/* =============================================
   Wasif Danesh — Portfolio Theme (2025 refresh)
   Responsive • Smooth interactions • Dual theme
============================================= */

/* ---------- Core Tokens ---------- */
:root {
    --font-family-base: 'Inter', sans-serif;
    --max-width: 1200px;
    --container-padding: clamp(1.25rem, 3vw, 3rem);
    --section-space: clamp(4.5rem, 7vw, 6.5rem);
    --header-offset: clamp(4.5rem, 6vw, 5.75rem);
    --radius-lg: 1.25rem;
    --radius-md: 1rem;
    --radius-sm: 0.75rem;
    --shadow-lg: 0 30px 60px rgba(15, 23, 42, 0.24);
    --shadow-hover: 0 36px 70px rgba(15, 23, 42, 0.28);
    --transition-fast: 0.2s ease;
    --transition-base: 0.35s ease;
}

body[data-theme='dark'] {
    color-scheme: dark;
    --color-background: #050a16;
    --color-surface: #0e1628;
    --color-surface-strong: #141f36;
    --color-border: rgba(148, 163, 184, 0.2);
    --color-border-strong: rgba(148, 163, 184, 0.32);
    --color-text-primary: #f8fbff;
    --color-text-secondary: #c7d2fe;
    --color-muted: #94a3c6;
    --color-chip-bg: rgba(148, 163, 184, 0.16);
    --color-chip-border: rgba(148, 163, 184, 0.28);
    --color-chip-text: #e2e8ff;
    --color-icon: #a5b4fc;
    --color-icon-hover: #38bdf8;
    --gradient-accent: linear-gradient(135deg, #6366f1, #0ea5e9);
    --focus-ring: 0 0 0 3px rgba(99, 102, 241, 0.45);
}

body[data-theme='light'] {
    color-scheme: light;
    --color-background: #f5f7fb;
    --color-surface: #ffffff;
    --color-surface-strong: #eef2ff;
    --color-border: rgba(15, 23, 42, 0.08);
    --color-border-strong: rgba(15, 23, 42, 0.18);
    --color-text-primary: #0f172a;
    --color-text-secondary: #475569;
    --color-muted: #64748b;
    --color-chip-bg: rgba(37, 99, 235, 0.08);
    --color-chip-border: rgba(37, 99, 235, 0.18);
    --color-chip-text: #1f2a44;
    --color-icon: #334155;
    --color-icon-hover: #2563eb;
    --gradient-accent: linear-gradient(135deg, #2563eb, #0ea5e9);
    --focus-ring: 0 0 0 3px rgba(37, 99, 235, 0.35);
    --shadow-lg: 0 24px 48px rgba(15, 23, 42, 0.12);
    --shadow-hover: 0 32px 60px rgba(37, 99, 235, 0.16);
}

/* ---------- Base Reset ---------- */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { height: 100%; scroll-behavior: smooth; }
body {
    min-height: 100%;
    background: var(--color-background);
    color: var(--color-text-primary);
    font-family: var(--font-family-base);
    line-height: 1.6;
    padding-top: var(--header-offset);
    transition: background 0.4s ease, color 0.4s ease;
}
body.theme-transition *,
body.theme-transition { transition: background 0.4s ease, color 0.4s ease; }
body.no-scroll { overflow: hidden; }

main { display: block; }
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }

::selection { background: rgba(99, 102, 241, 0.45); color: #fff; }

.container { width: min(var(--max-width), 100%); margin-inline: auto; padding-inline: var(--container-padding); }
section {
    position: relative;
    padding-block: var(--section-space);
    opacity: 0;
    transform: translateY(60px);
    transition: opacity 0.8s ease, transform 0.8s ease;
    scroll-margin-top: calc(var(--header-offset) + 1.5rem);
}
section.visible { opacity: 1; transform: translateY(0); }

.section-title {
    text-align: center;
    font-size: clamp(2.1rem, 4vw, 2.75rem);
    font-weight: 800;
    margin-bottom: clamp(2.5rem, 5vw, 3.5rem);
    letter-spacing: -0.02em;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    color: transparent;
}

.section-intro {
    max-width: 640px;
    margin: 0 auto;
    text-align: center;
    color: var(--color-text-secondary);
}

/* ---------- Header & Navigation ---------- */
.site-header {
    position: fixed;
    inset: 0 0 auto 0;
    background: var(--color-surface);
    background: color-mix(in srgb, var(--color-surface) 75%, transparent);
    border-bottom: 1px solid var(--color-border);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    z-index: 1000;
    transition: background var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base), transform 0.4s ease;
}
.site-header.scrolled {
    background: var(--color-surface-strong);
    background: color-mix(in srgb, var(--color-surface-strong) 90%, transparent);
    border-color: var(--color-border-strong);
    box-shadow: 0 18px 35px rgba(15, 23, 42, 0.2);
}

.nav-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1.5rem;
    padding-block: 1rem;
}
.brand {
    display: inline-flex;
    align-items: center;
    gap: 0.65rem;
    font-weight: 700;
    font-size: 1.2rem;
}
.brand-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 0.85rem;
    background: var(--gradient-accent);
    color: #fff;
    font-weight: 800;
    letter-spacing: 0.03em;
}

.main-nav ul {
    display: flex;
    align-items: center;
    gap: 1.75rem;
    list-style: none;
}
.main-nav a {
    font-weight: 500;
    color: var(--color-text-secondary);
    transition: color var(--transition-fast);
}
.main-nav a:hover,
.main-nav a:focus-visible {
    color: var(--color-icon-hover);
}

.theme-toggle {
    border: none;
    background: none;
    color: var(--color-icon);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 999px;
    padding: 0.35rem;
    font-size: 1.9rem;
    cursor: pointer;
    transition: color var(--transition-fast), transform var(--transition-fast);
}
.theme-toggle:hover,
.theme-toggle:focus-visible {
    color: var(--color-icon-hover);
    transform: rotate(12deg) scale(1.05);
}
.theme-toggle:focus-visible { outline: none; box-shadow: var(--focus-ring); }

.menu-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    border: none;
    background: none;
    color: var(--color-icon);
    cursor: pointer;
    font-size: 1.9rem;
    line-height: 1;
    transition: color var(--transition-fast);
}
.menu-toggle:hover,
.menu-toggle:focus-visible { color: var(--color-icon-hover); }
.menu-toggle:focus-visible { outline: none; box-shadow: var(--focus-ring); border-radius: 999px; }

@media (max-width: 960px) {
    .main-nav { display: none; }
    .menu-toggle { display: inline-flex; }
}

/* Mobile drawer */
.mobile-drawer {
    position: fixed;
    top: 0;
    right: 0;
    width: min(320px, 78vw);
    height: 100dvh;
    background: var(--color-surface-strong);
    background: color-mix(in srgb, var(--color-surface-strong) 92%, transparent);
    border-left: 1px solid var(--color-border);
    padding: 1.5rem clamp(1.25rem, 5vw, 2.25rem);
    display: flex;
    flex-direction: column;
    gap: 1.1rem;
    transform: translateX(100%);
    transition: transform 0.4s ease;
    z-index: 1200;
    box-shadow: -24px 0 60px rgba(15, 23, 42, 0.3);
}
.mobile-drawer.open { transform: translateX(0); }
.mobile-drawer a {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text-primary);
    border-bottom: 1px solid var(--color-border);
    border-bottom: 1px solid color-mix(in srgb, var(--color-border) 70%, transparent);
    padding-block: 0.65rem;
}
.mobile-drawer .drawer-footer {
    margin-top: auto;
    padding-top: 1.25rem;
    border-top: 1px solid color-mix(in srgb, var(--color-border) 70%, transparent);
}
.mobile-drawer .theme-toggle {
    display: flex;
    width: 100%;
    justify-content: flex-start;
    gap: 0.75rem;
    padding: 0.7rem 0.9rem;
    font-size: 1.75rem;
    color: var(--color-icon);
    background: color-mix(in srgb, var(--color-surface) 94%, transparent);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    transition: background var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
    transform: none;
}
.mobile-drawer .theme-toggle__label {
    display: inline-flex;
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text-primary);
    letter-spacing: 0.01em;
}
.mobile-drawer .theme-toggle:hover,
.mobile-drawer .theme-toggle:focus-visible {
    background: color-mix(in srgb, var(--color-surface-strong) 92%, transparent);
    border-color: color-mix(in srgb, var(--color-border) 35%, var(--color-icon-hover) 65%);
    color: var(--color-icon-hover);
    transform: none;
}
.mobile-drawer .theme-toggle:focus-visible { box-shadow: var(--focus-ring); }

.mobile-drawer .theme-toggle:hover .theme-toggle__label,
.mobile-drawer .theme-toggle:focus-visible .theme-toggle__label {
    color: var(--color-icon-hover);
}

.close-btn {
    align-self: flex-end;
    border: none;
    background: none;
    color: var(--color-icon);
    font-size: 2rem;
    cursor: pointer;
    transition: color var(--transition-fast);
}
.close-btn:hover,
.close-btn:focus-visible { color: var(--color-icon-hover); }
.close-btn:focus-visible { outline: none; box-shadow: var(--focus-ring); border-radius: 999px; }

/* ---------- Hero ---------- */
.hero {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    align-items: center;
    gap: clamp(2.5rem, 6vw, 5rem);
    min-height: clamp(32rem, 70vh, 42rem);
}
.hero-content { display: flex; flex-direction: column; gap: 1.5rem; }
.hero-tagline {
    font-size: 0.95rem;
    letter-spacing: 0.28em;
    text-transform: uppercase;
    font-weight: 600;
    color: var(--color-icon-hover);
}
.hero h1 {
    font-size: clamp(2.8rem, 5.5vw, 4.4rem);
    line-height: 1.05;
    font-weight: 800;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    color: transparent;
}
.hero-sub {
    font-size: clamp(1.05rem, 2.1vw, 1.25rem);
    color: var(--color-text-secondary);
    max-width: 620px;
}
.hero-cta { display: flex; flex-wrap: wrap; gap: 1rem; }

.hero-media {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: clamp(1rem, 4vw, 2rem);
}
.hero-media img {
    max-width: 520px;
    width: 100%;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}
.hero-media img:hover {
    transform: translateY(-6px) scale(1.02);
    box-shadow: var(--shadow-hover);
}

@media (max-width: 1024px) {
    .hero { grid-template-columns: minmax(0, 1fr); text-align: center; }
    .hero-content { align-items: center; }
    .hero-media { order: -1; }
}

@media (max-width: 640px) {
    .hero-cta { justify-content: center; }
    .hero-tagline { font-size: 0.85rem; letter-spacing: 0.2em; }
}

/* ---------- Buttons ---------- */
.btn-primary,
.btn-secondary {
    border-radius: 999px;
    font-weight: 700;
    padding: 0.9rem 1.8rem;
    border: 1px solid transparent;
    cursor: pointer;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast);
}
.btn-primary {
    background: var(--gradient-accent);
    color: #fff;
    box-shadow: 0 15px 35px rgba(14, 165, 233, 0.28);
}
.btn-primary:hover,
.btn-primary:focus-visible {
    transform: translateY(-3px);
    box-shadow: 0 22px 40px rgba(14, 165, 233, 0.35);
}
.btn-secondary {
    background: var(--color-chip-bg);
    border-color: var(--color-chip-border);
    color: var(--color-chip-text);
}
.btn-secondary:hover,
.btn-secondary:focus-visible {
    transform: translateY(-3px);
    border-color: var(--color-icon-hover);
}
.btn-primary:focus-visible,
.btn-secondary:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring);
}

.btn-glow { box-shadow: 0 15px 35px rgba(14, 165, 233, 0.28); }

/* ---------- Content Blocks ---------- */
:is(.about-card, .service-card, .expertise-card, .process-step, .contact-card, .info-card, .portfolio-card) {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: clamp(1.8rem, 4vw, 2.4rem);
    box-shadow: var(--shadow-lg);
    transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}
:is(.about-card, .service-card, .expertise-card, .process-step, .contact-card, .info-card, .portfolio-card):hover {
    transform: translateY(-8px);
    border-color: var(--color-border-strong);
    box-shadow: var(--shadow-hover);
}

.about-grid,
.services-grid,
.expertise-grid,
.process-grid,
.contact-grid,
.portfolio-grid {
    display: grid;
    gap: clamp(1.75rem, 4vw, 2.5rem);
}

.about-grid { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.services-grid { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.expertise-grid { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.portfolio-grid { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }

@media (min-width: 992px) {
    .services-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

.process-grid {
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    justify-items: stretch;
}

@media (min-width: 1024px) {
    .process-grid {
        grid-template-columns: repeat(5, minmax(0, 1fr));
    }
}
.contact-grid { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }

.about-card h3,
.service-card h3,
.expertise-card h3,
.process-step h3,
.contact-card h3,
.info-card h3 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.about-card p,
.service-card p,
.expertise-card p,
.process-step p,
.contact-card p,
.info-card p {
    color: var(--color-text-secondary);
    font-size: 0.97rem;
}

.about-card ul.icon-list {
    list-style: none;
    display: grid;
    gap: 0.5rem;
    color: var(--color-text-secondary);
}
.about-card ul.icon-list li::before {
    content: '•';
    margin-right: 0.5rem;
    color: var(--color-icon-hover);
}

.service-header {
    display: flex;
    align-items: center;
    gap: 0.85rem;
    margin-bottom: 1rem;
}
.service-header h3 {
    margin: 0;
    line-height: 1.25;
}
.step-header {
    display: flex;
    align-items: center;
    gap: 0.9rem;
    margin-bottom: 0.9rem;
}

.service-icon,
.social-links a {
    background: var(--color-surface-strong);
    background: color-mix(in srgb, var(--color-surface-strong) 65%, transparent);
    border: 1px solid var(--color-border);
    color: var(--color-icon);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 12px 24px rgba(15, 23, 42, 0.18);
    transition: background var(--transition-fast), transform var(--transition-fast), color var(--transition-fast);
}

.service-icon { width: 48px; height: 48px; border-radius: 0.85rem; font-size: 1.4rem; }
.social-links a { width: 42px; height: 42px; border-radius: 50%; }

.service-icon:hover,
.social-links a:hover {
    background: var(--color-chip-bg);
    background: color-mix(in srgb, var(--color-chip-bg) 60%, var(--color-surface));
    color: var(--color-icon-hover);
    transform: translateY(-3px);
}

.process-step {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
    width: 100%;
    min-height: 100%;
}
.process-step .step-header {
    gap: 0.65rem;
    margin-bottom: 0;
}
.step-badge {
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 12px;
    font-weight: 700;
    font-size: 0.85rem;
    letter-spacing: 0.01em;
    color: var(--color-text-primary);
    background:
        radial-gradient(140% 140% at 30% 25%, rgba(255, 255, 255, 0.65), transparent 62%),
        linear-gradient(135deg, rgba(99, 102, 241, 0.65), rgba(14, 165, 233, 0.7));
    border: 1px solid color-mix(in srgb, var(--color-border) 35%, rgba(99, 102, 241, 0.45));
    box-shadow:
        0 4px 10px rgba(15, 23, 42, 0.22),
        inset 0 1px 0 rgba(255, 255, 255, 0.35);
    flex-shrink: 0;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}
.step-badge::after {
    content: '';
    position: absolute;
    inset: 18% 12%;
    border-radius: 10px;
    background: radial-gradient(120% 120% at 70% 75%, rgba(14, 165, 233, 0.35), transparent 70%);
    opacity: 0.8;
    pointer-events: none;
}
.step-number {
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 26px;
    height: 26px;
    border-radius: 50%;
    background:
        radial-gradient(130% 130% at 25% 20%, rgba(255, 255, 255, 0.9), transparent 70%),
        linear-gradient(135deg, rgba(99, 102, 241, 0.8), rgba(14, 165, 233, 0.72));
    color: #fff;
    box-shadow:
        0 6px 12px rgba(14, 165, 233, 0.24),
        inset 0 1px 3px rgba(255, 255, 255, 0.4);
    text-shadow: 0 2px 6px rgba(15, 23, 42, 0.22);
    font-size: 0.82rem;
    line-height: 1;
}
.process-step h3 {
    margin: 0;
    line-height: 1.25;
}
.process-step p {
    margin: 0;
}
.process-step:hover .step-badge {
    transform: translateY(-4px);
    box-shadow: 0 16px 28px rgba(14, 165, 233, 0.26);
}
.process-step:hover .step-number {
    box-shadow:
        0 9px 16px rgba(14, 165, 233, 0.28),
        inset 0 1px 4px rgba(255, 255, 255, 0.45);
}

.service-tags,
.expertise-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.55rem;
    margin-top: 1.1rem;
}
.service-tags span,
.expertise-tags span {
    display: inline-flex;
    align-items: center;
    padding: 0.45rem 0.9rem;
    border-radius: 999px;
    background: var(--color-chip-bg);
    border: 1px solid var(--color-chip-border);
    color: var(--color-chip-text);
    font-size: 0.85rem;
    transition: transform var(--transition-fast), background var(--transition-fast);
}
.service-tags span:hover,
.expertise-tags span:hover { transform: translateY(-2px); background: var(--gradient-accent); color: #fff; }

.quick-info {
    border-left: 4px solid var(--color-icon-hover);
    padding-left: 1.2rem;
    margin: 1.5rem 0;
    color: var(--color-text-secondary);
}

.info-list { list-style: none; display: grid; gap: 0.85rem; color: var(--color-text-secondary); }
.info-list li {
    display: flex;
    align-items: center;
    gap: 0.7rem;
}
.info-list .material-symbols-rounded {
    color: var(--color-icon);
    font-size: 1.35rem;
    flex-shrink: 0;
}

.social-links { display: flex; gap: 0.9rem; }
.info-card .social-links { margin-top: 1.4rem; }
.social-links a:hover { box-shadow: 0 18px 35px rgba(14, 165, 233, 0.28); }

/* ---------- Process Section Connector ---------- */
@media (max-width: 600px) {
    .process-section::before {
        content: '';
        position: absolute;
        top: 48%;
        left: 8%;
        right: 8%;
        height: 2px;
        background: var(--color-border);
        background: color-mix(in srgb, var(--color-border) 70%, transparent);
        z-index: 0;
    }
}
.process-grid { position: relative; z-index: 1; }

/* ---------- Scroll Animations ---------- */
[data-animate] {
    opacity: 0;
    transform: translate3d(0, 40px, 0) scale(0.98);
    transition: transform 0.9s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.9s ease;
    transition-delay: var(--scroll-delay, 0s);
    will-change: transform, opacity;
}
[data-animate="fade-up"] {
    transform: translate3d(0, 64px, 0) scale(0.98);
}
[data-animate="fade-right"] {
    transform: translate3d(-56px, 0, 0) scale(0.98);
}
[data-animate="fade-left"] {
    transform: translate3d(56px, 0, 0) scale(0.98);
}
[data-animate="scale"] {
    transform: translate3d(0, 0, 0) scale(0.9);
}
[data-animate].is-inview {
    opacity: 1;
    transform: translate3d(0, 0, 0) scale(1);
}

@media (prefers-reduced-motion: reduce) {
    [data-animate] {
        opacity: 1;
        transform: none !important;
        transition: none !important;
    }
}

/* ---------- Forms ---------- */
#contactForm {
    display: grid;
    gap: 0.9rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.95rem 1rem;
    border-radius: 0.75rem;
    border: 1px solid var(--color-border);
    background: var(--color-surface);
    background: color-mix(in srgb, var(--color-surface) 80%, transparent);
    color: var(--color-text-primary);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.form-group input::placeholder,
.form-group textarea::placeholder { color: var(--color-muted); }
.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-icon-hover);
    box-shadow: var(--focus-ring);
}

/* ---------- Portfolio ---------- */
.portfolio-card {
    text-align: center;
    padding: 0;
    padding-bottom: 1.6rem;
    overflow: hidden;
    cursor: pointer;
}
.portfolio-card img {
    width: 100%;
    height: 220px;
    object-fit: cover;
}
.portfolio-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    margin: 1.25rem 0 0.4rem;
    padding-inline: 1.6rem;
    color: var(--color-text-primary);
}
.portfolio-card p {
    color: var(--color-text-secondary);
    margin-bottom: 0;
    padding-inline: 1.6rem;
}

/* Modal */
.portfolio-modal {
    position: fixed;
    inset: 0;
    display: none;
    align-items: center;
    justify-content: center;
    padding: clamp(1.25rem, 3vw, 2rem);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    background: rgba(5, 10, 22, 0.75);
    background: color-mix(in srgb, var(--color-background) 85%, rgba(5, 10, 22, 0.65));
    z-index: 1400;
}
.portfolio-modal.active { display: flex; animation: fade-in 0.35s ease; }

.modal-content {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    padding: clamp(1.5rem, 3vw, 2.4rem);
    width: min(850px, 100%);
    box-shadow: var(--shadow-hover);
    color: var(--color-text-primary);
    text-align: center;
}
.modal-content img {
    width: 100%;
    max-height: 480px;
    object-fit: contain;
    border-radius: var(--radius-md);
    margin-bottom: 1.25rem;
}
.close-modal {
    position: absolute;
    top: 1.25rem;
    right: 1.25rem;
    font-size: 2rem;
    color: var(--color-icon);
    cursor: pointer;
    transition: color var(--transition-fast);
}
.close-modal:hover { color: var(--color-icon-hover); }

/* ---------- Footer & Back to top ---------- */
footer {
    padding: 2.5rem var(--container-padding);
    border-top: 1px solid var(--color-border);
    text-align: center;
    color: var(--color-text-secondary);
}
.footer-links {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin: 1rem auto 0;
    flex-wrap: wrap;
}
.footer-links a { opacity: 0.85; }
.footer-links a:hover { opacity: 1; color: var(--color-icon-hover); }

#backToTop {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 52px;
    height: 52px;
    border-radius: 50%;
    border: none;
    background: var(--gradient-accent);
    color: #fff;
    font-size: 1.5rem;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: 0 22px 40px rgba(14, 165, 233, 0.28);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), opacity var(--transition-fast);
}
#backToTop:hover { transform: translateY(-4px) scale(1.05); box-shadow: 0 28px 50px rgba(14, 165, 233, 0.35); }

/* ---------- Typography Responsiveness ---------- */
@media (max-width: 768px) {
    .nav-row { padding-block: 0.75rem; }
    footer { text-align: center; }
}

@media (max-width: 540px) {
    body { padding-top: calc(var(--header-offset) + 0.5rem); }
    section { padding-block: clamp(3.5rem, 9vw, 4.5rem); }
    .hero h1 { font-size: clamp(2.35rem, 8vw, 2.85rem); }
    .hero-sub { font-size: 1rem; }
}

/* ---------- Motion preferences ---------- */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
    section { transform: none !important; opacity: 1 !important; }
}

/* ---------- Keyframes ---------- */
@keyframes fade-in {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}