/* ========================================
   Hacker English - Modern Dark Theme
   ======================================== */

/* CSS Variables */
:root {
    --color-bg-primary: #0a0a0a;
    --color-bg-secondary: #121212;
    --color-bg-tertiary: #1a1a1a;
    --color-bg-card: #161616;
    --color-bg-card-hover: #1e1e1e;
    
    --color-text-primary: #ffffff;
    --color-text-secondary: #b0b0b0;
    --color-text-muted: #6b6b6b;
    --color-text-accent: #d4af37;
    
    --color-border: #2a2a2a;
    --color-border-light: #3a3a3a;
    
    --color-primary: #d4af37;
    --color-primary-hover: #e5c150;
    --color-primary-dark: #b89628;
    
    --color-accent: #c9a961;
    --color-accent-glow: rgba(212, 175, 55, 0.3);
    
    --gradient-primary: linear-gradient(135deg, #d4af37 0%, #f4d06f 100%);
    --gradient-dark: linear-gradient(180deg, #0a0a0a 0%, #121212 100%);
    --gradient-card: linear-gradient(145deg, #1a1a1a 0%, #141414 100%);
    
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(212, 175, 55, 0.15);
    
    --font-primary: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-display: 'Playfair Display', Georgia, serif;
    
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 5rem;
    --spacing-3xl: 8rem;
    
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 20px;
    --radius-full: 9999px;
    
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-fast);
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    display: block;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    letter-spacing: -0.02em;
}

.section-title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.section-tag {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
    padding: var(--spacing-xs) var(--spacing-sm);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-full);
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-sm) var(--spacing-lg);
    font-family: var(--font-primary);
    font-size: 0.9375rem;
    font-weight: 500;
    letter-spacing: 0.02em;
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all var(--transition-base);
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--color-bg-primary);
    border-color: var(--color-primary);
}

.btn-primary:hover {
    background: var(--color-primary-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

.btn-outline {
    background: transparent;
    color: var(--color-text-primary);
    border-color: var(--color-border-light);
}

.btn-outline:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    transform: translateY(-2px);
}

.btn-large {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1rem;
}

.btn-full {
    width: 100%;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: var(--spacing-md) 0;
    background: rgba(10, 10, 10, 0.9);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--color-border);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 600;
    font-size: 1.125rem;
}

.logo-icon {
    font-size: 1.5rem;
}

.logo-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    gap: var(--spacing-xl);
}

.nav-links a {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    transition: color var(--transition-fast);
}

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

.nav-cta {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: 0.875rem;
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-3xl) var(--spacing-lg);
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(ellipse at 30% 20%, rgba(212, 175, 55, 0.08) 0%, transparent 50%),
        radial-gradient(ellipse at 70% 80%, rgba(212, 175, 55, 0.05) 0%, transparent 50%);
    z-index: -1;
}

.hero-content {
    text-align: center;
    max-width: 900px;
}

.hero-title {
    margin-bottom: var(--spacing-lg);
}

.title-line {
    display: block;
    font-size: clamp(2.5rem, 8vw, 5rem);
    font-weight: 700;
    line-height: 1.1;
}

.title-line.highlight {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-slogan {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
    font-weight: 500;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
    line-height: 1.8;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

.hero-scroll {
    position: absolute;
    bottom: var(--spacing-xl);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.scroll-indicator {
    width: 24px;
    height: 40px;
    border: 2px solid var(--color-border-light);
    border-radius: var(--radius-full);
    position: relative;
}

.scroll-indicator::before {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: var(--color-primary);
    border-radius: var(--radius-full);
    animation: scroll 2s infinite;
}

@keyframes scroll {
    0%, 100% { opacity: 0; transform: translateX(-50%) translateY(0); }
    50% { opacity: 1; transform: translateX(-50%) translateY(12px); }
}

/* About Section */
.about {
    padding: var(--spacing-3xl) 0;
    background: var(--color-bg-primary);
}

.about-content {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.about-text .section-tag {
    margin-bottom: var(--spacing-sm);
}

.about-text .section-title {
    margin-bottom: var(--spacing-lg);
    text-align: left;
}

.about-description {
    margin-bottom: var(--spacing-xl);
}

.about-description .lead {
    font-size: 1.25rem;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.about-description p {
    font-size: 1rem;
    color: var(--color-text-secondary);
    line-height: 1.8;
}

.about-highlights {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.highlight-item {
    display: flex;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--gradient-card);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    transition: all var(--transition-base);
}

.highlight-item:hover {
    border-color: var(--color-primary);
    transform: translateX(4px);
}

.highlight-icon {
    font-size: 1.75rem;
    flex-shrink: 0;
}

.highlight-item h4 {
    font-size: 1rem;
    margin-bottom: var(--spacing-xs);
    color: var(--color-text-primary);
}

.highlight-item p {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

.about-visual {
    display: flex;
    align-items: center;
    justify-content: center;
}

.visual-box {
    width: 280px;
    height: 280px;
    background: var(--gradient-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.visual-box::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(212, 175, 55, 0.08) 0%, transparent 70%);
    animation: pulse 8s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 0.5; }
    50% { transform: scale(1.1); opacity: 0.8; }
}

.box-content {
    text-align: center;
    z-index: 1;
}

.box-title {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 0.15em;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.box-subtitle {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: 0.2em;
    color: var(--color-text-primary);
    margin-top: var(--spacing-xs);
}

.box-tag {
    display: inline-block;
    font-size: 0.75rem;
    color: var(--color-text-muted);
    letter-spacing: 0.1em;
    margin-top: var(--spacing-md);
    padding: var(--spacing-xs) var(--spacing-md);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-full);
}

/* Philosophy Section */
.philosophy {
    padding: var(--spacing-3xl) 0;
    background: var(--color-bg-secondary);
}

.philosophy-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--spacing-lg);
}

.philosophy-card {
    background: var(--gradient-card);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    transition: all var(--transition-base);
}

.philosophy-card:hover {
    border-color: var(--color-primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-glow);
}

.card-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.philosophy-card h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-primary);
}

.philosophy-card p {
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
    line-height: 1.7;
}

/* Value Proposition */
.value-prop {
    padding: var(--spacing-3xl) 0;
    background: var(--color-bg-primary);
}

.value-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.value-points {
    margin-top: var(--spacing-xl);
}

.value-point {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.point-marker {
    width: 8px;
    height: 8px;
    background: var(--color-primary);
    border-radius: var(--radius-full);
    margin-top: 0.5rem;
    flex-shrink: 0;
}

.point-content h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
    color: var(--color-text-primary);
}

.point-content p {
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
}

.value-visual {
    display: flex;
    align-items: center;
    justify-content: center;
}

.visual-circle {
    width: 300px;
    height: 300px;
    border: 2px solid var(--color-border-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.visual-circle::before {
    content: '';
    position: absolute;
    width: 260px;
    height: 260px;
    border: 1px dashed var(--color-border);
    border-radius: 50%;
    animation: rotate 30s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.circle-inner {
    text-align: center;
}

.circle-text {
    display: block;
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: 0.2em;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.circle-sub {
    display: block;
    font-size: 0.875rem;
    color: var(--color-text-muted);
    letter-spacing: 0.1em;
    margin-top: var(--spacing-xs);
}

/* Method Section */
.method {
    padding: var(--spacing-3xl) 0;
    background: var(--color-bg-secondary);
}

.method-steps {
    display: grid;
    gap: var(--spacing-lg);
}

.method-step {
    display: flex;
    gap: var(--spacing-xl);
    padding: var(--spacing-xl);
    background: var(--gradient-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    transition: all var(--transition-base);
}

.method-step:hover {
    border-color: var(--color-primary);
}

.step-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-primary);
    opacity: 0.5;
    flex-shrink: 0;
}

.step-content h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
}

.step-content p {
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
}

/* Features Section */
.features {
    padding: var(--spacing-3xl) 0;
    background: var(--color-bg-primary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.feature-card {
    background: var(--gradient-card);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    text-align: center;
    transition: all var(--transition-base);
}

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

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.feature-card h3 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-sm);
}

.feature-card p {
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
}

/* CTA Section */
.cta-section {
    padding: var(--spacing-3xl) 0;
    background: linear-gradient(135deg, var(--color-bg-tertiary) 0%, var(--color-bg-secondary) 100%);
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}

.cta-content {
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
}

.cta-content h2 {
    font-size: clamp(1.5rem, 4vw, 2.25rem);
    margin-bottom: var(--spacing-md);
}

.cta-content p {
    color: var(--color-text-secondary);
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xl);
}

.cta-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* Contact Section */
.contact {
    padding: var(--spacing-3xl) 0;
    background: var(--color-bg-secondary);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.contact-item {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
}

.contact-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.contact-item h4 {
    font-size: 1rem;
    margin-bottom: var(--spacing-xs);
    color: var(--color-text-primary);
}

.contact-item p {
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: var(--spacing-md);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-family: var(--font-primary);
    font-size: 0.9375rem;
    transition: all var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(212, 175, 55, 0.1);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--color-text-muted);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* Footer */
.footer {
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
    background: var(--color-bg-primary);
    border-top: 1px solid var(--color-border);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-3xl);
    margin-bottom: var(--spacing-xl);
}

.footer-brand .logo-icon {
    font-size: 2rem;
}

.footer-brand .logo-text {
    display: block;
    font-size: 1.25rem;
    margin-top: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.footer-brand p {
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
}

.footer-column h4 {
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-md);
}

.footer-column ul {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-column a {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
}

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

.footer-bottom {
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--color-border);
    text-align: center;
}

.footer-bottom p {
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.footer-bottom p + p {
    margin-top: var(--spacing-xs);
}

/* Responsive */
@media (max-width: 968px) {
    .value-content,
    .contact-grid,
    .footer-content,
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .nav-links {
        display: none;
    }
    
    .footer-links {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .visual-circle {
        width: 240px;
        height: 240px;
    }
    
    .about-text .section-title {
        text-align: center;
    }
    
    .about-visual {
        order: -1;
    }
}

@media (max-width: 640px) {
    .hero-cta,
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn-large {
        width: 100%;
        max-width: 280px;
    }
    
    .method-step {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .footer-links {
        grid-template-columns: 1fr;
    }
}