/* ===================================
   GRID-BASED DESIGN SYSTEM
   Echoes the landing page grid theme
   =================================== */

/* ===================================
   GRID SPACING SYSTEM
   Base unit: 8px (1 grid unit)
   =================================== */
:root {
    --grid-unit: 8px;
    --grid-2: calc(var(--grid-unit) * 2);   /* 16px */
    --grid-3: calc(var(--grid-unit) * 3);   /* 24px */
    --grid-4: calc(var(--grid-unit) * 4);   /* 32px */
    --grid-6: calc(var(--grid-unit) * 6);   /* 48px */
    --grid-8: calc(var(--grid-unit) * 8);   /* 64px */
    --grid-12: calc(var(--grid-unit) * 12); /* 96px */
    --grid-16: calc(var(--grid-unit) * 16); /* 128px */

    --transition-smooth: cubic-bezier(0.215, 0.61, 0.355, 1);
}

/* ===================================
   HORIZONTAL DIVIDERS (GRID LINES)
   Background structural grid elements - DASHED for visibility
   =================================== */
.section-divider {
    border-top: 1px dashed var(--color-border);
    margin: 0;
    padding: 0;
}

.section-divider-thick {
    border-top: 2px dashed var(--color-border);
    margin: 0;
    padding: 0;
}

/* ===================================
   GRID-ALIGNED SECTIONS
   =================================== */
.grid-section {
    padding-top: var(--grid-12);
    padding-bottom: var(--grid-12);
    position: relative;
}

.grid-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background-color: var(--color-border);
    opacity: 0.5;
}

.grid-section:first-of-type::before {
    display: none;
}

/* Section spacing variants */
.grid-section--small {
    padding-top: var(--grid-8);
    padding-bottom: var(--grid-8);
}

.grid-section--large {
    padding-top: var(--grid-16);
    padding-bottom: var(--grid-16);
}

/* ===================================
   NAVIGATION (GRID-ALIGNED)
   =================================== */
.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    transition: all 0.3s var(--transition-smooth);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--grid-3) var(--grid-4);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-family: var(--font-heading);
    font-size: clamp(1.25rem, 2.5vw, 1.5rem);
    font-weight: 700;
    color: var(--color-primary);
    text-decoration: none;
    letter-spacing: -0.02em;
    transition: opacity 0.3s var(--transition-smooth);
}

.logo:hover {
    opacity: 0.7;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--grid-4);
    margin: 0;
    padding: 0;
}

.nav-link {
    font-family: var(--font-body);
    font-size: 0.9375rem;
    color: var(--color-primary);
    text-decoration: none;
    position: relative;
    transition: opacity 0.3s var(--transition-smooth);
}

.nav-link:hover {
    opacity: 0.6;
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 100%;
    height: 1px;
    background-color: var(--color-primary);
}

/* ===================================
   TYPOGRAPHY GRID SYSTEM
   =================================== */
.page-title {
    font-family: var(--font-heading);
    font-size: clamp(3rem, 8vw, 5rem);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.03em;
    margin: 0 0 var(--grid-3) 0;
}

.page-subtitle {
    font-family: var(--font-body);
    font-size: clamp(1.125rem, 2.5vw, 1.5rem);
    line-height: 1.5;
    color: var(--color-primary);
    opacity: 0.7;
    margin: 0 0 var(--grid-6) 0;
}

.section-title {
    font-family: var(--font-heading);
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.02em;
    margin: 0 0 var(--grid-6) 0;
}

.section-heading {
    font-family: var(--font-heading);
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 600;
    line-height: 1.3;
    letter-spacing: -0.01em;
    margin: 0 0 var(--grid-4) 0;
}

/* ===================================
   GRID-BASED CONTAINERS
   =================================== */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding-left: var(--grid-4);
    padding-right: var(--grid-4);
}

.container-narrow {
    max-width: 900px;
    margin: 0 auto;
    padding-left: var(--grid-4);
    padding-right: var(--grid-4);
}

@media (max-width: 768px) {
    .container,
    .container-narrow {
        padding-left: var(--grid-3);
        padding-right: var(--grid-3);
    }
}

/* ===================================
   GRID LAYOUT HELPERS
   =================================== */
.grid-2-col {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--grid-6);
}

.grid-3-col {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--grid-4);
}

.grid-4-col {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--grid-4);
}

@media (max-width: 1024px) {
    .grid-4-col {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .grid-2-col,
    .grid-3-col,
    .grid-4-col {
        grid-template-columns: 1fr;
        gap: var(--grid-3);
    }
}

/* ===================================
   CARDS WITH GRID BORDERS
   UI component borders - SOLID for definition
   =================================== */
.grid-card {
    border: 1px solid var(--color-border);
    padding: var(--grid-4);
    transition: all 0.3s var(--transition-smooth);
    background-color: var(--color-bg);
}

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

.grid-card--no-hover:hover {
    transform: none;
}

/* ===================================
   HORIZONTAL LINE ELEMENTS
   =================================== */
.h-line {
    width: 100%;
    height: 1px;
    background-color: var(--color-border);
    margin: var(--grid-6) 0;
}

.h-line--thick {
    height: 2px;
}

.h-line--primary {
    background-color: var(--color-primary);
}

/* ===================================
   BUTTONS (GRID-ALIGNED)
   UI component borders - SOLID for definition
   =================================== */
.btn {
    font-family: var(--font-body);
    font-size: 0.9375rem;
    font-weight: 500;
    padding: var(--grid-2) var(--grid-4);
    border: 1px solid var(--color-primary);
    background-color: var(--color-primary);
    color: var(--color-bg);
    text-decoration: none;
    display: inline-block;
    cursor: pointer;
    transition: all 0.3s var(--transition-smooth);
}

.btn:hover {
    background-color: transparent;
    color: var(--color-primary);
}

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

.btn--outline:hover {
    background-color: var(--color-primary);
    color: var(--color-bg);
}

/* ===================================
   FOOTER (GRID-ALIGNED)
   =================================== */
.footer {
    border-top: 1px solid var(--color-border);
    padding: var(--grid-8) 0;
    margin-top: var(--grid-16);
}

.footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--grid-3);
}

.footer p {
    margin: 0;
    font-size: 0.875rem;
    color: var(--color-primary);
    opacity: 0.6;
}

.social-links {
    display: flex;
    gap: var(--grid-3);
}

.social-links a {
    font-size: 0.875rem;
    color: var(--color-primary);
    text-decoration: none;
    transition: opacity 0.3s var(--transition-smooth);
}

.social-links a:hover {
    opacity: 0.6;
}

/* ===================================
   PROJECT GRID (SPECIAL LAYOUT)
   UI component borders - SOLID for definition
   =================================== */
.projects-grid .grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: var(--grid-4);
}

.project-card {
    border: 1px solid var(--color-border);
    overflow: hidden;
    transition: all 0.3s var(--transition-smooth);
}

.project-card:hover {
    border-color: var(--color-primary);
}

.project-info {
    padding: var(--grid-3);
    border-top: 1px solid var(--color-border);
}

.project-title {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 600;
    margin: 0 0 var(--grid-unit) 0;
}

.project-category {
    font-size: 0.875rem;
    opacity: 0.6;
    margin: 0 0 var(--grid-2) 0;
}

.project-description {
    font-size: 0.9375rem;
    line-height: 1.6;
    margin: 0;
}

/* ===================================
   RESPONSIVE ADJUSTMENTS
   =================================== */
@media (max-width: 768px) {
    :root {
        --grid-12: calc(var(--grid-unit) * 8);  /* 64px */
        --grid-16: calc(var(--grid-unit) * 10); /* 80px */
    }

    .grid-section {
        padding-top: var(--grid-8);
        padding-bottom: var(--grid-8);
    }

    .projects-grid .grid {
        grid-template-columns: 1fr;
    }
}

/* ===================================
   ACCESSIBILITY
   =================================== */
@media (prefers-reduced-motion: reduce) {
    * {
        transition: none !important;
        animation: none !important;
    }
}