/* =====================================================================
   TargaSystem Messenger - Landing Page Styles
   ===================================================================== */

/* --- CSS Variables --- */
:root {
    --primary: #1a237e;
    --primary-light: #3949ab;
    --primary-dark: #0d1442;
    --accent: #42a5f5;
    --accent-light: #80d6ff;
    --accent-dark: #0077c2;
    --bg: #ffffff;
    --bg-alt: #f8f9fc;
    --bg-dark: #0d1b2a;
    --text: #212121;
    --text-secondary: #616161;
    --text-light: #e0e0e0;
    --border: #e0e0e0;
    --shadow: 0 2px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.12);
    --radius: 12px;
    --radius-sm: 8px;
    --radius-lg: 20px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --max-width: 1200px;
}

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

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

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

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

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

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

/* --- Container --- */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* --- Buttons --- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 28px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.95rem;
    font-family: var(--font);
    cursor: pointer;
    border: 2px solid transparent;
    transition: var(--transition);
    text-decoration: none;
    white-space: nowrap;
}

.btn--primary {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

.btn--primary:hover {
    background: var(--primary-light);
    border-color: var(--primary-light);
    color: #fff;
    transform: translateY(-1px);
    box-shadow: 0 4px 20px rgba(26, 35, 126, 0.3);
}

.btn--outline {
    background: transparent;
    color: var(--primary);
    border-color: var(--primary);
}

.btn--outline:hover {
    background: var(--primary);
    color: #fff;
    transform: translateY(-1px);
}

.btn--large {
    padding: 16px 36px;
    font-size: 1.05rem;
}

/* --- Section Title --- */
.section__title {
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--primary-dark);
    margin-bottom: 12px;
    text-align: center;
}

.section__subtitle {
    font-size: 1.15rem;
    color: var(--text-secondary);
    text-align: center;
    max-width: 600px;
    margin: 0 auto 48px;
}

/* ===================================================================
   HEADER
   =================================================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    padding: 0 0;
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

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

.header__logo-img {
    height: 40px;
    width: auto;
    object-fit: contain;
}

.header__icon {
    width: 36px;
    height: 36px;
}

.header__brand {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--primary);
}

.header__nav {
    display: flex;
    gap: 32px;
}

.header__nav a {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: var(--transition);
}

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

/* ===================================================================
   HERO
   =================================================================== */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(135deg, #f8f9fc 0%, #e8eaf6 50%, #e3f2fd 100%);
    overflow: hidden;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero__title {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.15;
    color: var(--primary-dark);
    margin-bottom: 20px;
}

.hero__highlight {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero__subtitle {
    font-size: 1.15rem;
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.7;
}

.hero__cta {
    display: flex;
    gap: 16px;
    margin-bottom: 48px;
    flex-wrap: wrap;
}

.hero__stats {
    display: flex;
    gap: 40px;
}

.stat {
    text-align: center;
}

.stat__number {
    display: block;
    font-size: 1.6rem;
    font-weight: 800;
    color: var(--primary);
}

.stat__label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Chat Preview */
.chat-preview {
    background: #fff;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    transform: perspective(1000px) rotateY(-5deg) rotateX(2deg);
    transition: var(--transition);
}

.chat-preview:hover {
    transform: perspective(1000px) rotateY(0deg) rotateX(0deg);
}

.chat-preview__header {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 14px 20px;
    background: var(--primary-dark);
}

.chat-preview__dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.chat-preview__dot--red { background: #ff5f56; }
.chat-preview__dot--yellow { background: #ffbd2e; }
.chat-preview__dot--green { background: #27c93f; }

.chat-preview__title {
    color: #fff;
    font-size: 0.85rem;
    font-weight: 600;
    margin-left: 8px;
}

.chat-preview__body {
    padding: 24px 20px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.chat-msg {
    display: flex;
    gap: 12px;
    max-width: 85%;
}

.chat-msg--sent {
    align-self: flex-end;
    flex-direction: row-reverse;
}

.chat-msg__avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.85rem;
    flex-shrink: 0;
}

.chat-msg__content {
    background: var(--bg-alt);
    padding: 10px 16px;
    border-radius: var(--radius-sm);
    position: relative;
}

.chat-msg--sent .chat-msg__content {
    background: #e3f2fd;
}

.chat-msg__name {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--primary);
    display: block;
    margin-bottom: 4px;
}

.chat-msg__content p {
    font-size: 0.9rem;
    line-height: 1.5;
    color: var(--text);
}

.chat-msg__time {
    font-size: 0.7rem;
    color: var(--text-secondary);
    display: block;
    text-align: right;
    margin-top: 4px;
}

.chat-preview__encrypted {
    display: flex;
    align-items: center;
    gap: 6px;
    justify-content: center;
    padding: 10px;
    background: #e8f5e9;
    color: #2e7d32;
    font-size: 0.8rem;
    font-weight: 500;
    border-radius: var(--radius-sm);
}

/* ===================================================================
   FEATURES
   =================================================================== */
.features {
    padding: 100px 0;
    background: var(--bg);
}

.features__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.feature-card {
    padding: 36px 28px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    transition: var(--transition);
    background: #fff;
}

.feature-card:hover {
    border-color: var(--accent);
    box-shadow: var(--shadow);
    transform: translateY(-4px);
}

.feature-card__icon {
    width: 48px;
    height: 48px;
    background: #e8eaf6;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.feature-card__icon svg {
    width: 24px;
    height: 24px;
    stroke: var(--primary);
}

.feature-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--primary-dark);
    margin-bottom: 10px;
}

.feature-card p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===================================================================
   SECURITY
   =================================================================== */
.security {
    padding: 100px 0;
    background: var(--bg-alt);
}

.security__grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    margin-top: 40px;
}

.security__item {
    display: flex;
    gap: 16px;
    padding: 24px;
    background: #fff;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    transition: var(--transition);
}

.security__item:hover {
    border-color: #4caf50;
    box-shadow: var(--shadow);
}

.security__check {
    width: 36px;
    height: 36px;
    background: #e8f5e9;
    color: #2e7d32;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    flex-shrink: 0;
}

.security__item h4 {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--primary-dark);
    margin-bottom: 4px;
}

.security__item p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* ===================================================================
   DOWNLOAD
   =================================================================== */
.download {
    padding: 100px 0;
    background: var(--bg);
}

.download__grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-bottom: 48px;
}

.download-card {
    text-align: center;
    padding: 36px 24px;
    border-radius: var(--radius);
    border: 2px solid var(--border);
    transition: var(--transition);
    display: block;
    color: var(--text);
}

.download-card:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow);
    transform: translateY(-4px);
    color: var(--primary);
}

.download-card svg {
    width: 48px;
    height: 48px;
    stroke: var(--primary);
    margin-bottom: 16px;
}

.download-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.download-card p {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.download__config {
    text-align: center;
    padding: 32px;
    background: var(--bg-alt);
    border-radius: var(--radius);
    border: 1px solid var(--border);
}

.download__config h3 {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--primary-dark);
    margin-bottom: 8px;
}

.download__config p {
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.download__server {
    display: inline-block;
    background: var(--primary-dark);
    color: var(--accent-light);
    padding: 12px 24px;
    border-radius: var(--radius-sm);
    font-family: 'Courier New', monospace;
    font-size: 1.05rem;
    font-weight: 600;
    user-select: all;
}

/* ===================================================================
   CONTACT
   =================================================================== */
.contact {
    padding: 100px 0;
    background: var(--bg-alt);
}

.contact__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.contact-card {
    text-align: center;
    padding: 40px 24px;
    background: #fff;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    transition: var(--transition);
}

.contact-card:hover {
    border-color: var(--accent);
    box-shadow: var(--shadow);
}

.contact-card svg {
    width: 40px;
    height: 40px;
    stroke: var(--primary);
    margin-bottom: 16px;
}

.contact-card h3 {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--primary-dark);
}

.contact-card a {
    color: var(--accent-dark);
    font-weight: 500;
}

.contact-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* ===================================================================
   FOOTER
   =================================================================== */
.footer {
    background: var(--bg-dark);
    color: var(--text-light);
    padding: 60px 0 30px;
}

.footer__top {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 40px;
}

.footer__brand {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.2rem;
    font-weight: 700;
    color: #fff;
}

.footer__icon {
    width: 32px;
    height: 32px;
}

.footer__desc {
    max-width: 400px;
    font-size: 0.9rem;
    color: #90a4ae;
    line-height: 1.6;
}

.footer__links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    padding-bottom: 40px;
    border-bottom: 1px solid #263238;
}

.footer__links h4 {
    font-size: 0.95rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 16px;
}

.footer__links a {
    display: block;
    color: #90a4ae;
    font-size: 0.9rem;
    margin-bottom: 10px;
    transition: var(--transition);
}

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

.footer__bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 24px;
    font-size: 0.85rem;
    color: #607d8b;
}

.footer__bottom a {
    color: var(--accent);
}

/* ===================================================================
   RESPONSIVE
   =================================================================== */
@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero__cta {
        justify-content: center;
    }

    .hero__stats {
        justify-content: center;
    }

    .hero__visual {
        max-width: 500px;
        margin: 0 auto;
    }

    .chat-preview {
        transform: none;
    }

    .features__grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .download__grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .header__nav {
        display: none;
    }

    .hero__title {
        font-size: 2rem;
    }

    .section__title {
        font-size: 1.7rem;
    }

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

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

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

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

    .footer__links {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .footer__bottom {
        flex-direction: column;
        gap: 8px;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 110px 0 60px;
    }

    .hero__title {
        font-size: 1.7rem;
    }

    .hero__cta {
        flex-direction: column;
        align-items: center;
    }

    .hero__stats {
        flex-direction: column;
        gap: 16px;
    }

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

    .btn--large {
        width: 100%;
        justify-content: center;
    }
}