/* ===== CSS Variables ===== */
:root {
    /* Colors */
    --color-black: #0a0a0a;
    --color-dark: #141414;
    --color-darker: #1a1a1a;
    --color-gray-dark: #2a2a2a;
    --color-gray: #4a4a4a;
    --color-gray-light: #8a8a8a;
    --color-silver: #c0c0c0;
    --color-chrome: #e8e8e8;
    --color-white: #ffffff;
    --color-blue: #3b82f6;
    --color-blue-dark: #1d4ed8;
    --color-blue-light: #60a5fa;
    
    /* Gradients */
    --gradient-chrome: linear-gradient(135deg, #c0c0c0 0%, #e8e8e8 50%, #a0a0a0 100%);
    --gradient-dark: linear-gradient(180deg, #1a1a1a 0%, #0a0a0a 100%);
    --gradient-blue: linear-gradient(135deg, #1d4ed8 0%, #3b82f6 100%);
    
    /* Typography */
    --font-heading: 'Playfair Display', Georgia, serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    
    /* Spacing */
    --section-padding: 6rem;
    --container-max: 1200px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-body);
    background-color: var(--color-black);
    color: var(--color-chrome);
    line-height: 1.6;
    overflow-x: hidden;
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-fast);
}

ul {
    list-style: none;
}

button {
    cursor: pointer;
    border: none;
    background: none;
    font-family: inherit;
}

/* ===== Utility Classes ===== */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 1.5rem;
}

.section {
    padding: var(--section-padding) 0;
}

.section__subtitle {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.2em;
    color: var(--color-blue-light);
    margin-bottom: 1rem;
}

.section__title {
    font-family: var(--font-heading);
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 600;
    color: var(--color-white);
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.section__description {
    font-size: 1.125rem;
    color: var(--color-gray-light);
    max-width: 600px;
}

.section__header {
    text-align: center;
    margin-bottom: 4rem;
}

.section__header .section__description {
    margin: 0 auto;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2rem;
    font-size: 0.9375rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    border-radius: 4px;
    transition: all var(--transition-normal);
}

.btn--primary {
    background: var(--gradient-blue);
    color: var(--color-white);
    box-shadow: 0 4px 20px rgba(59, 130, 246, 0.3);
}

.btn--primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 30px rgba(59, 130, 246, 0.4);
}

.btn--outline {
    border: 1px solid var(--color-silver);
    color: var(--color-silver);
}

.btn--outline:hover {
    background: var(--color-silver);
    color: var(--color-black);
}

.btn--full {
    width: 100%;
}

/* ===== Header & Navigation ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 1rem 0;
    transition: all var(--transition-normal);
}

.header.scrolled {
    background: rgba(10, 10, 10, 0.95);
    backdrop-filter: blur(10px);
    padding: 0.75rem 0;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.5);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav__logo {
    z-index: 1001;
}

.logo-img {
    height: 120px;
    width: auto;
    transition: all var(--transition-normal);
}

.header.scrolled .logo-img {
    height: 80px;
}

.nav__list {
    display: flex;
    gap: 2.5rem;
}

.nav__link {
    font-size: 0.9375rem;
    font-weight: 400;
    color: var(--color-silver);
    position: relative;
    padding: 0.5rem 0;
}

.nav__link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--color-blue-light);
    transition: width var(--transition-normal);
}

.nav__link:hover,
.nav__link.active {
    color: var(--color-white);
}

.nav__link:hover::after,
.nav__link.active::after {
    width: 100%;
}

.nav__toggle,
.nav__close {
    display: none;
}

/* ===== Hero Section ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: url('../images/conference.jpg') center/cover no-repeat;
}

.hero__overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(
        135deg,
        rgba(10, 10, 10, 0.95) 0%,
        rgba(10, 10, 10, 0.8) 50%,
        rgba(29, 78, 216, 0.3) 100%
    );
}

.hero__content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    padding-top: 6rem;
}

.hero__subtitle {
    display: inline-block;
    font-size: 0.875rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.3em;
    color: var(--color-blue-light);
    margin-bottom: 1.5rem;
    padding: 0.5rem 1rem;
    border: 1px solid rgba(96, 165, 250, 0.3);
    border-radius: 2px;
}

.hero__title {
    font-family: var(--font-heading);
    font-size: clamp(2.5rem, 7vw, 4.5rem);
    font-weight: 600;
    color: var(--color-white);
    line-height: 1.1;
    margin-bottom: 1.5rem;
}

.hero__description {
    font-size: 1.25rem;
    color: var(--color-silver);
    margin-bottom: 2.5rem;
    max-width: 600px;
}

.hero__buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.hero__scroll {
    position: absolute;
    bottom: 3rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1;
}

.scroll-indicator {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    color: var(--color-gray-light);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.2em;
}

.scroll-line {
    width: 1px;
    height: 60px;
    background: linear-gradient(to bottom, var(--color-blue-light), transparent);
    animation: scrollPulse 2s ease-in-out infinite;
}

@keyframes scrollPulse {
    0%, 100% { opacity: 0.3; transform: scaleY(0.8); }
    50% { opacity: 1; transform: scaleY(1); }
}

/* ===== About Section ===== */
.about {
    background: var(--gradient-dark);
}

.about__grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about__text {
    color: var(--color-gray-light);
    margin-bottom: 1.5rem;
    font-size: 1.0625rem;
}

.about__stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 3rem;
    padding-top: 3rem;
    border-top: 1px solid var(--color-gray-dark);
}

.stat {
    text-align: center;
}

.stat__number {
    display: block;
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 600;
    color: var(--color-white);
    background: var(--gradient-chrome);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat__label {
    font-size: 0.875rem;
    color: var(--color-gray-light);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.about__image {
    position: relative;
}

.about__image img {
    border-radius: 8px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.about__image-accent {
    position: absolute;
    top: -20px;
    right: -20px;
    width: 100%;
    height: 100%;
    border: 2px solid var(--color-blue);
    border-radius: 8px;
    z-index: -1;
}

/* ===== Services Section ===== */
.services {
    background: var(--color-black);
}

.services__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.service-card {
    background: var(--color-darker);
    padding: 2.5rem;
    border-radius: 8px;
    border: 1px solid var(--color-gray-dark);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--gradient-chrome);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-normal);
}

.service-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-gray);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.service-card:hover::before {
    transform: scaleX(1);
}

.service-card__icon {
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-gray-dark);
    border-radius: 8px;
    margin-bottom: 1.5rem;
}

.service-card__icon svg {
    width: 28px;
    height: 28px;
    color: var(--color-blue-light);
}

.service-card__title {
    font-family: var(--font-heading);
    font-size: 1.375rem;
    font-weight: 500;
    color: var(--color-white);
    margin-bottom: 1rem;
}

.service-card__description {
    color: var(--color-gray-light);
    font-size: 0.9375rem;
    line-height: 1.7;
}

.service-card--featured {
    background: linear-gradient(135deg, var(--color-darker) 0%, rgba(29, 78, 216, 0.15) 100%);
    border-color: var(--color-blue);
}

.service-card--featured::before {
    background: var(--gradient-blue);
    transform: scaleX(1);
}

.service-card__badge {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-blue-light);
    background: rgba(59, 130, 246, 0.2);
    padding: 0.25rem 0.75rem;
    border-radius: 2px;
}

/* ===== Featured Section ===== */
.featured {
    background: var(--gradient-dark);
}

.featured__grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    grid-template-rows: repeat(2, 250px);
    gap: 1.5rem;
}

.featured__item {
    position: relative;
    border-radius: 8px;
    overflow: hidden;
}

.featured__item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.featured__item:hover img {
    transform: scale(1.05);
}

.featured__item--large {
    grid-row: span 2;
}

.featured__overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(10, 10, 10, 0.9) 0%, transparent 60%);
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: 2rem;
}

.featured__category {
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--color-blue-light);
    margin-bottom: 0.5rem;
}

.featured__title {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--color-white);
}

/* ===== Contact Section ===== */
.contact {
    background: var(--color-black);
}

.contact__grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.contact__description {
    color: var(--color-gray-light);
    font-size: 1.0625rem;
    margin-bottom: 3rem;
}

.contact__offices {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.office__title {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--color-white);
    margin-bottom: 1rem;
}

.office__address {
    font-style: normal;
    color: var(--color-gray-light);
    font-size: 0.9375rem;
    line-height: 1.8;
    margin-bottom: 0.75rem;
}

.office__phone {
    color: var(--color-silver);
    font-weight: 500;
}

.office__phone:hover {
    color: var(--color-blue-light);
}

.contact__email {
    display: inline-block;
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--color-blue-light);
    border-bottom: 1px solid transparent;
    transition: border-color var(--transition-fast);
}

.contact__email:hover {
    border-color: var(--color-blue-light);
}

.contact__form-wrapper {
    background: var(--color-darker);
    padding: 3rem;
    border-radius: 8px;
    border: 1px solid var(--color-gray-dark);
}

.form__group {
    margin-bottom: 1.5rem;
}

.form__label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-silver);
    margin-bottom: 0.5rem;
}

.form__input,
.form__select,
.form__textarea {
    width: 100%;
    padding: 1rem;
    font-size: 1rem;
    font-family: inherit;
    color: var(--color-white);
    background: var(--color-dark);
    border: 1px solid var(--color-gray-dark);
    border-radius: 4px;
    transition: border-color var(--transition-fast);
}

.form__input:focus,
.form__select:focus,
.form__textarea:focus {
    outline: none;
    border-color: var(--color-blue);
}

.form__input::placeholder,
.form__textarea::placeholder {
    color: var(--color-gray);
}

.form__select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%238a8a8a' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1rem center;
}

.form__textarea {
    resize: vertical;
    min-height: 120px;
}

/* ===== Footer ===== */
.footer {
    background: var(--color-dark);
    padding: 4rem 0 2rem;
    border-top: 1px solid var(--color-gray-dark);
}

.footer__grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer__logo {
    height: 40px;
    width: auto;
    margin-bottom: 1rem;
}

.footer__tagline {
    color: var(--color-gray-light);
    font-size: 0.9375rem;
}

.footer__title {
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 500;
    color: var(--color-white);
    margin-bottom: 1.5rem;
}

.footer__links ul {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.footer__links a {
    color: var(--color-gray-light);
    font-size: 0.9375rem;
    transition: color var(--transition-fast);
}

.footer__links a:hover {
    color: var(--color-blue-light);
}

.footer__contact p {
    color: var(--color-gray-light);
    font-size: 0.9375rem;
    margin-bottom: 0.5rem;
}

.footer__bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 2rem;
    border-top: 1px solid var(--color-gray-dark);
    color: var(--color-gray);
    font-size: 0.875rem;
}

/* ===== Responsive Design ===== */

/* Tablet */
@media (max-width: 992px) {
    :root {
        --section-padding: 4rem;
    }
    
    .logo-img {
        height: 100px;
    }
    
    .header.scrolled .logo-img {
        height: 70px;
    }
    
    .about__grid {
        grid-template-columns: 1fr;
        gap: 3rem;
    }
    
    .about__image {
        order: -1;
    }
    
    .services__grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .featured__grid {
        grid-template-columns: 1fr;
        grid-template-rows: auto;
    }
    
    .featured__item--large {
        grid-row: span 1;
    }
    
    .featured__item {
        height: 300px;
    }
    
    .contact__grid {
        grid-template-columns: 1fr;
        gap: 3rem;
    }
    
    .footer__grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Mobile */
@media (max-width: 768px) {
    .logo-img {
        height: 80px;
    }
    
    .header.scrolled .logo-img {
        height: 60px;
    }
    
    .nav__menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 400px;
        height: 100vh;
        background: var(--color-dark);
        padding: 6rem 2rem 2rem;
        transition: right var(--transition-normal);
        box-shadow: -10px 0 30px rgba(0, 0, 0, 0.5);
    }
    
    .nav__menu.show {
        right: 0;
    }
    
    .nav__list {
        flex-direction: column;
        gap: 1.5rem;
    }
    
    .nav__link {
        font-size: 1.25rem;
    }
    
    .nav__toggle {
        display: flex;
        flex-direction: column;
        gap: 5px;
        z-index: 1001;
    }
    
    .nav__toggle span {
        width: 25px;
        height: 2px;
        background: var(--color-silver);
        transition: all var(--transition-fast);
    }
    
    .nav__toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .nav__toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .nav__toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }
    
    .nav__close {
        display: block;
        position: absolute;
        top: 1.5rem;
        right: 1.5rem;
        font-size: 2rem;
        color: var(--color-silver);
    }
    
    .hero__content {
        padding-top: 8rem;
    }
    
    .hero__buttons {
        flex-direction: column;
    }
    
    .hero__scroll {
        display: none;
    }
    
    .about__stats {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .services__grid {
        grid-template-columns: 1fr;
    }
    
    .contact__offices {
        grid-template-columns: 1fr;
    }
    
    .contact__form-wrapper {
        padding: 2rem;
    }
    
    .footer__grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .footer__bottom {
        flex-direction: column;
        gap: 0.5rem;
        text-align: center;
    }
}

/* Small Mobile */
@media (max-width: 480px) {
    .hero__title {
        font-size: 2rem;
    }
    
    .hero__description {
        font-size: 1rem;
    }
    
    .section__title {
        font-size: 1.75rem;
    }
    
    .service-card {
        padding: 1.5rem;
    }
    
    .stat__number {
        font-size: 2rem;
    }
}

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

.animate-fade-in {
    animation: fadeInUp 0.6s ease forwards;
}

/* Smooth scroll offset for fixed header */
html {
    scroll-padding-top: 80px;
}