:root {
    --ph-blue: #1A1A5F;       /* Deep Blue from screenshot */
    --ph-blue-light: #2B2B8A;
    --ph-bg: #F5F7FA;
    --ph-white: #FFFFFF;
    --ph-text-dark: #333333;
    --ph-text-light: #888888;
    --ph-orange: #FF8C00;
    --ph-green: #28a745;
    --ph-red: #dc3545;
    --font-main: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: var(--font-main); }

body {
    background-color: var(--ph-blue);
    display: flex;
    justify-content: center;
    min-height: 100vh;
}

.app-container {
    width: 100%;
    max-width: 480px; /* Locks width on desktop */
    background-color: var(--ph-bg);
    min-height: 100vh;
    position: relative;
    padding-bottom: 70px;
    overflow-x: hidden;
    box-shadow: 0 0 20px rgba(0,0,0,0.3);
}

/* Headers */
.top-header, .page-header {
    background: var(--ph-blue);
    color: white;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.user-info { display: flex; align-items: center; gap: 10px; }
.avatar { width: 40px; height: 40px; background: var(--ph-blue-light); border-radius: 50%; display: flex; justify-content: center; align-items: center; font-size: 1.2rem; }
.user-details h2 { font-size: 1rem; }
.user-details p { font-size: 0.75rem; color: #aaa; }

/* Bottom Nav */
.bottom-nav {
    position: fixed;
    bottom: 0;
    width: 100%;
    max-width: 480px;
    background: var(--ph-blue);
    display: flex;
    justify-content: space-around;
    padding: 10px 0;
    z-index: 100;
    border-top: 1px solid rgba(255,255,255,0.1);
}
.nav-item { display: flex; flex-direction: column; align-items: center; gap: 4px; color: #8899bb; cursor: pointer; }
.nav-item i { font-size: 1.2rem; }
.nav-item span { font-size: 0.7rem; }
.nav-item.active { color: white; }

/* Screens */
.screen { display: none; }
.screen.active { display: block; }

/* Utility */
.btn-primary { background: var(--ph-blue); color: white; padding: 12px; border-radius: 8px; border: none; font-weight: bold; cursor: pointer; }
.btn-outline { background: transparent; border: 1px solid var(--ph-blue); color: var(--ph-blue); padding: 12px; border-radius: 8px; font-weight: bold; cursor: pointer; }
.main-card { background: white; border-radius: 15px; padding: 20px; margin: 15px; box-shadow: 0 4px 10px rgba(0,0,0,0.05); }