);
    font-size: 14px;
}

.nav-link:hover {
    color: var(--text-primary);
    text-decoration: none;
}

.nav-btn {
    padding: 8px 16px;
    background: var(--primary-color);
    color: white;
    border-radius: var(--radius-sm);
    font-size: 14px;
    text-decoration: none;
}

.nav-btn:hover {
    background: var(--primary-hover);
    text-decoration: none;
}

.hero {
    padding: 160px 40px 100px;
    text-align: center;
}

.hero-content h1 {
    font-size: 72px;
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 24px;
}

.subtitle {
    font-size: 20px;
    color: var(--text-secondary);
    margin-bottom: 40px;
}

.cta-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
}

/* ===== Features Section ===== */
.features {
    padding: 80px 40px;
    text-align: center;
    background: var(--bg-secondary);
}

.features h2 {
    font-size: 36px;
    margin-bottom: 48px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
    max-width: 1200px;
    margin: 0 auto;
}

.feature-card {
    background: var(--bg-tertiary);
    padding: 32px 24px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    transition: transform 0.2s, border-color 0.2s;
}

.feature-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary-color);
}

.feature-icon {
    font-size: 40px;
    margin-bottom: 16px;
}

.feature-card h3 {
    font-size: 18px;
    margin-bottom: 8px;
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 14px;
}

/* ===== Models Section ===== */
.models-section {
    padding: 80px 40px;
    text-align: center;
}

.models-section h2 {
    font-size: 36px;
    margin-bottom: 12px;
}

.models-subtitle {
    color: var(--text-secondary);
    margin-bottom: 40px;
}

.models-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
    max-width: 900px;
    margin: 0 auto;
}

.model-tag {
    padding: 10px 20px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 100px;
    font-size: 14px;
    color: var(--text-secondary);
}

/* ===== Pricing Section ===== */
.pricing-section {
    padding: 80px 40px;
    text-align: center;
    background: var(--bg-secondary);
}

.pricing-section h2 {
    font-size: 36px;
    margin-bottom: 48px;
}

.pricing-cards {
    display: flex;
    gap: 24px;
    justify-content: center;
    flex-wrap: wrap;
    max-width: 800px;
    margin: 0 auto;
}

.pricing-card {
    background: var(--bg-tertiary);
    padding: 40px 32px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    width: 100%;
    max-width: 360px;
    text-align: center;
}

.pricing-card.featured {
    border-color: var(--primary-color);
    position: relative;
}

.pricing-card .badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary-color);
    color: white;
    padding: 4px 16px;
    border-radius: 100px;
    font-size: 12px;
    font-weight: 600;
}

.pricing-card h3 {
    font-size: 24px;
    margin-bottom: 16px;
}

.price {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 24px;
}

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

.pricing-card ul {
    list-style: none;
    text-align: left;
    margin-bottom: 32px;
}

.pricing-card li {
    padding: 8px 0;
    color: var(--text-secondary);
    font-size: 14px;
}

/* ===== Footer ===== */
.footer {
    padding: 40px;
    text-align: center;
    color: var(--text-tertiary);
    font-size: 14px;
    border-top: 1px solid var(--border-color);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .navbar {
        padding: 16px 20px;
    }

    .hero {
        padding: 120px 20px 60px;
    }

    .hero-content h1 {
        font-size: 42px;
    }

    .subtitle {
        font-size: 16px;
    }

    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }

    .features, .models-section, .pricing-section {
        padding: 60px 20px;
    }

    .features h2, .models-section h2, .pricing-section h2 {
        font-size: 28px;
    }

    .pricing-cards {
        flex-direction: column;
        align-items: center;
    }
}