/* Base Reset and Variables */
:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --success-color: #16a34a;
    --error-color: #dc2626;
    --background: #ffffff;
    --background-secondary: #f9fafb;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --border-radius: 8px;
    --transition: 150ms ease;
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background-secondary);
    min-height: 100vh;
}

/* Container */
.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 1rem;
}

@media (min-width: 640px) {
    .container {
        padding: 2rem;
    }
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    line-height: 1.2;
    font-weight: 600;
}

.app-title {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

/* Utility Classes */
.hidden {
    display: none !important;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* Views */
.view {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

#login-view {
    padding: 2rem 0;
}

#posting-view {
    display: block;
    min-height: 100vh;
    padding-top: 0;
}

/* Header */
.app-header {
    background: var(--background);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    margin-bottom: 2rem;
}

.app-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 0;
    padding-bottom: 0;
}

.app-header .app-title {
    font-size: 1.5rem;
    margin-bottom: 0;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.user-domain {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
}

input[type="url"],
input[type="file"],
textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-family: inherit;
    font-size: 1rem;
    transition: border-color var(--transition), box-shadow var(--transition);
}

input[type="url"]:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

input[type="file"] {
    padding: 0.5rem;
    cursor: pointer;
}

.compose-textarea {
    resize: vertical;
    min-height: 100px;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius);
    font-family: inherit;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color var(--transition), color var(--transition), opacity var(--transition);
    text-align: center;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
    background-color: var(--primary-hover);
}

.btn-primary:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.3);
}

.btn-text {
    background: transparent;
    color: var(--text-secondary);
    padding: 0.5rem 1rem;
}

.btn-text:hover {
    color: var(--text-primary);
}

/* Messages */
.message {
    padding: 1rem;
    border-radius: var(--border-radius);
    margin-top: 1rem;
    font-size: 0.875rem;
}

.message-success {
    background-color: #d1fae5;
    color: #065f46;
    border: 1px solid #6ee7b7;
}

.message-error {
    background-color: #fee2e2;
    color: #991b1b;
    border: 1px solid #fca5a5;
}

.message a {
    color: inherit;
    text-decoration: underline;
    font-weight: 600;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.loading-content {
    background: var(--background);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    text-align: center;
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.loading-message {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 640px) {
    .app-header .container {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }

    .user-info {
        width: 100%;
        justify-content: space-between;
    }
}