/* ==============================================
   PREMIUM DARK METALLIC THEME
   Professional Landing Page for 16-Year Expertise
   ============================================== */

:root {
    /* Dark Metallic Color Palette - NVIDIA Inspired */
    --color-bg-primary: hsl(220, 30%, 8%);
    --color-bg-secondary: hsl(220, 25%, 12%);
    --color-bg-tertiary: hsl(220, 22%, 16%);
    
    /* Circuit Board Accents */
    --color-accent-cyan: hsl(180, 85%, 55%);
    --color-accent-teal: hsl(175, 70%, 50%);
    --color-accent-gold: hsl(45, 95%, 65%);
    --color-accent-electric: hsl(200, 100%, 60%);
    
    /* Metallic Grays */
    --color-metal-light: hsl(220, 15%, 75%);
    --color-metal-mid: hsl(220, 12%, 55%);
    --color-metal-dark: hsl(220, 10%, 35%);
    
    /* Text Colors */
    --color-text-primary: hsl(0, 0%, 95%);
    --color-text-secondary: hsl(220, 10%, 70%);
    --color-text-tertiary: hsl(220, 10%, 50%);
    
    /* Gradients */
    --gradient-hero: linear-gradient(135deg, 
        hsl(220, 30%, 10%) 0%, 
        hsl(200, 35%, 12%) 50%, 
        hsl(180, 40%, 10%) 100%);
    
    --gradient-card: linear-gradient(145deg,
        hsl(220, 25%, 14%) 0%,
        hsl(220, 20%, 10%) 100%);
    
    --gradient-circuit: linear-gradient(90deg,
        transparent 0%,
        var(--color-accent-cyan) 50%,
        transparent 100%);
    
    /* Shadows & Glows */
    --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-elevated: 0 16px 48px rgba(0, 0, 0, 0.7);
    --glow-accent: 0 0 20px rgba(119, 234, 245, 0.3);
    --glow-button: 0 0 30px rgba(119, 234, 245, 0.5);
    
    /* Typography */
    --font-heading: 'Inter', 'Segoe UI', sans-serif;
    --font-body: 'Inter', 'Segoe UI', system-ui, sans-serif;
    --font-mono: 'Consolas', 'Monaco', monospace;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2.5rem;
    --spacing-xl: 4rem;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ==============================================
   GLOBAL RESET & BASE STYLES
   ============================================== */

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

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

body {
    font-family: var(--font-body);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-text-primary);
    background: var(--color-bg-primary);
    background-image: 
        /* Circuit board pattern */
        repeating-linear-gradient(
            0deg,
            transparent,
            transparent 2px,
            rgba(119, 234, 245, 0.03) 2px,
            rgba(119, 234, 245, 0.03) 4px
        ),
        repeating-linear-gradient(
            90deg,
            transparent,
            transparent 2px,
            rgba(119, 234, 245, 0.03) 2px,
            rgba(119, 234, 245, 0.03) 4px
        );
    background-size: 80px 80px;
    overflow-x: hidden;
}

#app {
    min-height: 100vh;
    position: relative;
}

/* ==============================================
   TYPOGRAPHY
   ============================================== */

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-text-primary);
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4.5rem);
    margin-bottom: var(--spacing-md);
}

h2 {
    font-size: clamp(2rem, 4vw, 3rem);
    margin-bottom: var(--spacing-md);
}

h3 {
    font-size: clamp(1.5rem, 3vw, 2rem);
    margin-bottom: var(--spacing-sm);
}

p {
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-secondary);
}

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

a:hover {
    color: var(--color-accent-electric);
}

code {
    font-family: var(--font-mono);
    background: var(--color-bg-tertiary);
    padding: 0.2em 0.4em;
    border-radius: var(--radius-sm);
    font-size: 0.9em;
    color: var(--color-accent-gold);
}

/* ==============================================
   LAYOUT COMPONENTS
   ============================================== */

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.container-wide {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section {
    padding: var(--spacing-xl) 0;
    position: relative;
}

/* ==============================================
   HERO SECTION - Fogg Motivation (Hope)
   ============================================== */

.hero {
    min-height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    background: var(--gradient-hero);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(
        circle at 20% 50%,
        rgba(119, 234, 245, 0.08) 0%,
        transparent 50%
    );
    pointer-events: none;
}

.hero::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(
        circle at 80% 30%,
        rgba(241, 196, 15, 0.05) 0%,
        transparent 40%
    );
    pointer-events: none;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 900px;
}

.hero-headline {
    font-size: clamp(2.2rem, 5vw, 4rem);
    font-weight: 800;
    margin-bottom: var(--spacing-md);
    background: linear-gradient(
        135deg,
        var(--color-text-primary) 0%,
        var(--color-accent-cyan) 50%,
        var(--color-accent-gold) 100%
    );
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: fadeInUp 1s ease-out;
}

.hero-subheadline {
    font-size: clamp(1.2rem, 2.5vw, 1.8rem);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
    animation: fadeInUp 1s ease-out 0.2s backwards;
}

.hero-cta {
    display: inline-flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
    justify-content: center;
    animation: fadeInUp 1s ease-out 0.4s backwards;
}

/* ==============================================
   CARDS & PANELS
   ============================================== */

.card {
    background: var(--gradient-card);
    border: 1px solid rgba(119, 234, 245, 0.1);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-card);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--gradient-circuit);
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-elevated), var(--glow-accent);
    border-color: rgba(119, 234, 245, 0.3);
}

.card:hover::before {
    opacity: 1;
}

.card-header {
    margin-bottom: var(--spacing-md);
}

.card-title {
    font-size: 1.5rem;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.card-subtitle {
    color: var(--color-text-tertiary);
    font-size: 0.9rem;
}

.card-body {
    color: var(--color-text-secondary);
}

.legal-body h2,
.legal-body h3 {
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-xs);
}

.legal-body h2:first-child,
.legal-body h3:first-child {
    margin-top: 0;
}

.legal-body ul {
    margin: 0 0 var(--spacing-md) 1.25rem;
    color: var(--color-text-secondary);
}

.legal-body li {
    margin-bottom: 0.35rem;
}

/* ==============================================
   BUTTONS - Fogg Ability (Simplicity)
   ============================================== */

.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    text-align: center;
    text-decoration: none;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-normal);
    font-family: var(--font-heading);
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: linear-gradient(
        135deg,
        var(--color-accent-cyan) 0%,
        var(--color-accent-electric) 100%
    );
    color: var(--color-bg-primary);
    box-shadow: 0 4px 16px rgba(119, 234, 245, 0.3);
}

.btn-primary::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(
        135deg,
        var(--color-accent-electric) 0%,
        var(--color-accent-cyan) 100%
    );
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.btn-primary:hover::before {
    opacity: 1;
}

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

.btn-primary span {
    position: relative;
    z-index: 1;
}

.btn-secondary {
    background: transparent;
    color: var(--color-accent-cyan);
    border: 2px solid var(--color-accent-cyan);
}

.btn-secondary:hover {
    background: var(--color-accent-cyan);
    color: var(--color-bg-primary);
    transform: translateY(-2px);
}

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

/* ==============================================
   GRID SYSTEM
   ============================================== */

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

.grid-2 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

/* ==============================================
   TECH STACK TAGS
   ============================================== */

.tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-sm);
}

.tech-tag {
    background: rgba(119, 234, 245, 0.1);
    border: 1px solid rgba(119, 234, 245, 0.3);
    color: var(--color-accent-cyan);
    padding: 0.35rem 0.75rem;
    border-radius:var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.tech-tag:hover {
    background: rgba(119, 234, 245, 0.2);
    border-color: var(--color-accent-cyan);
    box-shadow: 0 0 10px rgba(119, 234, 245, 0.2);
}

/* ==============================================
   TIMELINE - Career Visualization
   ============================================== */

.timeline {
    position: relative;
    padding-left: var(--spacing-lg);
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(
        to bottom,
        var(--color-accent-cyan),
        var(--color-accent-teal)
    );
}

.timeline-item {
    position: relative;
    padding-bottom: var(--spacing-lg);
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: calc(-1 * var(--spacing-lg) - 6px);
    top: 4px;
    width: 14px;
    height: 14px;
    background: var(--color-accent-cyan);
    border: 3px solid var(--color-bg-primary);
    border-radius: 50%;
    box-shadow: var(--glow-accent);
}

/* ==============================================
   RESPONSIVE DESIGN
   ============================================== */

@media (max-width: 768px) {
    :root {
        --spacing-lg: 2rem;
        --spacing-xl: 3rem;
    }
    
    .hero {
        min-height: 70vh;
    }
    
    .grid-2,
    .grid-3 {
        grid-template-columns: 1fr;
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: stretch;
    }
    
    .btn {
        width: 100%;
    }
}

/* ==============================================
   ANIMATIONS
   ============================================== */

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

@keyframes shimmer {
    0% {
        background-position: -1000px 0;
    }
    100% {
        background-position: 1000px 0;
    }
}

.animate-pulse {
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

/* ==============================================
   BLAZOR SPECIFIC OVERRIDES
   ============================================== */

.valid.modified:not([type=checkbox]) {
    outline: 2px solid var(--color-accent-cyan);
}

.invalid {
    outline: 2px solid hsl(0, 70%, 50%);
}

.validation-message {
    color: hsl(0, 70%, 60%);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

#blazor-error-ui {
    background: hsl(0, 60%, 40%);
    bottom: 0;
    box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.5);
    display: none;
    left: 0;
    padding: 0.75rem 1.5rem;
    position: fixed;
    width: 100%;
    z-index: 1000;
    color: white;
}

#blazor-error-ui .dismiss {
    cursor: pointer;
    position: absolute;
    right: 1rem;
    top: 0.75rem;
    font-size: 1.5rem;
}

.blazor-error-boundary {
    background: hsl(0, 60%, 35%);
    padding: 1rem;
    color: white;
    border-radius: var(--radius-md);
}

.loading-progress {
    position: fixed;
    display: block;
    width: 8rem;
    height: 8rem;
    inset: 40vh 0 auto 0;
    margin: 0 auto;
    z-index: 1000;
}

.loading-progress circle {
    fill: none;
    stroke: var(--color-metal-dark);
    stroke-width: 0.6rem;
    transform-origin: 50% 50%;
    transform: rotate(-90deg);
}

.loading-progress circle:last-child {
    stroke: var(--color-accent-cyan);
    stroke-dasharray: calc(3.141 * var(--blazor-load-percentage, 0%) * 0.8), 500%;
    transition: stroke-dasharray 0.05s ease-in-out;
}

.loading-progress-text {
    position: fixed;
    text-align: center;
    font-weight: 600;
    font-family: var(--font-heading);
    color: var(--color-accent-cyan);
    inset: calc(40vh + 4.5rem) 0 auto 0;
}

.loading-progress-text:after {
    content: var(--blazor-load-percentage-text, "로딩 중...");
}