:root {
    --bg-color: #080b11;
    --card-bg: rgba(17, 24, 39, 0.85);
    --border-color: rgba(255, 255, 255, 0.12);
    --border-hover: rgba(56, 189, 248, 0.5);
    --accent-color: #38bdf8;
    --accent-secondary: #818cf8;
    --accent-glow: rgba(56, 189, 248, 0.2);
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --btn-gradient: linear-gradient(135deg, #3b82f6 0%, #06b6d4 100%);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Plus Jakarta Sans', sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    background-image: radial-gradient(circle at 50% 0%, #1e1b4b 0%, transparent 40%);
}

/* Navbar */
.navbar {
    width: 100%;
    border-bottom: 1px solid var(--border-color);
    padding: 1.2rem 2.5rem;
    background: rgba(8, 11, 17, 0.9);
    backdrop-filter: blur(16px);
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 800;
    font-size: 1.6rem;
    letter-spacing: -0.5px;
}

.logo-icon-wrapper {
    background: linear-gradient(135deg, #1e293b, #0f172a);
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    border-radius: 10px;
    font-size: 1.3rem;
}

.badge {
    background: var(--btn-gradient);
    color: #ffffff;
    font-size: 0.75rem;
    padding: 3px 8px;
    border-radius: 6px;
    font-weight: 800;
    margin-left: 6px;
    letter-spacing: 0.5px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 1rem;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--text-main);
}

.nav-btn-highlight {
    background: var(--accent-glow);
    border: 1px solid var(--accent-color);
    color: var(--accent-color) !important;
    padding: 0.7rem 1.4rem;
    border-radius: 10px;
    font-weight: 600;
    transition: all 0.2s;
}

.nav-btn-highlight:hover {
    background: var(--accent-color);
    color: #080b11 !important;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 5rem 1.5rem 3rem 1.5rem;
    max-width: 900px;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1.2rem;
    letter-spacing: -1px;
}

.gradient-text {
    background: linear-gradient(135deg, #38bdf8 0%, #818cf8 50%, #c084fc 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    color: var(--text-muted);
    font-size: 1.2rem;
    line-height: 1.6;
}

/* Features Section (Centered 3-Column Layout) */
.features-section {
    max-width: 1200px;
    margin: 2rem auto 5rem auto;
    padding: 0 2rem;
    width: 100%;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.2rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
}

.section-header p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

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

@media(max-width: 900px) {
    .features-grid {
        grid-template-columns: 1fr;
    }
}

.feature-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: 2.5rem 2rem;
    border-radius: 20px;
    backdrop-filter: blur(12px);
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    transition: all 0.3s ease;
}

.feature-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.5);
}

.f-icon {
    font-size: 2.2rem;
    background: rgba(56, 189, 248, 0.1);
    border: 1px solid rgba(56, 189, 248, 0.2);
    width: 70px;
    height: 70px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 16px;
    margin-bottom: 1.5rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.8rem;
    color: var(--text-main);
}

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

/* Calculator Section (Centered & Spacious) */
.calculator-section {
    max-width: 800px;
    margin: 0 auto 6rem auto;
    padding: 0 2rem;
    width: 100%;
}

.calculator-container {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: 3.5rem;
    border-radius: 24px;
    backdrop-filter: blur(16px);
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.6);
}

.calc-header {
    margin-bottom: 2.5rem;
    text-align: center;
}

.calc-header h2 {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
}

.calc-header p {
    color: var(--text-muted);
    font-size: 1.05rem;
}

.input-grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

@media(max-width: 650px) {
    .input-grid-2 {
        grid-template-columns: 1fr;
    }
}

.input-group {
    margin-bottom: 1.8rem;
}

.input-group label {
    display: block;
    font-size: 1.05rem;
    color: var(--text-main);
    margin-bottom: 0.6rem;
    font-weight: 700;
}

.input-group input {
    width: 100%;
    padding: 1.1rem 1.2rem;
    background: rgba(15, 23, 42, 0.9);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    color: var(--text-main);
    font-size: 1.2rem;
    font-weight: 600;
    outline: none;
    transition: all 0.2s ease;
}

.input-group input:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 4px var(--accent-glow);
}

/* Primary Button */
.primary-btn {
    width: 100%;
    padding: 1.2rem;
    background: var(--btn-gradient);
    color: #ffffff;
    border: none;
    border-radius: 14px;
    font-weight: 800;
    font-size: 1.15rem;
    cursor: pointer;
    transition: all 0.2s ease;
    margin-top: 1rem;
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.4);
}

.primary-btn:hover {
    opacity: 0.95;
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(59, 130, 246, 0.6);
}

/* Results Card */
.results-card {
    margin-top: 2.5rem;
    background: rgba(56, 189, 248, 0.05);
    border: 1px solid rgba(56, 189, 248, 0.35);
    padding: 2rem;
    border-radius: 18px;
}

.results-card h3 {
    font-size: 1.3rem;
    font-weight: 800;
    margin-bottom: 1.2rem;
    color: var(--accent-color);
    text-align: center;
}

.result-item {
    display: flex;
    justify-content: space-between;
    font-size: 1.05rem;
    margin-bottom: 0.9rem;
    color: var(--text-muted);
}

.result-item strong {
    color: var(--text-main);
    font-size: 1.1rem;
}

.highlight-share {
    border-top: 1px solid rgba(255, 255, 255, 0.15);
    padding-top: 1.2rem;
    margin-top: 1.2rem;
    font-size: 1.2rem;
}

.highlight-share strong {
    color: var(--accent-color);
    font-size: 1.5rem;
    font-weight: 900;
}

.result-subtext {
    margin-top: 1.2rem;
    font-size: 0.95rem;
    color: var(--text-muted);
    font-style: italic;
    text-align: center;
}

.hidden {
    display: none;
}

/* Footer */
footer {
    width: 100%;
    text-align: center;
    padding: 2.5rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-top: auto;
}