/* =============================================================================
   Base Styles & Reset
   ============================================================================= */

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

/* Document */
html {
    scroll-behavior: smooth;
    -webkit-tap-highlight-color: transparent;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-primary);
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-normal);
    line-height: var(--line-height-normal);
    color: var(--color-text-primary);
    background: var(--color-bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
    transition: 
        background var(--transition-theme),
        color var(--transition-theme);
}

/* Canvas Background */
#bgCanvas {
    position: fixed;
    inset: 0;
    width: 100%;
    height: 100%;
    z-index: var(--z-canvas);
    pointer-events: none;
}

/* Accessibility */
.skip-link {
    position: absolute;
    top: -100px;
    left: var(--space-4);
    background: var(--color-accent);
    color: white;
    padding: var(--space-2) var(--space-4);
    border-radius: var(--radius-sm);
    font-weight: var(--font-weight-semibold);
    text-decoration: none;
    z-index: calc(var(--z-modal) + 1);
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: var(--space-4);
}

/* Main Content Container */
.main {
    position: relative;
    z-index: var(--z-main);
}

/* Section Fade Animation */
.section--fade {
    opacity: 0;
    transform: translateY(80px);
    filter: blur(6px);
    transition: 
        opacity 0.8s cubic-bezier(0.4, 0, 0.2, 1),
        transform 0.8s cubic-bezier(0.4, 0, 0.2, 1),
        filter 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.section--fade.is-visible {
    opacity: 1;
    transform: translateY(0);
    filter: blur(0);
}

.section--fade.is-fading-out {
    opacity: 0;
    transform: translateY(-60px);
    filter: blur(6px);
}

/* Utility Classes */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Spinner Animation */
.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(255, 255, 255, 0.1);
    border-top-color: var(--color-accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Focus Styles */
:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

/* Selection */
::selection {
    background: var(--color-accent);
    color: white;
}

/* Scrollbar (Webkit) */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-border-hover);
}