:root {
    --background: #ffffff;
    --surface: #f5f5f7;
    --text-primary: #1d1d1f;
    --text-secondary: #86868b;
    --accent: #0071e3;
    --accent-hover: #0077ed;
    --border: #d2d2d7;
    --radius: 12px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --font-stack: "SF Pro Text", "SF Pro Icons", "Helvetica Neue", "Helvetica", "Arial", sans-serif;
}

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

body {
    font-family: var(--font-stack);
    background-color: var(--background);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: opacity 0.2s;
}

a:hover {
    text-decoration: underline;
}

/* Layout */
.container {
    max-width: 980px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 44px;
}

.logo {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 1.1rem;
    text-decoration: none;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 24px;
}

nav a {
    color: var(--text-secondary);
    font-size: 12px;
    text-decoration: none;
}

nav a:hover {
    color: var(--text-primary);
    text-decoration: none;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.mobile-menu-toggle span {
    width: 20px;
    height: 2px;
    background: var(--text-primary);
    transition: all 0.3s;
}

@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: flex;
    }
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 120px 0 80px;
    max-width: 800px;
    margin: 0 auto;
    opacity: 0;
    animation: fadeInUp 1s cubic-bezier(0.165, 0.84, 0.44, 1) forwards;
}

.hero h1 {
    font-size: 64px;
    line-height: 1.05;
    font-weight: 700;
    letter-spacing: -0.015em;
    margin-bottom: 24px;
    background: linear-gradient(135deg, #000 0%, #333 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 24px;
    line-height: 1.4;
    color: var(--text-secondary);
    font-weight: 400;
    margin-bottom: 40px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    opacity: 0;
    animation: fadeInUp 1s cubic-bezier(0.165, 0.84, 0.44, 1) forwards;
}

.delay-1 {
    animation-delay: 0.2s;
}

.delay-2 {
    animation-delay: 0.4s;
}

.delay-3 {
    animation-delay: 0.6s;
}

/* Features Section */
.section-title {
    font-size: 40px;
    font-weight: 600;
    text-align: center;
    margin-bottom: 60px;
    letter-spacing: -0.01em;
}

.features {
    padding: 100px 0;
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
    /* Thin line separator */
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    text-align: center;
}

.feature-item h4 {
    font-size: 21px;
    margin-bottom: 12px;
    font-weight: 600;
}

.feature-item p {
    font-size: 17px;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* Documents Grid override */
.grid {
    gap: 30px;
    padding: 60px 0;
}

.card {
    background: white;
    padding: 40px 30px;
    border: 1px solid rgba(0, 0, 0, 0.08);
    /* Very subtle border */
    box-shadow: none;
    /* Apple prefers subtle borders or very soft shadows */
    border-radius: 18px;
    transition: all 0.3s cubic-bezier(0.25, 1, 0.5, 1);
    text-align: center;
}

.card:hover {
    transform: scale(1.02);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.06);
    border-color: transparent;
}

.card h3 {
    font-size: 24px;
    margin-bottom: 12px;
}

/* Buttons */
.button {
    display: inline-block;
    background-color: var(--accent);
    color: white;
    padding: 8px 16px;
    border-radius: 980px;
    font-size: 14px;
    font-weight: 500;
    transition: background-color 0.2s;
    border: none;
    cursor: pointer;
}

.button:hover {
    background-color: var(--accent-hover);
    text-decoration: none;
}

.button.secondary {
    background-color: transparent;
    color: var(--accent);
    border: 1px solid var(--accent);
}

.button.secondary:hover {
    background-color: rgba(0, 113, 227, 0.1);
}

/* Cards */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    padding: 40px 0;
}

.card {
    background: var(--surface);
    padding: 30px;
    border-radius: var(--radius);
    transition: transform 0.3s ease;
}

.card:hover {
    transform: scale(1.02);
}

.card h3 {
    margin-bottom: 10px;
    font-size: 20px;
}

.card p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 20px;
}

/* Forms */
form {
    max-width: 600px;
    margin: 40px auto;
}

.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    font-size: 14px;
}

input[type="text"],
input[type="email"],
input[type="date"],
input[type="number"],
textarea,
select {
    width: 100%;
    padding: 14px 16px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    font-size: 16px;
    font-family: inherit;
    transition: border-color 0.2s;
}

input:focus,
textarea:focus,
select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 4px rgba(0, 113, 227, 0.1);
}

/* Footer */
footer {
    background: var(--surface);
    padding: 40px 0;
    font-size: 12px;
    color: var(--text-secondary);
    border-top: 1px solid var(--border);
    margin-top: 80px;
}

/* Document Result */
#result {
    margin-top: 40px;
    padding: 40px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: white;
    display: none;
}

.toolbar {
    margin-bottom: 20px;
    display: flex;
    gap: 10px;
    justify-content: flex-end;
}

/* Responsive Design */
@media (max-width: 1024px) {

    /* Tablet */
    .container {
        max-width: 100%;
        padding: 0 30px;
    }

    .hero h1 {
        font-size: 48px;
    }

    .feature-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 30px;
    }

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

@media (max-width: 768px) {

    /* Mobile */
    .container {
        padding: 0 20px;
    }

    /* Header Navigation */
    header {
        position: relative;
    }

    .nav-wrapper {
        flex-wrap: wrap;
    }

    nav ul {
        display: none;
        position: absolute;
        top: 44px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 20px;
        box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
        border-top: 1px solid rgba(0, 0, 0, 0.05);
        z-index: 100;
    }

    nav ul.active {
        display: flex;
    }

    nav ul li {
        margin: 0;
        padding: 12px 0;
        border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    }

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

    nav a {
        font-size: 14px;
        display: block;
    }

    /* Hero */
    .hero {
        padding: 80px 0 60px;
    }

    .hero h1 {
        font-size: 36px;
        line-height: 1.1;
    }

    .hero p {
        font-size: 18px;
    }

    /* Features */
    .features {
        padding: 60px 0;
    }

    .feature-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .section-title {
        font-size: 32px;
        margin-bottom: 40px;
    }

    /* Grid */
    .grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    /* Cards */
    .card {
        padding: 30px 20px;
    }

    .card h3 {
        font-size: 20px;
    }

    /* Forms */
    form {
        max-width: 100%;
    }

    input[type="text"],
    input[type="email"],
    input[type="date"],
    input[type="number"],
    textarea,
    select {
        font-size: 16px;
        /* Prevents zoom on iOS */
    }

    /* Buttons */
    .button {
        width: 100%;
        text-align: center;
        padding: 12px 20px;
    }

    .button.secondary {
        width: auto;
    }
}

@media (max-width: 480px) {

    /* Small Mobile */
    .container {
        padding: 0 16px;
    }

    .hero h1 {
        font-size: 28px;
    }

    .hero p {
        font-size: 16px;
    }

    .section-title {
        font-size: 28px;
    }

    .card {
        padding: 24px 16px;
    }
}