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

:root {
    --color-white: #ffffff;
    --color-accent-green: #a8f75d;
    --color-accent-purple: #a85df7;
    --color-accent-dark-purple: #6d007f;
    --color-text-dark: #333333;
    --color-text-black: #262626;
    --color-border: #262626;
    --color-yellow: #f7d15d;
}

/* Theme Enhancements */
:root {
    --ps-bg: #ffffff;
    --ps-ink: #1a1a1a;
    --ps-muted: #6a6a6a;
    --ps-border-soft: #eae7ff;
    --ps-surface: #f8f7ff;
    --ps-gradient: linear-gradient(135deg, var(--color-accent-purple) 0%, #9747FF 100%);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    color: var(--color-text-dark);
    line-height: 1.6;
    background-color: var(--color-white);
}

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

/* Header */
.header {
    background-color: var(--color-white);
    height: 120px;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    box-shadow: 0px 1px 3px rgba(0, 0, 0, 0);
    border-bottom: 1px solid rgba(0,0,0,0.04);
    backdrop-filter: saturate(140%) blur(6px);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 40px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.header-left {
    flex-shrink: 0;
}

.logo {
    max-width: 170px;
    height: auto;
    display: block;
}

.header-nav {
    flex: 1;
    display: flex;
    justify-content: center;
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 30px;
    align-items: center;
}

.nav-link {
    color: var(--color-text-dark);
    text-decoration: none;
    font-size: 16px;
    font-weight: 400;
    transition: color 0.3s ease;
    letter-spacing: .01em;
}

.nav-link:hover,
.nav-link:focus {
    color: var(--color-accent-purple);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 20px;
}

.social-links {
    display: flex;
    gap: 10px;
}

.social-link {
    display: inline-block;
    width: 30px;
    height: 30px;
}

.header-buttons {
    display: flex;
    gap: 10px;
}

.header-langs {
    display: flex;
    gap: 10px;
}

.lang-link {
    color: var(--color-text-dark);
    text-decoration: none;
    font-size: 16px;
    font-weight: 400;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 10px 20px;
    border-radius: 4px;
    text-decoration: none;
    font-size: 16px;
    font-weight: 400;
    transition: all 0.2s ease;
    border: none;
    cursor: pointer;
    text-align: center;
    border-radius: 12px;
    font-weight: 600;
}

.btn-outline {
    color: var(--color-text-dark);
    border: 1px solid var(--color-accent-green);
    background-color: transparent;
    border-color: var(--color-accent-green);
    box-shadow: 0 0 0 0 rgba(168,247,93,0.0);
}

.btn-outline:hover {
    background-color: var(--color-accent-green);
    color: var(--color-text-dark);
    box-shadow: 0 6px 18px rgba(168,247,93,0.35);
}

.btn-primary {
    color: var(--color-white);
    background-color: var(--color-accent-green);
    background-image: linear-gradient(0.5turn, rgba(206,159,252,1) 0%, rgba(115,103,240,1) 100%);
    box-shadow: 0 6px 0 0 #CE9FFC;
}

.btn-primary:hover {
    background-color: var(--color-accent-dark-purple);
    transform: translateY(-1px);
    box-shadow: 0 8px 14px rgba(115,103,240,0.35);
}

.btn-large {
    padding: 15px 30px;
    font-size: 18px;
}

.btn-submit {
    background-color: var(--color-accent-dark-purple);
    color: var(--color-white);
    font-weight: 600;
    width: 100%;
    padding: 12px;
}

.btn-submit:hover {
    background-color: #1b1b1b;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
    width: 28px;
    height: 20px;
    position: relative;
}

.mobile-menu-toggle span {
    display: block;
    width: 100%;
    height: 3px;
    background-color: var(--color-yellow);
    transition: all 0.3s ease;
}

.mobile-menu-toggle.active span:nth-child(1),
.mobile-menu-toggle.active span:nth-child(4) {
    opacity: 0;
}

.mobile-menu-toggle.active span:nth-child(2) {
    transform: rotate(45deg);
    position: absolute;
    top: 50%;
}

.mobile-menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg);
    position: absolute;
    top: 50%;
}

/* Main Content */
.main {
    margin-top: 120px;
}

/* Hero Section */
.hero {
    padding: 105px 0 60px;
    text-align: center;
    background:
      radial-gradient(900px 500px at -10% -20%, rgba(168,247,93,.10), transparent 60%),
      radial-gradient(900px 500px at 110% -30%, rgba(168,93,247,.10), transparent 60%);
}

.hero-title {
    font-size: 42px;
    font-weight: 700;
    color: var(--color-text-black);
    margin-bottom: 20px;
    line-height: 1.1;
}

.hero-author {
    font-size: 18px;
    color: var(--ps-muted);
}

.hero-author a {
    color: var(--color-accent-purple);
    text-decoration: none;
}

/* Introduction */
.intro {
    padding: 60px 0;
    background: var(--ps-surface);
    border-top: 1px solid var(--ps-border-soft);
    border-bottom: 1px solid var(--ps-border-soft);
}

.intro-content {
    max-width: 800px;
    margin: 0 auto;
}

.intro-content p {
    font-size: 18px;
    margin-bottom: 20px;
    line-height: 1.8;
}

/* Hero Image Section */
.hero-image-section {
    padding: 75px 0;
}

.hero-image {
    width: 100%;
    max-width: 100%;
    height: auto;
    display: block;
    margin: 0 auto;
}

.hero-image-title {
    text-align: center;
    font-size: 24px;
    font-weight: 600;
    margin-top: 20px;
    color: var(--color-text-black);
}

/* Article */
.article {
    padding: 60px 0;
}

.article-content {
    max-width: 800px;
    margin: 0 auto;
}

.article-content p {
    font-size: 18px;
    margin-bottom: 20px;
    line-height: 1.8;
}

.article-section-title {
    font-size: 28px;
    font-weight: 700;
    color: var(--color-text-black);
    margin: 40px 0 20px;
    text-align: left;
}

.article-section-title-center {
    text-align: center;
}

.article-subtitle {
    font-size: 22px;
    font-weight: 600;
    color: var(--color-text-black);
    margin: 30px 0 15px;
}

.article-list {
    list-style: none;
    padding-left: 0;
    margin: 20px 0;
}

.article-list li {
    font-size: 18px;
    margin-bottom: 15px;
    padding-left: 25px;
    position: relative;
}

.article-list li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-accent-purple);
    font-size: 24px;
    line-height: 1;
    text-shadow: 0 0 12px rgba(168,93,247,.25);
}

.faq {
    background-color: #f9f9f9;
    padding: 20px;
    border-radius: 8px;
    margin: 30px 0;
}

.faq p {
    margin-bottom: 10px;
}

.article-author {
    margin-top: 40px;
    font-weight: 600;
    font-size: 18px;
}

/* Footer */
.footer {
    padding: 45px 0;
    text-align: center;
    background: #f9f8ff;
    border-top: 1px solid var(--ps-border-soft);
}

/* Popup Modal */
.popup-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.7);
    z-index: 2000;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.popup-overlay.active {
    display: flex;
}

.popup {
    background-color: var(--color-white);
    border-radius: 8px;
    padding: 40px;
    max-width: 600px;
    width: 100%;
    position: relative;
    max-height: 90vh;
    overflow-y: auto;
}

.popup-close {
    position: absolute;
    top: 20px;
    right: 20px;
    background: none;
    border: none;
    font-size: 32px;
    color: var(--color-text-dark);
    cursor: pointer;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
}

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

.popup-title {
    font-size: 28px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 30px;
    color: var(--color-text-black);
}

/* Form */
.form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-label {
    font-size: 16px;
    font-weight: 500;
    color: var(--color-text-dark);
}

.form-subtitle {
    font-size: 14px;
    color: var(--color-text-dark);
    opacity: 0.7;
    margin: 0;
}

.form-input,
.form-textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--color-border);
    border-radius: 4px;
    font-size: 16px;
    font-family: inherit;
    color: var(--color-text-black);
    background-color: var(--color-white);
}

.form-input::placeholder,
.form-textarea::placeholder {
    color: var(--color-text-black);
    opacity: 0.5;
}

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--color-accent-purple);
}

.form-textarea {
    resize: vertical;
    min-height: 102px;
}

.form-error {
    color: #d32f2f;
    font-size: 14px;
    display: none;
}

.form-error.active {
    display: block;
}

.form-success {
    text-align: center;
    padding: 20px;
    color: var(--color-text-black);
    font-size: 18px;
}

/* Responsive */
@media screen and (max-width: 980px) {
    .header-container {
        padding: 0 20px;
    }
    
    .header-nav {
        position: fixed;
        top: 120px;
        left: 0;
        right: 0;
        background-color: var(--color-accent-purple);
        padding: 20px;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
        z-index: 999;
    }
    
    .header-nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-list {
        flex-direction: column;
        gap: 20px;
        align-items: flex-start;
    }
    
    .nav-link {
        color: var(--color-white);
        font-size: 18px;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .header-right {
        gap: 15px;
    }
    
    .header-buttons {
        flex-direction: column;
        gap: 8px;
    }
    
    .btn {
        font-size: 14px;
        padding: 8px 16px;
        border-radius: 10px;
    }
    
    .social-links {
        display: none;
    }
    
    .hero-title {
        font-size: 32px;
    }
    
    .article-section-title {
        font-size: 24px;
    }
    
    .popup {
        padding: 30px 20px;
    }
}

@media screen and (max-width: 640px) {
    .header {
        height: 80px;
    }
    
    .main {
        margin-top: 80px;
    }
    
    .header-container {
        padding: 0 15px;
    }
    
    .logo {
        max-width: 120px;
    }
    
    .hero {
        padding: 60px 0 40px;
    }
    
    .hero-title {
        font-size: 28px;
    }
    
    .intro-content p,
    .article-content p {
        font-size: 16px;
    }
    
    .article-section-title {
        font-size: 22px;
    }
    
    .header-nav {
        top: 80px;
    }
}

/* Elevation helpers */
.elev-1 { box-shadow: 0 1px 2px rgba(0,0,0,.04), 0 1px 8px rgba(0,0,0,.04); }
.elev-2 { box-shadow: 0 4px 14px rgba(0,0,0,.08); }

/* Smooth hover for buttons/links */
.btn, .nav-link, .article a { transition: all .2s ease; }