/* =============================================
   CSS Custom Properties (Variables)
   ============================================= */
:root {
    --color-primary: #2563EB;
    --color-primary-hover: #1d4ed8;
    --color-secondary: #1E293B;
    --color-accent: #F59E0B;
    --color-accent-hover: #d97706;
    --color-bg: #F8FAFC;
    --color-text: #334155;
    --color-text-light: #64748B;
    --color-white: #FFFFFF;
    --color-dark: #0F172A;
    --color-border: #E2E8F0;
    --color-success: #10B981;
    --color-shadow: rgba(37, 99, 235, 0.08);
    --color-shadow-hover: rgba(37, 99, 235, 0.18);

    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --container-width: 1160px;
    --header-height: 72px;
    --border-radius: 12px;
    --border-radius-sm: 8px;

    --transition: 0.3s ease;
}

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

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

body {
    font-family: var(--font-family);
    font-weight: 400;
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

ul {
    list-style: none;
}

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

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

input,
textarea {
    font: inherit;
    color: inherit;
}

/* =============================================
   Container
   ============================================= */
.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* =============================================
   Buttons
   ============================================= */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    font-family: var(--font-family);
    font-weight: 600;
    font-size: 0.95rem;
    border-radius: var(--border-radius-sm);
    transition: all var(--transition);
    cursor: pointer;
    border: none;
    white-space: nowrap;
}

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

.btn--primary:hover {
    background-color: var(--color-primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px var(--color-shadow-hover);
}

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

.btn--accent:hover {
    background-color: var(--color-accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(245, 158, 11, 0.35);
}

/* =============================================
   Section common
   ============================================= */
.section {
    padding: 90px 0;
}

.section__title {
    font-weight: 700;
    font-size: 2.2rem;
    text-align: center;
    color: var(--color-secondary);
    margin-bottom: 12px;
}

.section__subtitle {
    text-align: center;
    color: var(--color-text-light);
    font-size: 1.1rem;
    margin-bottom: 56px;
}

/* =============================================
   HEADER / NAVBAR
   ============================================= */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
    transition: box-shadow var(--transition);
}

.header--scrolled {
    box-shadow: 0 4px 20px var(--color-shadow);
}

.header__container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.header__logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.4rem;
    color: var(--color-primary);
}

.header__logo i {
    font-size: 1.6rem;
}

.header__nav-list {
    display: flex;
    align-items: center;
    gap: 32px;
}

.header__nav-link {
    font-weight: 500;
    font-size: 0.95rem;
    color: var(--color-text);
    position: relative;
    padding: 4px 0;
}

.header__nav-link::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-primary);
    transition: width var(--transition);
}

.header__nav-link:hover {
    color: var(--color-primary);
}

.header__nav-link:hover::after {
    width: 100%;
}

.header__cta {
    padding: 10px 24px;
    font-size: 0.9rem;
}

/* Burger */
.header__burger {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    cursor: pointer;
    gap: 5px;
}

.header__burger span {
    display: block;
    width: 24px;
    height: 2.5px;
    background-color: var(--color-secondary);
    border-radius: 2px;
    transition: all var(--transition);
}

.header__burger.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.header__burger.active span:nth-child(2) {
    opacity: 0;
}

.header__burger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* =============================================
   HERO
   ============================================= */
.hero {
    padding: 160px 0 100px;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #1E293B 0%, #2563EB 50%, #1E293B 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 50%, rgba(255,255,255,0.03) 0%, transparent 50%);
    pointer-events: none;
}

.hero__container {
    position: relative;
    z-index: 1;
    text-align: center;
}

.hero__title {
    font-weight: 700;
    font-size: 3.2rem;
    color: var(--color-white);
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero__subtitle {
    font-size: 1.2rem;
    color: rgba(255, 255, 255, 0.8);
    max-width: 700px;
    margin: 0 auto 36px;
    line-height: 1.7;
}

.hero__btn {
    padding: 16px 40px;
    font-size: 1.1rem;
    border-radius: var(--border-radius);
}

/* =============================================
   ADVANTAGES
   ============================================= */
.advantages {
    background-color: var(--color-white);
}

.advantages__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.advantage-card {
    background-color: var(--color-bg);
    border-radius: var(--border-radius);
    padding: 32px 28px;
    text-align: center;
    transition: all var(--transition);
    border: 1px solid transparent;
}

.advantage-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 36px var(--color-shadow);
    border-color: var(--color-border);
    background-color: var(--color-white);
}

.advantage-card__icon {
    width: 60px;
    height: 60px;
    border-radius: 16px;
    background-color: rgba(37, 99, 235, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 1.6rem;
    color: var(--color-primary);
    transition: all var(--transition);
}

.advantage-card:hover .advantage-card__icon {
    background-color: var(--color-primary);
    color: var(--color-white);
}

.advantage-card__title {
    font-weight: 700;
    font-size: 1.15rem;
    color: var(--color-secondary);
    margin-bottom: 10px;
}

.advantage-card__text {
    font-size: 0.95rem;
    color: var(--color-text-light);
    line-height: 1.6;
}

/* =============================================
   SERVICES
   ============================================= */
.services {
    background-color: var(--color-bg);
}

.services__table {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.service-card {
    background-color: var(--color-white);
    border-radius: var(--border-radius);
    padding: 36px 28px;
    text-align: center;
    transition: all var(--transition);
    border: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.service-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 36px var(--color-shadow);
    border-color: var(--color-primary);
}

.service-card__icon {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background-color: rgba(37, 99, 235, 0.08);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    font-size: 1.4rem;
    color: var(--color-primary);
    transition: all var(--transition);
}

.service-card:hover .service-card__icon {
    background-color: var(--color-primary);
    color: var(--color-white);
}

.service-card__title {
    font-weight: 700;
    font-size: 1.15rem;
    color: var(--color-secondary);
    margin-bottom: 8px;
}

.service-card__desc {
    font-size: 0.9rem;
    color: var(--color-text-light);
    margin-bottom: 20px;
}

.service-card__price {
    font-weight: 700;
    font-size: 1.6rem;
    color: var(--color-primary);
    margin-bottom: 6px;
}

.service-card__time {
    font-size: 0.85rem;
    color: var(--color-text-light);
    display: flex;
    align-items: center;
    gap: 6px;
}

/* =============================================
   PROCESS / TIMELINE
   ============================================= */
.process {
    background-color: var(--color-white);
}

.process__timeline {
    position: relative;
    max-width: 720px;
    margin: 0 auto;
    padding-left: 40px;
}

.process__timeline::before {
    content: '';
    position: absolute;
    top: 0;
    left: 19px;
    width: 3px;
    height: 100%;
    background: linear-gradient(to bottom, var(--color-primary), var(--color-accent));
    border-radius: 2px;
}

.process__step {
    display: flex;
    gap: 28px;
    margin-bottom: 44px;
    position: relative;
}

.process__step:last-child {
    margin-bottom: 0;
}

.process__step-number {
    flex-shrink: 0;
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background-color: var(--color-primary);
    color: var(--color-white);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.1rem;
    position: relative;
    z-index: 1;
    margin-left: -40px;
}

.process__step-content {
    padding-top: 6px;
}

.process__step-title {
    font-weight: 700;
    font-size: 1.15rem;
    color: var(--color-secondary);
    margin-bottom: 6px;
}

.process__step-text {
    font-size: 0.95rem;
    color: var(--color-text-light);
    line-height: 1.6;
}

/* =============================================
   REVIEWS
   ============================================= */
.reviews {
    background-color: var(--color-bg);
}

.reviews__slider {
    display: flex;
    gap: 24px;
    overflow: hidden;
    scroll-behavior: smooth;
    padding-bottom: 8px;
}

.review-card {
    flex-shrink: 0;
    width: calc(33.333% - 16px);
    background-color: var(--color-white);
    border-radius: var(--border-radius);
    padding: 32px 28px;
    border: 1px solid var(--color-border);
    transition: all var(--transition);
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.review-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 28px var(--color-shadow);
}

.review-card__avatar {
    font-size: 3.2rem;
    color: var(--color-primary);
    opacity: 0.3;
    line-height: 1;
}

.review-card__body {
    flex: 1;
}

.review-card__text {
    font-size: 0.95rem;
    color: var(--color-text);
    line-height: 1.7;
    margin-bottom: 20px;
    font-style: italic;
}

.review-card__author {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.review-card__name {
    font-weight: 700;
    font-size: 0.95rem;
    color: var(--color-secondary);
}

.review-card__company {
    font-size: 0.85rem;
    color: var(--color-text-light);
}

/* Dots for slider */
.reviews__dots {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 36px;
}

.reviews__dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: var(--color-border);
    border: none;
    cursor: pointer;
    transition: all var(--transition);
}

.reviews__dot.active {
    background-color: var(--color-primary);
    transform: scale(1.2);
}

/* =============================================
   CONTACT FORM
   ============================================= */
.contact {
    background-color: var(--color-white);
}

.contact__form {
    max-width: 640px;
    margin: 0 auto;
    background-color: var(--color-bg);
    padding: 44px 40px;
    border-radius: var(--border-radius);
    border: 1px solid var(--color-border);
}

.contact__form-row {
    display: flex;
    gap: 16px;
    margin-bottom: 16px;
}

.contact__form-input {
    width: 100%;
    padding: 14px 18px;
    border: 1.5px solid var(--color-border);
    border-radius: var(--border-radius-sm);
    background-color: var(--color-white);
    font-size: 0.95rem;
    transition: border-color var(--transition), box-shadow var(--transition);
    outline: none;
}

.contact__form-input:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

.contact__form-input::placeholder {
    color: var(--color-text-light);
}

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

.contact__form-btn {
    width: 100%;
    padding: 14px 28px;
    font-size: 1rem;
    margin-top: 4px;
}

/* =============================================
   FOOTER
   ============================================= */
.footer {
    background-color: var(--color-secondary);
    color: rgba(255, 255, 255, 0.8);
    padding: 60px 0 0;
}

.footer__container {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 48px;
    padding-bottom: 40px;
}

.footer__logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.3rem;
    color: var(--color-white);
    margin-bottom: 16px;
}

.footer__logo i {
    color: var(--color-primary);
}

.footer__text {
    font-size: 0.92rem;
    line-height: 1.7;
    color: rgba(255, 255, 255, 0.6);
    max-width: 360px;
}

.footer__heading {
    font-weight: 600;
    font-size: 1.05rem;
    color: var(--color-white);
    margin-bottom: 16px;
}

.footer__links {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer__links a {
    font-size: 0.92rem;
    color: rgba(255, 255, 255, 0.6);
    transition: color var(--transition);
}

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

.footer__socials {
    display: flex;
    gap: 12px;
}

.footer__social-link {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.08);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    color: rgba(255, 255, 255, 0.6);
    transition: all var(--transition);
}

.footer__social-link:hover {
    background-color: var(--color-primary);
    color: var(--color-white);
    transform: translateY(-3px);
}

.footer__bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    padding: 24px 0;
    text-align: center;
}

.footer__copyright {
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.4);
}

/* =============================================
   NOTIFICATION TOAST
   ============================================= */
.notification {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(120px);
    background-color: var(--color-secondary);
    color: var(--color-white);
    padding: 18px 32px;
    border-radius: var(--border-radius);
    box-shadow: 0 12px 36px rgba(0, 0, 0, 0.2);
    z-index: 2000;
    opacity: 0;
    transition: all 0.4s ease;
    pointer-events: none;
}

.notification.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
    pointer-events: auto;
}

.notification__content {
    display: flex;
    align-items: center;
    gap: 12px;
}

.notification__icon {
    font-size: 1.4rem;
    color: var(--color-success);
}

.notification__text {
    font-size: 1rem;
    font-weight: 500;
}

/* =============================================
   ANIMATIONS (fade-in, slide-up)
   ============================================= */

/* @keyframes definitions */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Utility animation classes */
.fade-in {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Animation via @keyframes (can be applied via JS or directly in HTML) */
.animate-fade-in {
    animation: fadeIn 0.8s ease forwards;
}

.animate-slide-up {
    animation: slideUp 0.8s ease forwards;
}

/* Staggered delays for grid items */
.advantages__grid .fade-in:nth-child(1) { transition-delay: 0.05s; }
.advantages__grid .fade-in:nth-child(2) { transition-delay: 0.1s; }
.advantages__grid .fade-in:nth-child(3) { transition-delay: 0.15s; }
.advantages__grid .fade-in:nth-child(4) { transition-delay: 0.2s; }
.advantages__grid .fade-in:nth-child(5) { transition-delay: 0.25s; }
.advantages__grid .fade-in:nth-child(6) { transition-delay: 0.3s; }

.services__table .fade-in:nth-child(1) { transition-delay: 0.05s; }
.services__table .fade-in:nth-child(2) { transition-delay: 0.1s; }
.services__table .fade-in:nth-child(3) { transition-delay: 0.15s; }
.services__table .fade-in:nth-child(4) { transition-delay: 0.2s; }

.process__step.fade-in:nth-child(1) { transition-delay: 0.05s; }
.process__step.fade-in:nth-child(2) { transition-delay: 0.1s; }
.process__step.fade-in:nth-child(3) { transition-delay: 0.15s; }
.process__step.fade-in:nth-child(4) { transition-delay: 0.2s; }
.process__step.fade-in:nth-child(5) { transition-delay: 0.25s; }

/* =============================================
   MEDIA QUERIES
   ============================================= */

/* Tablet: 481px – 768px */
@media (max-width: 768px) {
    .section {
        padding: 64px 0;
    }

    .section__title {
        font-size: 1.8rem;
    }

    .section__subtitle {
        font-size: 1rem;
        margin-bottom: 40px;
    }

    /* Header */
    .header__nav {
        position: fixed;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background-color: var(--color-white);
        border-bottom: 1px solid var(--color-border);
        padding: 20px 0;
        transform: translateY(-100%);
        opacity: 0;
        pointer-events: none;
        transition: all var(--transition);
    }

    .header__nav.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
    }

    .header__nav-list {
        flex-direction: column;
        gap: 16px;
        padding: 0 20px;
    }

    .header__cta {
        display: none;
    }

    .header__burger {
        display: flex;
    }

    /* Hero */
    .hero {
        padding: 130px 0 70px;
        min-height: auto;
    }

    .hero__title {
        font-size: 2.2rem;
    }

    .hero__subtitle {
        font-size: 1.05rem;
    }

    /* Advantages */
    .advantages__grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }

    /* Services */
    .services__table {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }

    /* Reviews */
    .review-card {
        width: calc(50% - 12px);
    }

    /* Footer */
    .footer__container {
        grid-template-columns: 1fr 1fr;
        gap: 32px;
    }

    .contact__form {
        padding: 32px 24px;
    }
}

/* Mobile: ≤ 480px */
@media (max-width: 480px) {
    .section {
        padding: 48px 0;
    }

    .section__title {
        font-size: 1.5rem;
    }

    .section__subtitle {
        font-size: 0.95rem;
        margin-bottom: 32px;
    }

    .container {
        padding: 0 16px;
    }

    /* Hero */
    .hero__title {
        font-size: 1.8rem;
    }

    .hero__subtitle {
        font-size: 0.95rem;
    }

    .hero__btn {
        padding: 14px 32px;
        font-size: 1rem;
    }

    /* Advantages */
    .advantages__grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .advantage-card {
        padding: 24px 20px;
    }

    /* Services */
    .services__table {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .service-card {
        padding: 28px 20px;
    }

    /* Process */
    .process__timeline {
        padding-left: 36px;
    }

    .process__step {
        gap: 20px;
    }

    .process__step-number {
        width: 36px;
        height: 36px;
        font-size: 0.95rem;
        margin-left: -36px;
    }

    .process__timeline::before {
        left: 16px;
    }

    /* Reviews */
    .reviews__slider {
        gap: 16px;
    }

    .review-card {
        width: 100%;
        padding: 24px 20px;
    }

    /* Contact form */
    .contact__form {
        padding: 24px 16px;
    }

    .contact__form-row {
        flex-direction: column;
        gap: 12px;
    }

    /* Footer */
    .footer__container {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .footer {
        padding: 40px 0 0;
    }

    /* Notification */
    .notification {
        padding: 14px 20px;
        max-width: calc(100% - 32px);
    }
}

/* Extra small: ≤ 360px */
@media (max-width: 360px) {
    .hero__title {
        font-size: 1.5rem;
    }

    .header__logo span {
        font-size: 1.1rem;
    }
}

/* Desktop ≥ 769px - already default styles */
@media (min-width: 769px) {
    .header__nav {
        display: block !important;
        opacity: 1 !important;
        pointer-events: auto !important;
        transform: none !important;
        position: static !important;
        border: none !important;
        padding: 0 !important;
        background: transparent !important;
    }

    .header__nav-list {
        flex-direction: row !important;
    }
}