/* ============================================
   Base Styles - Typography, Utilities, Animations
   ============================================ */

body {
    font-family: var(--font-primary);
    font-size: var(--text-base);
    font-weight: var(--font-weight-regular);
    line-height: var(--leading-normal);
    color: var(--color-text-primary);
    background-color: var(--color-primary);
}

/* Headings */
h1 {
    font-size: clamp(2rem, 5vw, var(--text-6xl));
    line-height: var(--leading-tight);
    letter-spacing: -0.02em;
}

h2 {
    font-size: clamp(1.75rem, 4vw, var(--text-4xl));
    line-height: var(--leading-tight);
    letter-spacing: -0.01em;
}

h3 {
    font-size: clamp(1.25rem, 2.5vw, var(--text-2xl));
    line-height: var(--leading-tight);
}

h4 {
    font-size: var(--text-xl);
    line-height: var(--leading-tight);
}

h5 {
    font-size: var(--text-lg);
}

h6 {
    font-size: var(--text-base);
    font-weight: var(--font-weight-semibold);
}

p {
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
}

strong {
    font-weight: var(--font-weight-semibold);
}

/* Links */
a {
    transition: color var(--transition-fast);
}

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

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

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

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

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

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

/* 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;
}

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-accent { color: var(--color-accent-light); }
.text-white { color: var(--color-white); }
.text-dark { color: var(--color-text-dark); }
.text-secondary { color: var(--color-text-secondary); }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

/* Section Label */
.section-label {
    display: inline-block;
    font-size: var(--text-sm);
    font-weight: var(--font-weight-semibold);
    color: var(--color-accent-light);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--spacing-sm);
}

.section-title {
    margin-bottom: var(--spacing-md);
}

.section-description {
    font-size: var(--text-lg);
    max-width: 700px;
}

.section-header {
    margin-bottom: var(--spacing-2xl);
}

.section-header.text-center .section-description {
    margin-left: auto;
    margin-right: auto;
}

/* Scroll Animations */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate-on-scroll.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.animate-delay-1 { transition-delay: 0.1s; }
.animate-delay-2 { transition-delay: 0.2s; }
.animate-delay-3 { transition-delay: 0.3s; }
.animate-delay-4 { transition-delay: 0.4s; }
.animate-delay-5 { transition-delay: 0.5s; }

/* Dark/Light Section Backgrounds */
.section-dark {
    background-color: var(--color-primary);
    color: var(--color-text-primary);
}

.section-darker {
    background-color: var(--color-primary-dark);
    color: var(--color-text-primary);
}

.section-surface {
    background-color: var(--color-surface);
    color: var(--color-text-primary);
}

.section-light {
    background-color: var(--color-surface-light);
    color: var(--color-text-dark);
}

.section-light p {
    color: var(--color-text-dark-secondary);
}

.section-light .section-label {
    color: var(--color-accent);
}