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

/* Variáveis CSS para temas */
:root {
    /* Tema Claro - Inspirado em luz solar e tons pastéis vibrantes */
    --background: linear-gradient(135deg, #fef9e7, #e0f7fa);
    --text-color: #2d3748;
    --navbar-bg: #ffffff;
    --navbar-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
    --hero-bg: linear-gradient(to right, #ff6f61, #ff6f61, #ff6f61);
    --hero-text: #fff;
    --card-bg: #ffffff;
    --card-shadow: 0 8px 25px rgba(255, 111, 97, 0.2);
    --input-border: #b2ebf2;
    --label-color: #ff6f61;
    --btn-convert-bg: #ff6f61;
    --btn-convert-hover: #e65a50;
    --btn-save-bg: #40c4ff;
    --btn-save-hover: #33a8db;
    --result-bg: #e0f7fa;
    --result-border: 2px dashed #ffccbc;
    --result-text: #4a5568;
    --history-bg: #fef9e7;
    --history-item-bg: #fff5f5;
    --history-item-border: #ff6f61;
    --footer-bg: linear-gradient(to right, #ff6f61, #ff6f61, #ff6f61);
    --footer-text: #fff;
    --history-item-border-frequency: #00bcd4; /* Cyan for frequency */
    --history-item-border-voltage: #ff9800;
    --history-item-border-density: #4caf50;
}

[data-theme="dark"] {
    /* Tema Escuro - Inspirado em céu noturno com texto realçado */
    --background: linear-gradient(135deg, #0d1b2a, #1b263b);
    --text-color: #f1f5f9; /* Branco quase puro para máximo contraste */
    --navbar-bg: #1b263b;
    --navbar-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
    --hero-bg: linear-gradient(to right, #6b7280, #2d3748);
    --hero-text: #ffffff; /* Branco puro com sombra */
    --card-bg: #1b263b;
    --card-shadow: 0 8px 25px rgba(107, 114, 128, 0.5);
    --input-border: #778da9;
    --label-color: #bfdbfe; /* Azul claro vibrante */
    --btn-convert-bg: #a3bffa;
    --btn-convert-hover: #7f9cf5;
    --btn-save-bg: #68d391;
    --btn-save-hover: #4caf70;
    --result-bg: #0d1b2a;
    --result-border: 2px dashed #bfdbfe; /* Azul claro vibrante */
    --result-text: #e5e7eb; /* Cinza claro brilhante */
    --history-bg: #1b263b;
    --history-item-bg: #2d3748;
    --history-item-border: #68d391;
    --footer-bg: linear-gradient(to right, #6b7280, #2d3748);
    --footer-text: #ffffff; /* Branco puro */
    --history-item-border-frequency: #26c6da;
    --history-item-border-voltage: #ffb300;
    --history-item-border-density: #66bb6a;
}

/* Corpo da página */
body {
    font-family: 'Poppins', sans-serif;
    background: var(--background);
    color: var(--text-color);
    line-height: 1.6;
    transition: all 0.4s ease;
}

/* Realce de texto no modo escuro */
[data-theme="dark"] h1,
[data-theme="dark"] h2,
[data-theme="dark"] h3,
[data-theme="dark"] h4,
[data-theme="dark"] p,
[data-theme="dark"] label,
[data-theme="dark"] .navbar-brand,
[data-theme="dark"] .form-select,
[data-theme="dark"] .form-control,
[data-theme="dark"] .history-list li {
    text-shadow: 0 1px 4px rgba(163, 191, 250, 0.5); /* Sombra azul clara sutil */
}

/* Navbar */
.navbar {
    background: var(--navbar-bg);
    box-shadow: var(--navbar-shadow);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar-brand {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--label-color);
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: color 0.3s ease;
}

.navbar-brand:hover {
    color: var(--btn-convert-hover);
}

.navbar-options {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.navbar.scrolled {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}



.language-select {
    width: 150px;
    border-radius: 25px;
    padding: 0.6rem;
    background: var(--result-bg);
    border: 1px solid var(--input-border);
    color: var(--text-color);
    font-weight: 500;
    transition: transform 0.2s ease;
}

.language-select:hover {
    transform: scale(1.05);
}

.theme-toggle {
    background: none;
    border: none;
    font-size: 1.8rem;
    cursor: pointer;
    padding: 0.5rem;
    color: var(--label-color);
    transition: transform 0.3s ease;
}

.theme-toggle:hover {
    transform: rotate(15deg);
}

.theme-toggle .moon {
    display: none;
}

[data-theme="dark"] .theme-toggle .sun {
    display: none;
}

[data-theme="dark"] .theme-toggle .moon {
    display: inline;
}

/* Hero Section */
.hero {
    background: var(--hero-bg);
    color: var(--hero-text);
    padding: 5rem 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.2), transparent 70%);
    opacity: 0.5;
    z-index: 0;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    position: relative;
    z-index: 1;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
    animation: fadeInUp 1s ease-out;
}

[data-theme="dark"] .hero h1 {
    text-shadow: 0 2px 12px rgba(163, 191, 250, 0.7); /* Sombra mais forte no dark */
}

.hero .lead {
    font-size: 1.4rem;
    opacity: 0.9;
    position: relative;
    z-index: 1;
    animation: fadeInUp 1.2s ease-out 0.2s;
    animation-fill-mode: both;
}

/* Conversion Section */
.conversion-section {
    padding: 4rem 0;
}

.conversion-card {
    background: var(--card-bg);
    padding: 2.5rem;
    border-radius: 20px;
    box-shadow: var(--card-shadow);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.conversion-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 12px 35px rgba(0, 0, 0, 0.15);
}

.form-label {
    font-weight: 600;
    color: var(--label-color);
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.form-select, .form-control {
    border-radius: 12px;
    border: 2px solid var(--input-border);
    padding: 0.9rem;
    margin-bottom: 1.2rem;
    background: var(--result-bg);
    color: var(--text-color);
    font-size: 1rem;
    transition: border-color 0.3s ease, transform 0.2s ease;
    
}

.form-select:focus, .form-control:focus {
    border-color: var(--label-color);
    transform: scale(1.02);
    outline: none;
}


.button-group {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
}

.btn-convert, .btn-save {
    border: none;
    padding: 0.9rem 2.5rem;
    border-radius: 30px;
    color: #fff;
    font-weight: 600;
    font-size: 1.1rem;
    transition: transform 0.3s ease, background 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
}

.btn-convert {
    background: var(--btn-convert-bg);
}

.btn-convert:hover {
    background: var(--btn-convert-hover);
    transform: scale(1.1);
    box-shadow: 0 5px 15px rgba(163, 191, 250, 0.4); /* Sombra azul no dark */
}

.btn-save {
    background: var(--btn-save-bg);
}

.btn-save:hover {
    background: var(--btn-save-hover);
    transform: scale(1.1);
    box-shadow: 0 5px 15px rgba(104, 211, 145, 0.4); /* Sombra verde no dark */
}

.result-box {
    background: var(--result-bg);
    padding: 1.8rem;
    border-radius: 15px;
    border: var(--result-border);
    font-size: 1.2rem;
    color: var(--result-text);
    margin-top: 1.5rem;
    transition: transform 0.3s ease;
}

.result-box:hover {
    transform: scale(1.02);
}

/* History Section */
.history-section {
    padding: 4rem 0;
    background: var(--history-bg);
}

.history-section h2 {
    color: var(--label-color);
    font-weight: 700;
    font-size: 2.5rem;
    margin-bottom: 2.5rem;
    text-align: center;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    animation: fadeInUp 1s ease-out;
}

[data-theme="dark"] .history-section h2 {
    text-shadow: 0 2px 12px rgba(163, 191, 250, 0.7); /* Sombra mais forte no dark */
}

.history-list {
    list-style: none;
    padding: 0;
}

.history-list li {
    background: var(--history-item-bg);
    padding: 1.2rem;
    margin-bottom: 1rem;
    border-radius: 12px;
    border-left: 6px solid var(--history-item-border);
    font-size: 1.1rem;
    color: var(--text-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.history-list li:hover {
    transform: translateX(10px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.history-list li::before {
    content: '✔️'; /* Ou um ícone de sua escolha */
    margin-right: 10px;
}

.history-list li.frequency {
    border-left: 6px solid var(--history-item-border-frequency);
}

.history-list li.voltage {
    border-left: 6px solid var(--history-item-border-voltage);
}

.history-list li.density {
    border-left: 6px solid var(--history-item-border-density);
}

/* Footer */
.footer {
    background: var(--footer-bg);
    color: var(--footer-text);
    padding: 2rem 0;
    text-align: center;
    font-size: 1rem;
    position: relative;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1), transparent 70%);
    opacity: 0.5;
    z-index: 0;
}

.footer p {
    position: relative;
    z-index: 1;
}

/* Animações */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.history-list li {
    animation: slideIn 0.5s ease forwards;
}

/* Responsividade */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.2rem;
    }

    .hero .lead {
        font-size: 1.1rem;
    }

    .conversion-card {
        padding: 2rem;
    }

    .button-group {
        flex-direction: column;
        gap: 1rem;
    }

    .btn-convert, .btn-save {
        width: 100%;
    }

    .history-section h2 {
        font-size: 2rem;
    }
}