/* ===================================================================
 * SeMo Lab - Minimal Studio Website Styles
 * Inspired by sepehrmohammady.ir
 * =================================================================== */

/* ------------------------------------------------------------------- 
 * ## base styles
 * ------------------------------------------------------------------- */

:root {
    --color-bg: #0a0a0a;
    --color-bg-light: #111111;
    --color-text: #ffffff;
    --color-text-muted: rgba(255, 255, 255, 0.6);
    --color-accent: #00d4ff;
    --color-accent-hover: #00b8e6;
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --transition-base: 0.3s ease;
    --border-radius: 12px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 62.5%;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    font-size: 1.6rem;
    line-height: 1.7;
    color: var(--color-text);
    background-color: var(--color-bg);
    min-height: 100vh;
    overflow-x: hidden;
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color var(--transition-base);
}

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

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

/* ------------------------------------------------------------------- 
 * ## animated background circles
 * ------------------------------------------------------------------- */

.circles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    pointer-events: none;
    z-index: -1;
}

.circles span {
    position: absolute;
    display: block;
    width: 20px;
    height: 20px;
    background: rgba(255, 255, 255, 0.02);
    border-radius: 50%;
    animation: animate 25s linear infinite;
    bottom: -150px;
}

.circles span:nth-child(1) {
    left: 25%;
    width: 80px;
    height: 80px;
    animation-delay: 0s;
}

.circles span:nth-child(2) {
    left: 10%;
    width: 20px;
    height: 20px;
    animation-delay: 2s;
    animation-duration: 12s;
}

.circles span:nth-child(3) {
    left: 70%;
    width: 20px;
    height: 20px;
    animation-delay: 4s;
}

.circles span:nth-child(4) {
    left: 40%;
    width: 60px;
    height: 60px;
    animation-delay: 0s;
    animation-duration: 18s;
}

.circles span:nth-child(5) {
    left: 65%;
    width: 20px;
    height: 20px;
    animation-delay: 0s;
}

.circles span:nth-child(6) {
    left: 75%;
    width: 110px;
    height: 110px;
    animation-delay: 3s;
}

.circles span:nth-child(7) {
    left: 35%;
    width: 150px;
    height: 150px;
    animation-delay: 7s;
}

.circles span:nth-child(8) {
    left: 50%;
    width: 25px;
    height: 25px;
    animation-delay: 15s;
    animation-duration: 45s;
}

.circles span:nth-child(9) {
    left: 20%;
    width: 15px;
    height: 15px;
    animation-delay: 2s;
    animation-duration: 35s;
}

.circles span:nth-child(10) {
    left: 85%;
    width: 150px;
    height: 150px;
    animation-delay: 0s;
    animation-duration: 11s;
}

@keyframes animate {
    0% {
        transform: translateY(0) rotate(0deg);
        opacity: 1;
    }

    100% {
        transform: translateY(-1000px) rotate(720deg);
        opacity: 0;
    }
}

/* ------------------------------------------------------------------- 
 * ## page wrapper
 * ------------------------------------------------------------------- */

.page-wrap {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ------------------------------------------------------------------- 
 * ## header / navigation
 * ------------------------------------------------------------------- */

.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 2rem 4rem;
    z-index: 100;
    background: linear-gradient(to bottom, rgba(10, 10, 10, 0.9), transparent);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1400px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    gap: 1.2rem;
    font-size: 2rem;
    font-weight: 600;
    color: var(--color-text);
    text-decoration: none;
}

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

.nav {
    display: flex;
    gap: 3rem;
}

.nav a {
    color: var(--color-text-muted);
    font-size: 1.4rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    transition: color var(--transition-base);
}

.nav a:hover {
    color: var(--color-text);
}

/* ------------------------------------------------------------------- 
 * ## hero section
 * ------------------------------------------------------------------- */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 12rem 4rem 8rem;
}

.hero-content {
    max-width: 800px;
}

.hero-logo {
    width: 220px;
    height: auto;
    margin: 0 auto 1rem;
    animation: fadeIn 1s ease;
}

.hero-logo img {
    width: 100%;
    height: auto;
    object-fit: contain;
}

.hero .tagline {
    font-size: 2.2rem;
    font-weight: 300;
    color: var(--color-text);
    margin-bottom: 1rem;
    margin-top: 2rem;
    animation: slideUp 0.8s ease 0.1s backwards;
    letter-spacing: -0.01em;
}

.tagline-sub {
    font-size: 1.5rem;
    color: var(--color-text-muted);
    margin-bottom: 4rem;
    font-style: italic;
    font-weight: 300;
    animation: slideUp 0.8s ease 0.2s backwards;
}

.scroll-down {
    display: inline-block;
    animation: bounce 2s infinite;
    cursor: pointer;
}

.scroll-down svg {
    width: 24px;
    height: 24px;
    fill: var(--color-text-muted);
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes bounce {

    0%,
    20%,
    50%,
    80%,
    100% {
        transform: translateY(0);
    }

    40% {
        transform: translateY(-10px);
    }

    60% {
        transform: translateY(-5px);
    }
}

/* ------------------------------------------------------------------- 
 * ## section styles
 * ------------------------------------------------------------------- */

section {
    padding: 10rem 4rem;
}

.section-header {
    margin-bottom: 6rem;
}

.section-header .pretitle {
    display: inline-block;
    font-size: 1.2rem;
    text-transform: uppercase;
    letter-spacing: 0.3em;
    color: var(--color-accent);
    margin-bottom: 1.5rem;
    position: relative;
    padding-left: 6rem;
}

.section-header .pretitle::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    width: 4.5rem;
    height: 1px;
    background: var(--color-accent);
}

.section-header h2 {
    font-size: 4rem;
    font-weight: 600;
    line-height: 1.3;
}

/* ------------------------------------------------------------------- 
 * ## projects grid
 * ------------------------------------------------------------------- */

.projects {
    background: var(--color-bg-light);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2.5rem;
    max-width: 1200px;
    margin: 0 auto;
}

.project-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
    cursor: pointer;
    text-decoration: none;
    color: var(--color-text);
    display: block;
    position: relative;
}

.project-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--color-accent), transparent);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.project-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
    border-color: rgba(0, 212, 255, 0.2);
}

.project-card:hover::before {
    opacity: 1;
}

.project-card-image {
    position: relative;
    overflow: hidden;
    aspect-ratio: 16 / 9;
    background: var(--color-bg);
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-card-image img {
    width: 100px;
    height: 100px;
    object-fit: contain;
    transition: transform var(--transition-base);
}

.project-card:hover .project-card-image img {
    transform: scale(1.1);
}

.project-card-content {
    padding: 2rem;
}

.project-card-category {
    font-size: 1.1rem;
    text-transform: uppercase;
    letter-spacing: 0.2em;
    color: var(--color-accent);
    margin-bottom: 0.5rem;
}

.project-card h3 {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 0.8rem;
}

.project-card p {
    font-size: 1.4rem;
    color: var(--color-text-muted);
    line-height: 1.5;
}

.project-card-arrow {
    display: none;
}

/* ------------------------------------------------------------------- 
 * ## contact section
 * ------------------------------------------------------------------- */

.contact {
    padding: 10rem 4rem;
    max-width: 780px;
    margin: 0 auto;
}

.contact-intro {
    font-size: 1.6rem;
    color: var(--color-text-muted);
    line-height: 1.8;
    margin-bottom: 5rem;
}

/* Honeypot — hide from real users */
.hp-field {
    position: absolute;
    left: -9999px;
    top: -9999px;
    opacity: 0;
    pointer-events: none;
    visibility: hidden;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    position: relative;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.form-group label {
    font-size: 1.2rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-muted);
}

.form-group input,
.form-group select,
.form-group textarea {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    padding: 1.2rem 1.6rem;
    font-family: var(--font-primary);
    font-size: 1.5rem;
    color: var(--color-text);
    transition: border-color var(--transition-base), background var(--transition-base);
    outline: none;
    width: 100%;
}

.form-group select {
    appearance: none;
    -webkit-appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='rgba(255,255,255,0.4)' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1.6rem center;
    padding-right: 4rem;
    cursor: pointer;
}

.form-group select option {
    background: #1a1a1a;
    color: var(--color-text);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: rgba(0, 212, 255, 0.4);
    background: rgba(255, 255, 255, 0.06);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: rgba(255, 255, 255, 0.25);
}

.form-group textarea {
    resize: vertical;
    min-height: 140px;
}

.form-footer {
    display: flex;
    align-items: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.btn-submit {
    background: transparent;
    border: 1px solid var(--color-accent);
    color: var(--color-accent);
    padding: 1.2rem 3rem;
    font-family: var(--font-primary);
    font-size: 1.4rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    border-radius: 50px;
    cursor: pointer;
    transition: all var(--transition-base);
}

.btn-submit:hover:not(:disabled) {
    background: var(--color-accent);
    color: var(--color-bg);
}

.btn-submit:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.form-status {
    font-size: 1.4rem;
    padding: 0.8rem 1.4rem;
    border-radius: 6px;
}

.form-status.success {
    color: #4ade80;
    background: rgba(74, 222, 128, 0.1);
    border: 1px solid rgba(74, 222, 128, 0.2);
}

.form-status.error {
    color: #f87171;
    background: rgba(248, 113, 113, 0.1);
    border: 1px solid rgba(248, 113, 113, 0.2);
}

/* ------------------------------------------------------------------- 
 * ## footer
 * ------------------------------------------------------------------- */

.footer {
    padding: 4rem;
    text-align: center;
    margin-top: auto;
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 2rem;
}

.footer-copyright {
    font-size: 1.4rem;
    color: var(--color-text-muted);
}

.footer-links {
    display: flex;
    gap: 2rem;
}

.footer-links a {
    color: var(--color-text-muted);
    font-size: 1.8rem;
    transition: color var(--transition-base);
}

.footer-links a:hover {
    color: var(--color-text);
}

.footer-links a.footer-text-link {
    font-size: 1.4rem;
    letter-spacing: 0.02em;
}

/* ------------------------------------------------------------------- 
 * ## app page styles
 * ------------------------------------------------------------------- */

.app-hero {
    min-height: 60vh;
    display: flex;
    align-items: center;
    padding: 14rem 4rem 6rem;
    position: relative;
    overflow: hidden;
}

.app-hero-content {
    display: flex;
    align-items: center;
    position: relative;
    z-index: 1;
    gap: 4rem;
    max-width: 1400px;
    margin: 0 auto;
    width: 100%;
}

.app-logo {
    width: 120px;
    height: 120px;
    flex-shrink: 0;
}

.app-logo img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.app-info h1 {
    font-size: 4.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
}

.app-info .tagline {
    font-size: 2rem;
    color: var(--color-text-muted);
    margin-bottom: 2.5rem;
}

.app-buttons {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.8rem;
    padding: 1.4rem 2.8rem;
    font-size: 1.4rem;
    font-weight: 500;
    border-radius: 50px;
    text-decoration: none;
    transition: all var(--transition-base);
}

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

.btn-primary:hover {
    background: var(--color-accent-hover);
    color: var(--color-bg);
    transform: translateY(-2px);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: var(--color-text);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-2px);
}

.btn svg {
    width: 18px;
    height: 18px;
    fill: currentColor;
}

/* ------------------------------------------------------------------- 
 * ## features section
 * ------------------------------------------------------------------- */

.features {
    background: var(--color-bg-light);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 3rem;
    max-width: 1400px;
    margin: 0 auto;
}

.feature-item {
    padding: 3rem;
    background: rgba(255, 255, 255, 0.02);
    border-radius: var(--border-radius);
    transition: background var(--transition-base);
}

.feature-item:hover {
    background: rgba(255, 255, 255, 0.05);
}

.feature-icon {
    font-size: 2.4rem;
    margin-bottom: 1.5rem;
    color: var(--color-text-muted);
    opacity: 0.7;
}

.feature-item h3 {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.feature-item p {
    font-size: 1.5rem;
    color: var(--color-text-muted);
    line-height: 1.6;
}

/* ------------------------------------------------------------------- 
 * ## screenshots section
 * ------------------------------------------------------------------- */

.screenshots {
    padding: 10rem 4rem;
}

/* slider */
.screenshot-slider {
    position: relative;
    max-width: 360px;
    margin: 0 auto;
    padding: 0 6rem;
}

.slider-viewport {
    overflow: hidden;
    border-radius: var(--border-radius);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.45);
}

.slider-track {
    display: flex;
    transition: transform 0.45s cubic-bezier(0.4, 0, 0.2, 1);
}

.slide {
    min-width: 100%;
    overflow: hidden;
}

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

.slider-btn {
    position: absolute;
    top: 45%;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.14);
    color: var(--color-text);
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 2;
    transition: background var(--transition-base), transform 0.2s;
    backdrop-filter: blur(6px);
    font-size: 1.3rem;
}

.slider-btn:hover {
    background: rgba(255, 255, 255, 0.18);
    transform: translateY(-50%) scale(1.08);
}

.slider-prev { left: 0; }
.slider-next { right: 0; }

.slider-dots {
    display: flex;
    justify-content: center;
    gap: 0.8rem;
    margin-top: 2.4rem;
}

.dot {
    width: 8px;
    height: 8px;
    border-radius: 4px;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    padding: 0;
}

.dot.active {
    background: var(--color-accent);
    width: 24px;
}

/* ------------------------------------------------------------------- 
 * ## app visual decorations
 * ------------------------------------------------------------------- */

.app-visual {
    position: absolute;
    right: 7%;
    top: 50%;
    transform: translateY(-50%);
    pointer-events: none;
    user-select: none;
    z-index: 0;
}

/* Feed cards */
.visual-feed {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
    width: 200px;
    opacity: 0.12;
}

.vf-card {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 1rem;
    padding: 1.4rem;
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.vf-title {
    height: 1rem;
    background: rgba(255, 255, 255, 0.4);
    border-radius: 4px;
    display: block;
    width: 70%;
}

.vf-line {
    height: 0.7rem;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 4px;
    display: block;
}

.vf-line.short { width: 50%; }

/* Ledger */
.visual-ledger {
    width: 220px;
    opacity: 0.12;
}

.ledger-header {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.5);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 0.4rem;
}

.ledger-balance {
    font-size: 3.2rem;
    font-weight: 700;
    color: rgba(255, 255, 255, 0.6);
    margin-bottom: 1.4rem;
}

.ledger-row {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0.7rem 0;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    font-size: 1.3rem;
    color: rgba(255, 255, 255, 0.4);
}

.ledger-row .amount { margin-left: auto; }
.ledger-row.credit .amount { color: rgba(74, 222, 128, 0.7); }
.ledger-row.debit  .amount { color: rgba(248, 113, 113, 0.7); }

/* Equalizer */
.visual-eq {
    display: flex;
    align-items: flex-end;
    gap: 6px;
    height: 130px;
    opacity: 0.15;
}

.eq-bar {
    width: 12px;
    background: var(--color-accent);
    border-radius: 4px 4px 0 0;
    animation: eqBounce 1.2s ease-in-out infinite alternate;
}

.eq-bar:nth-child(1) { animation-delay: 0s; }
.eq-bar:nth-child(2) { animation-delay: 0.15s; }
.eq-bar:nth-child(3) { animation-delay: 0.3s; }
.eq-bar:nth-child(4) { animation-delay: 0.45s; }
.eq-bar:nth-child(5) { animation-delay: 0.6s; }
.eq-bar:nth-child(6) { animation-delay: 0.75s; }
.eq-bar:nth-child(7) { animation-delay: 0.9s; }

@keyframes eqBounce {
    from { height: 15%; }
    to   { height: var(--max-h, 80%); }
}

/* Weather widget */
.visual-weather {
    width: 190px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 1.8rem;
    padding: 2rem;
    opacity: 0.15;
    text-align: center;
}

.weather-icon-big {
    font-size: 4rem;
    color: rgba(255, 220, 80, 0.8);
    margin-bottom: 0.6rem;
}

.weather-temp {
    font-size: 3.2rem;
    font-weight: 700;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 1.2rem;
}

.weather-forecast {
    display: flex;
    justify-content: space-between;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    padding-top: 1rem;
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.4);
}

/* Clock */
.visual-clock {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.15);
    position: relative;
    opacity: 0.15;
}

.visual-clock::before {
    content: '';
    position: absolute;
    inset: 12px;
    border-radius: 50%;
    border: 1px solid rgba(255, 255, 255, 0.06);
}

.clock-hand {
    position: absolute;
    bottom: 50%;
    left: 50%;
    transform-origin: bottom center;
    background: rgba(255, 255, 255, 0.7);
    border-radius: 2px;
}

.clock-hand.hour {
    width: 3px;
    height: 38px;
    margin-left: -1.5px;
    transform: rotate(-60deg);
}

.clock-hand.minute {
    width: 2px;
    height: 52px;
    margin-left: -1px;
    transform: rotate(120deg);
}

.clock-dot {
    width: 8px;
    height: 8px;
    background: rgba(255, 255, 255, 0.7);
    border-radius: 50%;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

/* Shopping list */
.visual-list {
    width: 190px;
    opacity: 0.13;
}

.vlist-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.5);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 1rem;
}

.vlist-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0.6rem 0;
    font-size: 1.4rem;
    color: rgba(255, 255, 255, 0.4);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.vlist-item i { flex-shrink: 0; }

.vlist-item.done {
    color: rgba(255, 255, 255, 0.2);
    text-decoration: line-through;
}

.vlist-item.done i { color: rgba(74, 222, 128, 0.6); }

/* Match grid */
.visual-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 7px;
    opacity: 0.14;
}

.vg-tile {
    width: 40px;
    height: 40px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
}

/* ------------------------------------------------------------------- 
 * ## back link
 * ------------------------------------------------------------------- */

.back-link {
    position: fixed;
    top: 2.5rem;
    left: 4rem;
    display: flex;
    align-items: center;
    gap: 0.8rem;
    color: var(--color-text-muted);
    font-size: 1.4rem;
    text-decoration: none;
    z-index: 100;
    transition: color var(--transition-base);
}

.back-link:hover {
    color: var(--color-text);
}

.back-link svg {
    width: 16px;
    height: 16px;
    fill: currentColor;
}

/* ------------------------------------------------------------------- 
 * ## responsive styles
 * ------------------------------------------------------------------- */

@media screen and (max-width: 1024px) {
    .hero h1 {
        font-size: 4rem;
    }

    .section-header h2 {
        font-size: 3rem;
    }

    .app-info h1 {
        font-size: 3.5rem;
    }

    .app-visual { display: none; }

@media screen and (max-width: 768px) {
    html {
        font-size: 55%;
    }

    .header {
        padding: 1.5rem 2rem;
    }

    .nav {
        display: none;
    }

    .hero {
        padding: 10rem 2rem 6rem;
    }

    .hero h1 {
        font-size: 3.5rem;
    }

    .hero .tagline {
        font-size: 1.8rem;
    }

    section {
        padding: 6rem 2rem;
    }

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

    .contact {
        padding: 6rem 2rem;
    }

    .contact-layout {
        grid-template-columns: 1fr;
        gap: 4rem;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .app-hero {
        padding: 10rem 2rem 4rem;
    }

    .app-hero-content {
        flex-direction: column;
        text-align: center;
    }

    .app-buttons {
        justify-content: center;
    }

    .back-link {
        left: 2rem;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}

@media screen and (max-width: 480px) {
    .hero h1 {
        font-size: 2.8rem;
    }

    .hero-logo {
        width: 100px;
        height: 100px;
    }

    .section-header h2 {
        font-size: 2.4rem;
    }

    .app-info h1 {
        font-size: 2.8rem;
    }

    .app-logo {
        width: 80px;
        height: 80px;
    }

    .screenshot-slider {
        padding: 0 4rem;
    }
}