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

:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --secondary: #64748b;
    --text: #1e293b;
    --text-light: #64748b;
    --background: #ffffff;
    --background-alt: #f8fafc;
    --border: #e2e8f0;
    --shadow: rgba(0, 0, 0, 0.1);
    --shadow-lg: rgba(0, 0, 0, 0.15);
    --success: #10b981;
}

[data-theme="dark"] {
    --text: #f1f5f9;
    --text-light: #94a3b8;
    --background: #0f172a;
    --background-alt: #1e293b;
    --border: #334155;
    --shadow: rgba(0, 0, 0, 0.3);
    --shadow-lg: rgba(0, 0, 0, 0.5);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
    color: var(--text);
    background-color: var(--background);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header & Navigation */
.header {
    background: var(--background);
    box-shadow: 0 2px 10px var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.nav-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.theme-toggle {
    background: transparent;
    border: 2px solid var(--border);
    border-radius: 0.5rem;
    padding: 0.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    color: var(--text);
    transition: all 0.3s ease;
}

.theme-toggle:hover {
    background: var(--background-alt);
    border-color: var(--primary);
}

.theme-toggle svg {
    width: 20px;
    height: 20px;
    stroke: currentColor;
}

.lang-dropdown {
    position: relative;
}

.lang-toggle {
    background: transparent;
    border: 2px solid var(--border);
    border-radius: 0.5rem;
    padding: 0.5rem 0.75rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text);
    transition: all 0.3s ease;
    font-family: inherit;
}

.lang-toggle:hover {
    background: var(--background-alt);
    border-color: var(--primary);
}

.lang-text {
    font-size: 0.875rem;
    font-weight: 600;
}

.chevron-icon {
    width: 16px;
    height: 16px;
    stroke: currentColor;
    transition: transform 0.3s ease;
}

.lang-dropdown.active .chevron-icon {
    transform: rotate(180deg);
}

.lang-dropdown-menu {
    position: absolute;
    top: calc(100% + 0.5rem);
    right: 0;
    background: var(--background);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    box-shadow: 0 4px 12px var(--shadow-lg);
    min-width: 80px;
    display: none;
    flex-direction: column;
    overflow: hidden;
    z-index: 1000;
}

.lang-dropdown.active .lang-dropdown-menu {
    display: flex;
}

.lang-option {
    padding: 0.75rem 1rem;
    background: transparent;
    border: none;
    text-align: left;
    cursor: pointer;
    color: var(--text);
    font-size: 0.875rem;
    font-weight: 600;
    transition: background-color 0.2s ease;
    font-family: inherit;
}

.lang-option:hover {
    background: var(--background-alt);
}

.nav-actions {
    display: flex;
    gap: 1rem;
    align-items: center;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    font-family: inherit;
}

.btn-primary {
    background: var(--primary);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow-lg);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: white;
    color: var(--primary);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: white;
}

.btn-large {
    padding: 1rem 2.5rem;
    font-size: 1.125rem;
}

.btn-full {
    width: 100%;
    display: block;
    margin-top: 1rem;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 6rem 0;
    text-align: center;
}

.hero-content {
    max-width: 900px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.375rem;
    margin-bottom: 2.5rem;
    opacity: 0.95;
    line-height: 1.6;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Sections */
.section {
    padding: 5rem 0;
}

.section-alt {
    background: var(--background-alt);
    transition: background-color 0.3s ease;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text);
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-light);
}

/* Features */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--background);
    padding: 2.5rem;
    border-radius: 1rem;
    box-shadow: 0 4px 6px var(--shadow);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease;
    border: 1px solid var(--border);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px var(--shadow-lg);
}

.feature-icon {
    margin-bottom: 1.5rem;
    display: flex;
    justify-content: center;
    align-items: center;
}

.feature-icon svg {
    width: 48px;
    height: 48px;
    stroke: var(--primary);
    stroke-width: 2;
}

.feature-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text);
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.7;
}

/* Widget Demo Section */
.widget-demo {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.widget-demo-content h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text);
}

.widget-demo-content p {
    font-size: 1.125rem;
    color: var(--text-light);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.widget-features {
    list-style: none;
    margin-bottom: 2rem;
}

.widget-features li {
    padding: 0.75rem 0;
    font-size: 1.125rem;
    color: var(--text);
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.check-icon {
    width: 20px;
    height: 20px;
    stroke: var(--success);
    stroke-width: 3;
    flex-shrink: 0;
}

.widget-preview {
    display: flex;
    justify-content: center;
    align-items: center;
}

.widget-preview-box {
    background: var(--background);
    border-radius: 1rem;
    box-shadow: 0 8px 24px var(--shadow-lg);
    padding: 2rem;
    min-width: 300px;
    border: 1px solid var(--border);
    transition: background-color 0.3s ease;
}

.widget-preview-header {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    text-align: center;
    color: var(--text);
}

.widget-amounts {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.widget-amount-btn {
    padding: 0.75rem;
    background: var(--background-alt);
    border: 2px solid var(--border);
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    color: var(--text);
}

.widget-amount-btn:hover {
    border-color: var(--primary);
    background: var(--background);
}

.widget-donate-btn {
    width: 100%;
    padding: 1rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 0.5rem;
    font-weight: 600;
    font-size: 1.125rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.widget-donate-btn:hover {
    background: var(--primary-dark);
}

/* CTA Section */
.cta-section {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    text-align: center;
}

.cta-content h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: white;
}

.cta-content p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

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

.modal-content {
    background: var(--background);
    padding: 2.5rem;
    border-radius: 1rem;
    max-width: 500px;
    width: 90%;
    position: relative;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    transition: background-color 0.3s ease;
    border: 1px solid var(--border);
}

.modal-close {
    position: absolute;
    right: 1.5rem;
    top: 1.5rem;
    font-size: 2rem;
    font-weight: 300;
    color: var(--text-light);
    cursor: pointer;
    line-height: 1;
    transition: color 0.3s ease;
}

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

.modal-content h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text);
}

.modal-content > p {
    color: var(--text-light);
    margin-bottom: 2rem;
}

/* Form */
.register-form {
    margin-top: 1.5rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text);
}

.form-group input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border);
    border-radius: 0.5rem;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.3s ease, background-color 0.3s ease, color 0.3s ease;
    background: var(--background);
    color: var(--text);
}

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

.form-group input:invalid {
    border-color: #ef4444;
}

/* Footer */
.footer {
    background: var(--text);
    color: white;
    padding: 2rem 0;
    text-align: center;
}

.footer-content p {
    opacity: 0.8;
}

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

    .hero-subtitle {
        font-size: 1.125rem;
    }

    .section-header h2 {
        font-size: 2rem;
    }

    .nav-right {
        flex-wrap: wrap;
        gap: 0.5rem;
    }

    .nav-actions {
        gap: 0.5rem;
    }

    .btn {
        padding: 0.625rem 1rem;
        font-size: 0.9rem;
    }

    .widget-demo {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

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

@media (max-width: 480px) {
    .hero {
        padding: 4rem 0;
    }

    .hero-title {
        font-size: 2rem;
    }

    .section {
        padding: 3rem 0;
    }

    .nav-content {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-actions {
        width: 100%;
        justify-content: center;
    }
}