/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2196F3;
    --secondary-color: #03DAC5;
    --background: #F5F5F5;
    --text-dark: #212121;
    --text-light: #757575;
    --white: #FFFFFF;
    --success: #4CAF50;
    --warning: #FFC107;
    --card-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --card-shadow-hover: 0 8px 12px rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--background);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.navbar {
    background: var(--white);
    box-shadow: var(--card-shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.nav-brand .logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s;
}

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

.nav-buy-btn {
    background: var(--primary-color) !important;
    color: var(--white) !important;
    padding: 0.5rem 1.5rem !important;
    border-radius: 50px !important;
    font-weight: 600 !important;
}

/* Logo Images */
.logo-img {
    height: 50px;
    width: auto;
    display: block;
}

.logo-img-footer {
    height: 60px;
    width: auto;
    margin-bottom: 0.5rem;
}

/* Mobile Menu Button */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 5px;
    z-index: 1001;
}

.mobile-menu-btn span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    border-radius: 3px;
    transition: all 0.3s;
}

.mobile-menu-btn.active span:nth-child(1) {
    transform: rotate(45deg) translate(7px, 7px);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--white);
    padding: 6rem 0;
    min-height: 80vh;
    display: flex;
    align-items: center;
}

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

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

.hero-subtitle {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 2rem;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
}

.btn {
    padding: 1rem 2rem;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 50px;
    text-decoration: none;
    transition: all 0.3s;
    display: inline-block;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    background: transparent;
    color: var(--white);
    border: 2px solid var(--white);
}

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

/* Phone Mockup */
.phone-mockup {
    background: #1a1a1a;
    border-radius: 40px;
    padding: 12px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    max-width: 350px;
    margin: 0 auto;
}

.phone-screen {
    background: var(--white);
    border-radius: 30px;
    overflow: hidden;
    aspect-ratio: 9/19.5;
}

.app-preview {
    padding: 20px;
    background: var(--background);
    height: 100%;
}

.status-bar {
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-dark);
    margin-bottom: 10px;
}

.app-header {
    background: var(--primary-color);
    color: var(--white);
    padding: 15px;
    border-radius: 8px;
    text-align: center;
    font-weight: bold;
    font-size: 1.1rem;
    margin-bottom: 15px;
}

.connected-badge {
    background: var(--success);
    color: var(--white);
    padding: 10px 15px;
    border-radius: 8px;
    text-align: center;
    font-weight: 600;
    margin-bottom: 15px;
}

.water-stats {
    text-align: center;
    font-size: 1.8rem;
    font-weight: bold;
    color: var(--primary-color);
    margin: 15px 0;
}

.water-bottle-graphic {
    display: flex;
    justify-content: center;
    margin: 20px 0;
}

.bottle {
    width: 80px;
    height: 120px;
    background: var(--white);
    border: 3px solid var(--primary-color);
    border-radius: 8px;
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.water-fill {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(33, 150, 243, 0.5);
    transition: height 0.3s;
}

.plus-button {
    position: relative;
    z-index: 2;
    background: var(--primary-color);
    color: var(--white);
    width: 35px;
    height: 35px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: bold;
}

.settings-card {
    background: var(--white);
    border-radius: 8px;
    padding: 12px;
    margin-top: 15px;
}

.setting-row {
    display: flex;
    justify-content: space-between;
    padding: 8px 0;
    font-size: 0.85rem;
}

.setting-row:first-child {
    border-bottom: 1px solid var(--background);
}

.setting-row span:last-child {
    color: var(--primary-color);
    font-weight: bold;
}

/* Sections */
.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 3rem;
    color: var(--text-dark);
}

/* Features Section */
.features {
    padding: 6rem 0;
    background: var(--white);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--background);
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    transition: all 0.3s;
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--card-shadow-hover);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.8;
}

/* How It Works Section */
.how-it-works {
    padding: 6rem 0;
    background: var(--background);
}

.steps {
    display: flex;
    flex-direction: column;
    gap: 3rem;
    max-width: 800px;
    margin: 0 auto;
}

.step {
    display: flex;
    gap: 2rem;
    align-items: flex-start;
}

.step-number {
    background: var(--primary-color);
    color: var(--white);
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: bold;
    flex-shrink: 0;
}

.step-content h3 {
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
}

.step-content p {
    color: var(--text-light);
    font-size: 1.1rem;
}

/* Specs Section */
.specs {
    padding: 6rem 0;
    background: var(--white);
}

.specs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.spec-category {
    background: var(--background);
    padding: 2rem;
    border-radius: 12px;
}

.spec-category h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.spec-category ul {
    list-style: none;
}

.spec-category li {
    padding: 0.8rem 0;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    color: var(--text-light);
}

.spec-category li:last-child {
    border-bottom: none;
}

.spec-category strong {
    color: var(--text-dark);
}

/* Download Section */
.download {
    padding: 6rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--white);
    text-align: center;
}

.download .section-title {
    color: var(--white);
}

.download-subtitle {
    font-size: 1.25rem;
    margin-bottom: 3rem;
    opacity: 0.9;
}

.download-buttons {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2rem;
}

.download-btn {
    background: var(--white);
    color: var(--text-dark);
    padding: 1.5rem 2.5rem;
    border-radius: 12px;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: all 0.3s;
    box-shadow: var(--card-shadow);
}

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

.download-icon {
    font-size: 2.5rem;
}

.download-text {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.download-label {
    font-size: 0.9rem;
    color: var(--text-light);
}

.download-platform {
    font-size: 1.3rem;
    font-weight: bold;
}

.open-source-note {
    margin-top: 2rem;
    opacity: 0.9;
}

/* Footer */
.footer {
    background: var(--text-dark);
    color: var(--white);
    padding: 3rem 0 1rem;
}

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

.footer-brand .logo {
    font-size: 1.5rem;
    color: var(--white);
}

.footer-brand p {
    margin-top: 0.5rem;
    opacity: 0.8;
}

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

.footer-column h4 {
    margin-bottom: 1rem;
    color: var(--secondary-color);
}

.footer-column a {
    display: block;
    color: var(--white);
    text-decoration: none;
    margin-bottom: 0.5rem;
    opacity: 0.8;
    transition: opacity 0.3s;
}

.footer-column a:hover {
    opacity: 1;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    opacity: 0.6;
}

/* Responsive Design */
@media (max-width: 968px) {
    .navbar .container {
        flex-wrap: nowrap;
        justify-content: space-between;
        align-items: center;
    }

    .mobile-menu-btn {
        display: flex;
        order: 2;
    }

    .nav-menu {
        position: fixed;
        top: 73px;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        gap: 0;
        margin: 0;
        padding: 1rem 0;
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
        z-index: 1000;
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-menu li {
        width: 100%;
        text-align: center;
        border-bottom: 1px solid var(--background);
    }

    .nav-menu li:last-child {
        border-bottom: none;
    }

    .nav-menu a {
        display: block;
        padding: 1rem;
    }

    .hero {
        padding: 3rem 0;
        min-height: auto;
    }

    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }

    .hero-title {
        font-size: 2rem;
        line-height: 1.3;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-buttons {
        flex-direction: column;
        justify-content: center;
        gap: 0.8rem;
    }

    .btn {
        width: 100%;
        text-align: center;
    }

    .phone-mockup {
        max-width: 280px;
    }

    .features {
        padding: 3rem 0;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .how-it-works {
        padding: 3rem 0;
    }

    .step {
        flex-direction: column;
        text-align: center;
        gap: 1rem;
    }

    .specs {
        padding: 3rem 0;
    }

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

    .download {
        padding: 3rem 0;
    }

    .download-buttons {
        flex-direction: column;
        align-items: stretch;
        width: 100%;
    }

    .download-btn {
        width: 100%;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .footer-links {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

@media (max-width: 640px) {
    .container {
        padding: 0 15px;
    }

    .navbar .container {
        padding: 0.8rem 15px;
    }

    .nav-brand .logo {
        font-size: 1.2rem;
    }

    .hero {
        padding: 2rem 0;
    }

    .hero-title {
        font-size: 1.75rem;
    }

    .hero-subtitle {
        font-size: 0.95rem;
    }

    .btn {
        padding: 0.9rem 1.5rem;
        font-size: 1rem;
    }

    .section-title {
        font-size: 1.75rem;
        margin-bottom: 2rem;
    }

    .feature-card {
        padding: 1.5rem;
    }

    .feature-icon {
        font-size: 2.5rem;
    }

    .feature-card h3 {
        font-size: 1.25rem;
    }

    .step-number {
        width: 50px;
        height: 50px;
        font-size: 1.25rem;
    }

    .step-content h3 {
        font-size: 1.4rem;
    }

    .step-content p {
        font-size: 1rem;
    }

    .download-icon {
        font-size: 2rem;
    }

    .download-platform {
        font-size: 1.1rem;
    }

    .footer {
        padding: 2rem 0 1rem;
    }

    .footer-brand .logo {
        font-size: 1.2rem;
    }
}