/* ===================================
   Design System & CSS Variables
   =================================== */
:root {
    /* Colors */
    --color-bg: #0A0A0A;
    --color-text-primary: #FFFFFF;
    --color-text-secondary: rgba(255, 255, 255, 0.7);
    --color-accent: #4F46E5;

    /* Typography */
    --font-display: 'Playfair Display', serif;
    --font-body: 'Inter', sans-serif;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-medium: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.8s cubic-bezier(0.4, 0, 0.2, 1);

    /* Z-index */
    --z-header: 1000;
    --z-left-panel: 100;
    --z-right-panel: 50;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background-color: var(--color-bg);
    color: var(--color-text-primary);
    overflow-x: hidden;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

a {
    text-decoration: none;
    color: inherit;
}

/* ===================================
   Global Header
   =================================== */
.global-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-header);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-xl);
    pointer-events: none;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    pointer-events: auto;
}

.logo {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    object-fit: cover;
    transition: transform var(--transition-fast);
}

.logo:hover {
    transform: scale(1.05);
}

.dev-info {
    display: flex;
    flex-direction: column;
    justify-content: center;
    line-height: 1.2;
    mix-blend-mode: difference;
}

.app-brand {
    font-weight: 800;
    font-size: 1.125rem;
    letter-spacing: -0.02em;
}

.dev-name {
    font-weight: 400;
    font-size: 0.875rem;
    opacity: 0.8;
    transition: opacity var(--transition-fast);
}

.dev-name:hover {
    opacity: 1;
}

/* Ko-fi Button */
.kofi-button {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.75rem 1.25rem;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 100px;
    font-weight: 600;
    font-size: 0.875rem;
    transition: all var(--transition-medium);
    pointer-events: auto;
    overflow: hidden;
    position: relative;
}

.kofi-icon {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
    transition: transform var(--transition-medium);
}

.kofi-text {
    max-width: 0;
    opacity: 0;
    white-space: nowrap;
    transition: all var(--transition-medium);
}

.kofi-button:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.3);
    padding-right: 1.5rem;
}

.kofi-button:hover .kofi-icon {
    transform: rotate(-10deg);
}

.kofi-button:hover .kofi-text {
    max-width: 150px;
    opacity: 1;
    margin-left: var(--spacing-xs);
}

/* ===================================
   Split Container
   =================================== */
.split-container {
    display: flex;
    min-height: 100vh;
}

/* ===================================
   Left Panel (Context)
   =================================== */
.left-panel {
    position: sticky;
    top: 0;
    left: 0;
    width: 50vw;
    height: 100vh;
    background-color: var(--color-accent);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: var(--spacing-2xl);
    padding-top: calc(var(--spacing-2xl) + 80px);
    transition: background-color var(--transition-slow);
    z-index: var(--z-left-panel);
}

.project-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: var(--spacing-lg);
}

.project-title {
    font-family: var(--font-display);
    font-size: clamp(3rem, 6vw, 5rem);
    font-weight: 900;
    line-height: 1.1;
    letter-spacing: -0.03em;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp var(--transition-slow) forwards;
}

.project-descriptor {
    font-size: clamp(1.125rem, 2vw, 1.5rem);
    font-weight: 500;
    line-height: 1.4;
    opacity: 0.9;
    max-width: 500px;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp var(--transition-slow) 0.1s forwards;
}

.tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp var(--transition-slow) 0.2s forwards;
}

.tech-tag {
    padding: 0.5rem 1rem;
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    border-radius: 100px;
    font-size: 0.875rem;
    font-weight: 600;
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: all var(--transition-fast);
}

.tech-tag:hover {
    background: rgba(255, 255, 255, 0.25);
    transform: translateY(-2px);
}

.project-button {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 1rem 2rem;
    background: var(--color-text-primary);
    color: var(--color-bg);
    font-weight: 700;
    font-size: 1.125rem;
    border-radius: 12px;
    transition: all var(--transition-medium);
    width: fit-content;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp var(--transition-slow) 0.3s forwards;
    position: relative;
    overflow: hidden;
}

.project-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.5s;
}

.project-button:hover::before {
    left: 100%;
}

.project-button:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.project-button svg {
    transition: transform var(--transition-fast);
}

.project-button:hover svg {
    transform: translate(4px, -4px);
}

.project-counter {
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 700;
    opacity: 0.6;
    letter-spacing: 0.1em;
}


/* ===================================
   Right Panel (Content)
   =================================== */
.right-panel {
    width: 50vw;
    background-color: var(--color-bg);
    z-index: var(--z-right-panel);
}

.project-section {
    padding: var(--spacing-2xl);
    padding-top: calc(var(--spacing-2xl) + 80px);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.project-section:not(:last-child) {
    margin-bottom: var(--spacing-2xl);
}

.project-section:last-child {
    padding-bottom: 40vh;
    /* Extra space to prevent previous projects from showing when content is short */
}

.screenshot-container {
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
    transition: transform var(--transition-medium);
}

.screenshot-container:hover {
    transform: scale(1.02);
}

.screenshot {
    width: 100%;
    height: auto;
    display: block;
}

/* ===================================
   Animations
   =================================== */
@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===================================
   Mobile Responsive (Adaptive)
   =================================== */
@media (max-width: 768px) {
    .split-container {
        flex-direction: column;
    }

    .left-panel {
        position: sticky;
        top: 0;
        width: 100vw;
        height: auto;
        min-height: 40vh;
        padding: var(--spacing-lg);
        padding-top: calc(var(--spacing-lg) + 70px);
        z-index: var(--z-left-panel);
    }

    .right-panel {
        width: 100vw;
    }

    .project-section {
        padding: var(--spacing-lg);
        padding-top: var(--spacing-md);
    }

    .project-title {
        font-size: clamp(2rem, 8vw, 3rem);
    }

    .project-descriptor {
        font-size: 1rem;
    }

    .project-button {
        font-size: 1rem;
        padding: 0.875rem 1.5rem;
    }

    .project-counter {
        font-size: 1.5rem;
    }

    /* Mobile Header */
    .global-header {
        padding: var(--spacing-sm) var(--spacing-md);
        background: rgba(10, 10, 10, 0.8);
        backdrop-filter: blur(20px);
        transition: transform var(--transition-medium);
    }

    .global-header.hidden {
        transform: translateY(-100%);
    }

    .logo {
        width: 40px;
        height: 40px;
    }

    .app-brand {
        font-size: 0.9rem;
    }

    .dev-name {
        font-size: 0.75rem;
    }

    .kofi-button {
        padding: 0.625rem 1rem;
        font-size: 0.8rem;
    }

    .kofi-text {
        display: none;
    }

    .screenshot-container {
        border-radius: 12px;
    }
}

/* ===================================
   Tablet Responsive
   =================================== */
@media (min-width: 769px) and (max-width: 1024px) {
    .left-panel {
        padding: var(--spacing-xl);
        padding-top: calc(var(--spacing-xl) + 80px);
    }

    .project-section {
        padding: var(--spacing-xl);
        padding-top: calc(var(--spacing-xl) + 80px);
    }

    .project-title {
        font-size: clamp(2.5rem, 5vw, 4rem);
    }
}

/* ===================================
   Accessibility
   =================================== */
@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for keyboard navigation */
a:focus-visible,
button:focus-visible {
    outline: 2px solid var(--color-text-primary);
    outline-offset: 4px;
}