:root {
    --color-bg: #0a0a12;
    --color-surface: #12121a;
    --color-accent: #00d9ff;
    --color-accent-secondary: #b84dff;
    --color-accent-tertiary: #00ff88;
    --color-text: #ffffff;
    --color-text-muted: #8b8b9f;
    --color-border: rgba(255, 255, 255, 0.08);

    --font-display: 'Cormorant Garamond', serif;
    --font-mono: 'Space Mono', monospace;

    --spacing-unit: 8px;
    --border-radius: 12px;
    --transition-smooth: cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: var(--font-mono);
    background: var(--color-bg);
    color: var(--color-text);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    -webkit-tap-highlight-color: transparent;
}

/* Grain texture overlay */
.grain-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 100;
    opacity: 0.03;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 400 400' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='4' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E");
    animation: grain 8s steps(10) infinite;
}

@keyframes grain {
    0%, 100% { transform: translate(0, 0); }
    10% { transform: translate(-5%, -10%); }
    20% { transform: translate(-15%, 5%); }
    30% { transform: translate(7%, -25%); }
    40% { transform: translate(-5%, 25%); }
    50% { transform: translate(-15%, 10%); }
    60% { transform: translate(15%, 0%); }
    70% { transform: translate(0%, 15%); }
    80% { transform: translate(3%, 35%); }
    90% { transform: translate(-10%, 10%); }
}

/* Animated background orbs */
.background-orbs {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
    overflow: hidden;
}

.orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.15;
    animation: float 20s ease-in-out infinite;
}

.orb-1 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, var(--color-accent) 0%, transparent 70%);
    top: -10%;
    right: -10%;
    animation-delay: 0s;
}

.orb-2 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, var(--color-accent-secondary) 0%, transparent 70%);
    bottom: -5%;
    left: -5%;
    animation-delay: -7s;
}

.orb-3 {
    width: 350px;
    height: 350px;
    background: radial-gradient(circle, var(--color-accent-tertiary) 0%, transparent 70%);
    top: 40%;
    left: 50%;
    animation-delay: -14s;
}

@keyframes float {
    0%, 100% {
        transform: translate(0, 0) scale(1);
    }
    33% {
        transform: translate(30px, -30px) scale(1.1);
    }
    66% {
        transform: translate(-20px, 20px) scale(0.9);
    }
}

/* Container */
.container {
    max-width: 900px;
    margin: 0 auto;
    padding: calc(var(--spacing-unit) * 6) calc(var(--spacing-unit) * 3);
    position: relative;
    z-index: 1;
}

/* Masthead */
.masthead {
    text-align: center;
    margin-bottom: calc(var(--spacing-unit) * 8);
    animation: fadeInDown 1s var(--transition-smooth);
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.logo-mark {
    display: inline-block;
    margin-bottom: calc(var(--spacing-unit) * 3);
}

.icon-cart {
    width: 48px;
    height: 48px;
    color: var(--color-accent);
    animation: iconPulse 3s ease-in-out infinite;
}

@keyframes iconPulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.7;
        transform: scale(1.05);
    }
}

.title {
    font-family: var(--font-display);
    font-size: clamp(3rem, 8vw, 5rem);
    font-weight: 300;
    letter-spacing: 0.02em;
    margin-bottom: calc(var(--spacing-unit) * 2);
    background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-accent-secondary) 50%, var(--color-accent-tertiary) 100%);
    background-size: 200% 200%;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: gradientShift 8s ease infinite;
}

@keyframes gradientShift {
    0%, 100% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
}

.subtitle {
    font-size: 0.875rem;
    letter-spacing: 0.3em;
    text-transform: uppercase;
    color: var(--color-text-muted);
}

/* Exchange Banner */
.exchange-banner {
    margin-bottom: calc(var(--spacing-unit) * 6);
    animation: fadeInUp 1s var(--transition-smooth) 0.2s backwards;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.ticker-wrap {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: calc(var(--spacing-unit) * 2) calc(var(--spacing-unit) * 3);
    backdrop-filter: blur(20px);
    position: relative;
    overflow: hidden;
}

.ticker-wrap::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(0, 217, 255, 0.1), transparent);
    animation: shimmer 3s infinite;
}

@keyframes shimmer {
    0% {
        left: -100%;
    }
    100% {
        left: 100%;
    }
}

.ticker-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: calc(var(--spacing-unit) * 2);
    font-size: 0.875rem;
}

.ticker-label {
    color: var(--color-text-muted);
    letter-spacing: 0.2em;
}

.ticker-rate {
    color: var(--color-accent);
    font-weight: 700;
}

.ticker-pulse {
    width: 8px;
    height: 8px;
    background: var(--color-accent-tertiary);
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.3;
        transform: scale(1.3);
    }
}

/* Sections */
.add-section,
.items-section {
    margin-bottom: calc(var(--spacing-unit) * 8);
    animation: fadeInUp 1s var(--transition-smooth) 0.4s backwards;
}

.section-header {
    position: relative;
    margin-bottom: calc(var(--spacing-unit) * 4);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 400;
    color: var(--color-text);
}

.section-accent {
    height: 1px;
    flex: 1;
    margin-left: calc(var(--spacing-unit) * 3);
    background: linear-gradient(90deg, var(--color-accent) 0%, transparent 100%);
    opacity: 0.3;
}

/* Luxury Form */
.luxury-form {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: calc(var(--spacing-unit) * 4);
    backdrop-filter: blur(20px);
    position: relative;
}

.form-field {
    margin-bottom: calc(var(--spacing-unit) * 4);
    position: relative;
}

.field-label {
    display: block;
    font-size: 0.75rem;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--color-text-muted);
    margin-bottom: calc(var(--spacing-unit) * 1.5);
}

.optional {
    font-size: 0.7rem;
    opacity: 0.5;
}

.luxury-input {
    width: 100%;
    background: transparent;
    border: none;
    border-bottom: 1px solid var(--color-border);
    padding: calc(var(--spacing-unit) * 1.5) 0;
    font-family: var(--font-mono);
    font-size: 1rem;
    color: var(--color-text);
    transition: all 0.3s var(--transition-smooth);
    outline: none;
}

.luxury-input::placeholder {
    color: var(--color-text-muted);
    opacity: 0.3;
}

.luxury-input:focus {
    border-bottom-color: var(--color-accent);
}

.luxury-input:focus + .field-underline {
    transform: scaleX(1);
}

.luxury-input.computed {
    color: var(--color-accent-tertiary);
    font-weight: 700;
}

.field-underline {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, var(--color-accent), var(--color-accent-secondary));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s var(--transition-smooth);
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: calc(var(--spacing-unit) * 3);
}

/* Primary Button */
.btn-primary {
    width: 100%;
    background: linear-gradient(135deg, var(--color-accent), var(--color-accent-secondary));
    border: none;
    border-radius: var(--border-radius);
    padding: calc(var(--spacing-unit) * 2.5) calc(var(--spacing-unit) * 4);
    font-family: var(--font-mono);
    font-size: 0.875rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-bg);
    cursor: pointer;
    position: relative;
    overflow: hidden;
    transition: all 0.3s var(--transition-smooth);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: calc(var(--spacing-unit) * 2);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(0, 217, 255, 0.3);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-text {
    position: relative;
    z-index: 2;
}

.btn-icon {
    width: 20px;
    height: 20px;
    position: relative;
    z-index: 2;
}

.btn-shimmer {
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    animation: btnShimmer 3s infinite;
}

@keyframes btnShimmer {
    0% {
        left: -100%;
    }
    100% {
        left: 100%;
    }
}

/* Clear Button */
.btn-clear {
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: calc(var(--border-radius) / 2);
    padding: calc(var(--spacing-unit) * 1) calc(var(--spacing-unit) * 2);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-text-muted);
    cursor: pointer;
    transition: all 0.3s var(--transition-smooth);
}

.btn-clear:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

/* Items Grid */
.items-grid {
    display: grid;
    gap: calc(var(--spacing-unit) * 2);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: calc(var(--spacing-unit) * 10) calc(var(--spacing-unit) * 3);
    opacity: 0.5;
}

.empty-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto calc(var(--spacing-unit) * 3);
    color: var(--color-text-muted);
    animation: float 6s ease-in-out infinite;
}

.empty-text {
    font-family: var(--font-display);
    font-size: 1.5rem;
    margin-bottom: calc(var(--spacing-unit));
}

.empty-subtext {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

/* Item Card */
.item-card {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: calc(var(--spacing-unit) * 3);
    backdrop-filter: blur(20px);
    position: relative;
    overflow: hidden;
    transition: all 0.3s var(--transition-smooth);
    animation: itemSlideIn 0.5s var(--transition-smooth) backwards;
}

@keyframes itemSlideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.item-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 3px;
    height: 100%;
    background: linear-gradient(180deg, var(--color-accent), var(--color-accent-secondary));
    transform: scaleY(0);
    transform-origin: top;
    transition: transform 0.3s var(--transition-smooth);
}

.item-card:hover {
    border-color: var(--color-accent);
    transform: translateX(5px);
}

.item-card:hover::before {
    transform: scaleY(1);
}

.item-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.item-name {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 400;
    color: var(--color-text);
    flex: 1;
}

.btn-delete {
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: 50%;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s var(--transition-smooth);
    flex-shrink: 0;
}

.btn-delete:hover {
    border-color: #ff4d6d;
    background: rgba(255, 77, 109, 0.1);
    transform: rotate(90deg);
}

.btn-delete svg {
    width: 14px;
    height: 14px;
    color: var(--color-text-muted);
}

.btn-delete:hover svg {
    color: #ff4d6d;
}

.item-prices {
    display: flex;
    align-items: baseline;
    gap: calc(var(--spacing-unit) * 2);
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.price {
    font-family: var(--font-mono);
    font-size: 1.125rem;
    font-weight: 700;
}

.price-rub {
    color: var(--color-accent);
}

.price-usdt {
    color: var(--color-accent-tertiary);
}

.item-link {
    display: inline-flex;
    align-items: center;
    gap: calc(var(--spacing-unit));
    font-size: 0.75rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-text-muted);
    text-decoration: none;
    transition: color 0.3s var(--transition-smooth);
}

.item-link:hover {
    color: var(--color-accent);
}

.item-link svg {
    width: 12px;
    height: 12px;
}

/* Total Card */
.total-card {
    margin-top: calc(var(--spacing-unit) * 4);
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: calc(var(--spacing-unit) * 4);
    position: relative;
    overflow: hidden;
    animation: fadeInUp 0.5s var(--transition-smooth);
}

.total-decoration {
    position: absolute;
    top: 0;
    right: 0;
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, var(--color-accent-secondary) 0%, transparent 70%);
    opacity: 0.1;
    pointer-events: none;
}

.total-label {
    font-size: 0.75rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--color-text-muted);
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.total-amounts {
    display: flex;
    align-items: baseline;
    gap: calc(var(--spacing-unit) * 2);
    flex-wrap: wrap;
}

.amount-rub,
.amount-usdt {
    display: flex;
    align-items: baseline;
    gap: calc(var(--spacing-unit));
}

.amount-value {
    font-family: var(--font-display);
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 600;
}

.amount-rub {
    color: var(--color-accent);
}

.amount-usdt {
    color: var(--color-accent-tertiary);
}

.amount-divider {
    color: var(--color-text-muted);
    font-size: 1.5rem;
    opacity: 0.3;
}

.currency-symbol {
    font-size: 1rem;
    color: var(--color-text-muted);
}

/* Responsive */
@media (max-width: 768px) {
    :root {
        --spacing-unit: 6px;
    }

    body {
        padding: 0;
    }

    .container {
        padding: calc(var(--spacing-unit) * 3) calc(var(--spacing-unit) * 2);
    }

    /* Masthead mobile */
    .masthead {
        margin-bottom: calc(var(--spacing-unit) * 5);
        padding-top: calc(var(--spacing-unit) * 2);
    }

    .logo-mark {
        margin-bottom: calc(var(--spacing-unit) * 2);
    }

    .icon-cart {
        width: 36px;
        height: 36px;
    }

    .title {
        font-size: clamp(2.5rem, 12vw, 3.5rem);
        margin-bottom: calc(var(--spacing-unit) * 1.5);
    }

    .subtitle {
        font-size: 0.75rem;
        letter-spacing: 0.2em;
    }

    /* Exchange banner mobile */
    .exchange-banner {
        margin-bottom: calc(var(--spacing-unit) * 4);
    }

    .ticker-wrap {
        padding: calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 2);
    }

    .ticker-content {
        flex-wrap: wrap;
        gap: calc(var(--spacing-unit) * 1.5);
        font-size: 0.75rem;
    }

    .ticker-label {
        font-size: 0.7rem;
    }

    /* Sections mobile */
    .add-section,
    .items-section {
        margin-bottom: calc(var(--spacing-unit) * 5);
    }

    .section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: calc(var(--spacing-unit) * 2);
        margin-bottom: calc(var(--spacing-unit) * 3);
    }

    .section-title {
        font-size: clamp(1.5rem, 6vw, 2rem);
    }

    .section-accent {
        display: none;
    }

    .btn-clear {
        align-self: flex-end;
        font-size: 0.7rem;
        padding: calc(var(--spacing-unit) * 0.75) calc(var(--spacing-unit) * 1.5);
    }

    /* Form mobile */
    .luxury-form {
        padding: calc(var(--spacing-unit) * 3);
        border-radius: calc(var(--border-radius) * 0.75);
    }

    .form-field {
        margin-bottom: calc(var(--spacing-unit) * 3);
    }

    .field-label {
        font-size: 0.7rem;
        margin-bottom: calc(var(--spacing-unit));
    }

    .luxury-input {
        font-size: 0.9rem;
        padding: calc(var(--spacing-unit) * 1.25) 0;
    }

    .luxury-input::placeholder {
        font-size: 0.85rem;
    }

    .form-grid {
        grid-template-columns: 1fr;
        gap: calc(var(--spacing-unit) * 2);
    }

    /* Button mobile */
    .btn-primary {
        padding: calc(var(--spacing-unit) * 2) calc(var(--spacing-unit) * 3);
        font-size: 0.8rem;
        border-radius: calc(var(--border-radius) * 0.75);
    }

    .btn-icon {
        width: 16px;
        height: 16px;
    }

    /* Items mobile */
    .items-grid {
        gap: calc(var(--spacing-unit) * 1.5);
    }

    .item-card {
        padding: calc(var(--spacing-unit) * 2.5);
        border-radius: calc(var(--border-radius) * 0.75);
    }

    .item-card:hover {
        transform: translateX(0);
    }

    .item-card:active {
        transform: scale(0.98);
    }

    .item-header {
        margin-bottom: calc(var(--spacing-unit) * 1.5);
        gap: calc(var(--spacing-unit) * 1.5);
    }

    .item-name {
        font-size: 1.25rem;
        line-height: 1.3;
    }

    .btn-delete {
        width: 28px;
        height: 28px;
    }

    .btn-delete svg {
        width: 12px;
        height: 12px;
    }

    .item-prices {
        flex-direction: column;
        gap: calc(var(--spacing-unit));
        margin-bottom: calc(var(--spacing-unit) * 1.5);
    }

    .price {
        font-size: 1rem;
    }

    .item-link {
        font-size: 0.7rem;
    }

    /* Total card mobile */
    .total-card {
        margin-top: calc(var(--spacing-unit) * 3);
        padding: calc(var(--spacing-unit) * 3);
        border-radius: calc(var(--border-radius) * 0.75);
    }

    .total-label {
        font-size: 0.7rem;
        margin-bottom: calc(var(--spacing-unit) * 1.5);
    }

    .total-amounts {
        flex-direction: column;
        gap: calc(var(--spacing-unit));
        align-items: flex-start;
    }

    .amount-value {
        font-size: clamp(1.75rem, 8vw, 2.25rem);
    }

    .currency-symbol {
        font-size: 0.9rem;
    }

    .amount-divider {
        display: none;
    }

    .total-decoration {
        width: 150px;
        height: 150px;
    }

    /* Empty state mobile */
    .empty-state {
        padding: calc(var(--spacing-unit) * 6) calc(var(--spacing-unit) * 2);
    }

    .empty-icon {
        width: 60px;
        height: 60px;
        margin-bottom: calc(var(--spacing-unit) * 2);
    }

    .empty-text {
        font-size: 1.25rem;
        margin-bottom: calc(var(--spacing-unit) * 0.75);
    }

    .empty-subtext {
        font-size: 0.8rem;
    }

    /* Background orbs mobile - reduce for performance */
    .orb {
        filter: blur(60px);
    }

    .orb-1 {
        width: 300px;
        height: 300px;
    }

    .orb-2 {
        width: 250px;
        height: 250px;
    }

    .orb-3 {
        width: 200px;
        height: 200px;
    }
}

/* Small phones */
@media (max-width: 375px) {
    .container {
        padding: calc(var(--spacing-unit) * 2) calc(var(--spacing-unit) * 1.5);
    }

    .title {
        font-size: 2.25rem;
    }

    .luxury-form {
        padding: calc(var(--spacing-unit) * 2.5);
    }

    .item-card {
        padding: calc(var(--spacing-unit) * 2);
    }

    .item-name {
        font-size: 1.1rem;
    }

    .price {
        font-size: 0.95rem;
    }
}

/* Large tablets and small desktops */
@media (min-width: 769px) and (max-width: 1024px) {
    .container {
        max-width: 750px;
        padding: calc(var(--spacing-unit) * 5) calc(var(--spacing-unit) * 3);
    }

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

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
    /* Larger touch targets */
    .luxury-input {
        padding: calc(var(--spacing-unit) * 2) 0;
        font-size: 16px; /* Prevent zoom on iOS */
    }

    .btn-primary {
        padding: calc(var(--spacing-unit) * 2.5) calc(var(--spacing-unit) * 4);
        min-height: 48px;
    }

    .btn-delete {
        width: 44px;
        height: 44px;
        min-width: 44px;
        min-height: 44px;
    }

    .btn-clear {
        min-height: 36px;
        padding: calc(var(--spacing-unit) * 1) calc(var(--spacing-unit) * 2);
    }

    /* Remove hover effects on touch */
    .item-card:hover {
        border-color: var(--color-border);
        transform: none;
    }

    .item-card:hover::before {
        transform: scaleY(0);
    }

    /* Add active states instead */
    .item-card:active {
        transform: scale(0.98);
        border-color: var(--color-accent);
    }

    .btn-primary:active {
        transform: scale(0.95);
    }

    .btn-delete:active {
        transform: scale(0.9);
    }
}

/* Landscape mobile */
@media (max-width: 768px) and (orientation: landscape) {
    .masthead {
        margin-bottom: calc(var(--spacing-unit) * 3);
    }

    .title {
        font-size: 2rem;
    }

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

/* Very large screens */
@media (min-width: 1400px) {
    .container {
        max-width: 1000px;
    }
}