:root {
    /* Base Colors & Typography */
    --font-main: 'Outfit', sans-serif;
    
    /* Light / Day Theme */
    --clr-bg: #f0f7fb;
    --clr-text: #1a202c;
    --clr-text-muted: #4a5568;
    --clr-primary: #3182ce;
    --clr-primary-hover: #2b6cb0;
    --clr-card-bg: rgba(255, 255, 255, 0.7);
    --clr-card-border: rgba(255, 255, 255, 0.5);
    --clr-nav-bg: rgba(255, 255, 255, 0.85);
    --clr-shadow: rgba(0, 0, 0, 0.05);
    --clr-gradient: linear-gradient(135deg, #a0c4ff, #cbf0f8);
    --clr-error: #e53e3e;
}

body[data-theme="night"] {
    /* Dark / Night Theme */
    --clr-bg: #1a202c;
    --clr-text: #f7fafc;
    --clr-text-muted: #a0aec0;
    --clr-primary: #63b3ed;
    --clr-primary-hover: #4299e1;
    --clr-card-bg: rgba(45, 55, 72, 0.6);
    --clr-card-border: rgba(255, 255, 255, 0.1);
    --clr-nav-bg: rgba(26, 32, 44, 0.85);
    --clr-shadow: rgba(0, 0, 0, 0.2);
    --clr-gradient: linear-gradient(135deg, #2a4365, #1a202c);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    background-color: var(--clr-bg);
    color: var(--clr-text);
    background-image: var(--clr-gradient);
    background-attachment: fixed;
    min-height: 100vh;
    transition: background 0.5s ease, color 0.5s ease;
    overflow-x: hidden;
}

/* Typography elements */
h1, h2, h3 { font-weight: 600; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* Utilities */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}
.hidden {
    display: none !important;
}

/* Buttons */
.btn {
    padding: 10px 20px;
    border-radius: 8px;
    font-family: var(--font-main);
    font-weight: 500;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
}
.btn.primary {
    background-color: var(--clr-primary);
    color: white;
}
.btn.primary:hover {
    background-color: var(--clr-primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--clr-shadow);
}
.btn.outline {
    background-color: transparent;
    border: 2px solid var(--clr-text);
    color: var(--clr-text);
}
.btn.outline:hover {
    background-color: var(--clr-text);
    color: var(--clr-bg);
}

/* Navigation Bar */
#navbar {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    background: var(--clr-nav-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px var(--clr-shadow);
    transition: all 0.3s ease;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 15px 20px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--clr-primary);
}

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-links a {
    font-weight: 500;
    position: relative;
    padding-bottom: 5px;
    transition: color 0.3s;
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: var(--clr-primary);
    transition: width 0.3s;
}

.nav-links a:hover::after {
    width: 100%;
}
.nav-links a:hover {
    color: var(--clr-primary);
}

.nav-controls {
    display: flex;
    align-items: center;
    gap: 15px;
}

/* Hamburger */
.hamburger {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--clr-text);
    cursor: pointer;
}

/* Mobile Menu */
.mobile-menu {
    position: fixed;
    top: 70px;
    left: 0;
    width: 100%;
    background: var(--clr-nav-bg);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--clr-card-border);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all 0.3s ease;
    z-index: 999;
    box-shadow: 0 4px 6px var(--clr-shadow);
}
.mobile-menu.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
}
.mobile-nav-links {
    display: flex;
    flex-direction: column;
    padding: 20px;
    gap: 20px;
}
.mobile-link {
    font-weight: 500;
    font-size: 1.2rem;
    display: block;
}

/* Hero & Search Section */
.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 70px; /* Offset for navbar */
    text-align: center;
}
.hero-content {
    max-width: 800px;
    padding: 40px 20px;
}
.hero-content h1 {
    font-size: 3.5rem;
    margin-bottom: 15px;
    line-height: 1.2;
}
.hero-content p {
    font-size: 1.2rem;
    color: var(--clr-text-muted);
    margin-bottom: 40px;
}
.search-container {
    display: flex;
    background: var(--clr-card-bg);
    border: 1px solid var(--clr-card-border);
    border-radius: 50px;
    padding: 5px 5px 5px 20px;
    backdrop-filter: blur(16px);
    box-shadow: 0 8px 32px var(--clr-shadow);
    align-items: center;
    max-width: 600px;
    margin: 0 auto;
    transition: transform 0.3s, box-shadow 0.3s;
}
.search-container:focus-within {
    transform: translateY(-3px);
    box-shadow: 0 12px 40px var(--clr-shadow);
}
.search-icon {
    color: var(--clr-text-muted);
}
#search-input {
    flex: 1;
    border: none;
    background: transparent;
    padding: 15px;
    font-size: 1.1rem;
    color: var(--clr-text);
    outline: none;
    font-family: var(--font-main);
}
#search-input::placeholder {
    color: var(--clr-text-muted);
}
.search-container .btn {
    border-radius: 40px;
    padding: 12px 30px;
}

.error-msg {
    margin-top: 20px;
    color: var(--clr-error);
    background: rgba(229, 62, 62, 0.1);
    padding: 10px 20px;
    border-radius: 8px;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 500;
    animation: fadeIn 0.3s ease;
}

/* Weather Details Section */
.weather-section {
    padding: 60px 20px;
    min-height: 80vh;
}

.weather-container {
    max-width: 1000px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
}
@media(min-width: 800px) {
    .weather-container {
        grid-template-columns: 1fr 1fr;
    }
}

.highlight-card {
    background: var(--clr-card-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--clr-card-border);
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 8px 32px var(--clr-shadow);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: transform 0.3s ease;
}
.highlight-card:hover {
    transform: translateY(-5px);
}

.top-row {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}
#city-name {
    font-size: 2rem;
    margin-bottom: 5px;
}
#current-date {
    color: var(--clr-text-muted);
}
.weather-icon-large {
    font-size: 4rem;
    color: var(--clr-primary);
}

.middle-row {
    margin: 30px 0;
}
#current-temp {
    font-size: 5rem;
    font-weight: 700;
    line-height: 1;
}
#weather-desc {
    font-size: 1.5rem;
    margin-top: 10px;
    text-transform: capitalize;
}

.bottom-row.metrics {
    display: flex;
    justify-content: space-between;
    background: rgba(0,0,0,0.05); /* slightly darker background for contrast */
    body[data-theme="night"] & {
        background: rgba(0,0,0,0.2);
    }
    padding: 20px;
    border-radius: 12px;
}
.metric {
    display: flex;
    align-items: center;
    gap: 10px;
}
.metric i {
    font-size: 1.5rem;
    color: var(--clr-primary);
}
.metric div {
    display: flex;
    flex-direction: column;
}
.metric span {
    font-size: 0.85rem;
    color: var(--clr-text-muted);
}
.metric strong {
    font-size: 1.1rem;
}

/* Weekly forecast */
.weekly-forecast {
    background: var(--clr-card-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--clr-card-border);
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 8px 32px var(--clr-shadow);
}
.weekly-forecast h3 {
    margin-bottom: 20px;
    font-size: 1.5rem;
}
.forecast-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
}
.forecast-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--clr-card-border);
}
.forecast-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
}
.forecast-day {
    flex: 1;
    font-weight: 500;
}
.forecast-icon {
    flex: 1;
    text-align: center;
    color: var(--clr-primary);
    font-size: 1.5rem;
}
.forecast-temps {
    flex: 1;
    text-align: right;
    font-weight: 600;
}
.forecast-temps span {
    color: var(--clr-text-muted);
    font-weight: 400;
    margin-left: 10px;
    font-size: 0.9rem;
}

/* About Section */
.about-section {
    padding: 100px 20px;
    background: var(--clr-card-bg);
    backdrop-filter: blur(10px);
    border-top: 1px solid var(--clr-card-border);
    border-bottom: 1px solid var(--clr-card-border);
}
.about-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 50px;
}
@media(min-width: 800px) {
    .about-container {
        flex-direction: row;
        justify-content: space-between;
    }
    .about-text, .about-image {
        flex: 1;
    }
}
.about-text h2 {
    font-size: 2.5rem;
    margin-bottom: 20px;
    color: var(--clr-primary);
}
.about-text p {
    font-size: 1.1rem;
    line-height: 1.6;
    margin-bottom: 15px;
    color: var(--clr-text-muted);
}
.about-image {
    display: flex;
    justify-content: center;
}
.blob-wrapper {
    width: 250px;
    height: 250px;
    background: var(--clr-gradient);
    border-radius: 40% 60% 70% 30% / 40% 50% 60% 50%;
    animation: morph 8s ease-in-out infinite;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 10px 30px var(--clr-shadow);
}
.large-icon {
    font-size: 5rem;
    color: white;
    filter: drop-shadow(0 4px 6px rgba(0,0,0,0.2));
}

@keyframes morph {
    0%, 100% { border-radius: 40% 60% 70% 30% / 40% 50% 60% 50%; }
    34% { border-radius: 70% 30% 50% 50% / 30% 30% 70% 70%; }
    67% { border-radius: 100% 60% 60% 100% / 100% 100% 60% 60%; }
}

/* Footer */
footer {
    padding: 60px 20px 20px;
}
.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 30px;
    text-align: center;
    border-bottom: 1px solid var(--clr-card-border);
    padding-bottom: 40px;
}
@media(min-width: 768px) {
    .footer-content {
        flex-direction: row;
        justify-content: space-between;
        text-align: left;
    }
}
.footer-brand p {
    margin-top: 10px;
    color: var(--clr-text-muted);
}
.social-cta {
    text-align: center;
}
@media(min-width: 768px) {
    .social-cta { text-align: right; }
}

.social-links {
    margin-bottom: 20px;
    display: flex;
    gap: 15px;
    justify-content: center;
}
@media(min-width: 768px) {
    .social-links { justify-content: flex-end; }
}
.social-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--clr-card-bg);
    border: 1px solid var(--clr-card-border);
    font-size: 1.2rem;
    transition: all 0.3s ease;
}
.social-links a:hover {
    background: var(--clr-primary);
    color: white;
    transform: translateY(-3px);
}
.demo-links {
    display: flex;
    gap: 20px;
    font-size: 0.9rem;
    color: var(--clr-text-muted);
}
.demo-links a:hover {
    color: var(--clr-primary);
    text-decoration: underline;
}
.footer-bottom {
    text-align: center;
    padding-top: 20px;
    color: var(--clr-text-muted);
    font-size: 0.9rem;
}

/* Back to Top */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--clr-primary);
    color: white;
    border: none;
    font-size: 1.2rem;
    cursor: pointer;
    box-shadow: 0 4px 15px var(--clr-shadow);
    transition: all 0.3s ease;
    z-index: 99;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
}
.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}
.back-to-top:hover {
    background: var(--clr-primary-hover);
    transform: translateY(-5px);
}

/* Responsive Overrides */
@media (max-width: 768px) {
    .nav-links { display: none; }
    .hamburger { display: block; }
    .hero-content h1 { font-size: 2.5rem; }
    .bottom-row.metrics {
        flex-direction: column;
        gap: 15px;
        align-items: flex-start;
    }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Mouse Glow Effect */
.mouse-glow {
    position: fixed;
    top: 0;
    left: 0;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle closest-side, rgba(255, 255, 255, 0.15), transparent);
    /* In dark mode, we will make it a subtle blue/cyan glow */
    border-radius: 50%;
    transform: translate(calc(var(--mouse-x, -1000px) - 50%), calc(var(--mouse-y, -1000px) - 50%));
    pointer-events: none;
    z-index: 1; /* Below the main interactive content */
    mix-blend-mode: soft-light;
    opacity: 0;
    transition: opacity 0.5s ease;
}

body:hover .mouse-glow {
    opacity: 1; /* Fade in when mouse is over the page */
}

body[data-theme="night"] .mouse-glow {
    background: radial-gradient(circle closest-side, rgba(99, 179, 237, 0.08), transparent);
    mix-blend-mode: color-dodge;
}